[PATCH 00/12] signal: sort out si_trapno and si_perf

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Revision v1 of 2 in this series.

13 messages, 1 author, 2021-05-03 · open the first message on its own page

[PATCH 00/12] signal: sort out si_trapno and si_perf

From: Eric W. Biederman <hidden>
Date: 2021-05-03 20:25:26

This is my attempt to sort out the ABI issues with SIGTRAP TRAP_PERF
before any userspace code starts using the new ABI.

The big ideas are:
- Placing the asserts first to prevent unexpected ABI changes
- si_trapno can become an ordinary fault subfield.
- Reworking siginfo so that si_perf_data can be a 64bit field.
- struct signalfd_siginfo is almost full

Marco I have incorporated your static_assert changes and built
on them to prevent having unexpected ABI changes.

The field si_trapno is changed to become an ordinary extension of the
_sigfault member of siginfo.

The code is refactored a bit and then si_perf_data is made a 64bit,
and si_perf_type is made distinct from si_errno.

Finally the signalfd_siginfo fields are removed as they appear to be
filling up the structure without userspace actually being able to use
them.

v1: https://lkml.kernel.org/r/m1zgxfs7zq.fsf_-_@fess.ebiederm.org

Eric W. Biederman (9):
      siginfo: Move si_trapno inside the union inside _si_fault
      signal: Implement SIL_FAULT_TRAPNO
      signal: Use dedicated helpers to send signals with si_trapno set
      signal: Remove __ARCH_SI_TRAPNO
      signal: Rename SIL_PERF_EVENT SIL_FAULT_PERF_EVENT for consistency
      signal: Factor force_sig_perf out of perf_sigtrap
      signal: Redefine signinfo so 64bit fields are possible
      signal: Deliver all of the siginfo perf data in _perf
      signalfd: Remove SIL_FAULT_PERF_EVENT fields from signalfd_siginfo

Marco Elver (3):
      sparc64: Add compile-time asserts for siginfo_t offsets
      arm: Add compile-time asserts for siginfo_t offsets
      arm64: Add compile-time asserts for siginfo_t offsets

 arch/alpha/include/uapi/asm/siginfo.h              |   2 -
 arch/alpha/kernel/osf_sys.c                        |   2 +-
 arch/alpha/kernel/signal.c                         |   4 +-
 arch/alpha/kernel/traps.c                          |  24 ++---
 arch/alpha/mm/fault.c                              |   4 +-
 arch/arm/kernel/signal.c                           |  37 +++++++
 arch/arm64/kernel/signal.c                         |  37 +++++++
 arch/arm64/kernel/signal32.c                       |  37 +++++++
 arch/mips/include/uapi/asm/siginfo.h               |   2 -
 arch/sparc/include/uapi/asm/siginfo.h              |   3 -
 arch/sparc/kernel/process_64.c                     |   2 +-
 arch/sparc/kernel/signal32.c                       |  35 +++++++
 arch/sparc/kernel/signal_64.c                      |  34 +++++++
 arch/sparc/kernel/sys_sparc_32.c                   |   2 +-
 arch/sparc/kernel/sys_sparc_64.c                   |   2 +-
 arch/sparc/kernel/traps_32.c                       |  22 ++--
 arch/sparc/kernel/traps_64.c                       |  44 ++++----
 arch/sparc/kernel/unaligned_32.c                   |   2 +-
 arch/sparc/mm/fault_32.c                           |   2 +-
 arch/sparc/mm/fault_64.c                           |   2 +-
 arch/x86/kernel/signal_compat.c                    |  20 ++--
 fs/signalfd.c                                      |  23 ++---
 include/linux/compat.h                             |  38 ++++---
 include/linux/sched/signal.h                       |  13 +--
 include/linux/signal.h                             |   3 +-
 include/uapi/asm-generic/siginfo.h                 |  57 +++++++----
 include/uapi/linux/signalfd.h                      |   4 +-
 kernel/events/core.c                               |  11 +-
 kernel/signal.c                                    | 113 +++++++++++++--------
 .../selftests/perf_events/sigtrap_threads.c        |  12 +--
 30 files changed, 402 insertions(+), 191 deletions(-)

[PATCH 01/12] sparc64: Add compile-time asserts for siginfo_t offsets

From: Eric W. Beiderman <hidden>
Date: 2021-05-03 20:39:00

From: Marco Elver <elver@google.com>

To help catch ABI breaks at compile-time, add compile-time assertions to
verify the siginfo_t layout. Unlike other architectures, sparc64 is
special, because it is one of few architectures requiring si_trapno.
ABI breaks around that field would only be caught here.

Link: https://lkml.kernel.org/r/m11rat9f85.fsf@fess.ebiederm.org
Suggested-by: Eric W. Biederman <redacted>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Eric W. Biederman <redacted>
---
 arch/sparc/kernel/signal32.c  | 34 ++++++++++++++++++++++++++++++++++
 arch/sparc/kernel/signal_64.c | 33 +++++++++++++++++++++++++++++++++
 2 files changed, 67 insertions(+)

diff --git a/arch/sparc/kernel/signal32.c b/arch/sparc/kernel/signal32.c
index e9695a06492f..778ed5c26d4a 100644
--- a/arch/sparc/kernel/signal32.c
+++ b/arch/sparc/kernel/signal32.c

@@ -745,3 +745,37 @@ asmlinkage int do_sys32_sigstack(u32 u_ssptr, u32 u_ossptr, unsigned long sp)
 out:
 	return ret;
 }
+
+/*
+ * Compile-time assertions for siginfo_t offsets. Check NSIG* as well, as
+ * changes likely come with new fields that should be added below.
+ */
+static_assert(NSIGILL	== 11);
+static_assert(NSIGFPE	== 15);
+static_assert(NSIGSEGV	== 9);
+static_assert(NSIGBUS	== 5);
+static_assert(NSIGTRAP	== 6);
+static_assert(NSIGCHLD	== 6);
+static_assert(NSIGSYS	== 2);
+static_assert(offsetof(compat_siginfo_t, si_signo)	== 0x00);
+static_assert(offsetof(compat_siginfo_t, si_errno)	== 0x04);
+static_assert(offsetof(compat_siginfo_t, si_code)	== 0x08);
+static_assert(offsetof(compat_siginfo_t, si_pid)	== 0x0c);
+static_assert(offsetof(compat_siginfo_t, si_uid)	== 0x10);
+static_assert(offsetof(compat_siginfo_t, si_tid)	== 0x0c);
+static_assert(offsetof(compat_siginfo_t, si_overrun)	== 0x10);
+static_assert(offsetof(compat_siginfo_t, si_status)	== 0x14);
+static_assert(offsetof(compat_siginfo_t, si_utime)	== 0x18);
+static_assert(offsetof(compat_siginfo_t, si_stime)	== 0x1c);
+static_assert(offsetof(compat_siginfo_t, si_value)	== 0x14);
+static_assert(offsetof(compat_siginfo_t, si_int)	== 0x14);
+static_assert(offsetof(compat_siginfo_t, si_ptr)	== 0x14);
+static_assert(offsetof(compat_siginfo_t, si_addr)	== 0x0c);
+static_assert(offsetof(compat_siginfo_t, si_trapno)	== 0x10);
+static_assert(offsetof(compat_siginfo_t, si_addr_lsb)	== 0x14);
+static_assert(offsetof(compat_siginfo_t, si_lower)	== 0x18);
+static_assert(offsetof(compat_siginfo_t, si_upper)	== 0x1c);
+static_assert(offsetof(compat_siginfo_t, si_pkey)	== 0x18);
+static_assert(offsetof(compat_siginfo_t, si_perf)	== 0x14);
+static_assert(offsetof(compat_siginfo_t, si_band)	== 0x0c);
+static_assert(offsetof(compat_siginfo_t, si_fd)		== 0x10);

diff --git a/arch/sparc/kernel/signal_64.c b/arch/sparc/kernel/signal_64.c
index a0eec62c825d..c9bbf5f29078 100644
--- a/arch/sparc/kernel/signal_64.c
+++ b/arch/sparc/kernel/signal_64.c

@@ -556,3 +556,36 @@ void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, unsigned long
 	user_enter();
 }
 
+/*
+ * Compile-time assertions for siginfo_t offsets. Check NSIG* as well, as
+ * changes likely come with new fields that should be added below.
+ */
+static_assert(NSIGILL	== 11);
+static_assert(NSIGFPE	== 15);
+static_assert(NSIGSEGV	== 9);
+static_assert(NSIGBUS	== 5);
+static_assert(NSIGTRAP	== 6);
+static_assert(NSIGCHLD	== 6);
+static_assert(NSIGSYS	== 2);
+static_assert(offsetof(siginfo_t, si_signo)	== 0x00);
+static_assert(offsetof(siginfo_t, si_errno)	== 0x04);
+static_assert(offsetof(siginfo_t, si_code)	== 0x08);
+static_assert(offsetof(siginfo_t, si_pid)	== 0x10);
+static_assert(offsetof(siginfo_t, si_uid)	== 0x14);
+static_assert(offsetof(siginfo_t, si_tid)	== 0x10);
+static_assert(offsetof(siginfo_t, si_overrun)	== 0x14);
+static_assert(offsetof(siginfo_t, si_status)	== 0x18);
+static_assert(offsetof(siginfo_t, si_utime)	== 0x20);
+static_assert(offsetof(siginfo_t, si_stime)	== 0x28);
+static_assert(offsetof(siginfo_t, si_value)	== 0x18);
+static_assert(offsetof(siginfo_t, si_int)	== 0x18);
+static_assert(offsetof(siginfo_t, si_ptr)	== 0x18);
+static_assert(offsetof(siginfo_t, si_addr)	== 0x10);
+static_assert(offsetof(siginfo_t, si_trapno)	== 0x18);
+static_assert(offsetof(siginfo_t, si_addr_lsb)	== 0x20);
+static_assert(offsetof(siginfo_t, si_lower)	== 0x28);
+static_assert(offsetof(siginfo_t, si_upper)	== 0x30);
+static_assert(offsetof(siginfo_t, si_pkey)	== 0x28);
+static_assert(offsetof(siginfo_t, si_perf)	== 0x20);
+static_assert(offsetof(siginfo_t, si_band)	== 0x10);
+static_assert(offsetof(siginfo_t, si_fd)	== 0x14);

-- 
2.30.1

[PATCH 02/12] arm: Add compile-time asserts for siginfo_t offsets

From: Eric W. Beiderman <hidden>
Date: 2021-05-03 20:39:04

From: Marco Elver <elver@google.com>

To help catch ABI breaks at compile-time, add compile-time assertions to
verify the siginfo_t layout.

This could have caught that we cannot portably add 64-bit integers to
siginfo_t on 32-bit architectures like Arm before reaching -next:
https://lkml.kernel.org/r/20210422191823.79012-1-elver@google.com

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Eric W. Biederman <redacted>
---
 arch/arm/kernel/signal.c | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index a3a38d0a4c85..2dac5d2c5cf6 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c

@@ -725,3 +725,39 @@ asmlinkage void do_rseq_syscall(struct pt_regs *regs)
 	rseq_syscall(regs);
 }
 #endif
+
+/*
+ * Compile-time assertions for siginfo_t offsets. Check NSIG* as well, as
+ * changes likely come with new fields that should be added below.
+ */
+static_assert(NSIGILL	== 11);
+static_assert(NSIGFPE	== 15);
+static_assert(NSIGSEGV	== 9);
+static_assert(NSIGBUS	== 5);
+static_assert(NSIGTRAP	== 6);
+static_assert(NSIGCHLD	== 6);
+static_assert(NSIGSYS	== 2);
+static_assert(offsetof(siginfo_t, si_signo)	== 0x00);
+static_assert(offsetof(siginfo_t, si_errno)	== 0x04);
+static_assert(offsetof(siginfo_t, si_code)	== 0x08);
+static_assert(offsetof(siginfo_t, si_pid)	== 0x0c);
+static_assert(offsetof(siginfo_t, si_uid)	== 0x10);
+static_assert(offsetof(siginfo_t, si_tid)	== 0x0c);
+static_assert(offsetof(siginfo_t, si_overrun)	== 0x10);
+static_assert(offsetof(siginfo_t, si_status)	== 0x14);
+static_assert(offsetof(siginfo_t, si_utime)	== 0x18);
+static_assert(offsetof(siginfo_t, si_stime)	== 0x1c);
+static_assert(offsetof(siginfo_t, si_value)	== 0x14);
+static_assert(offsetof(siginfo_t, si_int)	== 0x14);
+static_assert(offsetof(siginfo_t, si_ptr)	== 0x14);
+static_assert(offsetof(siginfo_t, si_addr)	== 0x0c);
+static_assert(offsetof(siginfo_t, si_addr_lsb)	== 0x10);
+static_assert(offsetof(siginfo_t, si_lower)	== 0x14);
+static_assert(offsetof(siginfo_t, si_upper)	== 0x18);
+static_assert(offsetof(siginfo_t, si_pkey)	== 0x14);
+static_assert(offsetof(siginfo_t, si_perf)	== 0x10);
+static_assert(offsetof(siginfo_t, si_band)	== 0x0c);
+static_assert(offsetof(siginfo_t, si_fd)	== 0x10);
+static_assert(offsetof(siginfo_t, si_call_addr)	== 0x0c);
+static_assert(offsetof(siginfo_t, si_syscall)	== 0x10);
+static_assert(offsetof(siginfo_t, si_arch)	== 0x14);

-- 
2.30.1

[PATCH 03/12] arm64: Add compile-time asserts for siginfo_t offsets

From: Eric W. Beiderman <hidden>
Date: 2021-05-03 20:39:06

From: Marco Elver <elver@google.com>

To help catch ABI breaks at compile-time, add compile-time assertions to
verify the siginfo_t layout.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Eric W. Biederman <redacted>
---
 arch/arm64/kernel/signal.c   | 36 ++++++++++++++++++++++++++++++++++++
 arch/arm64/kernel/signal32.c | 36 ++++++++++++++++++++++++++++++++++++
 2 files changed, 72 insertions(+)

diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c
index 6237486ff6bb..af8bd2af1298 100644
--- a/arch/arm64/kernel/signal.c
+++ b/arch/arm64/kernel/signal.c

@@ -973,3 +973,39 @@ void __init minsigstksz_setup(void)
 		round_up(sizeof(struct frame_record), 16) +
 		16; /* max alignment padding */
 }
+
+/*
+ * Compile-time assertions for siginfo_t offsets. Check NSIG* as well, as
+ * changes likely come with new fields that should be added below.
+ */
+static_assert(NSIGILL	== 11);
+static_assert(NSIGFPE	== 15);
+static_assert(NSIGSEGV	== 9);
+static_assert(NSIGBUS	== 5);
+static_assert(NSIGTRAP	== 6);
+static_assert(NSIGCHLD	== 6);
+static_assert(NSIGSYS	== 2);
+static_assert(offsetof(siginfo_t, si_signo)	== 0x00);
+static_assert(offsetof(siginfo_t, si_errno)	== 0x04);
+static_assert(offsetof(siginfo_t, si_code)	== 0x08);
+static_assert(offsetof(siginfo_t, si_pid)	== 0x10);
+static_assert(offsetof(siginfo_t, si_uid)	== 0x14);
+static_assert(offsetof(siginfo_t, si_tid)	== 0x10);
+static_assert(offsetof(siginfo_t, si_overrun)	== 0x14);
+static_assert(offsetof(siginfo_t, si_status)	== 0x18);
+static_assert(offsetof(siginfo_t, si_utime)	== 0x20);
+static_assert(offsetof(siginfo_t, si_stime)	== 0x28);
+static_assert(offsetof(siginfo_t, si_value)	== 0x18);
+static_assert(offsetof(siginfo_t, si_int)	== 0x18);
+static_assert(offsetof(siginfo_t, si_ptr)	== 0x18);
+static_assert(offsetof(siginfo_t, si_addr)	== 0x10);
+static_assert(offsetof(siginfo_t, si_addr_lsb)	== 0x18);
+static_assert(offsetof(siginfo_t, si_lower)	== 0x20);
+static_assert(offsetof(siginfo_t, si_upper)	== 0x28);
+static_assert(offsetof(siginfo_t, si_pkey)	== 0x20);
+static_assert(offsetof(siginfo_t, si_perf)	== 0x18);
+static_assert(offsetof(siginfo_t, si_band)	== 0x10);
+static_assert(offsetof(siginfo_t, si_fd)	== 0x18);
+static_assert(offsetof(siginfo_t, si_call_addr)	== 0x10);
+static_assert(offsetof(siginfo_t, si_syscall)	== 0x18);
+static_assert(offsetof(siginfo_t, si_arch)	== 0x1c);

diff --git a/arch/arm64/kernel/signal32.c b/arch/arm64/kernel/signal32.c
index 2f507f565c48..b6afb646515f 100644
--- a/arch/arm64/kernel/signal32.c
+++ b/arch/arm64/kernel/signal32.c

@@ -457,3 +457,39 @@ void compat_setup_restart_syscall(struct pt_regs *regs)
 {
        regs->regs[7] = __NR_compat_restart_syscall;
 }
+
+/*
+ * Compile-time assertions for siginfo_t offsets. Check NSIG* as well, as
+ * changes likely come with new fields that should be added below.
+ */
+static_assert(NSIGILL	== 11);
+static_assert(NSIGFPE	== 15);
+static_assert(NSIGSEGV	== 9);
+static_assert(NSIGBUS	== 5);
+static_assert(NSIGTRAP	== 6);
+static_assert(NSIGCHLD	== 6);
+static_assert(NSIGSYS	== 2);
+static_assert(offsetof(compat_siginfo_t, si_signo)	== 0x00);
+static_assert(offsetof(compat_siginfo_t, si_errno)	== 0x04);
+static_assert(offsetof(compat_siginfo_t, si_code)	== 0x08);
+static_assert(offsetof(compat_siginfo_t, si_pid)	== 0x0c);
+static_assert(offsetof(compat_siginfo_t, si_uid)	== 0x10);
+static_assert(offsetof(compat_siginfo_t, si_tid)	== 0x0c);
+static_assert(offsetof(compat_siginfo_t, si_overrun)	== 0x10);
+static_assert(offsetof(compat_siginfo_t, si_status)	== 0x14);
+static_assert(offsetof(compat_siginfo_t, si_utime)	== 0x18);
+static_assert(offsetof(compat_siginfo_t, si_stime)	== 0x1c);
+static_assert(offsetof(compat_siginfo_t, si_value)	== 0x14);
+static_assert(offsetof(compat_siginfo_t, si_int)	== 0x14);
+static_assert(offsetof(compat_siginfo_t, si_ptr)	== 0x14);
+static_assert(offsetof(compat_siginfo_t, si_addr)	== 0x0c);
+static_assert(offsetof(compat_siginfo_t, si_addr_lsb)	== 0x10);
+static_assert(offsetof(compat_siginfo_t, si_lower)	== 0x14);
+static_assert(offsetof(compat_siginfo_t, si_upper)	== 0x18);
+static_assert(offsetof(compat_siginfo_t, si_pkey)	== 0x14);
+static_assert(offsetof(compat_siginfo_t, si_perf)	== 0x10);
+static_assert(offsetof(compat_siginfo_t, si_band)	== 0x0c);
+static_assert(offsetof(compat_siginfo_t, si_fd)		== 0x10);
+static_assert(offsetof(compat_siginfo_t, si_call_addr)	== 0x0c);
+static_assert(offsetof(compat_siginfo_t, si_syscall)	== 0x10);
+static_assert(offsetof(compat_siginfo_t, si_arch)	== 0x14);

-- 
2.30.1

[PATCH 04/12] siginfo: Move si_trapno inside the union inside _si_fault

From: Eric W. Beiderman <hidden>
Date: 2021-05-03 20:39:12

From: "Eric W. Biederman" <redacted>

It turns out that linux uses si_trapno very sparingly, and as such it
can be considered extra information for a very narrow selection of
signals, rather than information that is present with every fault
reported in siginfo.

As such move si_trapno inside the union inside of _si_fault.  This
results in no change in placement, and makes it eaiser
to extend _si_fault in the future as this reduces the number of
special cases.  In particular with si_trapno included in the union it
is no longer a concern that the union must be pointer alligned on most
architectures because the union followes immediately after si_addr
which is a pointer.

This change results in a difference in siginfo field placement on
sparc and alpha for the fields si_addr_lsb, si_lower, si_upper,
si_pkey, and si_perf.  These architectures do not implement the
signals that would use si_addr_lsb, si_lower, si_upper, si_pkey, and
si_perf.  Further these architecture have not yet implemented the
userspace that would use si_perf.

The point of this change is in fact to correct these placement issues
before sparc or alpha grow userspace that cares.  This change was
discussed[1] and the agreement is that this change is currently safe.

[1]: https://lkml.kernel.org/r/CAK8P3a0+uKYwL1NhY6Hvtieghba2hKYGD6hcKx5n8=4Gtt+pHA@mail.gmail.com
Acked-by: Marco Elver <elver@google.com>
v1: https://lkml.kernel.org/r/m1tunns7yf.fsf_-_@fess.ebiederm.org
Signed-off-by: "Eric W. Biederman" <redacted>
---
 arch/sparc/kernel/signal32.c       | 10 +++++-----
 arch/sparc/kernel/signal_64.c      | 10 +++++-----
 arch/x86/kernel/signal_compat.c    |  3 +++
 include/linux/compat.h             |  5 ++---
 include/uapi/asm-generic/siginfo.h |  7 ++-----
 kernel/signal.c                    |  1 +
 6 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/arch/sparc/kernel/signal32.c b/arch/sparc/kernel/signal32.c
index 778ed5c26d4a..73fd8700df3e 100644
--- a/arch/sparc/kernel/signal32.c
+++ b/arch/sparc/kernel/signal32.c

@@ -772,10 +772,10 @@ static_assert(offsetof(compat_siginfo_t, si_int)	== 0x14);
 static_assert(offsetof(compat_siginfo_t, si_ptr)	== 0x14);
 static_assert(offsetof(compat_siginfo_t, si_addr)	== 0x0c);
 static_assert(offsetof(compat_siginfo_t, si_trapno)	== 0x10);
-static_assert(offsetof(compat_siginfo_t, si_addr_lsb)	== 0x14);
-static_assert(offsetof(compat_siginfo_t, si_lower)	== 0x18);
-static_assert(offsetof(compat_siginfo_t, si_upper)	== 0x1c);
-static_assert(offsetof(compat_siginfo_t, si_pkey)	== 0x18);
-static_assert(offsetof(compat_siginfo_t, si_perf)	== 0x14);
+static_assert(offsetof(compat_siginfo_t, si_addr_lsb)	== 0x10);
+static_assert(offsetof(compat_siginfo_t, si_lower)	== 0x14);
+static_assert(offsetof(compat_siginfo_t, si_upper)	== 0x18);
+static_assert(offsetof(compat_siginfo_t, si_pkey)	== 0x14);
+static_assert(offsetof(compat_siginfo_t, si_perf)	== 0x10);
 static_assert(offsetof(compat_siginfo_t, si_band)	== 0x0c);
 static_assert(offsetof(compat_siginfo_t, si_fd)		== 0x10);

diff --git a/arch/sparc/kernel/signal_64.c b/arch/sparc/kernel/signal_64.c
index c9bbf5f29078..17913daa66c6 100644
--- a/arch/sparc/kernel/signal_64.c
+++ b/arch/sparc/kernel/signal_64.c

@@ -582,10 +582,10 @@ static_assert(offsetof(siginfo_t, si_int)	== 0x18);
 static_assert(offsetof(siginfo_t, si_ptr)	== 0x18);
 static_assert(offsetof(siginfo_t, si_addr)	== 0x10);
 static_assert(offsetof(siginfo_t, si_trapno)	== 0x18);
-static_assert(offsetof(siginfo_t, si_addr_lsb)	== 0x20);
-static_assert(offsetof(siginfo_t, si_lower)	== 0x28);
-static_assert(offsetof(siginfo_t, si_upper)	== 0x30);
-static_assert(offsetof(siginfo_t, si_pkey)	== 0x28);
-static_assert(offsetof(siginfo_t, si_perf)	== 0x20);
+static_assert(offsetof(siginfo_t, si_addr_lsb)	== 0x18);
+static_assert(offsetof(siginfo_t, si_lower)	== 0x20);
+static_assert(offsetof(siginfo_t, si_upper)	== 0x28);
+static_assert(offsetof(siginfo_t, si_pkey)	== 0x20);
+static_assert(offsetof(siginfo_t, si_perf)	== 0x18);
 static_assert(offsetof(siginfo_t, si_band)	== 0x10);
 static_assert(offsetof(siginfo_t, si_fd)	== 0x14);

diff --git a/arch/x86/kernel/signal_compat.c b/arch/x86/kernel/signal_compat.c
index 0e5d0a7e203b..a9fcabd8a5e5 100644
--- a/arch/x86/kernel/signal_compat.c
+++ b/arch/x86/kernel/signal_compat.c

@@ -127,6 +127,9 @@ static inline void signal_compat_build_tests(void)
 	BUILD_BUG_ON(offsetof(siginfo_t, si_addr) != 0x10);
 	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_addr) != 0x0C);
 
+	BUILD_BUG_ON(offsetof(siginfo_t, si_trapno) != 0x18);
+	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_trapno) != 0x10);
+
 	BUILD_BUG_ON(offsetof(siginfo_t, si_addr_lsb) != 0x18);
 	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_addr_lsb) != 0x10);

diff --git a/include/linux/compat.h b/include/linux/compat.h
index f0d2dd35d408..6af7bef15e94 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h

@@ -214,12 +214,11 @@ typedef struct compat_siginfo {
 		/* SIGILL, SIGFPE, SIGSEGV, SIGBUS, SIGTRAP, SIGEMT */
 		struct {
 			compat_uptr_t _addr;	/* faulting insn/memory ref. */
-#ifdef __ARCH_SI_TRAPNO
-			int _trapno;	/* TRAP # which caused the signal */
-#endif
 #define __COMPAT_ADDR_BND_PKEY_PAD  (__alignof__(compat_uptr_t) < sizeof(short) ? \
 				     sizeof(short) : __alignof__(compat_uptr_t))
 			union {
+				/* used on alpha and sparc */
+				int _trapno;	/* TRAP # which caused the signal */
 				/*
 				 * used when si_code=BUS_MCEERR_AR or
 				 * used when si_code=BUS_MCEERR_AO

diff --git a/include/uapi/asm-generic/siginfo.h b/include/uapi/asm-generic/siginfo.h
index 03d6f6d2c1fe..e663bf117b46 100644
--- a/include/uapi/asm-generic/siginfo.h
+++ b/include/uapi/asm-generic/siginfo.h

@@ -63,9 +63,6 @@ union __sifields {
 	/* SIGILL, SIGFPE, SIGSEGV, SIGBUS, SIGTRAP, SIGEMT */
 	struct {
 		void __user *_addr; /* faulting insn/memory ref. */
-#ifdef __ARCH_SI_TRAPNO
-		int _trapno;	/* TRAP # which caused the signal */
-#endif
 #ifdef __ia64__
 		int _imm;		/* immediate value for "break" */
 		unsigned int _flags;	/* see ia64 si_flags */

@@ -75,6 +72,8 @@ union __sifields {
 #define __ADDR_BND_PKEY_PAD  (__alignof__(void *) < sizeof(short) ? \
 			      sizeof(short) : __alignof__(void *))
 		union {
+			/* used on alpha and sparc */
+			int _trapno;	/* TRAP # which caused the signal */
 			/*
 			 * used when si_code=BUS_MCEERR_AR or
 			 * used when si_code=BUS_MCEERR_AO

@@ -150,9 +149,7 @@ typedef struct siginfo {
 #define si_int		_sifields._rt._sigval.sival_int
 #define si_ptr		_sifields._rt._sigval.sival_ptr
 #define si_addr		_sifields._sigfault._addr
-#ifdef __ARCH_SI_TRAPNO
 #define si_trapno	_sifields._sigfault._trapno
-#endif
 #define si_addr_lsb	_sifields._sigfault._addr_lsb
 #define si_lower	_sifields._sigfault._addr_bnd._lower
 #define si_upper	_sifields._sigfault._addr_bnd._upper

diff --git a/kernel/signal.c b/kernel/signal.c
index c3017aa8024a..65888aec65a0 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c

@@ -4607,6 +4607,7 @@ static inline void siginfo_buildtime_checks(void)
 
 	/* sigfault */
 	CHECK_OFFSET(si_addr);
+	CHECK_OFFSET(si_trapno);
 	CHECK_OFFSET(si_addr_lsb);
 	CHECK_OFFSET(si_lower);
 	CHECK_OFFSET(si_upper);

-- 
2.30.1

[PATCH 05/12] signal: Implement SIL_FAULT_TRAPNO

From: Eric W. Beiderman <hidden>
Date: 2021-05-03 20:39:17

From: "Eric W. Biederman" <redacted>

Now that si_trapno is part of the union in _si_fault and available on
all architectures, add SIL_FAULT_TRAPNO and update siginfo_layout to
return SIL_FAULT_TRAPNO when si_trapno is actually used.

Update the code that uses siginfo_layout to deal with SIL_FAULT_TRAPNO
and have the same code ignore si_trapno in in all other cases.

v1: https://lkml.kernel.org/r/m1o8dvs7s7.fsf_-_@fess.ebiederm.org
Signed-off-by: "Eric W. Biederman" <redacted>
---
 fs/signalfd.c          |  8 +++-----
 include/linux/signal.h |  1 +
 kernel/signal.c        | 37 +++++++++++++++----------------------
 3 files changed, 19 insertions(+), 27 deletions(-)

diff --git a/fs/signalfd.c b/fs/signalfd.c
index 040a1142915f..e87e59581653 100644
--- a/fs/signalfd.c
+++ b/fs/signalfd.c

@@ -123,15 +123,13 @@ static int signalfd_copyinfo(struct signalfd_siginfo __user *uinfo,
 		 */
 	case SIL_FAULT:
 		new.ssi_addr = (long) kinfo->si_addr;
-#ifdef __ARCH_SI_TRAPNO
+		break;
+	case SIL_FAULT_TRAPNO:
+		new.ssi_addr = (long) kinfo->si_addr;
 		new.ssi_trapno = kinfo->si_trapno;
-#endif
 		break;
 	case SIL_FAULT_MCEERR:
 		new.ssi_addr = (long) kinfo->si_addr;
-#ifdef __ARCH_SI_TRAPNO
-		new.ssi_trapno = kinfo->si_trapno;
-#endif
 		new.ssi_addr_lsb = (short) kinfo->si_addr_lsb;
 		break;
 	case SIL_PERF_EVENT:

diff --git a/include/linux/signal.h b/include/linux/signal.h
index 1e98548d7cf6..5160fd45e5ca 100644
--- a/include/linux/signal.h
+++ b/include/linux/signal.h

@@ -40,6 +40,7 @@ enum siginfo_layout {
 	SIL_TIMER,
 	SIL_POLL,
 	SIL_FAULT,
+	SIL_FAULT_TRAPNO,
 	SIL_FAULT_MCEERR,
 	SIL_FAULT_BNDERR,
 	SIL_FAULT_PKUERR,

diff --git a/kernel/signal.c b/kernel/signal.c
index 65888aec65a0..3d3ba7949788 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c

@@ -1194,6 +1194,7 @@ static inline bool has_si_pid_and_uid(struct kernel_siginfo *info)
 	case SIL_TIMER:
 	case SIL_POLL:
 	case SIL_FAULT:
+	case SIL_FAULT_TRAPNO:
 	case SIL_FAULT_MCEERR:
 	case SIL_FAULT_BNDERR:
 	case SIL_FAULT_PKUERR:

@@ -2527,6 +2528,7 @@ static void hide_si_addr_tag_bits(struct ksignal *ksig)
 {
 	switch (siginfo_layout(ksig->sig, ksig->info.si_code)) {
 	case SIL_FAULT:
+	case SIL_FAULT_TRAPNO:
 	case SIL_FAULT_MCEERR:
 	case SIL_FAULT_BNDERR:
 	case SIL_FAULT_PKUERR:

@@ -3206,6 +3208,13 @@ enum siginfo_layout siginfo_layout(unsigned sig, int si_code)
 			if ((sig == SIGBUS) &&
 			    (si_code >= BUS_MCEERR_AR) && (si_code <= BUS_MCEERR_AO))
 				layout = SIL_FAULT_MCEERR;
+			else if (IS_ENABLED(CONFIG_ALPHA) &&
+				 ((sig == SIGFPE) ||
+				  ((sig == SIGTRAP) && (si_code == TRAP_UNK))))
+				layout = SIL_FAULT_TRAPNO;
+			else if (IS_ENABLED(CONFIG_SPARC) &&
+				 (sig == SIGILL) && (si_code == ILL_ILLTRP))
+				layout = SIL_FAULT_TRAPNO;
 			else if ((sig == SIGSEGV) && (si_code == SEGV_BNDERR))
 				layout = SIL_FAULT_BNDERR;
 #ifdef SEGV_PKUERR

@@ -3317,30 +3326,22 @@ void copy_siginfo_to_external32(struct compat_siginfo *to,
 		break;
 	case SIL_FAULT:
 		to->si_addr = ptr_to_compat(from->si_addr);
-#ifdef __ARCH_SI_TRAPNO
+		break;
+	case SIL_FAULT_TRAPNO:
+		to->si_addr = ptr_to_compat(from->si_addr);
 		to->si_trapno = from->si_trapno;
-#endif
 		break;
 	case SIL_FAULT_MCEERR:
 		to->si_addr = ptr_to_compat(from->si_addr);
-#ifdef __ARCH_SI_TRAPNO
-		to->si_trapno = from->si_trapno;
-#endif
 		to->si_addr_lsb = from->si_addr_lsb;
 		break;
 	case SIL_FAULT_BNDERR:
 		to->si_addr = ptr_to_compat(from->si_addr);
-#ifdef __ARCH_SI_TRAPNO
-		to->si_trapno = from->si_trapno;
-#endif
 		to->si_lower = ptr_to_compat(from->si_lower);
 		to->si_upper = ptr_to_compat(from->si_upper);
 		break;
 	case SIL_FAULT_PKUERR:
 		to->si_addr = ptr_to_compat(from->si_addr);
-#ifdef __ARCH_SI_TRAPNO
-		to->si_trapno = from->si_trapno;
-#endif
 		to->si_pkey = from->si_pkey;
 		break;
 	case SIL_PERF_EVENT:

@@ -3401,30 +3402,22 @@ static int post_copy_siginfo_from_user32(kernel_siginfo_t *to,
 		break;
 	case SIL_FAULT:
 		to->si_addr = compat_ptr(from->si_addr);
-#ifdef __ARCH_SI_TRAPNO
+		break;
+	case SIL_FAULT_TRAPNO:
+		to->si_addr = compat_ptr(from->si_addr);
 		to->si_trapno = from->si_trapno;
-#endif
 		break;
 	case SIL_FAULT_MCEERR:
 		to->si_addr = compat_ptr(from->si_addr);
-#ifdef __ARCH_SI_TRAPNO
-		to->si_trapno = from->si_trapno;
-#endif
 		to->si_addr_lsb = from->si_addr_lsb;
 		break;
 	case SIL_FAULT_BNDERR:
 		to->si_addr = compat_ptr(from->si_addr);
-#ifdef __ARCH_SI_TRAPNO
-		to->si_trapno = from->si_trapno;
-#endif
 		to->si_lower = compat_ptr(from->si_lower);
 		to->si_upper = compat_ptr(from->si_upper);
 		break;
 	case SIL_FAULT_PKUERR:
 		to->si_addr = compat_ptr(from->si_addr);
-#ifdef __ARCH_SI_TRAPNO
-		to->si_trapno = from->si_trapno;
-#endif
 		to->si_pkey = from->si_pkey;
 		break;
 	case SIL_PERF_EVENT:

-- 
2.30.1

[PATCH 06/12] signal: Use dedicated helpers to send signals with si_trapno set

From: Eric W. Beiderman <hidden>
Date: 2021-05-03 20:39:24

From: "Eric W. Biederman" <redacted>

Now that si_trapno is no longer expected to be present for every fault
reported using siginfo on alpha and sparc remove the trapno parameter
from force_sig_fault, force_sig_fault_to_task and send_sig_fault.

Add two new helpers force_sig_fault_trapno and send_sig_fautl_trapno
for those signals where trapno is expected to be set.

v1: https://lkml.kernel.org/r/m1eeers7q7.fsf_-_@fess.ebiederm.org
Signed-off-by: "Eric W. Biederman" <redacted>
---
 arch/alpha/kernel/osf_sys.c      |  2 +-
 arch/alpha/kernel/signal.c       |  4 +--
 arch/alpha/kernel/traps.c        | 24 ++++++++---------
 arch/alpha/mm/fault.c            |  4 +--
 arch/sparc/kernel/process_64.c   |  2 +-
 arch/sparc/kernel/sys_sparc_32.c |  2 +-
 arch/sparc/kernel/sys_sparc_64.c |  2 +-
 arch/sparc/kernel/traps_32.c     | 22 ++++++++--------
 arch/sparc/kernel/traps_64.c     | 44 ++++++++++++++------------------
 arch/sparc/kernel/unaligned_32.c |  2 +-
 arch/sparc/mm/fault_32.c         |  2 +-
 arch/sparc/mm/fault_64.c         |  2 +-
 include/linux/sched/signal.h     | 12 +++------
 kernel/signal.c                  | 41 +++++++++++++++++++++--------
 14 files changed, 88 insertions(+), 77 deletions(-)

diff --git a/arch/alpha/kernel/osf_sys.c b/arch/alpha/kernel/osf_sys.c
index d5367a1c6300..80c5d7fbe66a 100644
--- a/arch/alpha/kernel/osf_sys.c
+++ b/arch/alpha/kernel/osf_sys.c

@@ -878,7 +878,7 @@ SYSCALL_DEFINE5(osf_setsysinfo, unsigned long, op, void __user *, buffer,
 
 			send_sig_fault(SIGFPE, si_code,
 				       (void __user *)NULL,  /* FIXME */
-				       0, current);
+				       current);
  		}
 		return 0;
 	}

diff --git a/arch/alpha/kernel/signal.c b/arch/alpha/kernel/signal.c
index 948b89789da8..bc077babafab 100644
--- a/arch/alpha/kernel/signal.c
+++ b/arch/alpha/kernel/signal.c

@@ -219,7 +219,7 @@ do_sigreturn(struct sigcontext __user *sc)
 
 	/* Send SIGTRAP if we're single-stepping: */
 	if (ptrace_cancel_bpt (current)) {
-		send_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *) regs->pc, 0,
+		send_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *) regs->pc,
 			       current);
 	}
 	return;

@@ -247,7 +247,7 @@ do_rt_sigreturn(struct rt_sigframe __user *frame)
 
 	/* Send SIGTRAP if we're single-stepping: */
 	if (ptrace_cancel_bpt (current)) {
-		send_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *) regs->pc, 0,
+		send_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *) regs->pc,
 			       current);
 	}
 	return;

diff --git a/arch/alpha/kernel/traps.c b/arch/alpha/kernel/traps.c
index 921d4b6e4d95..0dddf9ecc1f4 100644
--- a/arch/alpha/kernel/traps.c
+++ b/arch/alpha/kernel/traps.c

@@ -227,7 +227,7 @@ do_entArith(unsigned long summary, unsigned long write_mask,
 	}
 	die_if_kernel("Arithmetic fault", regs, 0, NULL);
 
-	send_sig_fault(SIGFPE, si_code, (void __user *) regs->pc, 0, current);
+	send_sig_fault_trapno(SIGFPE, si_code, (void __user *) regs->pc, 0, current);
 }
 
 asmlinkage void

@@ -268,12 +268,12 @@ do_entIF(unsigned long type, struct pt_regs *regs)
 			regs->pc -= 4;	/* make pc point to former bpt */
 		}
 
-		send_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->pc, 0,
+		send_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->pc,
 			       current);
 		return;
 
 	      case 1: /* bugcheck */
-		send_sig_fault(SIGTRAP, TRAP_UNK, (void __user *) regs->pc, 0,
+		send_sig_fault(SIGTRAP, TRAP_UNK, (void __user *) regs->pc,
 			       current);
 		return;

@@ -335,8 +335,8 @@ do_entIF(unsigned long type, struct pt_regs *regs)
 			break;
 		}
 
-		send_sig_fault(signo, code, (void __user *) regs->pc, regs->r16,
-			       current);
+		send_sig_fault_trapno(signo, code, (void __user *) regs->pc,
+				      regs->r16, current);
 		return;
 
 	      case 4: /* opDEC */

@@ -360,9 +360,9 @@ do_entIF(unsigned long type, struct pt_regs *regs)
 			if (si_code == 0)
 				return;
 			if (si_code > 0) {
-				send_sig_fault(SIGFPE, si_code,
-					       (void __user *) regs->pc, 0,
-					       current);
+				send_sig_fault_trapno(SIGFPE, si_code,
+						      (void __user *) regs->pc,
+						      0, current);
 				return;
 			}
 		}

@@ -387,7 +387,7 @@ do_entIF(unsigned long type, struct pt_regs *regs)
 		      ;
 	}
 
-	send_sig_fault(SIGILL, ILL_ILLOPC, (void __user *)regs->pc, 0, current);
+	send_sig_fault(SIGILL, ILL_ILLOPC, (void __user *)regs->pc, current);
 }
 
 /* There is an ifdef in the PALcode in MILO that enables a

@@ -402,7 +402,7 @@ do_entDbg(struct pt_regs *regs)
 {
 	die_if_kernel("Instruction fault", regs, 0, NULL);
 
-	force_sig_fault(SIGILL, ILL_ILLOPC, (void __user *)regs->pc, 0);
+	force_sig_fault(SIGILL, ILL_ILLOPC, (void __user *)regs->pc);
 }

@@ -964,12 +964,12 @@ do_entUnaUser(void __user * va, unsigned long opcode,
 			si_code = SEGV_MAPERR;
 		mmap_read_unlock(mm);
 	}
-	send_sig_fault(SIGSEGV, si_code, va, 0, current);
+	send_sig_fault(SIGSEGV, si_code, va, current);
 	return;
 
 give_sigbus:
 	regs->pc -= 4;
-	send_sig_fault(SIGBUS, BUS_ADRALN, va, 0, current);
+	send_sig_fault(SIGBUS, BUS_ADRALN, va, current);
 	return;
 }

diff --git a/arch/alpha/mm/fault.c b/arch/alpha/mm/fault.c
index 09172f017efc..eee5102c3d88 100644
--- a/arch/alpha/mm/fault.c
+++ b/arch/alpha/mm/fault.c

@@ -219,13 +219,13 @@ do_page_fault(unsigned long address, unsigned long mmcsr,
 	mmap_read_unlock(mm);
 	/* Send a sigbus, regardless of whether we were in kernel
 	   or user mode.  */
-	force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *) address, 0);
+	force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *) address);
 	if (!user_mode(regs))
 		goto no_context;
 	return;
 
  do_sigsegv:
-	force_sig_fault(SIGSEGV, si_code, (void __user *) address, 0);
+	force_sig_fault(SIGSEGV, si_code, (void __user *) address);
 	return;
 
 #ifdef CONFIG_ALPHA_LARGE_VMALLOC

diff --git a/arch/sparc/kernel/process_64.c b/arch/sparc/kernel/process_64.c
index 7afd0a859a78..29e67854d5a4 100644
--- a/arch/sparc/kernel/process_64.c
+++ b/arch/sparc/kernel/process_64.c

@@ -518,7 +518,7 @@ void synchronize_user_stack(void)
 
 static void stack_unaligned(unsigned long sp)
 {
-	force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *) sp, 0);
+	force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *) sp);
 }
 
 static const char uwfault32[] = KERN_INFO \

diff --git a/arch/sparc/kernel/sys_sparc_32.c b/arch/sparc/kernel/sys_sparc_32.c
index be77538bc038..082a551897ed 100644
--- a/arch/sparc/kernel/sys_sparc_32.c
+++ b/arch/sparc/kernel/sys_sparc_32.c

@@ -151,7 +151,7 @@ sparc_breakpoint (struct pt_regs *regs)
 #ifdef DEBUG_SPARC_BREAKPOINT
         printk ("TRAP: Entering kernel PC=%x, nPC=%x\n", regs->pc, regs->npc);
 #endif
-	force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->pc, 0);
+	force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->pc);
 
 #ifdef DEBUG_SPARC_BREAKPOINT
 	printk ("TRAP: Returning to space: PC=%x nPC=%x\n", regs->pc, regs->npc);

diff --git a/arch/sparc/kernel/sys_sparc_64.c b/arch/sparc/kernel/sys_sparc_64.c
index 6b92fadb6ec7..1e9a9e016237 100644
--- a/arch/sparc/kernel/sys_sparc_64.c
+++ b/arch/sparc/kernel/sys_sparc_64.c

@@ -514,7 +514,7 @@ asmlinkage void sparc_breakpoint(struct pt_regs *regs)
 #ifdef DEBUG_SPARC_BREAKPOINT
         printk ("TRAP: Entering kernel PC=%lx, nPC=%lx\n", regs->tpc, regs->tnpc);
 #endif
-	force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->tpc, 0);
+	force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->tpc);
 #ifdef DEBUG_SPARC_BREAKPOINT
 	printk ("TRAP: Returning to space: PC=%lx nPC=%lx\n", regs->tpc, regs->tnpc);
 #endif

diff --git a/arch/sparc/kernel/traps_32.c b/arch/sparc/kernel/traps_32.c
index 247a0d9683b2..5630e5a395e0 100644
--- a/arch/sparc/kernel/traps_32.c
+++ b/arch/sparc/kernel/traps_32.c

@@ -102,8 +102,8 @@ void do_hw_interrupt(struct pt_regs *regs, unsigned long type)
 	if(regs->psr & PSR_PS)
 		die_if_kernel("Kernel bad trap", regs);
 
-	force_sig_fault(SIGILL, ILL_ILLTRP,
-			(void __user *)regs->pc, type - 0x80);
+	force_sig_fault_trapno(SIGILL, ILL_ILLTRP,
+			       (void __user *)regs->pc, type - 0x80);
 }
 
 void do_illegal_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,

@@ -116,7 +116,7 @@ void do_illegal_instruction(struct pt_regs *regs, unsigned long pc, unsigned lon
 	       regs->pc, *(unsigned long *)regs->pc);
 #endif
 
-	send_sig_fault(SIGILL, ILL_ILLOPC, (void __user *)pc, 0, current);
+	send_sig_fault(SIGILL, ILL_ILLOPC, (void __user *)pc, current);
 }
 
 void do_priv_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,

@@ -124,7 +124,7 @@ void do_priv_instruction(struct pt_regs *regs, unsigned long pc, unsigned long n
 {
 	if(psr & PSR_PS)
 		die_if_kernel("Penguin instruction from Penguin mode??!?!", regs);
-	send_sig_fault(SIGILL, ILL_PRVOPC, (void __user *)pc, 0, current);
+	send_sig_fault(SIGILL, ILL_PRVOPC, (void __user *)pc, current);
 }
 
 /* XXX User may want to be allowed to do this. XXX */

@@ -145,7 +145,7 @@ void do_memaccess_unaligned(struct pt_regs *regs, unsigned long pc, unsigned lon
 #endif
 	send_sig_fault(SIGBUS, BUS_ADRALN,
 		       /* FIXME: Should dig out mna address */ (void *)0,
-		       0, current);
+		       current);
 }
 
 static unsigned long init_fsr = 0x0UL;

@@ -291,7 +291,7 @@ void do_fpe_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 		else if (fsr & 0x01)
 			code = FPE_FLTRES;
 	}
-	send_sig_fault(SIGFPE, code, (void __user *)pc, 0, fpt);
+	send_sig_fault(SIGFPE, code, (void __user *)pc, fpt);
 #ifndef CONFIG_SMP
 	last_task_used_math = NULL;
 #endif

@@ -305,7 +305,7 @@ void handle_tag_overflow(struct pt_regs *regs, unsigned long pc, unsigned long n
 {
 	if(psr & PSR_PS)
 		die_if_kernel("Penguin overflow trap from kernel mode", regs);
-	send_sig_fault(SIGEMT, EMT_TAGOVF, (void __user *)pc, 0, current);
+	send_sig_fault(SIGEMT, EMT_TAGOVF, (void __user *)pc, current);
 }
 
 void handle_watchpoint(struct pt_regs *regs, unsigned long pc, unsigned long npc,

@@ -327,13 +327,13 @@ void handle_reg_access(struct pt_regs *regs, unsigned long pc, unsigned long npc
 	printk("Register Access Exception at PC %08lx NPC %08lx PSR %08lx\n",
 	       pc, npc, psr);
 #endif
-	force_sig_fault(SIGBUS, BUS_OBJERR, (void __user *)pc, 0);
+	force_sig_fault(SIGBUS, BUS_OBJERR, (void __user *)pc);
 }
 
 void handle_cp_disabled(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 			unsigned long psr)
 {
-	send_sig_fault(SIGILL, ILL_COPROC, (void __user *)pc, 0, current);
+	send_sig_fault(SIGILL, ILL_COPROC, (void __user *)pc, current);
 }
 
 void handle_cp_exception(struct pt_regs *regs, unsigned long pc, unsigned long npc,

@@ -343,13 +343,13 @@ void handle_cp_exception(struct pt_regs *regs, unsigned long pc, unsigned long n
 	printk("Co-Processor Exception at PC %08lx NPC %08lx PSR %08lx\n",
 	       pc, npc, psr);
 #endif
-	send_sig_fault(SIGILL, ILL_COPROC, (void __user *)pc, 0, current);
+	send_sig_fault(SIGILL, ILL_COPROC, (void __user *)pc, current);
 }
 
 void handle_hw_divzero(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 		       unsigned long psr)
 {
-	send_sig_fault(SIGFPE, FPE_INTDIV, (void __user *)pc, 0, current);
+	send_sig_fault(SIGFPE, FPE_INTDIV, (void __user *)pc, current);
 }
 
 #ifdef CONFIG_DEBUG_BUGVERBOSE

diff --git a/arch/sparc/kernel/traps_64.c b/arch/sparc/kernel/traps_64.c
index a850dccd78ea..6863025ed56d 100644
--- a/arch/sparc/kernel/traps_64.c
+++ b/arch/sparc/kernel/traps_64.c

@@ -107,8 +107,8 @@ void bad_trap(struct pt_regs *regs, long lvl)
 		regs->tpc &= 0xffffffff;
 		regs->tnpc &= 0xffffffff;
 	}
-	force_sig_fault(SIGILL, ILL_ILLTRP,
-			(void __user *)regs->tpc, lvl);
+	force_sig_fault_trapno(SIGILL, ILL_ILLTRP,
+			       (void __user *)regs->tpc, lvl);
 }
 
 void bad_trap_tl1(struct pt_regs *regs, long lvl)

@@ -201,8 +201,7 @@ void spitfire_insn_access_exception(struct pt_regs *regs, unsigned long sfsr, un
 		regs->tpc &= 0xffffffff;
 		regs->tnpc &= 0xffffffff;
 	}
-	force_sig_fault(SIGSEGV, SEGV_MAPERR,
-			(void __user *)regs->tpc, 0);
+	force_sig_fault(SIGSEGV, SEGV_MAPERR, (void __user *)regs->tpc);
 out:
 	exception_exit(prev_state);
 }

@@ -237,7 +236,7 @@ void sun4v_insn_access_exception(struct pt_regs *regs, unsigned long addr, unsig
 		regs->tpc &= 0xffffffff;
 		regs->tnpc &= 0xffffffff;
 	}
-	force_sig_fault(SIGSEGV, SEGV_MAPERR, (void __user *) addr, 0);
+	force_sig_fault(SIGSEGV, SEGV_MAPERR, (void __user *) addr);
 }
 
 void sun4v_insn_access_exception_tl1(struct pt_regs *regs, unsigned long addr, unsigned long type_ctx)

@@ -321,7 +320,7 @@ void spitfire_data_access_exception(struct pt_regs *regs, unsigned long sfsr, un
 	if (is_no_fault_exception(regs))
 		return;
 
-	force_sig_fault(SIGSEGV, SEGV_MAPERR, (void __user *)sfar, 0);
+	force_sig_fault(SIGSEGV, SEGV_MAPERR, (void __user *)sfar);
 out:
 	exception_exit(prev_state);
 }

@@ -385,13 +384,13 @@ void sun4v_data_access_exception(struct pt_regs *regs, unsigned long addr, unsig
 	 */
 	switch (type) {
 	case HV_FAULT_TYPE_INV_ASI:
-		force_sig_fault(SIGILL, ILL_ILLADR, (void __user *)addr, 0);
+		force_sig_fault(SIGILL, ILL_ILLADR, (void __user *)addr);
 		break;
 	case HV_FAULT_TYPE_MCD_DIS:
-		force_sig_fault(SIGSEGV, SEGV_ACCADI, (void __user *)addr, 0);
+		force_sig_fault(SIGSEGV, SEGV_ACCADI, (void __user *)addr);
 		break;
 	default:
-		force_sig_fault(SIGSEGV, SEGV_MAPERR, (void __user *)addr, 0);
+		force_sig_fault(SIGSEGV, SEGV_MAPERR, (void __user *)addr);
 		break;
 	}
 }

@@ -568,7 +567,7 @@ static void spitfire_ue_log(unsigned long afsr, unsigned long afar, unsigned lon
 		regs->tpc &= 0xffffffff;
 		regs->tnpc &= 0xffffffff;
 	}
-	force_sig_fault(SIGBUS, BUS_OBJERR, (void *)0, 0);
+	force_sig_fault(SIGBUS, BUS_OBJERR, (void *)0);
 }
 
 void spitfire_access_error(struct pt_regs *regs, unsigned long status_encoded, unsigned long afar)

@@ -2069,8 +2068,7 @@ void do_mcd_err(struct pt_regs *regs, struct sun4v_error_entry ent)
 	/* Send SIGSEGV to the userspace process with the right signal
 	 * code
 	 */
-	force_sig_fault(SIGSEGV, SEGV_ADIDERR, (void __user *)ent.err_raddr,
-			0);
+	force_sig_fault(SIGSEGV, SEGV_ADIDERR, (void __user *)ent.err_raddr);
 }
 
 /* We run with %pil set to PIL_NORMAL_MAX and PSTATE_IE enabled in %pstate.

@@ -2184,7 +2182,7 @@ bool sun4v_nonresum_error_user_handled(struct pt_regs *regs,
 	}
 	if (attrs & SUN4V_ERR_ATTRS_PIO) {
 		force_sig_fault(SIGBUS, BUS_ADRERR,
-				(void __user *)sun4v_get_vaddr(regs), 0);
+				(void __user *)sun4v_get_vaddr(regs));
 		return true;
 	}

@@ -2340,8 +2338,7 @@ static void do_fpe_common(struct pt_regs *regs)
 			else if (fsr & 0x01)
 				code = FPE_FLTRES;
 		}
-		force_sig_fault(SIGFPE, code,
-				(void __user *)regs->tpc, 0);
+		force_sig_fault(SIGFPE, code, (void __user *)regs->tpc);
 	}
 }

@@ -2395,8 +2392,7 @@ void do_tof(struct pt_regs *regs)
 		regs->tpc &= 0xffffffff;
 		regs->tnpc &= 0xffffffff;
 	}
-	force_sig_fault(SIGEMT, EMT_TAGOVF,
-			(void __user *)regs->tpc, 0);
+	force_sig_fault(SIGEMT, EMT_TAGOVF, (void __user *)regs->tpc);
 out:
 	exception_exit(prev_state);
 }

@@ -2415,8 +2411,7 @@ void do_div0(struct pt_regs *regs)
 		regs->tpc &= 0xffffffff;
 		regs->tnpc &= 0xffffffff;
 	}
-	force_sig_fault(SIGFPE, FPE_INTDIV,
-			(void __user *)regs->tpc, 0);
+	force_sig_fault(SIGFPE, FPE_INTDIV, (void __user *)regs->tpc);
 out:
 	exception_exit(prev_state);
 }

@@ -2612,7 +2607,7 @@ void do_illegal_instruction(struct pt_regs *regs)
 			}
 		}
 	}
-	force_sig_fault(SIGILL, ILL_ILLOPC, (void __user *)pc, 0);
+	force_sig_fault(SIGILL, ILL_ILLOPC, (void __user *)pc);
 out:
 	exception_exit(prev_state);
 }

@@ -2632,7 +2627,7 @@ void mem_address_unaligned(struct pt_regs *regs, unsigned long sfar, unsigned lo
 	if (is_no_fault_exception(regs))
 		return;
 
-	force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *)sfar, 0);
+	force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *)sfar);
 out:
 	exception_exit(prev_state);
 }

@@ -2650,7 +2645,7 @@ void sun4v_do_mna(struct pt_regs *regs, unsigned long addr, unsigned long type_c
 	if (is_no_fault_exception(regs))
 		return;
 
-	force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *) addr, 0);
+	force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *) addr);
 }
 
 /* sun4v_mem_corrupt_detect_precise() - Handle precise exception on an ADI

@@ -2697,7 +2692,7 @@ void sun4v_mem_corrupt_detect_precise(struct pt_regs *regs, unsigned long addr,
 		regs->tpc &= 0xffffffff;
 		regs->tnpc &= 0xffffffff;
 	}
-	force_sig_fault(SIGSEGV, SEGV_ADIPERR, (void __user *)addr, 0);
+	force_sig_fault(SIGSEGV, SEGV_ADIPERR, (void __user *)addr);
 }
 
 void do_privop(struct pt_regs *regs)

@@ -2712,8 +2707,7 @@ void do_privop(struct pt_regs *regs)
 		regs->tpc &= 0xffffffff;
 		regs->tnpc &= 0xffffffff;
 	}
-	force_sig_fault(SIGILL, ILL_PRVOPC,
-			(void __user *)regs->tpc, 0);
+	force_sig_fault(SIGILL, ILL_PRVOPC, (void __user *)regs->tpc);
 out:
 	exception_exit(prev_state);
 }

diff --git a/arch/sparc/kernel/unaligned_32.c b/arch/sparc/kernel/unaligned_32.c
index ef5c5207c9ff..455f0258c745 100644
--- a/arch/sparc/kernel/unaligned_32.c
+++ b/arch/sparc/kernel/unaligned_32.c

@@ -278,5 +278,5 @@ asmlinkage void user_unaligned_trap(struct pt_regs *regs, unsigned int insn)
 {
 	send_sig_fault(SIGBUS, BUS_ADRALN,
 		       (void __user *)safe_compute_effective_address(regs, insn),
-		       0, current);
+		       current);
 }

diff --git a/arch/sparc/mm/fault_32.c b/arch/sparc/mm/fault_32.c
index de2031c2b2d7..fa858626b85b 100644
--- a/arch/sparc/mm/fault_32.c
+++ b/arch/sparc/mm/fault_32.c

@@ -83,7 +83,7 @@ static void __do_fault_siginfo(int code, int sig, struct pt_regs *regs,
 		show_signal_msg(regs, sig, code,
 				addr, current);
 
-	force_sig_fault(sig, code, (void __user *) addr, 0);
+	force_sig_fault(sig, code, (void __user *) addr);
 }
 
 static unsigned long compute_si_addr(struct pt_regs *regs, int text_fault)

diff --git a/arch/sparc/mm/fault_64.c b/arch/sparc/mm/fault_64.c
index 0a6bcc85fba7..9a9652a15fed 100644
--- a/arch/sparc/mm/fault_64.c
+++ b/arch/sparc/mm/fault_64.c

@@ -176,7 +176,7 @@ static void do_fault_siginfo(int code, int sig, struct pt_regs *regs,
 	if (unlikely(show_unhandled_signals))
 		show_signal_msg(regs, sig, code, addr, current);
 
-	force_sig_fault(sig, code, (void __user *) addr, 0);
+	force_sig_fault(sig, code, (void __user *) addr);
 }
 
 static unsigned int get_fault_insn(struct pt_regs *regs, unsigned int insn)

diff --git a/include/linux/sched/signal.h b/include/linux/sched/signal.h
index 3f6a0fcaa10c..7daa425f3055 100644
--- a/include/linux/sched/signal.h
+++ b/include/linux/sched/signal.h

@@ -298,11 +298,6 @@ static inline void kernel_signal_stop(void)
 
 	schedule();
 }
-#ifdef __ARCH_SI_TRAPNO
-# define ___ARCH_SI_TRAPNO(_a1) , _a1
-#else
-# define ___ARCH_SI_TRAPNO(_a1)
-#endif
 #ifdef __ia64__
 # define ___ARCH_SI_IA64(_a1, _a2, _a3) , _a1, _a2, _a3
 #else

@@ -310,14 +305,11 @@ static inline void kernel_signal_stop(void)
 #endif
 
 int force_sig_fault_to_task(int sig, int code, void __user *addr
-	___ARCH_SI_TRAPNO(int trapno)
 	___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr)
 	, struct task_struct *t);
 int force_sig_fault(int sig, int code, void __user *addr
-	___ARCH_SI_TRAPNO(int trapno)
 	___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr));
 int send_sig_fault(int sig, int code, void __user *addr
-	___ARCH_SI_TRAPNO(int trapno)
 	___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr)
 	, struct task_struct *t);

@@ -327,6 +319,10 @@ int send_sig_mceerr(int code, void __user *, short, struct task_struct *);
 int force_sig_bnderr(void __user *addr, void __user *lower, void __user *upper);
 int force_sig_pkuerr(void __user *addr, u32 pkey);
 
+int force_sig_fault_trapno(int sig, int code, void __user *addr, int trapno);
+int send_sig_fault_trapno(int sig, int code, void __user *addr, int trapno,
+			  struct task_struct *task);
+
 int force_sig_ptrace_errno_trap(int errno, void __user *addr);
 
 extern int send_sig_info(int, struct kernel_siginfo *, struct task_struct *);

diff --git a/kernel/signal.c b/kernel/signal.c
index 3d3ba7949788..7eaa8d84db4c 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c

@@ -1651,7 +1651,6 @@ void force_sigsegv(int sig)
 }
 
 int force_sig_fault_to_task(int sig, int code, void __user *addr
-	___ARCH_SI_TRAPNO(int trapno)
 	___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr)
 	, struct task_struct *t)
 {

@@ -1662,9 +1661,6 @@ int force_sig_fault_to_task(int sig, int code, void __user *addr
 	info.si_errno = 0;
 	info.si_code  = code;
 	info.si_addr  = addr;
-#ifdef __ARCH_SI_TRAPNO
-	info.si_trapno = trapno;
-#endif
 #ifdef __ia64__
 	info.si_imm = imm;
 	info.si_flags = flags;

@@ -1674,16 +1670,13 @@ int force_sig_fault_to_task(int sig, int code, void __user *addr
 }
 
 int force_sig_fault(int sig, int code, void __user *addr
-	___ARCH_SI_TRAPNO(int trapno)
 	___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr))
 {
 	return force_sig_fault_to_task(sig, code, addr
-				       ___ARCH_SI_TRAPNO(trapno)
 				       ___ARCH_SI_IA64(imm, flags, isr), current);
 }
 
 int send_sig_fault(int sig, int code, void __user *addr
-	___ARCH_SI_TRAPNO(int trapno)
 	___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr)
 	, struct task_struct *t)
 {

@@ -1694,9 +1687,6 @@ int send_sig_fault(int sig, int code, void __user *addr
 	info.si_errno = 0;
 	info.si_code  = code;
 	info.si_addr  = addr;
-#ifdef __ARCH_SI_TRAPNO
-	info.si_trapno = trapno;
-#endif
 #ifdef __ia64__
 	info.si_imm = imm;
 	info.si_flags = flags;

@@ -1763,6 +1753,37 @@ int force_sig_pkuerr(void __user *addr, u32 pkey)
 }
 #endif
 
+#if IS_ENABLED(CONFIG_SPARC)
+int force_sig_fault_trapno(int sig, int code, void __user *addr, int trapno)
+{
+	struct kernel_siginfo info;
+
+	clear_siginfo(&info);
+	info.si_signo = sig;
+	info.si_errno = 0;
+	info.si_code  = code;
+	info.si_addr  = addr;
+	info.si_trapno = trapno;
+	return force_sig_info(&info);
+}
+#endif
+
+#if IS_ENABLED(CONFIG_ALPHA)
+int send_sig_fault_trapno(int sig, int code, void __user *addr, int trapno,
+			  struct task_struct *t)
+{
+	struct kernel_siginfo info;
+
+	clear_siginfo(&info);
+	info.si_signo = sig;
+	info.si_errno = 0;
+	info.si_code  = code;
+	info.si_addr  = addr;
+	info.si_trapno = trapno;
+	return send_sig_info(info.si_signo, &info, t);
+}
+#endif
+
 /* For the crazy architectures that include trap information in
  * the errno field, instead of an actual errno value.
  */

-- 
2.30.1

[PATCH 08/12] signal: Rename SIL_PERF_EVENT SIL_FAULT_PERF_EVENT for consistency

From: Eric W. Beiderman <hidden>
Date: 2021-05-03 20:39:33

From: "Eric W. Biederman" <redacted>

It helps to know which part of the siginfo structure the siginfo_layout
value is talking about.

v1: https://lkml.kernel.org/r/m18s4zs7nu.fsf_-_@fess.ebiederm.org
Acked-by: Marco Elver <elver@google.com>
Signed-off-by: Eric W. Biederman <redacted>
---
 fs/signalfd.c          |  2 +-
 include/linux/signal.h |  2 +-
 kernel/signal.c        | 10 +++++-----
 3 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/fs/signalfd.c b/fs/signalfd.c
index e87e59581653..83130244f653 100644
--- a/fs/signalfd.c
+++ b/fs/signalfd.c

@@ -132,7 +132,7 @@ static int signalfd_copyinfo(struct signalfd_siginfo __user *uinfo,
 		new.ssi_addr = (long) kinfo->si_addr;
 		new.ssi_addr_lsb = (short) kinfo->si_addr_lsb;
 		break;
-	case SIL_PERF_EVENT:
+	case SIL_FAULT_PERF_EVENT:
 		new.ssi_addr = (long) kinfo->si_addr;
 		new.ssi_perf = kinfo->si_perf;
 		break;

diff --git a/include/linux/signal.h b/include/linux/signal.h
index 5160fd45e5ca..ed896d790e46 100644
--- a/include/linux/signal.h
+++ b/include/linux/signal.h

@@ -44,7 +44,7 @@ enum siginfo_layout {
 	SIL_FAULT_MCEERR,
 	SIL_FAULT_BNDERR,
 	SIL_FAULT_PKUERR,
-	SIL_PERF_EVENT,
+	SIL_FAULT_PERF_EVENT,
 	SIL_CHLD,
 	SIL_RT,
 	SIL_SYS,

diff --git a/kernel/signal.c b/kernel/signal.c
index 7eaa8d84db4c..697c5fe58db8 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c

@@ -1198,7 +1198,7 @@ static inline bool has_si_pid_and_uid(struct kernel_siginfo *info)
 	case SIL_FAULT_MCEERR:
 	case SIL_FAULT_BNDERR:
 	case SIL_FAULT_PKUERR:
-	case SIL_PERF_EVENT:
+	case SIL_FAULT_PERF_EVENT:
 	case SIL_SYS:
 		ret = false;
 		break;

@@ -2553,7 +2553,7 @@ static void hide_si_addr_tag_bits(struct ksignal *ksig)
 	case SIL_FAULT_MCEERR:
 	case SIL_FAULT_BNDERR:
 	case SIL_FAULT_PKUERR:
-	case SIL_PERF_EVENT:
+	case SIL_FAULT_PERF_EVENT:
 		ksig->info.si_addr = arch_untagged_si_addr(
 			ksig->info.si_addr, ksig->sig, ksig->info.si_code);
 		break;

@@ -3243,7 +3243,7 @@ enum siginfo_layout siginfo_layout(unsigned sig, int si_code)
 				layout = SIL_FAULT_PKUERR;
 #endif
 			else if ((sig == SIGTRAP) && (si_code == TRAP_PERF))
-				layout = SIL_PERF_EVENT;
+				layout = SIL_FAULT_PERF_EVENT;
 		}
 		else if (si_code <= NSIGPOLL)
 			layout = SIL_POLL;

@@ -3365,7 +3365,7 @@ void copy_siginfo_to_external32(struct compat_siginfo *to,
 		to->si_addr = ptr_to_compat(from->si_addr);
 		to->si_pkey = from->si_pkey;
 		break;
-	case SIL_PERF_EVENT:
+	case SIL_FAULT_PERF_EVENT:
 		to->si_addr = ptr_to_compat(from->si_addr);
 		to->si_perf = from->si_perf;
 		break;

@@ -3441,7 +3441,7 @@ static int post_copy_siginfo_from_user32(kernel_siginfo_t *to,
 		to->si_addr = compat_ptr(from->si_addr);
 		to->si_pkey = from->si_pkey;
 		break;
-	case SIL_PERF_EVENT:
+	case SIL_FAULT_PERF_EVENT:
 		to->si_addr = compat_ptr(from->si_addr);
 		to->si_perf = from->si_perf;
 		break;

-- 
2.30.1

[PATCH 07/12] signal: Remove __ARCH_SI_TRAPNO

From: Eric W. Beiderman <hidden>
Date: 2021-05-03 20:39:38

From: "Eric W. Biederman" <redacted>

Now that this define is no longer used remove it from the kernel.

v1: https://lkml.kernel.org/r/m18s4zs7nu.fsf_-_@fess.ebiederm.org
Signed-off-by: "Eric W. Biederman" <redacted>
---
 arch/alpha/include/uapi/asm/siginfo.h | 2 --
 arch/mips/include/uapi/asm/siginfo.h  | 2 --
 arch/sparc/include/uapi/asm/siginfo.h | 3 ---
 3 files changed, 7 deletions(-)

diff --git a/arch/alpha/include/uapi/asm/siginfo.h b/arch/alpha/include/uapi/asm/siginfo.h
index 6e1a2af2f962..e08eae88182b 100644
--- a/arch/alpha/include/uapi/asm/siginfo.h
+++ b/arch/alpha/include/uapi/asm/siginfo.h

@@ -2,8 +2,6 @@
 #ifndef _ALPHA_SIGINFO_H
 #define _ALPHA_SIGINFO_H
 
-#define __ARCH_SI_TRAPNO
-
 #include <asm-generic/siginfo.h>
 
 #endif

diff --git a/arch/mips/include/uapi/asm/siginfo.h b/arch/mips/include/uapi/asm/siginfo.h
index c34c7eef0a1c..8cb8bd061a68 100644
--- a/arch/mips/include/uapi/asm/siginfo.h
+++ b/arch/mips/include/uapi/asm/siginfo.h

@@ -10,9 +10,7 @@
 #ifndef _UAPI_ASM_SIGINFO_H
 #define _UAPI_ASM_SIGINFO_H
 
-
 #define __ARCH_SIGEV_PREAMBLE_SIZE (sizeof(long) + 2*sizeof(int))
-#undef __ARCH_SI_TRAPNO /* exception code needs to fill this ...  */
 
 #define __ARCH_HAS_SWAPPED_SIGINFO

diff --git a/arch/sparc/include/uapi/asm/siginfo.h b/arch/sparc/include/uapi/asm/siginfo.h
index 68bdde4c2a2e..0e7c27522aed 100644
--- a/arch/sparc/include/uapi/asm/siginfo.h
+++ b/arch/sparc/include/uapi/asm/siginfo.h

@@ -8,9 +8,6 @@
 
 #endif /* defined(__sparc__) && defined(__arch64__) */
 
-
-#define __ARCH_SI_TRAPNO
-
 #include <asm-generic/siginfo.h>

-- 
2.30.1

[PATCH 09/12] signal: Factor force_sig_perf out of perf_sigtrap

From: Eric W. Beiderman <hidden>
Date: 2021-05-03 20:39:43

From: "Eric W. Biederman" <redacted>

Separate generating the signal from deciding it needs to be sent.

v1: https://lkml.kernel.org/r/m17dkjqqxz.fsf_-_@fess.ebiederm.org
Signed-off-by: "Eric W. Biederman" <redacted>
---
 include/linux/sched/signal.h |  1 +
 kernel/events/core.c         | 11 ++---------
 kernel/signal.c              | 13 +++++++++++++
 3 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/include/linux/sched/signal.h b/include/linux/sched/signal.h
index 7daa425f3055..1e2f61a1a512 100644
--- a/include/linux/sched/signal.h
+++ b/include/linux/sched/signal.h

@@ -318,6 +318,7 @@ int send_sig_mceerr(int code, void __user *, short, struct task_struct *);
 
 int force_sig_bnderr(void __user *addr, void __user *lower, void __user *upper);
 int force_sig_pkuerr(void __user *addr, u32 pkey);
+int force_sig_perf(void __user *addr, u32 type, u64 sig_data);
 
 int force_sig_fault_trapno(int sig, int code, void __user *addr, int trapno);
 int send_sig_fault_trapno(int sig, int code, void __user *addr, int trapno,

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 928b166d888e..48ea8863183b 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c

@@ -6394,8 +6394,6 @@ void perf_event_wakeup(struct perf_event *event)
 
 static void perf_sigtrap(struct perf_event *event)
 {
-	struct kernel_siginfo info;
-
 	/*
 	 * We'd expect this to only occur if the irq_work is delayed and either
 	 * ctx->task or current has changed in the meantime. This can be the

@@ -6410,13 +6408,8 @@ static void perf_sigtrap(struct perf_event *event)
 	if (current->flags & PF_EXITING)
 		return;
 
-	clear_siginfo(&info);
-	info.si_signo = SIGTRAP;
-	info.si_code = TRAP_PERF;
-	info.si_errno = event->attr.type;
-	info.si_perf = event->attr.sig_data;
-	info.si_addr = (void __user *)event->pending_addr;
-	force_sig_info(&info);
+	force_sig_perf((void __user *)event->pending_addr,
+		       event->attr.type, event->attr.sig_data);
 }
 
 static void perf_pending_event_disable(struct perf_event *event)

diff --git a/kernel/signal.c b/kernel/signal.c
index 697c5fe58db8..49560ceac048 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c

@@ -1753,6 +1753,19 @@ int force_sig_pkuerr(void __user *addr, u32 pkey)
 }
 #endif
 
+int force_sig_perf(void __user *addr, u32 type, u64 sig_data)
+{
+	struct kernel_siginfo info;
+
+	clear_siginfo(&info);
+	info.si_signo = SIGTRAP;
+	info.si_errno = type;
+	info.si_code  = TRAP_PERF;
+	info.si_addr  = addr;
+	info.si_perf  = sig_data;
+	return force_sig_info(&info);
+}
+
 #if IS_ENABLED(CONFIG_SPARC)
 int force_sig_fault_trapno(int sig, int code, void __user *addr, int trapno)
 {

-- 
2.30.1

[PATCH 10/12] signal: Redefine signinfo so 64bit fields are possible

From: Eric W. Beiderman <hidden>
Date: 2021-05-03 20:39:44

From: "Eric W. Biederman" <redacted>

The si_perf code really wants to add a u64 field.  This change enables
that by reorganizing the definition of siginfo_t, so that a 64bit
field can be added without increasing the alignment of other fields.

Signed-off-by: "Eric W. Biederman" <redacted>
---
 arch/x86/kernel/signal_compat.c    |  9 +++----
 include/linux/compat.h             | 28 +++++++++++++-------
 include/uapi/asm-generic/siginfo.h | 42 ++++++++++++++++++++----------
 3 files changed, 49 insertions(+), 30 deletions(-)

diff --git a/arch/x86/kernel/signal_compat.c b/arch/x86/kernel/signal_compat.c
index a9fcabd8a5e5..a5cd01c52dfb 100644
--- a/arch/x86/kernel/signal_compat.c
+++ b/arch/x86/kernel/signal_compat.c

@@ -17,8 +17,6 @@
  */
 static inline void signal_compat_build_tests(void)
 {
-	int _sifields_offset = offsetof(compat_siginfo_t, _sifields);
-
 	/*
 	 * If adding a new si_code, there is probably new data in
 	 * the siginfo.  Make sure folks bumping the si_code

@@ -40,8 +38,7 @@ static inline void signal_compat_build_tests(void)
 	 * in the ABI, of course.  Make sure none of them ever
 	 * move and are always at the beginning:
 	 */
-	BUILD_BUG_ON(offsetof(compat_siginfo_t, _sifields) != 3 * sizeof(int));
-#define CHECK_CSI_OFFSET(name)	  BUILD_BUG_ON(_sifields_offset != offsetof(compat_siginfo_t, _sifields.name))
+#define CHECK_CSI_OFFSET(name)	  BUILD_BUG_ON(0 != offsetof(compat_siginfo_t, _sifields.name))
 
 	BUILD_BUG_ON(offsetof(siginfo_t, si_signo) != 0);
 	BUILD_BUG_ON(offsetof(siginfo_t, si_errno) != 4);

@@ -63,8 +60,8 @@ static inline void signal_compat_build_tests(void)
 	 * structure stays within the padding size (checked
 	 * above).
 	 */
-#define CHECK_CSI_SIZE(name, size) BUILD_BUG_ON(size != sizeof(((compat_siginfo_t *)0)->_sifields.name))
-#define CHECK_SI_SIZE(name, size) BUILD_BUG_ON(size != sizeof(((siginfo_t *)0)->_sifields.name))
+#define CHECK_CSI_SIZE(name, size) BUILD_BUG_ON(((3*sizeof(int))+(size)) != sizeof(((compat_siginfo_t *)0)->_sifields.name))
+#define CHECK_SI_SIZE(name, size) BUILD_BUG_ON(((4*sizeof(int))+(size)) != sizeof(((siginfo_t *)0)->_sifields.name))
 
 	CHECK_CSI_OFFSET(_kill);
 	CHECK_CSI_SIZE  (_kill, 2*sizeof(int));

diff --git a/include/linux/compat.h b/include/linux/compat.h
index 6af7bef15e94..d81493248bf3 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h

@@ -158,27 +158,28 @@ typedef union compat_sigval {
 	compat_uptr_t	sival_ptr;
 } compat_sigval_t;
 
-typedef struct compat_siginfo {
-	int si_signo;
-#ifndef __ARCH_HAS_SWAPPED_SIGINFO
-	int si_errno;
-	int si_code;
-#else
-	int si_code;
-	int si_errno;
-#endif
+#define __COMPAT_SIGINFO_COMMON	\
+	___SIGINFO_COMMON;	\
+	int	_common_pad[__alignof__(compat_uptr_t) != __alignof__(int)]
 
+typedef struct compat_siginfo {
+	union {
+		struct {
+			__COMPAT_SIGINFO_COMMON;
+		};
 	union {
-		int _pad[128/sizeof(int) - 3];
+		int _pad[128/sizeof(int)];
 
 		/* kill() */
 		struct {
+			__COMPAT_SIGINFO_COMMON;
 			compat_pid_t _pid;	/* sender's pid */
 			__compat_uid32_t _uid;	/* sender's uid */
 		} _kill;
 
 		/* POSIX.1b timers */
 		struct {
+			__COMPAT_SIGINFO_COMMON;
 			compat_timer_t _tid;	/* timer id */
 			int _overrun;		/* overrun count */
 			compat_sigval_t _sigval;	/* same as below */

@@ -186,6 +187,7 @@ typedef struct compat_siginfo {
 
 		/* POSIX.1b signals */
 		struct {
+			__COMPAT_SIGINFO_COMMON;
 			compat_pid_t _pid;	/* sender's pid */
 			__compat_uid32_t _uid;	/* sender's uid */
 			compat_sigval_t _sigval;

@@ -193,6 +195,7 @@ typedef struct compat_siginfo {
 
 		/* SIGCHLD */
 		struct {
+			__COMPAT_SIGINFO_COMMON;
 			compat_pid_t _pid;	/* which child */
 			__compat_uid32_t _uid;	/* sender's uid */
 			int _status;		/* exit code */

@@ -203,6 +206,7 @@ typedef struct compat_siginfo {
 #ifdef CONFIG_X86_X32_ABI
 		/* SIGCHLD (x32 version) */
 		struct {
+			__COMPAT_SIGINFO_COMMON;
 			compat_pid_t _pid;	/* which child */
 			__compat_uid32_t _uid;	/* sender's uid */
 			int _status;		/* exit code */

@@ -213,6 +217,7 @@ typedef struct compat_siginfo {
 
 		/* SIGILL, SIGFPE, SIGSEGV, SIGBUS, SIGTRAP, SIGEMT */
 		struct {
+			__COMPAT_SIGINFO_COMMON;
 			compat_uptr_t _addr;	/* faulting insn/memory ref. */
 #define __COMPAT_ADDR_BND_PKEY_PAD  (__alignof__(compat_uptr_t) < sizeof(short) ? \
 				     sizeof(short) : __alignof__(compat_uptr_t))

@@ -242,16 +247,19 @@ typedef struct compat_siginfo {
 
 		/* SIGPOLL */
 		struct {
+			__COMPAT_SIGINFO_COMMON;
 			compat_long_t _band;	/* POLL_IN, POLL_OUT, POLL_MSG */
 			int _fd;
 		} _sigpoll;
 
 		struct {
+			__COMPAT_SIGINFO_COMMON;
 			compat_uptr_t _call_addr; /* calling user insn */
 			int _syscall;	/* triggering system call number */
 			unsigned int _arch;	/* AUDIT_ARCH_* of syscall */
 		} _sigsys;
 	} _sifields;
+	};
 } compat_siginfo_t;
 
 struct compat_rlimit {

diff --git a/include/uapi/asm-generic/siginfo.h b/include/uapi/asm-generic/siginfo.h
index e663bf117b46..1fcede623a73 100644
--- a/include/uapi/asm-generic/siginfo.h
+++ b/include/uapi/asm-generic/siginfo.h

@@ -29,15 +29,33 @@ typedef union sigval {
 #define __ARCH_SI_ATTRIBUTES
 #endif
 
+#ifndef __ARCH_HAS_SWAPPED_SIGINFO
+#define ___SIGINFO_COMMON	\
+	int	si_signo;	\
+	int	si_errno;	\
+	int	si_code
+#else
+#define ___SIGINFO_COMMON	\
+	int	si_signo;	\
+	int	si_code;	\
+	int	si_errno
+#endif /* __ARCH_HAS_SWAPPED_SIGINFO */
+
+#define __SIGINFO_COMMON	\
+	___SIGINFO_COMMON;	\
+	int	_common_pad[__alignof__(void *) != __alignof(int)]
+
 union __sifields {
 	/* kill() */
 	struct {
+		__SIGINFO_COMMON;
 		__kernel_pid_t _pid;	/* sender's pid */
 		__kernel_uid32_t _uid;	/* sender's uid */
 	} _kill;
 
 	/* POSIX.1b timers */
 	struct {
+		__SIGINFO_COMMON;
 		__kernel_timer_t _tid;	/* timer id */
 		int _overrun;		/* overrun count */
 		sigval_t _sigval;	/* same as below */

@@ -46,6 +64,7 @@ union __sifields {
 
 	/* POSIX.1b signals */
 	struct {
+		__SIGINFO_COMMON;
 		__kernel_pid_t _pid;	/* sender's pid */
 		__kernel_uid32_t _uid;	/* sender's uid */
 		sigval_t _sigval;

@@ -53,6 +72,7 @@ union __sifields {
 
 	/* SIGCHLD */
 	struct {
+		__SIGINFO_COMMON;
 		__kernel_pid_t _pid;	/* which child */
 		__kernel_uid32_t _uid;	/* sender's uid */
 		int _status;		/* exit code */

@@ -62,6 +82,7 @@ union __sifields {
 
 	/* SIGILL, SIGFPE, SIGSEGV, SIGBUS, SIGTRAP, SIGEMT */
 	struct {
+		__SIGINFO_COMMON;
 		void __user *_addr; /* faulting insn/memory ref. */
 #ifdef __ia64__
 		int _imm;		/* immediate value for "break" */

@@ -97,35 +118,28 @@ union __sifields {
 
 	/* SIGPOLL */
 	struct {
+		__SIGINFO_COMMON;
 		__ARCH_SI_BAND_T _band;	/* POLL_IN, POLL_OUT, POLL_MSG */
 		int _fd;
 	} _sigpoll;
 
 	/* SIGSYS */
 	struct {
+		__SIGINFO_COMMON;
 		void __user *_call_addr; /* calling user insn */
 		int _syscall;	/* triggering system call number */
 		unsigned int _arch;	/* AUDIT_ARCH_* of syscall */
 	} _sigsys;
 };
 
-#ifndef __ARCH_HAS_SWAPPED_SIGINFO
-#define __SIGINFO 			\
-struct {				\
-	int si_signo;			\
-	int si_errno;			\
-	int si_code;			\
-	union __sifields _sifields;	\
-}
-#else
+
 #define __SIGINFO 			\
-struct {				\
-	int si_signo;			\
-	int si_code;			\
-	int si_errno;			\
+union {					\
+	struct {			\
+		__SIGINFO_COMMON;	\
+	};				\
 	union __sifields _sifields;	\
 }
-#endif /* __ARCH_HAS_SWAPPED_SIGINFO */
 
 typedef struct siginfo {
 	union {

-- 
2.30.1

[PATCH 11/12] signal: Deliver all of the siginfo perf data in _perf

From: Eric W. Beiderman <hidden>
Date: 2021-05-03 20:39:46

From: "Eric W. Biederman" <redacted>

Don't abuse si_errno and deliver all of the perf data in _perf member
of siginfo_t.

Because it is possible increase the size of perf_data to 64bits.

v1: https://lkml.kernel.org/r/m11rarqqx2.fsf_-_@fess.ebiederm.org
Signed-off-by: "Eric W. Biederman" <redacted>
---
 arch/arm/kernel/signal.c                      |  3 ++-
 arch/arm64/kernel/signal.c                    |  3 ++-
 arch/arm64/kernel/signal32.c                  |  3 ++-
 arch/sparc/kernel/signal32.c                  |  3 ++-
 arch/sparc/kernel/signal_64.c                 |  3 ++-
 arch/x86/kernel/signal_compat.c               |  8 ++++---
 fs/signalfd.c                                 |  3 ++-
 include/linux/compat.h                        |  5 ++++-
 include/uapi/asm-generic/siginfo.h            |  8 +++++--
 include/uapi/linux/signalfd.h                 |  4 ++--
 kernel/signal.c                               | 21 ++++++++++++-------
 .../selftests/perf_events/sigtrap_threads.c   | 12 +++++------
 12 files changed, 48 insertions(+), 28 deletions(-)

diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index 2dac5d2c5cf6..ffd3cb8dadea 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c

@@ -755,7 +755,8 @@ static_assert(offsetof(siginfo_t, si_addr_lsb)	== 0x10);
 static_assert(offsetof(siginfo_t, si_lower)	== 0x14);
 static_assert(offsetof(siginfo_t, si_upper)	== 0x18);
 static_assert(offsetof(siginfo_t, si_pkey)	== 0x14);
-static_assert(offsetof(siginfo_t, si_perf)	== 0x10);
+static_assert(offsetof(siginfo_t, si_perf_data)	== 0x10);
+static_assert(offsetof(siginfo_t, si_perf_type)	== 0x18);
 static_assert(offsetof(siginfo_t, si_band)	== 0x0c);
 static_assert(offsetof(siginfo_t, si_fd)	== 0x10);
 static_assert(offsetof(siginfo_t, si_call_addr)	== 0x0c);

diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c
index af8bd2af1298..f6cbbc54861e 100644
--- a/arch/arm64/kernel/signal.c
+++ b/arch/arm64/kernel/signal.c

@@ -1003,7 +1003,8 @@ static_assert(offsetof(siginfo_t, si_addr_lsb)	== 0x18);
 static_assert(offsetof(siginfo_t, si_lower)	== 0x20);
 static_assert(offsetof(siginfo_t, si_upper)	== 0x28);
 static_assert(offsetof(siginfo_t, si_pkey)	== 0x20);
-static_assert(offsetof(siginfo_t, si_perf)	== 0x18);
+static_assert(offsetof(siginfo_t, si_perf_data)	== 0x18);
+static_assert(offsetof(siginfo_t, si_perf_type)	== 0x20);
 static_assert(offsetof(siginfo_t, si_band)	== 0x10);
 static_assert(offsetof(siginfo_t, si_fd)	== 0x18);
 static_assert(offsetof(siginfo_t, si_call_addr)	== 0x10);

diff --git a/arch/arm64/kernel/signal32.c b/arch/arm64/kernel/signal32.c
index b6afb646515f..8241dcc43d7f 100644
--- a/arch/arm64/kernel/signal32.c
+++ b/arch/arm64/kernel/signal32.c

@@ -487,7 +487,8 @@ static_assert(offsetof(compat_siginfo_t, si_addr_lsb)	== 0x10);
 static_assert(offsetof(compat_siginfo_t, si_lower)	== 0x14);
 static_assert(offsetof(compat_siginfo_t, si_upper)	== 0x18);
 static_assert(offsetof(compat_siginfo_t, si_pkey)	== 0x14);
-static_assert(offsetof(compat_siginfo_t, si_perf)	== 0x10);
+static_assert(offsetof(compat_siginfo_t, si_perf_data)	== 0x10);
+static_assert(offsetof(compat_siginfo_t, si_perf_type)	== 0x18);
 static_assert(offsetof(compat_siginfo_t, si_band)	== 0x0c);
 static_assert(offsetof(compat_siginfo_t, si_fd)		== 0x10);
 static_assert(offsetof(compat_siginfo_t, si_call_addr)	== 0x0c);

diff --git a/arch/sparc/kernel/signal32.c b/arch/sparc/kernel/signal32.c
index 73fd8700df3e..1c8b60dd27d8 100644
--- a/arch/sparc/kernel/signal32.c
+++ b/arch/sparc/kernel/signal32.c

@@ -776,6 +776,7 @@ static_assert(offsetof(compat_siginfo_t, si_addr_lsb)	== 0x10);
 static_assert(offsetof(compat_siginfo_t, si_lower)	== 0x14);
 static_assert(offsetof(compat_siginfo_t, si_upper)	== 0x18);
 static_assert(offsetof(compat_siginfo_t, si_pkey)	== 0x14);
-static_assert(offsetof(compat_siginfo_t, si_perf)	== 0x10);
+static_assert(offsetof(compat_siginfo_t, si_perf_data)	== 0x10);
+static_assert(offsetof(compat_siginfo_t, si_perf_type)	== 0x18);
 static_assert(offsetof(compat_siginfo_t, si_band)	== 0x0c);
 static_assert(offsetof(compat_siginfo_t, si_fd)		== 0x10);

diff --git a/arch/sparc/kernel/signal_64.c b/arch/sparc/kernel/signal_64.c
index 17913daa66c6..a58e0cc45d24 100644
--- a/arch/sparc/kernel/signal_64.c
+++ b/arch/sparc/kernel/signal_64.c

@@ -586,6 +586,7 @@ static_assert(offsetof(siginfo_t, si_addr_lsb)	== 0x18);
 static_assert(offsetof(siginfo_t, si_lower)	== 0x20);
 static_assert(offsetof(siginfo_t, si_upper)	== 0x28);
 static_assert(offsetof(siginfo_t, si_pkey)	== 0x20);
-static_assert(offsetof(siginfo_t, si_perf)	== 0x18);
+static_assert(offsetof(siginfo_t, si_perf_data)	== 0x18);
+static_assert(offsetof(siginfo_t, si_perf_type)	== 0x20);
 static_assert(offsetof(siginfo_t, si_band)	== 0x10);
 static_assert(offsetof(siginfo_t, si_fd)	== 0x14);

diff --git a/arch/x86/kernel/signal_compat.c b/arch/x86/kernel/signal_compat.c
index a5cd01c52dfb..a81310fe9e8a 100644
--- a/arch/x86/kernel/signal_compat.c
+++ b/arch/x86/kernel/signal_compat.c

@@ -118,7 +118,7 @@ static inline void signal_compat_build_tests(void)
 #endif
 
 	CHECK_CSI_OFFSET(_sigfault);
-	CHECK_CSI_SIZE  (_sigfault, 4*sizeof(int));
+	CHECK_CSI_SIZE  (_sigfault, 5*sizeof(int));
 	CHECK_SI_SIZE   (_sigfault, 8*sizeof(int));
 
 	BUILD_BUG_ON(offsetof(siginfo_t, si_addr) != 0x10);

@@ -138,8 +138,10 @@ static inline void signal_compat_build_tests(void)
 	BUILD_BUG_ON(offsetof(siginfo_t, si_pkey) != 0x20);
 	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_pkey) != 0x14);
 
-	BUILD_BUG_ON(offsetof(siginfo_t, si_perf) != 0x18);
-	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_perf) != 0x10);
+	BUILD_BUG_ON(offsetof(siginfo_t, si_perf_data) != 0x18);
+	BUILD_BUG_ON(offsetof(siginfo_t, si_perf_type) != 0x20);
+	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_perf_data) != 0x10);
+	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_perf_type) != 0x18);
 
 	CHECK_CSI_OFFSET(_sigpoll);
 	CHECK_CSI_SIZE  (_sigpoll, 2*sizeof(int));

diff --git a/fs/signalfd.c b/fs/signalfd.c
index 83130244f653..335ad39f3900 100644
--- a/fs/signalfd.c
+++ b/fs/signalfd.c

@@ -134,7 +134,8 @@ static int signalfd_copyinfo(struct signalfd_siginfo __user *uinfo,
 		break;
 	case SIL_FAULT_PERF_EVENT:
 		new.ssi_addr = (long) kinfo->si_addr;
-		new.ssi_perf = kinfo->si_perf;
+		new.ssi_perf_type = kinfo->si_perf_type;
+		new.ssi_perf_data = kinfo->si_perf_data;
 		break;
 	case SIL_CHLD:
 		new.ssi_pid    = kinfo->si_pid;

diff --git a/include/linux/compat.h b/include/linux/compat.h
index d81493248bf3..9190a1c2aac7 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h

@@ -241,7 +241,10 @@ typedef struct compat_siginfo {
 					u32 _pkey;
 				} _addr_pkey;
 				/* used when si_code=TRAP_PERF */
-				compat_ulong_t _perf;
+				struct {
+					u64 _data;
+					u32 _type;
+				} _perf;
 			};
 		} _sigfault;

diff --git a/include/uapi/asm-generic/siginfo.h b/include/uapi/asm-generic/siginfo.h
index 1fcede623a73..dbe3dd90876f 100644
--- a/include/uapi/asm-generic/siginfo.h
+++ b/include/uapi/asm-generic/siginfo.h

@@ -112,7 +112,10 @@ union __sifields {
 				__u32 _pkey;
 			} _addr_pkey;
 			/* used when si_code=TRAP_PERF */
-			unsigned long _perf;
+			struct {
+				__u64 _data;
+				__u32 _type;
+			} _perf;
 		};
 	} _sigfault;

@@ -168,7 +171,8 @@ typedef struct siginfo {
 #define si_lower	_sifields._sigfault._addr_bnd._lower
 #define si_upper	_sifields._sigfault._addr_bnd._upper
 #define si_pkey		_sifields._sigfault._addr_pkey._pkey
-#define si_perf		_sifields._sigfault._perf
+#define si_perf_data	_sifields._sigfault._perf._data
+#define si_perf_type	_sifields._sigfault._perf._type
 #define si_band		_sifields._sigpoll._band
 #define si_fd		_sifields._sigpoll._fd
 #define si_call_addr	_sifields._sigsys._call_addr

diff --git a/include/uapi/linux/signalfd.h b/include/uapi/linux/signalfd.h
index 7e333042c7e3..e78dddf433fc 100644
--- a/include/uapi/linux/signalfd.h
+++ b/include/uapi/linux/signalfd.h

@@ -39,8 +39,8 @@ struct signalfd_siginfo {
 	__s32 ssi_syscall;
 	__u64 ssi_call_addr;
 	__u32 ssi_arch;
-	__u32 __pad3;
-	__u64 ssi_perf;
+	__u32 ssi_perf_type;
+	__u64 ssi_perf_data;
 
 	/*
 	 * Pad strcture to 128 bytes. Remember to update the

diff --git a/kernel/signal.c b/kernel/signal.c
index 49560ceac048..7fec9d1c5b11 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c

@@ -1758,11 +1758,13 @@ int force_sig_perf(void __user *addr, u32 type, u64 sig_data)
 	struct kernel_siginfo info;
 
 	clear_siginfo(&info);
-	info.si_signo = SIGTRAP;
-	info.si_errno = type;
-	info.si_code  = TRAP_PERF;
-	info.si_addr  = addr;
-	info.si_perf  = sig_data;
+	info.si_signo     = SIGTRAP;
+	info.si_errno     = 0;
+	info.si_code      = TRAP_PERF;
+	info.si_addr      = addr;
+	info.si_perf_data = sig_data;
+	info.si_perf_type = type;
+
 	return force_sig_info(&info);
 }

@@ -3380,7 +3382,8 @@ void copy_siginfo_to_external32(struct compat_siginfo *to,
 		break;
 	case SIL_FAULT_PERF_EVENT:
 		to->si_addr = ptr_to_compat(from->si_addr);
-		to->si_perf = from->si_perf;
+		to->si_perf_data = from->si_perf_data;
+		to->si_perf_type = from->si_perf_type;
 		break;
 	case SIL_CHLD:
 		to->si_pid = from->si_pid;

@@ -3456,7 +3459,8 @@ static int post_copy_siginfo_from_user32(kernel_siginfo_t *to,
 		break;
 	case SIL_FAULT_PERF_EVENT:
 		to->si_addr = compat_ptr(from->si_addr);
-		to->si_perf = from->si_perf;
+		to->si_perf_data = from->si_perf_data;
+		to->si_perf_type = from->si_perf_type;
 		break;
 	case SIL_CHLD:
 		to->si_pid    = from->si_pid;

@@ -4639,7 +4643,8 @@ static inline void siginfo_buildtime_checks(void)
 	CHECK_OFFSET(si_lower);
 	CHECK_OFFSET(si_upper);
 	CHECK_OFFSET(si_pkey);
-	CHECK_OFFSET(si_perf);
+	CHECK_OFFSET(si_perf_data);
+	CHECK_OFFSET(si_perf_type);
 
 	/* sigpoll */
 	CHECK_OFFSET(si_band);

diff --git a/tools/testing/selftests/perf_events/sigtrap_threads.c b/tools/testing/selftests/perf_events/sigtrap_threads.c
index 78ddf5e11625..fde123066a8c 100644
--- a/tools/testing/selftests/perf_events/sigtrap_threads.c
+++ b/tools/testing/selftests/perf_events/sigtrap_threads.c

@@ -164,8 +164,8 @@ TEST_F(sigtrap_threads, enable_event)
 	EXPECT_EQ(ctx.signal_count, NUM_THREADS);
 	EXPECT_EQ(ctx.tids_want_signal, 0);
 	EXPECT_EQ(ctx.first_siginfo.si_addr, &ctx.iterate_on);
-	EXPECT_EQ(ctx.first_siginfo.si_errno, PERF_TYPE_BREAKPOINT);
-	EXPECT_EQ(ctx.first_siginfo.si_perf, TEST_SIG_DATA(&ctx.iterate_on));
+	EXPECT_EQ(ctx.first_siginfo.si_perf_type, PERF_TYPE_BREAKPOINT);
+	EXPECT_EQ(ctx.first_siginfo.si_perf_data, TEST_SIG_DATA(&ctx.iterate_on));
 
 	/* Check enabled for parent. */
 	ctx.iterate_on = 0;

@@ -183,8 +183,8 @@ TEST_F(sigtrap_threads, modify_and_enable_event)
 	EXPECT_EQ(ctx.signal_count, NUM_THREADS);
 	EXPECT_EQ(ctx.tids_want_signal, 0);
 	EXPECT_EQ(ctx.first_siginfo.si_addr, &ctx.iterate_on);
-	EXPECT_EQ(ctx.first_siginfo.si_errno, PERF_TYPE_BREAKPOINT);
-	EXPECT_EQ(ctx.first_siginfo.si_perf, TEST_SIG_DATA(&ctx.iterate_on));
+	EXPECT_EQ(ctx.first_siginfo.si_perf_type, PERF_TYPE_BREAKPOINT);
+	EXPECT_EQ(ctx.first_siginfo.si_perf_data, TEST_SIG_DATA(&ctx.iterate_on));
 
 	/* Check enabled for parent. */
 	ctx.iterate_on = 0;

@@ -203,8 +203,8 @@ TEST_F(sigtrap_threads, signal_stress)
 	EXPECT_EQ(ctx.signal_count, NUM_THREADS * ctx.iterate_on);
 	EXPECT_EQ(ctx.tids_want_signal, 0);
 	EXPECT_EQ(ctx.first_siginfo.si_addr, &ctx.iterate_on);
-	EXPECT_EQ(ctx.first_siginfo.si_errno, PERF_TYPE_BREAKPOINT);
-	EXPECT_EQ(ctx.first_siginfo.si_perf, TEST_SIG_DATA(&ctx.iterate_on));
+	EXPECT_EQ(ctx.first_siginfo.si_perf_type, PERF_TYPE_BREAKPOINT);
+	EXPECT_EQ(ctx.first_siginfo.si_perf_data, TEST_SIG_DATA(&ctx.iterate_on));
 }
 
 TEST_HARNESS_MAIN

-- 
2.30.1

[PATCH 12/12] signalfd: Remove SIL_FAULT_PERF_EVENT fields from signalfd_siginfo

From: Eric W. Beiderman <hidden>
Date: 2021-05-03 20:39:50

From: "Eric W. Biederman" <redacted>

With the addition of ssi_perf_data and ssi_perf_type struct signalfd_siginfo
is dangerously close to running out of space.  All that remains is just
enough space for two additional 64bit fields.  A practice of adding all
possible siginfo_t fields into struct singalfd_siginfo can not be supported
as adding the missing fields ssi_lower, ssi_upper, and ssi_pkey would
require two 64bit fields and one 32bit fields.  In practice the fields
ssi_perf_data and ssi_perf_type can never be used by signalfd as the signal
that generates them always delivers them synchronously to the thread that
triggers them.

Therefore until someone actually needs the fields ssi_perf_data and
ssi_perf_type in signalfd_siginfo remove them.  This leaves a bit more room
for future expansion.

Signed-off-by: "Eric W. Biederman" <redacted>
---
 fs/signalfd.c                 | 16 ++++++----------
 include/uapi/linux/signalfd.h |  4 +---
 2 files changed, 7 insertions(+), 13 deletions(-)

diff --git a/fs/signalfd.c b/fs/signalfd.c
index 335ad39f3900..040e1cf90528 100644
--- a/fs/signalfd.c
+++ b/fs/signalfd.c

@@ -114,12 +114,13 @@ static int signalfd_copyinfo(struct signalfd_siginfo __user *uinfo,
 		break;
 	case SIL_FAULT_BNDERR:
 	case SIL_FAULT_PKUERR:
+	case SIL_FAULT_PERF_EVENT:
 		/*
-		 * Fall through to the SIL_FAULT case.  Both SIL_FAULT_BNDERR
-		 * and SIL_FAULT_PKUERR are only generated by faults that
-		 * deliver them synchronously to userspace.  In case someone
-		 * injects one of these signals and signalfd catches it treat
-		 * it as SIL_FAULT.
+		 * Fall through to the SIL_FAULT case.  SIL_FAULT_BNDERR,
+		 * SIL_FAULT_PKUERR, and SIL_FAULT_PERF_EVENT are only
+		 * generated by faults that deliver them synchronously to
+		 * userspace.  In case someone injects one of these signals
+		 * and signalfd catches it treat it as SIL_FAULT.
 		 */
 	case SIL_FAULT:
 		new.ssi_addr = (long) kinfo->si_addr;

@@ -132,11 +133,6 @@ static int signalfd_copyinfo(struct signalfd_siginfo __user *uinfo,
 		new.ssi_addr = (long) kinfo->si_addr;
 		new.ssi_addr_lsb = (short) kinfo->si_addr_lsb;
 		break;
-	case SIL_FAULT_PERF_EVENT:
-		new.ssi_addr = (long) kinfo->si_addr;
-		new.ssi_perf_type = kinfo->si_perf_type;
-		new.ssi_perf_data = kinfo->si_perf_data;
-		break;
 	case SIL_CHLD:
 		new.ssi_pid    = kinfo->si_pid;
 		new.ssi_uid    = kinfo->si_uid;

diff --git a/include/uapi/linux/signalfd.h b/include/uapi/linux/signalfd.h
index e78dddf433fc..83429a05b698 100644
--- a/include/uapi/linux/signalfd.h
+++ b/include/uapi/linux/signalfd.h

@@ -39,8 +39,6 @@ struct signalfd_siginfo {
 	__s32 ssi_syscall;
 	__u64 ssi_call_addr;
 	__u32 ssi_arch;
-	__u32 ssi_perf_type;
-	__u64 ssi_perf_data;
 
 	/*
 	 * Pad strcture to 128 bytes. Remember to update the

@@ -51,7 +49,7 @@ struct signalfd_siginfo {
 	 * comes out of a read(2) and we really don't want to have
 	 * a compat on read(2).
 	 */
-	__u8 __pad[16];
+	__u8 __pad[28];
 };

-- 
2.30.1

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