Thread (2 messages) 2 messages, 2 authors, 2021-07-16

Re: [PATCH 4/6] signal/sparc: si_trapno is only used with SIGILL ILL_ILLTRP

From: Marco Elver <elver@google.com>
Date: 2021-07-16 11:49:26
Also in: linux-arch, lkml, sparclinux

On Thu, 15 Jul 2021 at 20:12, Eric W. Biederman [off-list ref] wrote:
While reviewing the signal handlers on sparc it became clear that
si_trapno is only set to a non-zero value when sending SIGILL with
si_code ILL_ILLTRP.

Add force_sig_fault_trapno and send SIGILL ILL_ILLTRP with it.

Remove the define of __ARCH_SI_TRAPNO and remove the always zero
si_trapno parameter from send_sig_fault and force_sig_fault.

v1: https://lkml.kernel.org/r/m1eeers7q7.fsf_-_@fess.ebiederm.org
v2: https://lkml.kernel.org/r/20210505141101.11519-7-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <redacted>
Reviewed-by: Marco Elver <elver@google.com>
quoted hunk ↗ jump to hunk
---
 arch/sparc/include/uapi/asm/siginfo.h |  3 --
 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          |  1 +
 kernel/signal.c                       | 19 ++++++++++++
 11 files changed, 56 insertions(+), 45 deletions(-)
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>

diff --git a/arch/sparc/kernel/process_64.c b/arch/sparc/kernel/process_64.c
index d33c58a58d4f..547b06b49ce3 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 b9126fe06c3f..99a9ab2b169a 100644
--- a/include/linux/sched/signal.h
+++ b/include/linux/sched/signal.h
@@ -329,6 +329,7 @@ int force_sig_pkuerr(void __user *addr, u32 pkey);
 int force_sig_perf(void __user *addr, u32 type, u64 sig_data);

 int force_sig_ptrace_errno_trap(int errno, void __user *addr);
+int force_sig_fault_trapno(int sig, int code, void __user *addr, int trapno);

 extern int send_sig_info(int, struct kernel_siginfo *, struct task_struct *);
 extern void force_sigsegv(int sig);
diff --git a/kernel/signal.c b/kernel/signal.c
index a3229add4455..87a374225277 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1808,6 +1808,22 @@ int force_sig_ptrace_errno_trap(int errno, void __user *addr)
        return force_sig_info(&info);
 }

+/* For the rare architectures that include trap information using
+ * si_trapno.
+ */
+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);
+}
+
 int kill_pgrp(struct pid *pid, int sig, int priv)
 {
        int ret;
@@ -3243,6 +3259,9 @@ enum siginfo_layout siginfo_layout(unsigned sig, int si_code)
 #endif
                        else if ((sig == SIGTRAP) && (si_code == TRAP_PERF))
                                layout = SIL_PERF_EVENT;
+                       else if (IS_ENABLED(CONFIG_SPARC) &&
+                                (sig == SIGILL) && (si_code == ILL_ILLTRP))
+                               layout = SIL_FAULT_TRAPNO;
 #ifdef __ARCH_SI_TRAPNO
                        else if (layout == SIL_FAULT)
                                layout = SIL_FAULT_TRAPNO;
--
2.20.1

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