Re: [PATCH 5/6] signal/alpha: si_trapno is only used with SIGFPE and SIGTRAP TRAP_UNK
From: Marco Elver <elver@google.com>
Date: 2021-07-16 11:48:54
Also in:
linux-api, lkml, sparclinux
On Thu, 15 Jul 2021 at 20:13, Eric W. Biederman [off-list ref] wrote:
While reviewing the signal handlers on alpha it became clear that si_trapno is only set to a non-zero value when sending SIGFPE and when sending SITGRAP with si_code TRAP_UNK. Add send_sig_fault_trapno and send SIGTRAP TRAP_UNK, and SIGFPE 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/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 | 26 +++++++++++++------------- arch/alpha/mm/fault.c | 4 ++-- include/linux/sched/signal.h | 2 ++ kernel/signal.c | 21 +++++++++++++++++++++ 7 files changed, 41 insertions(+), 20 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> #endifdiff --git a/arch/alpha/kernel/osf_sys.c b/arch/alpha/kernel/osf_sys.c index d5367a1c6300..bbdb1a9a5fd8 100644 --- a/arch/alpha/kernel/osf_sys.c +++ b/arch/alpha/kernel/osf_sys.c@@ -876,7 +876,7 @@ SYSCALL_DEFINE5(osf_setsysinfo, unsigned long, op, void __user *, buffer, if (fex & IEEE_TRAP_ENABLE_DZE) si_code = FPE_FLTDIV; if (fex & IEEE_TRAP_ENABLE_INV) si_code = FPE_FLTINV; - send_sig_fault(SIGFPE, si_code, + send_sig_fault_trapno(SIGFPE, si_code, (void __user *)NULL, /* FIXME */ 0, current); }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..e9e3de18793b 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@@ -268,13 +268,13 @@ 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, - current); + send_sig_fault_trapno(SIGTRAP, TRAP_UNK, + (void __user *) regs->pc, 0, current); return; case 2: /* gentrap */@@ -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_VMALLOCdiff --git a/include/linux/sched/signal.h b/include/linux/sched/signal.h index 99a9ab2b169a..6657184cef07 100644 --- a/include/linux/sched/signal.h +++ b/include/linux/sched/signal.h@@ -330,6 +330,8 @@ 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); +int send_sig_fault_trapno(int sig, int code, void __user *addr, int trapno, + struct task_struct *t); 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 87a374225277..ae06a424aa72 100644 --- a/kernel/signal.c +++ b/kernel/signal.c@@ -1824,6 +1824,23 @@ int force_sig_fault_trapno(int sig, int code, void __user *addr, int trapno) return force_sig_info(&info); } +/* For the rare architectures that include trap information using + * si_trapno. + */ +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); +} + int kill_pgrp(struct pid *pid, int sig, int priv) { int ret;@@ -3262,6 +3279,10 @@ enum siginfo_layout siginfo_layout(unsigned sig, int si_code) else if (IS_ENABLED(CONFIG_SPARC) && (sig == SIGILL) && (si_code == ILL_ILLTRP)) layout = SIL_FAULT_TRAPNO; + else if (IS_ENABLED(CONFIG_ALPHA) && + ((sig == SIGFPE) || + ((sig == SIGTRAP) && (si_code == TRAP_UNK)))) + layout = SIL_FAULT_TRAPNO; #ifdef __ARCH_SI_TRAPNO else if (layout == SIL_FAULT) layout = SIL_FAULT_TRAPNO; --2.20.1