From: Will Deacon Date: Tue, 20 Feb 2018 14:16:29 +0000 (+0000) Subject: arm64: signal: Make force_signal_inject more robust X-Git-Tag: v4.19~1308^2~63 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=2c9120f3a86a809518ece1787d76ae07dd01e01b;p=platform%2Fkernel%2Flinux-rpi.git arm64: signal: Make force_signal_inject more robust force_signal_inject is a little flakey: * It only knows about SIGILL and SIGSEGV, so can potentially deliver other signals based on a partially initialised siginfo_t * It sets si_addr to point at the PC for SIGSEGV * It always operates on current, so doesn't need the regs argument This patch fixes these issues by always assigning the si_addr field to the address parameter of the function and updates the callers (including those that indirectly call via arm64_notify_segfault) accordingly. Signed-off-by: Will Deacon --- diff --git a/arch/arm64/include/asm/traps.h b/arch/arm64/include/asm/traps.h index 178e338..1ee63dc 100644 --- a/arch/arm64/include/asm/traps.h +++ b/arch/arm64/include/asm/traps.h @@ -35,10 +35,8 @@ struct undef_hook { void register_undef_hook(struct undef_hook *hook); void unregister_undef_hook(struct undef_hook *hook); -void force_signal_inject(int signal, int code, struct pt_regs *regs, - unsigned long address); - -void arm64_notify_segfault(struct pt_regs *regs, unsigned long addr); +void force_signal_inject(int signal, int code, unsigned long address); +void arm64_notify_segfault(unsigned long addr); /* * Move regs->pc to next instruction and do necessary setup before it diff --git a/arch/arm64/kernel/armv8_deprecated.c b/arch/arm64/kernel/armv8_deprecated.c index 68450e9..6e47fc3 100644 --- a/arch/arm64/kernel/armv8_deprecated.c +++ b/arch/arm64/kernel/armv8_deprecated.c @@ -429,7 +429,7 @@ ret: fault: pr_debug("SWP{B} emulation: access caused memory abort!\n"); - arm64_notify_segfault(regs, address); + arm64_notify_segfault(address); return 0; } diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index e7226c4..6964ff8 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -285,8 +285,7 @@ static void task_fpsimd_save(void) * re-enter user with corrupt state. * There's no way to recover, so kill it: */ - force_signal_inject( - SIGKILL, 0, current_pt_regs(), 0); + force_signal_inject(SIGKILL, 0, 0); return; } @@ -831,7 +830,7 @@ asmlinkage void do_sve_acc(unsigned int esr, struct pt_regs *regs) { /* Even if we chose not to use SVE, the hardware could still trap: */ if (unlikely(!system_supports_sve()) || WARN_ON(is_compat_task())) { - force_signal_inject(SIGILL, ILL_ILLOPC, regs, 0); + force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc); return; } diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index eb2d151..c478d8e 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -311,12 +311,13 @@ exit: return fn ? fn(regs, instr) : 1; } -void force_signal_inject(int signal, int code, struct pt_regs *regs, - unsigned long address) +void force_signal_inject(int signal, int code, unsigned long address) { siginfo_t info; - void __user *pc = (void __user *)instruction_pointer(regs); const char *desc; + struct pt_regs *regs = current_pt_regs(); + + clear_siginfo(&info); switch (signal) { case SIGILL: @@ -332,15 +333,15 @@ void force_signal_inject(int signal, int code, struct pt_regs *regs, if (unhandled_signal(current, signal) && show_unhandled_signals_ratelimited()) { - pr_info("%s[%d]: %s: pc=%p\n", - current->comm, task_pid_nr(current), desc, pc); + pr_info("%s[%d]: %s: pc=%08llx\n", + current->comm, task_pid_nr(current), desc, regs->pc); dump_instr(KERN_INFO, regs); } info.si_signo = signal; info.si_errno = 0; info.si_code = code; - info.si_addr = pc; + info.si_addr = (void __user *)address; arm64_notify_die(desc, regs, &info, 0); } @@ -348,7 +349,7 @@ void force_signal_inject(int signal, int code, struct pt_regs *regs, /* * Set up process info to signal segmentation fault - called on access error. */ -void arm64_notify_segfault(struct pt_regs *regs, unsigned long addr) +void arm64_notify_segfault(unsigned long addr) { int code; @@ -359,7 +360,7 @@ void arm64_notify_segfault(struct pt_regs *regs, unsigned long addr) code = SEGV_ACCERR; up_read(¤t->mm->mmap_sem); - force_signal_inject(SIGSEGV, code, regs, addr); + force_signal_inject(SIGSEGV, code, addr); } asmlinkage void __exception do_undefinstr(struct pt_regs *regs) @@ -371,7 +372,7 @@ asmlinkage void __exception do_undefinstr(struct pt_regs *regs) if (call_undef_hook(regs) == 0) return; - force_signal_inject(SIGILL, ILL_ILLOPC, regs, 0); + force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc); } int cpu_enable_cache_maint_trap(void *__unused) @@ -426,12 +427,12 @@ static void user_cache_maint_handler(unsigned int esr, struct pt_regs *regs) __user_cache_maint("ic ivau", address, ret); break; default: - force_signal_inject(SIGILL, ILL_ILLOPC, regs, 0); + force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc); return; } if (ret) - arm64_notify_segfault(regs, address); + arm64_notify_segfault(address); else arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE); }