From: Will Deacon <will.deacon@arm.com>
Date: Tue, 20 Feb 2018 14:16:29 +0000 (+0000)
Subject: arm64: signal: Make force_signal_inject more robust
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=2c9120f3a86a809518ece1787d76ae07dd01e01b;p=linux.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 <will.deacon@arm.com>
---
diff --git a/arch/arm64/include/asm/traps.h b/arch/arm64/include/asm/traps.h
index 178e338d28897..1ee63dc38579b 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 68450e954d47d..6e47fc3ab5491 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 e7226c4c7493d..6964ff867d4ae 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 eb2d15147e8d3..c478d8e276491 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);
}