[REVIEW][PATCH 10/15] signal/arm64: Add and use arm64_force_sig_fault where appropriate

From: Eric W. Biederman
Date: Mon Sep 24 2018 - 05:12:46 EST


Wrap force_sig_fault with a helper that calls arm64_show_signal
and call arm64_force_sig_fault where appropraite.

Signed-off-by: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
---
arch/arm64/include/asm/traps.h | 1 +
arch/arm64/kernel/debug-monitors.c | 11 +++--------
arch/arm64/kernel/ptrace.c | 11 +++--------
arch/arm64/kernel/traps.c | 27 ++++++++++-----------------
arch/arm64/mm/fault.c | 26 ++++++++------------------
5 files changed, 25 insertions(+), 51 deletions(-)

diff --git a/arch/arm64/include/asm/traps.h b/arch/arm64/include/asm/traps.h
index cd3a2ca9c179..08e99901edbc 100644
--- a/arch/arm64/include/asm/traps.h
+++ b/arch/arm64/include/asm/traps.h
@@ -37,6 +37,7 @@ void register_undef_hook(struct undef_hook *hook);
void unregister_undef_hook(struct undef_hook *hook);
void force_signal_inject(int signal, int code, unsigned long address);
void arm64_notify_segfault(unsigned long addr);
+void arm64_force_sig_fault(int signo, int code, void __user *addr, const char *str);
void arm64_force_sig_info(struct siginfo *info, const char *str);

/*
diff --git a/arch/arm64/kernel/debug-monitors.c b/arch/arm64/kernel/debug-monitors.c
index e0d9502be5bf..d7bb6aefae0a 100644
--- a/arch/arm64/kernel/debug-monitors.c
+++ b/arch/arm64/kernel/debug-monitors.c
@@ -210,13 +210,6 @@ NOKPROBE_SYMBOL(call_step_hook);
static void send_user_sigtrap(int si_code)
{
struct pt_regs *regs = current_pt_regs();
- siginfo_t info;
-
- clear_siginfo(&info);
- info.si_signo = SIGTRAP;
- info.si_errno = 0;
- info.si_code = si_code;
- info.si_addr = (void __user *)instruction_pointer(regs);

if (WARN_ON(!user_mode(regs)))
return;
@@ -224,7 +217,9 @@ static void send_user_sigtrap(int si_code)
if (interrupts_enabled(regs))
local_irq_enable();

- arm64_force_sig_info(&info, "User debug trap");
+ arm64_force_sig_fault(SIGTRAP, si_code,
+ (void __user *)instruction_pointer(regs),
+ "User debug trap");
}

static int single_step_handler(unsigned long addr, unsigned int esr,
diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index 20b68cb31ecb..7ab75e78aa08 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -182,13 +182,6 @@ static void ptrace_hbptriggered(struct perf_event *bp,
struct pt_regs *regs)
{
struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp);
- siginfo_t info;
-
- clear_siginfo(&info);
- info.si_signo = SIGTRAP;
- info.si_errno = 0;
- info.si_code = TRAP_HWBKPT;
- info.si_addr = (void __user *)(bkpt->trigger);

#ifdef CONFIG_COMPAT
if (is_compat_task()) {
@@ -211,7 +204,9 @@ static void ptrace_hbptriggered(struct perf_event *bp,
force_sig_ptrace_errno_trap(si_errno, (void __user *)bkpt->trigger);
}
#endif
- arm64_force_sig_info(&info, "Hardware breakpoint trap (ptrace)");
+ arm64_force_sig_fault(SIGTRAP, TRAP_HWBKPT,
+ (void __user *)(bkpt->trigger),
+ "Hardware breakpoint trap (ptrace)");
}

/*
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index daee8c2ca561..37a3309863e0 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -248,6 +248,13 @@ static void arm64_show_signal(int signo, const char *str)
__show_regs(regs);
}

+void arm64_force_sig_fault(int signo, int code, void __user *addr,
+ const char *str)
+{
+ arm64_show_signal(signo, str);
+ force_sig_fault(signo, code, addr, current);
+}
+
void arm64_force_sig_info(struct siginfo *info, const char *str)
{
arm64_show_signal(info->si_signo, str);
@@ -259,19 +266,11 @@ void arm64_notify_die(const char *str, struct pt_regs *regs,
int err)
{
if (user_mode(regs)) {
- struct siginfo info;
-
WARN_ON(regs != current_pt_regs());
current->thread.fault_address = 0;
current->thread.fault_code = err;

- clear_siginfo(&info);
- info.si_signo = signo;
- info.si_errno = 0;
- info.si_code = sicode;
- info.si_addr = addr;
-
- arm64_force_sig_info(&info, str);
+ arm64_force_sig_fault(signo, sicode, addr, str);
} else {
die(str, regs, err);
}
@@ -616,19 +615,13 @@ asmlinkage void bad_mode(struct pt_regs *regs, int reason, unsigned int esr)
*/
asmlinkage void bad_el0_sync(struct pt_regs *regs, int reason, unsigned int esr)
{
- siginfo_t info;
void __user *pc = (void __user *)instruction_pointer(regs);

- clear_siginfo(&info);
- info.si_signo = SIGILL;
- info.si_errno = 0;
- info.si_code = ILL_ILLOPC;
- info.si_addr = pc;
-
current->thread.fault_address = 0;
current->thread.fault_code = esr;

- arm64_force_sig_info(&info, "Bad EL0 synchronous exception");
+ arm64_force_sig_fault(SIGILL, ILL_ILLOPC, pc,
+ "Bad EL0 synchronous exception");
}

#ifdef CONFIG_VMAP_STACK
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 959c4a565c8e..66c295019a9a 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -362,15 +362,10 @@ static void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *re
*/
if (user_mode(regs)) {
const struct fault_info *inf = esr_to_fault_info(esr);
- struct siginfo si;
-
- clear_siginfo(&si);
- si.si_signo = inf->sig;
- si.si_code = inf->code;
- si.si_addr = (void __user *)addr;

set_thread_esr(addr, esr);
- arm64_force_sig_info(&si, inf->name);
+ arm64_force_sig_fault(inf->sig, inf->code, (void __user *)addr,
+ inf->name);
} else {
__do_kernel_fault(addr, esr, regs);
}
@@ -570,11 +565,8 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
* We had some memory, but were unable to successfully fix up
* this page fault.
*/
- clear_siginfo(&si);
- si.si_signo = SIGBUS;
- si.si_code = BUS_ADRERR;
- si.si_addr = (void __user *)addr;
- arm64_force_sig_info(&si, inf->name);
+ arm64_force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)addr,
+ inf->name);
} else if (fault & (VM_FAULT_HWPOISON_LARGE | VM_FAULT_HWPOISON)) {
unsigned int lsb;

@@ -593,12 +585,10 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
* Something tried to access memory that isn't in our memory
* map.
*/
- clear_siginfo(&si);
- si.si_signo = SIGSEGV;
- si.si_code = fault == VM_FAULT_BADACCESS ?
- SEGV_ACCERR : SEGV_MAPERR;
- si.si_addr = (void __user *)addr;
- arm64_force_sig_info(&si, inf->name);
+ arm64_force_sig_fault(SIGSEGV,
+ fault == VM_FAULT_BADACCESS ? SEGV_ACCERR : SEGV_MAPERR,
+ (void __user *)addr,
+ inf->name);
}

return 0;
--
2.17.1