[REVIEW][PATCH 11/15] signal/arm64: Add and use arm64_force_sig_mceerr as appropriate

From: Eric W. Biederman
Date: Mon Sep 24 2018 - 05:16:30 EST


Add arm64_force_sig_mceerr for consistency with arm64_force_sig_fault,
and use it in the one location that can take advantage of it.

This removes the fiddly filling out of siginfo before sending a signal
reporting an memory error to userspace.

Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
---
arch/arm64/include/asm/traps.h | 1 +
arch/arm64/kernel/traps.c | 7 +++++++
arch/arm64/mm/fault.c | 9 ++-------
3 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/arch/arm64/include/asm/traps.h b/arch/arm64/include/asm/traps.h
index 08e99901edbc..193f0b0e8ee3 100644
--- a/arch/arm64/include/asm/traps.h
+++ b/arch/arm64/include/asm/traps.h
@@ -38,6 +38,7 @@ 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_mceerr(int code, void __user *addr, short lsb, const char *str);
void arm64_force_sig_info(struct siginfo *info, const char *str);

/*
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index 37a3309863e0..baa96dfffeec 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -255,6 +255,13 @@ void arm64_force_sig_fault(int signo, int code, void __user *addr,
force_sig_fault(signo, code, addr, current);
}

+void arm64_force_sig_mceerr(int code, void __user *addr, short lsb,
+ const char *str)
+{
+ arm64_show_signal(SIGBUS, str);
+ force_sig_mceerr(code, addr, lsb, current);
+}
+
void arm64_force_sig_info(struct siginfo *info, const char *str)
{
arm64_show_signal(info->si_signo, str);
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 66c295019a9a..f0ccb209d181 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -422,7 +422,6 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
const struct fault_info *inf;
struct task_struct *tsk;
struct mm_struct *mm;
- struct siginfo si;
vm_fault_t fault, major = 0;
unsigned long vm_flags = VM_READ | VM_WRITE;
unsigned int mm_flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
@@ -574,12 +573,8 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
if (fault & VM_FAULT_HWPOISON_LARGE)
lsb = hstate_index_to_shift(VM_FAULT_GET_HINDEX(fault));

- clear_siginfo(&si);
- si.si_signo = SIGBUS;
- si.si_code = BUS_MCEERR_AR;
- si.si_addr = (void __user *)addr;
- si.si_addr_lsb = lsb;
- arm64_force_sig_info(&si, inf->name);
+ arm64_force_sig_mceerr(BUS_MCEERR_AR, (void __user *)addr, lsb,
+ inf->name);
} else {
/*
* Something tried to access memory that isn't in our memory
--
2.17.1