[REVIEW][PATCH 08/15] signal/arm64: Only perform one esr_to_fault_info call in do_page_fault

From: Eric W. Biederman
Date: Mon Sep 24 2018 - 05:12:35 EST


As this work is truly common between all of the signal sending cases
there is no need to repeat it between the different cases.

Signed-off-by: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
---
arch/arm64/mm/fault.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 7df3d8b561c2..ab85533e2255 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -424,6 +424,7 @@ static bool is_el0_instruction_abort(unsigned int esr)
static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
struct pt_regs *regs)
{
+ const struct fault_info *inf;
struct task_struct *tsk;
struct mm_struct *mm;
struct siginfo si;
@@ -562,6 +563,7 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
return 0;
}

+ inf = esr_to_fault_info(esr);
if (fault & VM_FAULT_SIGBUS) {
/*
* We had some memory, but were unable to successfully fix up
@@ -572,7 +574,7 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
si.si_code = BUS_ADRERR;
si.si_addr = (void __user *)addr;
set_thread_esr(addr, esr);
- arm64_force_sig_info(&si, esr_to_fault_info(esr)->name);
+ arm64_force_sig_info(&si, inf->name);
} else if (fault & (VM_FAULT_HWPOISON_LARGE | VM_FAULT_HWPOISON)) {
unsigned int lsb;

@@ -586,7 +588,7 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
si.si_addr = (void __user *)addr;
si.si_addr_lsb = lsb;
set_thread_esr(addr, esr);
- arm64_force_sig_info(&si, esr_to_fault_info(esr)->name);
+ arm64_force_sig_info(&si, inf->name);
} else {
/*
* Something tried to access memory that isn't in our memory
@@ -598,7 +600,7 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
SEGV_ACCERR : SEGV_MAPERR;
si.si_addr = (void __user *)addr;
set_thread_esr(addr, esr);
- arm64_force_sig_info(&si, esr_to_fault_info(esr)->name);
+ arm64_force_sig_info(&si, inf->name);
}

return 0;
--
2.17.1