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authorVineet Gupta <vgupta@synopsys.com>2019-05-14 15:55:31 -0700
committerVineet Gupta <vgupta@synopsys.com>2019-07-01 11:02:22 -0700
commit5e91bf5ce9b8740076f5283f1ec3a5b023950920 (patch)
tree86ed8da02dd804bebc4e6eaed8d39f4c5a073117 /arch/arc/mm
parent98cb57ad70fb7c8a9c030d3e83fe66b546906e28 (diff)
downloadlinux-5e91bf5ce9b8740076f5283f1ec3a5b023950920.tar.bz2
ARC: mm: do_page_fault refactor #7: fold the various error handling
- single up_read() call vs. 4 - so much easier on eyes Technically it seems like @bad_area label moved up, but even in old regime, it was a special case of delivering SIGSEGV unconditionally which we now do as well, although with checks. Also note that @fault needs to be initialized since we can land in @bad_area (which reads it) without setting it up with return value of handle_mm_fault() - failing to do so did bite us although as a side effect of different patch: see [1] [1]: http://lists.infradead.org/pipermail/linux-snps-arc/2019-May/005803.html Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Diffstat (limited to 'arch/arc/mm')
-rw-r--r--arch/arc/mm/fault.c48
1 files changed, 14 insertions, 34 deletions
diff --git a/arch/arc/mm/fault.c b/arch/arc/mm/fault.c
index 2672ce24d741..6a78a2d776a9 100644
--- a/arch/arc/mm/fault.c
+++ b/arch/arc/mm/fault.c
@@ -63,9 +63,9 @@ void do_page_fault(unsigned long address, struct pt_regs *regs)
struct vm_area_struct *vma = NULL;
struct task_struct *tsk = current;
struct mm_struct *mm = tsk->mm;
- int si_code = SEGV_MAPERR;
+ int sig, si_code = SEGV_MAPERR;
unsigned int write = 0, exec = 0, mask;
- vm_fault_t fault; /* handle_mm_fault() output */
+ vm_fault_t fault = VM_FAULT_SIGSEGV; /* handle_mm_fault() output */
unsigned int flags; /* handle_mm_fault() input */
/*
@@ -174,47 +174,27 @@ retry:
return;
}
- if (fault & VM_FAULT_OOM)
- goto out_of_memory;
- else if (fault & VM_FAULT_SIGSEGV)
- goto bad_area;
- else if (fault & VM_FAULT_SIGBUS)
- goto do_sigbus;
-
- /* no man's land */
- BUG();
-
- /*
- * Something tried to access memory that isn't in our memory map..
- * Fix it, but check if it's kernel or user first..
- */
bad_area:
up_read(&mm->mmap_sem);
if (!user_mode(regs))
goto no_context;
- tsk->thread.fault_address = address;
- force_sig_fault(SIGSEGV, si_code, (void __user *)address, tsk);
- return;
-
-out_of_memory:
- up_read(&mm->mmap_sem);
-
- if (!user_mode(regs))
- goto no_context;
-
- pagefault_out_of_memory();
- return;
-
-do_sigbus:
- up_read(&mm->mmap_sem);
+ if (fault & VM_FAULT_OOM) {
+ pagefault_out_of_memory();
+ return;
+ }
- if (!user_mode(regs))
- goto no_context;
+ if (fault & VM_FAULT_SIGBUS) {
+ sig = SIGBUS;
+ si_code = BUS_ADRERR;
+ }
+ else {
+ sig = SIGSEGV;
+ }
tsk->thread.fault_address = address;
- force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)address, tsk);
+ force_sig_fault(sig, si_code, (void __user *)address, tsk);
return;
no_context: