From: Vineet Gupta <Vineet.Gupta1@synopsys.com>
To: <linux-snps-arc@lists.infradead.org>
Cc: <paltsev@snyopsys.com>, <linux-kernel@vger.kernel.org>,
Vineet Gupta <Vineet.Gupta1@synopsys.com>
Subject: [PATCH 8/9] ARC: mm: do_page_fault refactor #7: fold the various error handling
Date: Tue, 14 May 2019 17:29:35 -0700 [thread overview]
Message-ID: <1557880176-24964-9-git-send-email-vgupta@synopsys.com> (raw)
In-Reply-To: <1557880176-24964-1-git-send-email-vgupta@synopsys.com>
- 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.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
arch/arc/mm/fault.c | 46 +++++++++++++---------------------------------
1 file changed, 13 insertions(+), 33 deletions(-)
diff --git a/arch/arc/mm/fault.c b/arch/arc/mm/fault.c
index 0e1a222a97ad..20402217d9da 100644
--- a/arch/arc/mm/fault.c
+++ b/arch/arc/mm/fault.c
@@ -66,7 +66,7 @@ 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 */
unsigned int flags; /* handle_mm_fault() input */
@@ -177,47 +177,27 @@ void do_page_fault(unsigned long address, struct pt_regs *regs)
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:
--
2.7.4
next prev parent reply other threads:[~2019-05-15 0:30 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-15 0:29 [PATCH 0/9] ARC do_page_fault rework Vineet Gupta
2019-05-15 0:29 ` [PATCH 1/9] ARC: mm: SIGSEGV userspace trying to access kernel virtual memory Vineet Gupta
2019-05-15 0:29 ` [PATCH 2/9] ARC: mm: do_page_fault refactor #1: remove label @good_area Vineet Gupta
2019-05-15 0:29 ` [PATCH 3/9] ARC: mm: do_page_fault refactor #2: remove short lived variable Vineet Gupta
2019-05-15 0:29 ` [PATCH 4/9] ARC: mm: do_page_fault refactor #3: tidyup vma access permission code Vineet Gupta
2019-05-16 17:24 ` Eugeniy Paltsev
2019-05-16 17:37 ` Vineet Gupta
2019-05-16 17:44 ` Alexey Brodkin
2019-05-16 18:57 ` Vineet Gupta
2019-05-17 22:23 ` Eugeniy Paltsev
2019-05-30 17:58 ` extraneous generated EXTB (was Re: [PATCH 4/9] ARC: mm: do_page_fault refactor #3: tidyup vma access permission code) Vineet Gupta
2019-05-15 0:29 ` [PATCH 5/9] ARC: mm: do_page_fault refactor #4: consolidate retry related logic Vineet Gupta
2019-05-15 0:29 ` [PATCH 6/9] ARC: mm: do_page_fault refactor #5: scoot no_context to end Vineet Gupta
2019-05-15 0:29 ` [PATCH 7/9] ARC: mm: do_page_fault refactor #6: error handlers to use same pattern Vineet Gupta
2019-05-15 0:29 ` Vineet Gupta [this message]
2019-05-15 0:29 ` [PATCH 9/9] ARC: mm: do_page_fault refactor #8: release mmap_sem sooner Vineet Gupta
2019-05-30 16:48 ` Vineet Gupta
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