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authorLinus Torvalds <torvalds@linux-foundation.org>2012-07-23 19:10:12 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-07-23 19:10:12 -0700
commit474183b188b3c5af45831c71151f819fc70479b8 (patch)
tree8c82a7d60635fc0d9b0e8d8215e9f2e874f77421
parent47b170af84d18b736bb35932823ec01cfcfe1967 (diff)
parente9c31b32f1cc6d3aa190119103622fb8e4c257b1 (diff)
Merge tag 'please-pull-misc-3.6' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux
Pull misc Itanium fixes from Tony Luck. * tag 'please-pull-misc-3.6' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux: debug: Do not permit CONFIG_DEBUG_STACK_USAGE=y on IA64 or PARISC [IA64] Port OOM changes to ia64_do_page_fault
-rw-r--r--arch/ia64/mm/fault.c46
-rw-r--r--lib/Kconfig.debug2
2 files changed, 35 insertions, 13 deletions
diff --git a/arch/ia64/mm/fault.c b/arch/ia64/mm/fault.c
index 02d29c2a132..8443daf4f51 100644
--- a/arch/ia64/mm/fault.c
+++ b/arch/ia64/mm/fault.c
@@ -72,6 +72,10 @@ mapped_kernel_page_is_present (unsigned long address)
return pte_present(pte);
}
+# define VM_READ_BIT 0
+# define VM_WRITE_BIT 1
+# define VM_EXEC_BIT 2
+
void __kprobes
ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *regs)
{
@@ -81,6 +85,12 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re
struct siginfo si;
unsigned long mask;
int fault;
+ unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
+
+ mask = ((((isr >> IA64_ISR_X_BIT) & 1UL) << VM_EXEC_BIT)
+ | (((isr >> IA64_ISR_W_BIT) & 1UL) << VM_WRITE_BIT));
+
+ flags |= ((mask & VM_WRITE) ? FAULT_FLAG_WRITE : 0);
/* mmap_sem is performance critical.... */
prefetchw(&mm->mmap_sem);
@@ -109,6 +119,7 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re
if (notify_page_fault(regs, TRAP_BRKPT))
return;
+retry:
down_read(&mm->mmap_sem);
vma = find_vma_prev(mm, address, &prev_vma);
@@ -130,10 +141,6 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re
/* OK, we've got a good vm_area for this memory area. Check the access permissions: */
-# define VM_READ_BIT 0
-# define VM_WRITE_BIT 1
-# define VM_EXEC_BIT 2
-
# if (((1 << VM_READ_BIT) != VM_READ || (1 << VM_WRITE_BIT) != VM_WRITE) \
|| (1 << VM_EXEC_BIT) != VM_EXEC)
# error File is out of sync with <linux/mm.h>. Please update.
@@ -142,9 +149,6 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re
if (((isr >> IA64_ISR_R_BIT) & 1UL) && (!(vma->vm_flags & (VM_READ | VM_WRITE))))
goto bad_area;
- mask = ( (((isr >> IA64_ISR_X_BIT) & 1UL) << VM_EXEC_BIT)
- | (((isr >> IA64_ISR_W_BIT) & 1UL) << VM_WRITE_BIT));
-
if ((vma->vm_flags & mask) != mask)
goto bad_area;
@@ -153,7 +157,11 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re
* sure we exit gracefully rather than endlessly redo the
* fault.
*/
- fault = handle_mm_fault(mm, vma, address, (mask & VM_WRITE) ? FAULT_FLAG_WRITE : 0);
+ fault = handle_mm_fault(mm, vma, address, flags);
+
+ if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
+ return;
+
if (unlikely(fault & VM_FAULT_ERROR)) {
/*
* We ran out of memory, or some other thing happened
@@ -168,10 +176,24 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re
}
BUG();
}
- if (fault & VM_FAULT_MAJOR)
- current->maj_flt++;
- else
- current->min_flt++;
+
+ if (flags & FAULT_FLAG_ALLOW_RETRY) {
+ if (fault & VM_FAULT_MAJOR)
+ current->maj_flt++;
+ else
+ current->min_flt++;
+ if (fault & VM_FAULT_RETRY) {
+ flags &= ~FAULT_FLAG_ALLOW_RETRY;
+
+ /* No need to up_read(&mm->mmap_sem) as we would
+ * have already released it in __lock_page_or_retry
+ * in mm/filemap.c.
+ */
+
+ goto retry;
+ }
+ }
+
up_read(&mm->mmap_sem);
return;
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index ff5bdee4716..4a186508bf8 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -714,7 +714,7 @@ config STACKTRACE
config DEBUG_STACK_USAGE
bool "Stack utilization instrumentation"
- depends on DEBUG_KERNEL
+ depends on DEBUG_KERNEL && !IA64 && !PARISC
help
Enables the display of the minimum amount of free stack which each
task has ever had available in the sysrq-T and sysrq-P debug output.