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Diffstat (limited to 'arch/x86/mm/fault.c')
-rw-r--r--arch/x86/mm/fault.c63
1 files changed, 42 insertions, 21 deletions
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 79b0b372d2d..7d90ceb882a 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -11,6 +11,7 @@
#include <linux/kprobes.h> /* __kprobes, ... */
#include <linux/mmiotrace.h> /* kmmio_handler, ... */
#include <linux/perf_event.h> /* perf_sw_event */
+#include <linux/hugetlb.h> /* hstate_index_to_shift */
#include <asm/traps.h> /* dotraplinkage, ... */
#include <asm/pgalloc.h> /* pgd_*(), ... */
@@ -160,15 +161,20 @@ is_prefetch(struct pt_regs *regs, unsigned long error_code, unsigned long addr)
static void
force_sig_info_fault(int si_signo, int si_code, unsigned long address,
- struct task_struct *tsk)
+ struct task_struct *tsk, int fault)
{
+ unsigned lsb = 0;
siginfo_t info;
info.si_signo = si_signo;
info.si_errno = 0;
info.si_code = si_code;
info.si_addr = (void __user *)address;
- info.si_addr_lsb = si_code == BUS_MCEERR_AR ? PAGE_SHIFT : 0;
+ if (fault & VM_FAULT_HWPOISON_LARGE)
+ lsb = hstate_index_to_shift(VM_FAULT_GET_HINDEX(fault));
+ if (fault & VM_FAULT_HWPOISON)
+ lsb = PAGE_SHIFT;
+ info.si_addr_lsb = lsb;
force_sig_info(si_signo, &info, tsk);
}
@@ -722,7 +728,7 @@ __bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code,
tsk->thread.error_code = error_code | (address >= TASK_SIZE);
tsk->thread.trap_no = 14;
- force_sig_info_fault(SIGSEGV, si_code, address, tsk);
+ force_sig_info_fault(SIGSEGV, si_code, address, tsk, 0);
return;
}
@@ -807,14 +813,14 @@ do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address,
tsk->thread.trap_no = 14;
#ifdef CONFIG_MEMORY_FAILURE
- if (fault & VM_FAULT_HWPOISON) {
+ if (fault & (VM_FAULT_HWPOISON|VM_FAULT_HWPOISON_LARGE)) {
printk(KERN_ERR
"MCE: Killing %s:%d due to hardware memory corruption fault at %lx\n",
tsk->comm, tsk->pid, address);
code = BUS_MCEERR_AR;
}
#endif
- force_sig_info_fault(SIGBUS, code, address, tsk);
+ force_sig_info_fault(SIGBUS, code, address, tsk, fault);
}
static noinline void
@@ -824,7 +830,8 @@ mm_fault_error(struct pt_regs *regs, unsigned long error_code,
if (fault & VM_FAULT_OOM) {
out_of_memory(regs, error_code, address);
} else {
- if (fault & (VM_FAULT_SIGBUS|VM_FAULT_HWPOISON))
+ if (fault & (VM_FAULT_SIGBUS|VM_FAULT_HWPOISON|
+ VM_FAULT_HWPOISON_LARGE))
do_sigbus(regs, error_code, address, fault);
else
BUG();
@@ -912,9 +919,9 @@ spurious_fault(unsigned long error_code, unsigned long address)
int show_unhandled_signals = 1;
static inline int
-access_error(unsigned long error_code, int write, struct vm_area_struct *vma)
+access_error(unsigned long error_code, struct vm_area_struct *vma)
{
- if (write) {
+ if (error_code & PF_WRITE) {
/* write, present and write, not present: */
if (unlikely(!(vma->vm_flags & VM_WRITE)))
return 1;
@@ -949,8 +956,10 @@ do_page_fault(struct pt_regs *regs, unsigned long error_code)
struct task_struct *tsk;
unsigned long address;
struct mm_struct *mm;
- int write;
int fault;
+ int write = error_code & PF_WRITE;
+ unsigned int flags = FAULT_FLAG_ALLOW_RETRY |
+ (write ? FAULT_FLAG_WRITE : 0);
tsk = current;
mm = tsk->mm;
@@ -1061,6 +1070,7 @@ do_page_fault(struct pt_regs *regs, unsigned long error_code)
bad_area_nosemaphore(regs, error_code, address);
return;
}
+retry:
down_read(&mm->mmap_sem);
} else {
/*
@@ -1104,9 +1114,7 @@ do_page_fault(struct pt_regs *regs, unsigned long error_code)
* we can handle it..
*/
good_area:
- write = error_code & PF_WRITE;
-
- if (unlikely(access_error(error_code, write, vma))) {
+ if (unlikely(access_error(error_code, vma))) {
bad_area_access_error(regs, error_code, address);
return;
}
@@ -1116,21 +1124,34 @@ good_area:
* make sure we exit gracefully rather than endlessly redo
* the fault:
*/
- fault = handle_mm_fault(mm, vma, address, write ? FAULT_FLAG_WRITE : 0);
+ fault = handle_mm_fault(mm, vma, address, flags);
if (unlikely(fault & VM_FAULT_ERROR)) {
mm_fault_error(regs, error_code, address, fault);
return;
}
- if (fault & VM_FAULT_MAJOR) {
- tsk->maj_flt++;
- perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, 0,
- regs, address);
- } else {
- tsk->min_flt++;
- perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, 0,
- regs, address);
+ /*
+ * Major/minor page fault accounting is only done on the
+ * initial attempt. If we go through a retry, it is extremely
+ * likely that the page will be found in page cache at that point.
+ */
+ if (flags & FAULT_FLAG_ALLOW_RETRY) {
+ if (fault & VM_FAULT_MAJOR) {
+ tsk->maj_flt++;
+ perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, 0,
+ regs, address);
+ } else {
+ tsk->min_flt++;
+ perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, 0,
+ regs, address);
+ }
+ if (fault & VM_FAULT_RETRY) {
+ /* Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk
+ * of starvation. */
+ flags &= ~FAULT_FLAG_ALLOW_RETRY;
+ goto retry;
+ }
}
check_v8086_mode(regs, address, tsk);