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Diffstat (limited to 'arch/powerpc/mm/fault.c')
-rw-r--r--arch/powerpc/mm/fault.c41
1 files changed, 27 insertions, 14 deletions
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index 229951f..8726779 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -32,6 +32,7 @@
#include <linux/perf_event.h>
#include <linux/magic.h>
#include <linux/ratelimit.h>
+#include <linux/context_tracking.h>
#include <asm/firmware.h>
#include <asm/page.h>
@@ -196,6 +197,7 @@ static int mm_fault_error(struct pt_regs *regs, unsigned long addr, int fault)
int __kprobes do_page_fault(struct pt_regs *regs, unsigned long address,
unsigned long error_code)
{
+ enum ctx_state prev_state = exception_enter();
struct vm_area_struct * vma;
struct mm_struct *mm = current->mm;
unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
@@ -204,6 +206,7 @@ int __kprobes do_page_fault(struct pt_regs *regs, unsigned long address,
int trap = TRAP(regs);
int is_exec = trap == 0x400;
int fault;
+ int rc = 0;
#if !(defined(CONFIG_4xx) || defined(CONFIG_BOOKE))
/*
@@ -230,28 +233,30 @@ int __kprobes do_page_fault(struct pt_regs *regs, unsigned long address,
* look at it
*/
if (error_code & ICSWX_DSI_UCT) {
- int rc = acop_handle_fault(regs, address, error_code);
+ rc = acop_handle_fault(regs, address, error_code);
if (rc)
- return rc;
+ goto bail;
}
#endif /* CONFIG_PPC_ICSWX */
if (notify_page_fault(regs))
- return 0;
+ goto bail;
if (unlikely(debugger_fault_handler(regs)))
- return 0;
+ goto bail;
/* On a kernel SLB miss we can only check for a valid exception entry */
- if (!user_mode(regs) && (address >= TASK_SIZE))
- return SIGSEGV;
+ if (!user_mode(regs) && (address >= TASK_SIZE)) {
+ rc = SIGSEGV;
+ goto bail;
+ }
#if !(defined(CONFIG_4xx) || defined(CONFIG_BOOKE) || \
defined(CONFIG_PPC_BOOK3S_64))
if (error_code & DSISR_DABRMATCH) {
/* breakpoint match */
do_break(regs, address, error_code);
- return 0;
+ goto bail;
}
#endif
@@ -260,8 +265,10 @@ int __kprobes do_page_fault(struct pt_regs *regs, unsigned long address,
local_irq_enable();
if (in_atomic() || mm == NULL) {
- if (!user_mode(regs))
- return SIGSEGV;
+ if (!user_mode(regs)) {
+ rc = SIGSEGV;
+ goto bail;
+ }
/* in_atomic() in user mode is really bad,
as is current->mm == NULL. */
printk(KERN_EMERG "Page fault in user mode with "
@@ -417,9 +424,11 @@ good_area:
*/
fault = handle_mm_fault(mm, vma, address, flags);
if (unlikely(fault & (VM_FAULT_RETRY|VM_FAULT_ERROR))) {
- int rc = mm_fault_error(regs, address, fault);
+ rc = mm_fault_error(regs, address, fault);
if (rc >= MM_FAULT_RETURN)
- return rc;
+ goto bail;
+ else
+ rc = 0;
}
/*
@@ -454,7 +463,7 @@ good_area:
}
up_read(&mm->mmap_sem);
- return 0;
+ goto bail;
bad_area:
up_read(&mm->mmap_sem);
@@ -463,7 +472,7 @@ bad_area_nosemaphore:
/* User mode accesses cause a SIGSEGV */
if (user_mode(regs)) {
_exception(SIGSEGV, regs, code, address);
- return 0;
+ goto bail;
}
if (is_exec && (error_code & DSISR_PROTFAULT))
@@ -471,7 +480,11 @@ bad_area_nosemaphore:
" page (%lx) - exploit attempt? (uid: %d)\n",
address, from_kuid(&init_user_ns, current_uid()));
- return SIGSEGV;
+ rc = SIGSEGV;
+
+bail:
+ exception_exit(prev_state);
+ return rc;
}
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