Applies the counting-based method for monitoring lockless pgtable walks on
read_user_stack_slow.
local_irq_{save,restore} is already inside {begin,end}_lockless_pgtbl_walk,
so there is no need to repeat it here.
Variable that saves the irq mask was renamed from flags to irq_mask so it
doesn't lose meaning now it's not directly passed to local_irq_* functions.
Signed-off-by: Leonardo Bras <leonardo@xxxxxxxxxxxxx>
---
arch/powerpc/perf/callchain.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/perf/callchain.c b/arch/powerpc/perf/callchain.c
index c84bbd4298a0..43e49d8be344 100644
--- a/arch/powerpc/perf/callchain.c
+++ b/arch/powerpc/perf/callchain.c
@@ -116,14 +116,14 @@ static int read_user_stack_slow(void __user *ptr, void *buf, int nb)
unsigned shift;
unsigned long addr = (unsigned long) ptr;
unsigned long offset;
- unsigned long pfn, flags;
+ unsigned long pfn, irq_mask;
void *kaddr;
pgdir = current->mm->pgd;
if (!pgdir)
return -EFAULT;
- local_irq_save(flags);
+ irq_mask = begin_lockless_pgtbl_walk(current->mm);
ptep = find_current_mm_pte(pgdir, addr, NULL, &shift);
if (!ptep)
goto err_out;
@@ -145,7 +145,7 @@ static int read_user_stack_slow(void __user *ptr, void *buf, int nb)
memcpy(buf, kaddr + offset, nb);
ret = 0;
err_out:
- local_irq_restore(flags);
+ end_lockless_pgtbl_walk(current->mm, irq_mask);
return ret;
}
--
2.20.1
