[REVIEW][PATCH 16/20] signal/x86: Pass pkey not vma into __bad_area

From: Eric W. Biederman
Date: Mon Sep 17 2018 - 20:13:08 EST


There is only one caller of __bad_area that passes in PKUERR and thus
will generate a siginfo with si_pkey set. Therefore simplify the
logic and hoist reading of vma_pkey up into that caller, and just
pass *pkey into __bad_area.

Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
---
arch/x86/mm/fault.c | 18 +++++++-----------
1 file changed, 7 insertions(+), 11 deletions(-)

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index f82106578364..11a93f14a674 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -904,22 +904,16 @@ bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code,

static void
__bad_area(struct pt_regs *regs, unsigned long error_code,
- unsigned long address, struct vm_area_struct *vma, int si_code)
+ unsigned long address, u32 *pkey, int si_code)
{
struct mm_struct *mm = current->mm;
- u32 pkey;
-
- if (vma)
- pkey = vma_pkey(vma);
-
/*
* Something tried to access memory that isn't in our memory map..
* Fix it, but check if it's kernel or user first..
*/
up_read(&mm->mmap_sem);

- __bad_area_nosemaphore(regs, error_code, address,
- (vma) ? &pkey : NULL, si_code);
+ __bad_area_nosemaphore(regs, error_code, address, pkey, si_code);
}

static noinline void
@@ -954,10 +948,12 @@ bad_area_access_error(struct pt_regs *regs, unsigned long error_code,
* But, doing it this way allows compiler optimizations
* if pkeys are compiled out.
*/
- if (bad_area_access_from_pkeys(error_code, vma))
- __bad_area(regs, error_code, address, vma, SEGV_PKUERR);
+ if (bad_area_access_from_pkeys(error_code, vma)) {
+ u32 pkey = vma_pkey(vma);
+ __bad_area(regs, error_code, address, &pkey, SEGV_PKUERR);
+ }
else
- __bad_area(regs, error_code, address, vma, SEGV_ACCERR);
+ __bad_area(regs, error_code, address, NULL, SEGV_ACCERR);
}

static void
--
2.17.1