[REVIEW][PATCH 3/9] signal/powerpc: Call _exception_pkey directly from bad_key_fault_exception

From: Eric W. Biederman
Date: Tue Sep 18 2018 - 13:59:33 EST


This removes the need for other code paths to deal with pkey exceptions.

Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
---
arch/powerpc/mm/fault.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index e5725fa96a48..5afc1ee55043 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -145,7 +145,17 @@ static noinline int bad_area(struct pt_regs *regs, unsigned long address)
static int bad_key_fault_exception(struct pt_regs *regs, unsigned long address,
int pkey)
{
- return __bad_area_nosemaphore(regs, address, SEGV_PKUERR, pkey);
+ /*
+ * If we are in kernel mode, bail out with a SEGV, this will
+ * be caught by the assembly which will restore the non-volatile
+ * registers before calling bad_page_fault()
+ */
+ if (!user_mode(regs))
+ return SIGSEGV;
+
+ _exception_pkey(SIGSEGV, regs, SEGV_PKUERR, address, pkey);
+
+ return 0;
}

static noinline int bad_access(struct pt_regs *regs, unsigned long address)
--
2.17.1