Commit a0d14b8909de ("x86/mm, tracing: Fix CR2 corruption") added the
address parameter to do_async_page_fault, but does not pass it from the
32-bit entry point. To plumb it through, factor-out
common_exception_read_cr2 in the same fashion as common_exception, and
uses it from both page_fault and async_page_fault.
For a 32-bit KVM guest, this fixes:
[ 1.148669][ T1] Run /sbin/init as init process
[ 1.153328][ T1] Starting init: /sbin/init exists but couldn't execute it
(error -14)
Fixes: a0d14b8909de ("x86/mm, tracing: Fix CR2 corruption")
Signed-off-by: Matt Mullins <mmull...@fb.com>
---
arch/x86/entry/entry_32.S | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
index 2bb986f305ac..4f86928246e7 100644
--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -1443,8 +1443,12 @@ BUILD_INTERRUPT3(hv_stimer0_callback_vector,
HYPERV_STIMER0_VECTOR,
ENTRY(page_fault)
ASM_CLAC
- pushl $0; /* %gs's slot on the stack */
+ pushl $do_page_fault
+ jmp common_exception_read_cr2
+END(page_fault)
+common_exception_read_cr2:
+ /* the function address is in %gs's slot on the stack */
SAVE_ALL switch_stacks=1 skip_gs=1
ENCODE_FRAME_POINTER
@@ -1452,6 +1456,7 @@ ENTRY(page_fault)
/* fixup %gs */
GS_TO_REG %ecx
+ movl PT_GS(%esp), %edi
REG_TO_PTGS %ecx
SET_KERNEL_GS %ecx
@@ -1463,9 +1468,9 @@ ENTRY(page_fault)
TRACE_IRQS_OFF
movl %esp, %eax # pt_regs pointer
- call do_page_fault
+ CALL_NOSPEC %edi
jmp ret_from_exception
-END(page_fault)
+END(common_exception_read_cr2)
common_exception:
/* the function address is in %gs's slot on the stack */
@@ -1595,7 +1600,7 @@ END(general_protection)
ENTRY(async_page_fault)
ASM_CLAC
pushl $do_async_page_fault
- jmp common_exception
+ jmp common_exception_read_cr2
END(async_page_fault)
#endif
--
2.17.1
