| From 0c450ea1062e7d3d217cea5f2b4801375dc3e455 Mon Sep 17 00:00:00 2001 |
| From: Matt Mullins <mmullins@fb.com> |
| Date: Tue, 23 Jul 2019 21:20:58 -0700 |
| Subject: [PATCH] x86/entry/32: Pass cr2 to do_async_page_fault() |
| |
| commit b8f70953c1251d8b16276995816a95639f598e70 upstream. |
| |
| 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: |
| |
| Run /sbin/init as init process |
| 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 <mmullins@fb.com> |
| Signed-off-by: Thomas Gleixner <tglx@linutronix.de> |
| Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> |
| Link: https://lkml.kernel.org/r/20190724042058.24506-1-mmullins@fb.com |
| Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| 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 |
| |
| -- |
| 2.7.4 |
| |