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| author | Ahmad Fatoum <a.fatoum@pengutronix.de> | 2023-10-09 13:50:50 +0200 |
|---|---|---|
| committer | Sascha Hauer <s.hauer@pengutronix.de> | 2023-10-12 16:27:03 +0200 |
| commit | 5155dc05760174ab7b2d5ff931e3c9dea079b847 (patch) | |
| tree | 8dc606fb0975385f8c9ca0d108d92d1a4d17e746 /arch/x86/lib | |
| parent | f42e0ad1f85e060906a350ffd1fa502595229e2c (diff) | |
| download | barebox-5155dc05760174ab7b2d5ff931e3c9dea079b847.tar.gz barebox-5155dc05760174ab7b2d5ff931e3c9dea079b847.tar.xz | |
x86: lib: setjmp: fix stack alignment
x86 stack is expected to be 16-byte aligned to allow for instructions
like movaps that involve xmm operands to directly use the stack.
However the 16-byte alignment is what's expected at startup time.
All later functions will have the stack misaligned by a pointer size's
worth because call pushes the return address to the call stack.
Add the missing (mis)alignment. This fixes a segmentation fault observed
using initjmp on x86_64.
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Link: https://lore.barebox.org/20231009115051.1931562-1-a.fatoum@pengutronix.de
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Diffstat (limited to 'arch/x86/lib')
| -rw-r--r-- | arch/x86/lib/setjmp_32.S | 4 | ||||
| -rw-r--r-- | arch/x86/lib/setjmp_64.S | 2 |
2 files changed, 5 insertions, 1 deletions
diff --git a/arch/x86/lib/setjmp_32.S b/arch/x86/lib/setjmp_32.S index 38dcb68c1b..30db5f989a 100644 --- a/arch/x86/lib/setjmp_32.S +++ b/arch/x86/lib/setjmp_32.S @@ -8,6 +8,7 @@ #define _REGPARM #include <linux/linkage.h> +#include <asm-generic/pointer.h> .text .align 8 @@ -53,7 +54,8 @@ ENDPROC(longjmp) ENTRY(initjmp) movl %edx, 20(%eax) /* Return address */ - movl %ecx, 4(%eax) /* Post-return %esp! */ + sub $ASM_SZPTR, %ecx /* ESP - 4 has to be 16-byte aligned on entry */ + movl %ecx, 4(%eax) /* Stack top */ xorl %eax, %eax /* Return value */ ret diff --git a/arch/x86/lib/setjmp_64.S b/arch/x86/lib/setjmp_64.S index 28ea576cd2..d5cf99a155 100644 --- a/arch/x86/lib/setjmp_64.S +++ b/arch/x86/lib/setjmp_64.S @@ -6,6 +6,7 @@ */ #include <linux/linkage.h> +#include <asm-generic/pointer.h> .text .align 8 @@ -53,6 +54,7 @@ ENDPROC(longjmp) ENTRY(initjmp) movq %rsi, (%rdi) /* Return address */ + sub $ASM_SZPTR, %rdx /* RSP - 8 has to be 16-byte aligned on entry */ movq %rdx, 8(%rdi) /* Stack top */ xorq %rax, %rax ret |