x86/entry/vdso32: When using int $0x80, use it directly

Browse source

When neither sysenter32 nor syscall32 is available (on either
FRED-capable 64-bit hardware or old 32-bit hardware), there is no
reason to do a bunch of stack shuffling in __kernel_vsyscall.
Unfortunately, just overwriting the initial "push" instructions will
mess up the CFI annotations, so suffer the 3-byte NOP if not
applicable.

Similarly, inline the int $0x80 when doing inline system calls in the
vdso instead of calling __kernel_vsyscall.

Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://patch.msgid.link/20251216212606.1325678-11-hpa@zytor.com

...

This commit is contained in:

H. Peter Anvin 2025-12-16 13:26:04 -08:00 • committed by Dave Hansen

parent f49ecf5e11

commit 36d83c249e

2 changed files with 17 additions and 5 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

18

arch/x86/entry/vdso/vdso32/system_call.S

View file

4

arch/x86/include/asm/vdso/sys_call.h

View file