[PATCH v3 23/39] x86/alternative: Simplify int3_selftest_ip

From: Peter Zijlstra
Date: Thu Mar 03 2022 - 06:33:09 EST


Similar to ibt_selftest_ip, apply the same pattern.

Suggested-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
arch/x86/kernel/alternative.c | 13 +++----------
1 file changed, 3 insertions(+), 10 deletions(-)

--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -719,7 +719,7 @@ asm (
" .popsection\n"
);

-extern __initdata unsigned long int3_selftest_ip; /* defined in asm below */
+extern void int3_selftest_ip(void); /* defined in asm below */

static int __init
int3_exception_notify(struct notifier_block *self, unsigned long val, void *data)
@@ -733,7 +733,7 @@ int3_exception_notify(struct notifier_bl
if (val != DIE_INT3)
return NOTIFY_DONE;

- if (regs->ip - INT3_INSN_SIZE != int3_selftest_ip)
+ if (regs->ip - INT3_INSN_SIZE != (unsigned long)&int3_selftest_ip)
return NOTIFY_DONE;

int3_emulate_call(regs, (unsigned long)&int3_magic);
@@ -757,14 +757,7 @@ static void __init int3_selftest(void)
* then trigger the INT3, padded with NOPs to match a CALL instruction
* length.
*/
- asm volatile ("1: int3; nop; nop; nop; nop\n\t"
- ".pushsection .init.data,\"aw\"\n\t"
- ".align " __ASM_SEL(4, 8) "\n\t"
- ".type int3_selftest_ip, @object\n\t"
- ".size int3_selftest_ip, " __ASM_SEL(4, 8) "\n\t"
- "int3_selftest_ip:\n\t"
- __ASM_SEL(.long, .quad) " 1b\n\t"
- ".popsection\n\t"
+ asm volatile ("int3_selftest_ip: int3; nop; nop; nop; nop\n\t"
: ASM_CALL_CONSTRAINT
: __ASM_SEL_RAW(a, D) (&val)
: "memory");