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Commit 93db8a47 authored by Kees Cook's avatar Kees Cook Committed by Sami Tolvanen
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ANDROID: x86/alternatives: Use C int3 selftest but disable KASAN 



Instead of using inline asm for the int3 selftest (which confuses the
Clang's ThinLTO pass), this restores the C function but disables KASAN
(and tracing for good measure) to keep the things simple and avoid
unexpected side-effects. This attempts to keep the fix from commit
ecc60610 ("x86/alternatives: Fix int3_emulate_call() selftest stack
corruption") without using inline asm.

Bug: 145297900
Change-Id: I2b6e237d89968b677c34e162b71a520ed8375e2d
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarSami Tolvanen <samitolvanen@google.com>
parent e1b3a9f1

arch/x86/kernel/alternative.c

+4 −17
Original line number Diff line number Diff line
@@ -625,23 +625,10 @@ extern struct paravirt_patch_site __start_parainstructions[], 
 *

 * See entry_{32,64}.S for more details.

 */



/*

 * We define the int3_magic() function in assembly to control the calling

 * convention such that we can 'call' it from assembly.

 */



extern void int3_magic(unsigned int *ptr); /* defined in asm */



asm (

"	.pushsection	.init.text, \"ax\", @progbits\n"

"	.type		int3_magic, @function\n"

"int3_magic:\n"

"	movl	$1, (%" _ASM_ARG1 ")\n"

"	ret\n"

"	.size		int3_magic, .-int3_magic\n"

"	.popsection\n"

);

static void __init __no_sanitize_address notrace int3_magic(unsigned int *ptr)

{

	*ptr = 1;

}



extern __initdata unsigned long int3_selftest_ip; /* defined in asm below */