Commit b17c2baa authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Borislav Petkov
Browse files

x86: Prepare inline-asm for straight-line-speculation 



Replace all ret/retq instructions with ASM_RET in preparation of
making it more than a single instruction.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20211204134907.964635458@infradead.org
parent f94909ce

arch/x86/include/asm/linkage.h

+4 −0
Original line number Diff line number Diff line
@@ -18,6 +18,10 @@ 
#define __ALIGN_STR	__stringify(__ALIGN)

#endif



#else /* __ASSEMBLY__ */



#define ASM_RET	"ret\n\t"



#endif /* __ASSEMBLY__ */



#endif /* _ASM_X86_LINKAGE_H */

arch/x86/include/asm/paravirt.h

+1 −1
Original line number Diff line number Diff line
@@ -671,7 +671,7 @@ bool __raw_callee_save___native_vcpu_is_preempted(long cpu); 
	    "call " #func ";"						\

	    PV_RESTORE_ALL_CALLER_REGS					\

	    FRAME_END							\

	    "ret;"							\

	    ASM_RET							\

	    ".size " PV_THUNK_NAME(func) ", .-" PV_THUNK_NAME(func) ";"	\

	    ".popsection")

arch/x86/include/asm/qspinlock_paravirt.h

+2 −2
Original line number Diff line number Diff line
@@ -48,7 +48,7 @@ asm (".pushsection .text;" 
	"jne   .slowpath;"

	"pop   %rdx;"

	FRAME_END

	"ret;"

	ASM_RET

	".slowpath: "

	"push   %rsi;"

	"movzbl %al,%esi;"
@@ -56,7 +56,7 @@ asm (".pushsection .text;" 
	"pop    %rsi;"

	"pop    %rdx;"

	FRAME_END

	"ret;"

	ASM_RET

	".size " PV_UNLOCK ", .-" PV_UNLOCK ";"

	".popsection");

arch/x86/kernel/alternative.c

+1 −1
Original line number Diff line number Diff line
@@ -714,7 +714,7 @@ asm ( 
"	.type		int3_magic, @function\n"

"int3_magic:\n"

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

"	ret\n"

	ASM_RET

"	.size		int3_magic, .-int3_magic\n"

"	.popsection\n"

);

arch/x86/kernel/kprobes/core.c

+1 −1
Original line number Diff line number Diff line
@@ -1051,7 +1051,7 @@ asm( 
	"	addl $4, %esp\n"

	"	popfl\n"

#endif

	"	ret\n"

	ASM_RET

	".size __kretprobe_trampoline, .-__kretprobe_trampoline\n"

);

NOKPROBE_SYMBOL(__kretprobe_trampoline);