The following commit has been merged into the x86/percpu branch of tip: Commit-ID: 2adeed985a42ff3334e6898c8c0827e7626c1336 Gitweb: https://git.kernel.org/tip/2adeed985a42ff3334e6898c8c0827e7626c1336 Author: Uros Bizjak <ubizjak@xxxxxxxxx> AuthorDate: Sun, 05 Nov 2023 22:34:37 +01:00 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitterDate: Thu, 30 Nov 2023 20:06:17 +01:00 x86/callthunks: Fix and unify call thunks assembly snippets Currently thunk debug macros explicitly define %gs: segment register prefix for their percpu variables. This is not compatible with !CONFIG_SMP, which requires non-prefixed percpu variables. Fix call thunks debug macros to use PER_CPU_VAR macro from percpu.h to conditionally use %gs: segment register prefix, depending on CONFIG_SMP. Finally, unify ASM_ prefixed assembly macros with their non-prefixed variants. With support of %rip-relative relocations in place, call thunk templates allow %rip-relative addressing, so unified assembly snippet can be used everywhere. Signed-off-by: Uros Bizjak <ubizjak@xxxxxxxxx> Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Link: https://lore.kernel.org/r/20231105213731.1878100-4-ubizjak@xxxxxxxxx --- arch/x86/include/asm/nospec-branch.h | 23 +++++++---------------- 1 file changed, 7 insertions(+), 16 deletions(-) diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h index c55cc24..65fbf6b 100644 --- a/arch/x86/include/asm/nospec-branch.h +++ b/arch/x86/include/asm/nospec-branch.h @@ -59,13 +59,13 @@ #ifdef CONFIG_CALL_THUNKS_DEBUG # define CALL_THUNKS_DEBUG_INC_CALLS \ - incq %gs:__x86_call_count; + incq PER_CPU_VAR(__x86_call_count); # define CALL_THUNKS_DEBUG_INC_RETS \ - incq %gs:__x86_ret_count; + incq PER_CPU_VAR(__x86_ret_count); # define CALL_THUNKS_DEBUG_INC_STUFFS \ - incq %gs:__x86_stuffs_count; + incq PER_CPU_VAR(__x86_stuffs_count); # define CALL_THUNKS_DEBUG_INC_CTXSW \ - incq %gs:__x86_ctxsw_count; + incq PER_CPU_VAR(__x86_ctxsw_count); #else # define CALL_THUNKS_DEBUG_INC_CALLS # define CALL_THUNKS_DEBUG_INC_RETS @@ -80,9 +80,6 @@ #define CREDIT_CALL_DEPTH \ movq $-1, PER_CPU_VAR(pcpu_hot + X86_call_depth); -#define ASM_CREDIT_CALL_DEPTH \ - movq $-1, PER_CPU_VAR(pcpu_hot + X86_call_depth); - #define RESET_CALL_DEPTH \ xor %eax, %eax; \ bts $63, %rax; \ @@ -95,20 +92,14 @@ CALL_THUNKS_DEBUG_INC_CALLS #define INCREMENT_CALL_DEPTH \ - sarq $5, %gs:pcpu_hot + X86_call_depth; \ - CALL_THUNKS_DEBUG_INC_CALLS - -#define ASM_INCREMENT_CALL_DEPTH \ sarq $5, PER_CPU_VAR(pcpu_hot + X86_call_depth); \ CALL_THUNKS_DEBUG_INC_CALLS #else #define CREDIT_CALL_DEPTH -#define ASM_CREDIT_CALL_DEPTH #define RESET_CALL_DEPTH -#define INCREMENT_CALL_DEPTH -#define ASM_INCREMENT_CALL_DEPTH #define RESET_CALL_DEPTH_FROM_CALL +#define INCREMENT_CALL_DEPTH #endif /* @@ -158,7 +149,7 @@ jnz 771b; \ /* barrier for jnz misprediction */ \ lfence; \ - ASM_CREDIT_CALL_DEPTH \ + CREDIT_CALL_DEPTH \ CALL_THUNKS_DEBUG_INC_CTXSW #else /* @@ -325,7 +316,7 @@ .macro CALL_DEPTH_ACCOUNT #ifdef CONFIG_CALL_DEPTH_TRACKING ALTERNATIVE "", \ - __stringify(ASM_INCREMENT_CALL_DEPTH), X86_FEATURE_CALL_DEPTH + __stringify(INCREMENT_CALL_DEPTH), X86_FEATURE_CALL_DEPTH #endif .endm
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