From: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> commit 94c5cf2a0e193afffef8de48ddc42de6df7cac93 upstream. The arm and mips work-around for asm goto size guess issues are not properly documented, and lack reference to specific compiler versions, upstream compiler bug tracker entry, and reproducer. I can only find a loosely documented patch in my original LKML rseq post refering to gcc < 7 on ARM, but it does not appear to be sufficient to track the exact issue. Also, I am not sure MIPS really has the same limitation. Therefore, remove the work-around until we can properly document this. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Link: https://lore.kernel.org/lkml/20171121141900.18471-17-mathieu.desnoyers@xxxxxxxxxxxx/ Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- tools/testing/selftests/rseq/rseq-arm.h | 37 ------------------------------- tools/testing/selftests/rseq/rseq-mips.h | 37 ------------------------------- 2 files changed, 74 deletions(-) --- a/tools/testing/selftests/rseq/rseq-arm.h +++ b/tools/testing/selftests/rseq/rseq-arm.h @@ -147,14 +147,11 @@ do { \ teardown \ "b %l[" __rseq_str(cmpfail_label) "]\n\t" -#define rseq_workaround_gcc_asm_size_guess() __asm__ __volatile__("") - static inline __attribute__((always_inline)) int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu) { RSEQ_INJECT_C(9) - rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) @@ -198,14 +195,11 @@ int rseq_cmpeqv_storev(intptr_t *v, intp , error1, error2 #endif ); - rseq_workaround_gcc_asm_size_guess(); return 0; abort: - rseq_workaround_gcc_asm_size_guess(); RSEQ_INJECT_FAILED return -1; cmpfail: - rseq_workaround_gcc_asm_size_guess(); return 1; #ifdef RSEQ_COMPARE_TWICE error1: @@ -221,7 +215,6 @@ int rseq_cmpnev_storeoffp_load(intptr_t { RSEQ_INJECT_C(9) - rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) @@ -270,14 +263,11 @@ int rseq_cmpnev_storeoffp_load(intptr_t , error1, error2 #endif ); - rseq_workaround_gcc_asm_size_guess(); return 0; abort: - rseq_workaround_gcc_asm_size_guess(); RSEQ_INJECT_FAILED return -1; cmpfail: - rseq_workaround_gcc_asm_size_guess(); return 1; #ifdef RSEQ_COMPARE_TWICE error1: @@ -292,7 +282,6 @@ int rseq_addv(intptr_t *v, intptr_t coun { RSEQ_INJECT_C(9) - rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */ #ifdef RSEQ_COMPARE_TWICE @@ -328,10 +317,8 @@ int rseq_addv(intptr_t *v, intptr_t coun , error1 #endif ); - rseq_workaround_gcc_asm_size_guess(); return 0; abort: - rseq_workaround_gcc_asm_size_guess(); RSEQ_INJECT_FAILED return -1; #ifdef RSEQ_COMPARE_TWICE @@ -347,7 +334,6 @@ int rseq_cmpeqv_trystorev_storev(intptr_ { RSEQ_INJECT_C(9) - rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) @@ -398,14 +384,11 @@ int rseq_cmpeqv_trystorev_storev(intptr_ , error1, error2 #endif ); - rseq_workaround_gcc_asm_size_guess(); return 0; abort: - rseq_workaround_gcc_asm_size_guess(); RSEQ_INJECT_FAILED return -1; cmpfail: - rseq_workaround_gcc_asm_size_guess(); return 1; #ifdef RSEQ_COMPARE_TWICE error1: @@ -422,7 +405,6 @@ int rseq_cmpeqv_trystorev_storev_release { RSEQ_INJECT_C(9) - rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) @@ -474,14 +456,11 @@ int rseq_cmpeqv_trystorev_storev_release , error1, error2 #endif ); - rseq_workaround_gcc_asm_size_guess(); return 0; abort: - rseq_workaround_gcc_asm_size_guess(); RSEQ_INJECT_FAILED return -1; cmpfail: - rseq_workaround_gcc_asm_size_guess(); return 1; #ifdef RSEQ_COMPARE_TWICE error1: @@ -498,7 +477,6 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t * { RSEQ_INJECT_C(9) - rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) @@ -554,14 +532,11 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t * , error1, error2, error3 #endif ); - rseq_workaround_gcc_asm_size_guess(); return 0; abort: - rseq_workaround_gcc_asm_size_guess(); RSEQ_INJECT_FAILED return -1; cmpfail: - rseq_workaround_gcc_asm_size_guess(); return 1; #ifdef RSEQ_COMPARE_TWICE error1: @@ -582,7 +557,6 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_ RSEQ_INJECT_C(9) - rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) @@ -678,21 +652,16 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_ , error1, error2 #endif ); - rseq_workaround_gcc_asm_size_guess(); return 0; abort: - rseq_workaround_gcc_asm_size_guess(); RSEQ_INJECT_FAILED return -1; cmpfail: - rseq_workaround_gcc_asm_size_guess(); return 1; #ifdef RSEQ_COMPARE_TWICE error1: - rseq_workaround_gcc_asm_size_guess(); rseq_bug("cpu_id comparison failed"); error2: - rseq_workaround_gcc_asm_size_guess(); rseq_bug("expected value comparison failed"); #endif } @@ -706,7 +675,6 @@ int rseq_cmpeqv_trymemcpy_storev_release RSEQ_INJECT_C(9) - rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) @@ -803,21 +771,16 @@ int rseq_cmpeqv_trymemcpy_storev_release , error1, error2 #endif ); - rseq_workaround_gcc_asm_size_guess(); return 0; abort: - rseq_workaround_gcc_asm_size_guess(); RSEQ_INJECT_FAILED return -1; cmpfail: - rseq_workaround_gcc_asm_size_guess(); return 1; #ifdef RSEQ_COMPARE_TWICE error1: - rseq_workaround_gcc_asm_size_guess(); rseq_bug("cpu_id comparison failed"); error2: - rseq_workaround_gcc_asm_size_guess(); rseq_bug("expected value comparison failed"); #endif } --- a/tools/testing/selftests/rseq/rseq-mips.h +++ b/tools/testing/selftests/rseq/rseq-mips.h @@ -154,14 +154,11 @@ do { \ teardown \ "b %l[" __rseq_str(cmpfail_label) "]\n\t" -#define rseq_workaround_gcc_asm_size_guess() __asm__ __volatile__("") - static inline __attribute__((always_inline)) int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu) { RSEQ_INJECT_C(9) - rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) @@ -203,14 +200,11 @@ int rseq_cmpeqv_storev(intptr_t *v, intp , error1, error2 #endif ); - rseq_workaround_gcc_asm_size_guess(); return 0; abort: - rseq_workaround_gcc_asm_size_guess(); RSEQ_INJECT_FAILED return -1; cmpfail: - rseq_workaround_gcc_asm_size_guess(); return 1; #ifdef RSEQ_COMPARE_TWICE error1: @@ -226,7 +220,6 @@ int rseq_cmpnev_storeoffp_load(intptr_t { RSEQ_INJECT_C(9) - rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) @@ -273,14 +266,11 @@ int rseq_cmpnev_storeoffp_load(intptr_t , error1, error2 #endif ); - rseq_workaround_gcc_asm_size_guess(); return 0; abort: - rseq_workaround_gcc_asm_size_guess(); RSEQ_INJECT_FAILED return -1; cmpfail: - rseq_workaround_gcc_asm_size_guess(); return 1; #ifdef RSEQ_COMPARE_TWICE error1: @@ -295,7 +285,6 @@ int rseq_addv(intptr_t *v, intptr_t coun { RSEQ_INJECT_C(9) - rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */ #ifdef RSEQ_COMPARE_TWICE @@ -331,10 +320,8 @@ int rseq_addv(intptr_t *v, intptr_t coun , error1 #endif ); - rseq_workaround_gcc_asm_size_guess(); return 0; abort: - rseq_workaround_gcc_asm_size_guess(); RSEQ_INJECT_FAILED return -1; #ifdef RSEQ_COMPARE_TWICE @@ -350,7 +337,6 @@ int rseq_cmpeqv_trystorev_storev(intptr_ { RSEQ_INJECT_C(9) - rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) @@ -399,14 +385,11 @@ int rseq_cmpeqv_trystorev_storev(intptr_ , error1, error2 #endif ); - rseq_workaround_gcc_asm_size_guess(); return 0; abort: - rseq_workaround_gcc_asm_size_guess(); RSEQ_INJECT_FAILED return -1; cmpfail: - rseq_workaround_gcc_asm_size_guess(); return 1; #ifdef RSEQ_COMPARE_TWICE error1: @@ -423,7 +406,6 @@ int rseq_cmpeqv_trystorev_storev_release { RSEQ_INJECT_C(9) - rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) @@ -473,14 +455,11 @@ int rseq_cmpeqv_trystorev_storev_release , error1, error2 #endif ); - rseq_workaround_gcc_asm_size_guess(); return 0; abort: - rseq_workaround_gcc_asm_size_guess(); RSEQ_INJECT_FAILED return -1; cmpfail: - rseq_workaround_gcc_asm_size_guess(); return 1; #ifdef RSEQ_COMPARE_TWICE error1: @@ -497,7 +476,6 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t * { RSEQ_INJECT_C(9) - rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) @@ -549,14 +527,11 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t * , error1, error2, error3 #endif ); - rseq_workaround_gcc_asm_size_guess(); return 0; abort: - rseq_workaround_gcc_asm_size_guess(); RSEQ_INJECT_FAILED return -1; cmpfail: - rseq_workaround_gcc_asm_size_guess(); return 1; #ifdef RSEQ_COMPARE_TWICE error1: @@ -577,7 +552,6 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_ RSEQ_INJECT_C(9) - rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) @@ -670,21 +644,16 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_ , error1, error2 #endif ); - rseq_workaround_gcc_asm_size_guess(); return 0; abort: - rseq_workaround_gcc_asm_size_guess(); RSEQ_INJECT_FAILED return -1; cmpfail: - rseq_workaround_gcc_asm_size_guess(); return 1; #ifdef RSEQ_COMPARE_TWICE error1: - rseq_workaround_gcc_asm_size_guess(); rseq_bug("cpu_id comparison failed"); error2: - rseq_workaround_gcc_asm_size_guess(); rseq_bug("expected value comparison failed"); #endif } @@ -698,7 +667,6 @@ int rseq_cmpeqv_trymemcpy_storev_release RSEQ_INJECT_C(9) - rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) @@ -792,21 +760,16 @@ int rseq_cmpeqv_trymemcpy_storev_release , error1, error2 #endif ); - rseq_workaround_gcc_asm_size_guess(); return 0; abort: - rseq_workaround_gcc_asm_size_guess(); RSEQ_INJECT_FAILED return -1; cmpfail: - rseq_workaround_gcc_asm_size_guess(); return 1; #ifdef RSEQ_COMPARE_TWICE error1: - rseq_workaround_gcc_asm_size_guess(); rseq_bug("cpu_id comparison failed"); error2: - rseq_workaround_gcc_asm_size_guess(); rseq_bug("expected value comparison failed"); #endif }
