This is a note to let you know that I've just added the patch titled selftests/rseq: x86-32: use %gs segment selector for accessing rseq thread area to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: selftests-rseq-x86-32-use-gs-segment-selector-for-accessing-rseq-thread-area.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 127b6429d235ab7c358223bbfd8a8b8d8cc799b6 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> Date: Mon, 24 Jan 2022 12:12:53 -0500 Subject: selftests/rseq: x86-32: use %gs segment selector for accessing rseq thread area From: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> commit 127b6429d235ab7c358223bbfd8a8b8d8cc799b6 upstream. Rather than use rseq_get_abi() and pass its result through a register to the inline assembler, directly access the per-thread rseq area through a memory reference combining the %gs segment selector, the constant offset of the field in struct rseq, and the rseq_offset value (in a register). Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Link: https://lkml.kernel.org/r/20220124171253.22072-16-mathieu.desnoyers@xxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- tools/testing/selftests/rseq/rseq-x86.h | 66 ++++++++++++++++---------------- 1 file changed, 34 insertions(+), 32 deletions(-) --- a/tools/testing/selftests/rseq/rseq-x86.h +++ b/tools/testing/selftests/rseq/rseq-x86.h @@ -633,6 +633,8 @@ int rseq_cmpeqv_trymemcpy_storev_release #elif defined(__i386__) +#define RSEQ_ASM_TP_SEGMENT %%gs + #define rseq_smp_mb() \ __asm__ __volatile__ ("lock; addl $0,-128(%%esp)" ::: "memory", "cc") #define rseq_smp_rmb() \ @@ -732,14 +734,14 @@ int rseq_cmpeqv_storev(intptr_t *v, intp RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2]) #endif /* Start rseq by storing table entry pointer into rseq_cs. */ - RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi])) - RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f) + RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset])) + RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f) RSEQ_INJECT_ASM(3) "cmpl %[v], %[expect]\n\t" "jnz %l[cmpfail]\n\t" RSEQ_INJECT_ASM(4) #ifdef RSEQ_COMPARE_TWICE - RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1]) + RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), %l[error1]) "cmpl %[v], %[expect]\n\t" "jnz %l[error2]\n\t" #endif @@ -750,7 +752,7 @@ int rseq_cmpeqv_storev(intptr_t *v, intp RSEQ_ASM_DEFINE_ABORT(4, "", abort) : /* gcc asm goto does not allow outputs */ : [cpu_id] "r" (cpu), - [rseq_abi] "r" (rseq_get_abi()), + [rseq_offset] "r" (rseq_offset), [v] "m" (*v), [expect] "r" (expect), [newv] "r" (newv) @@ -798,15 +800,15 @@ int rseq_cmpnev_storeoffp_load(intptr_t RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2]) #endif /* Start rseq by storing table entry pointer into rseq_cs. */ - RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi])) - RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f) + RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset])) + RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f) RSEQ_INJECT_ASM(3) "movl %[v], %%ebx\n\t" "cmpl %%ebx, %[expectnot]\n\t" "je %l[cmpfail]\n\t" RSEQ_INJECT_ASM(4) #ifdef RSEQ_COMPARE_TWICE - RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1]) + RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), %l[error1]) "movl %[v], %%ebx\n\t" "cmpl %%ebx, %[expectnot]\n\t" "je %l[error2]\n\t" @@ -821,7 +823,7 @@ int rseq_cmpnev_storeoffp_load(intptr_t RSEQ_ASM_DEFINE_ABORT(4, "", abort) : /* gcc asm goto does not allow outputs */ : [cpu_id] "r" (cpu), - [rseq_abi] "r" (rseq_get_abi()), + [rseq_offset] "r" (rseq_offset), /* final store input */ [v] "m" (*v), [expectnot] "r" (expectnot), @@ -864,11 +866,11 @@ int rseq_addv(intptr_t *v, intptr_t coun RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1]) #endif /* Start rseq by storing table entry pointer into rseq_cs. */ - RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi])) - RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f) + RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset])) + RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f) RSEQ_INJECT_ASM(3) #ifdef RSEQ_COMPARE_TWICE - RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1]) + RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), %l[error1]) #endif /* final store */ "addl %[count], %[v]\n\t" @@ -877,7 +879,7 @@ int rseq_addv(intptr_t *v, intptr_t coun RSEQ_ASM_DEFINE_ABORT(4, "", abort) : /* gcc asm goto does not allow outputs */ : [cpu_id] "r" (cpu), - [rseq_abi] "r" (rseq_get_abi()), + [rseq_offset] "r" (rseq_offset), /* final store input */ [v] "m" (*v), [count] "ir" (count) @@ -916,14 +918,14 @@ int rseq_cmpeqv_trystorev_storev(intptr_ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2]) #endif /* Start rseq by storing table entry pointer into rseq_cs. */ - RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi])) - RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f) + RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset])) + RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f) RSEQ_INJECT_ASM(3) "cmpl %[v], %[expect]\n\t" "jnz %l[cmpfail]\n\t" RSEQ_INJECT_ASM(4) #ifdef RSEQ_COMPARE_TWICE - RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1]) + RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), %l[error1]) "cmpl %[v], %[expect]\n\t" "jnz %l[error2]\n\t" #endif @@ -938,7 +940,7 @@ int rseq_cmpeqv_trystorev_storev(intptr_ RSEQ_ASM_DEFINE_ABORT(4, "", abort) : /* gcc asm goto does not allow outputs */ : [cpu_id] "r" (cpu), - [rseq_abi] "r" (rseq_get_abi()), + [rseq_offset] "r" (rseq_offset), /* try store input */ [v2] "m" (*v2), [newv2] "m" (newv2), @@ -987,15 +989,15 @@ int rseq_cmpeqv_trystorev_storev_release RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2]) #endif /* Start rseq by storing table entry pointer into rseq_cs. */ - RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi])) - RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f) + RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset])) + RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f) RSEQ_INJECT_ASM(3) "movl %[expect], %%eax\n\t" "cmpl %[v], %%eax\n\t" "jnz %l[cmpfail]\n\t" RSEQ_INJECT_ASM(4) #ifdef RSEQ_COMPARE_TWICE - RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1]) + RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), %l[error1]) "movl %[expect], %%eax\n\t" "cmpl %[v], %%eax\n\t" "jnz %l[error2]\n\t" @@ -1011,7 +1013,7 @@ int rseq_cmpeqv_trystorev_storev_release RSEQ_ASM_DEFINE_ABORT(4, "", abort) : /* gcc asm goto does not allow outputs */ : [cpu_id] "r" (cpu), - [rseq_abi] "r" (rseq_get_abi()), + [rseq_offset] "r" (rseq_offset), /* try store input */ [v2] "m" (*v2), [newv2] "r" (newv2), @@ -1062,8 +1064,8 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t * RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error3]) #endif /* Start rseq by storing table entry pointer into rseq_cs. */ - RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi])) - RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f) + RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset])) + RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f) RSEQ_INJECT_ASM(3) "cmpl %[v], %[expect]\n\t" "jnz %l[cmpfail]\n\t" @@ -1072,7 +1074,7 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t * "jnz %l[cmpfail]\n\t" RSEQ_INJECT_ASM(5) #ifdef RSEQ_COMPARE_TWICE - RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1]) + RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), %l[error1]) "cmpl %[v], %[expect]\n\t" "jnz %l[error2]\n\t" "cmpl %[expect2], %[v2]\n\t" @@ -1086,7 +1088,7 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t * RSEQ_ASM_DEFINE_ABORT(4, "", abort) : /* gcc asm goto does not allow outputs */ : [cpu_id] "r" (cpu), - [rseq_abi] "r" (rseq_get_abi()), + [rseq_offset] "r" (rseq_offset), /* cmp2 input */ [v2] "m" (*v2), [expect2] "r" (expect2), @@ -1144,15 +1146,15 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_ "movl %[dst], %[rseq_scratch1]\n\t" "movl %[len], %[rseq_scratch2]\n\t" /* Start rseq by storing table entry pointer into rseq_cs. */ - RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi])) - RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f) + RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset])) + RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f) RSEQ_INJECT_ASM(3) "movl %[expect], %%eax\n\t" "cmpl %%eax, %[v]\n\t" "jnz 5f\n\t" RSEQ_INJECT_ASM(4) #ifdef RSEQ_COMPARE_TWICE - RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 6f) + RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 6f) "movl %[expect], %%eax\n\t" "cmpl %%eax, %[v]\n\t" "jnz 7f\n\t" @@ -1202,7 +1204,7 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_ #endif : /* gcc asm goto does not allow outputs */ : [cpu_id] "r" (cpu), - [rseq_abi] "r" (rseq_get_abi()), + [rseq_offset] "r" (rseq_offset), /* final store input */ [v] "m" (*v), [expect] "m" (expect), @@ -1261,15 +1263,15 @@ int rseq_cmpeqv_trymemcpy_storev_release "movl %[dst], %[rseq_scratch1]\n\t" "movl %[len], %[rseq_scratch2]\n\t" /* Start rseq by storing table entry pointer into rseq_cs. */ - RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi])) - RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f) + RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset])) + RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f) RSEQ_INJECT_ASM(3) "movl %[expect], %%eax\n\t" "cmpl %%eax, %[v]\n\t" "jnz 5f\n\t" RSEQ_INJECT_ASM(4) #ifdef RSEQ_COMPARE_TWICE - RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 6f) + RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 6f) "movl %[expect], %%eax\n\t" "cmpl %%eax, %[v]\n\t" "jnz 7f\n\t" @@ -1320,7 +1322,7 @@ int rseq_cmpeqv_trymemcpy_storev_release #endif : /* gcc asm goto does not allow outputs */ : [cpu_id] "r" (cpu), - [rseq_abi] "r" (rseq_get_abi()), + [rseq_offset] "r" (rseq_offset), /* final store input */ [v] "m" (*v), [expect] "m" (expect), Patches currently in stable-queue which might be from mathieu.desnoyers@xxxxxxxxxxxx are queue-5.4/selftests-rseq-fix-work-around-asm-goto-compiler-bugs.patch queue-5.4/selftests-rseq-remove-arm-mips-asm-goto-compiler-work-around.patch queue-5.4/selftests-rseq-uplift-rseq-selftests-for-compatibility-with-glibc-2.35.patch queue-5.4/selftests-rseq-introduce-thread-pointer-getters.patch queue-5.4/selftests-rseq-introduce-own-copy-of-rseq-uapi-header.patch queue-5.4/rseq-selftests-x86_64-add-rseq_offset_deref_addv.patch queue-5.4/selftests-rseq-introduce-rseq_get_abi-helper.patch queue-5.4/selftests-rseq-fix-ppc32-missing-instruction-selection-u-and-x-for-load-store.patch queue-5.4/selftests-rseq-change-type-of-rseq_offset-to-ptrdiff_t.patch queue-5.4/selftests-rseq-fix-ppc32-wrong-rseq_cs-32-bit-field-pointer-on-big-endian.patch queue-5.4/selftests-rseq-x86-32-use-gs-segment-selector-for-accessing-rseq-thread-area.patch queue-5.4/selftests-rseq-remove-volatile-from-__rseq_abi.patch queue-5.4/selftests-rseq-fix-warnings-about-if-checks-of-undefined-tokens.patch queue-5.4/selftests-rseq-fix-ppc32-offsets-by-using-long-rather-than-off_t.patch queue-5.4/selftests-rseq-remove-useless-assignment-to-cpu-variable.patch queue-5.4/selftests-rseq-x86-64-use-fs-segment-selector-for-accessing-rseq-thread-area.patch