This is a note to let you know that I've just added the patch titled selftests/rseq: x86-64: use %fs segment selector for accessing rseq thread area to the 5.10-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-x86-64-use-fs-segment-selector-for-accessing-rseq-thread-area.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 4e15bb766b6c6e963a4d33629034d0ec3b7637df Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> Date: Mon, 24 Jan 2022 12:12:52 -0500 Subject: selftests/rseq: x86-64: use %fs segment selector for accessing rseq thread area From: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> commit 4e15bb766b6c6e963a4d33629034d0ec3b7637df 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 %fs 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/20220124171253.22072-15-mathieu.desnoyers@xxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- tools/testing/selftests/rseq/rseq-x86.h | 58 ++++++++++++++++---------------- 1 file changed, 30 insertions(+), 28 deletions(-) --- a/tools/testing/selftests/rseq/rseq-x86.h +++ b/tools/testing/selftests/rseq/rseq-x86.h @@ -28,6 +28,8 @@ #ifdef __x86_64__ +#define RSEQ_ASM_TP_SEGMENT %%fs + #define rseq_smp_mb() \ __asm__ __volatile__ ("lock; addl $0,-128(%%rsp)" ::: "memory", "cc") #define rseq_smp_rmb() rseq_barrier() @@ -123,14 +125,14 @@ 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) "cmpq %[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]) "cmpq %[v], %[expect]\n\t" "jnz %l[error2]\n\t" #endif @@ -141,7 +143,7 @@ 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" ((long)rseq_offset), [v] "m" (*v), [expect] "r" (expect), [newv] "r" (newv) @@ -189,15 +191,15 @@ 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) "movq %[v], %%rbx\n\t" "cmpq %%rbx, %[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]) "movq %[v], %%rbx\n\t" "cmpq %%rbx, %[expectnot]\n\t" "je %l[error2]\n\t" @@ -212,7 +214,7 @@ 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" ((long)rseq_offset), /* final store input */ [v] "m" (*v), [expectnot] "r" (expectnot), @@ -255,11 +257,11 @@ 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 */ "addq %[count], %[v]\n\t" @@ -268,7 +270,7 @@ 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" ((long)rseq_offset), /* final store input */ [v] "m" (*v), [count] "er" (count) @@ -309,11 +311,11 @@ int rseq_offset_deref_addv(intptr_t *ptr 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 /* get p+v */ "movq %[ptr], %%rbx\n\t" @@ -327,7 +329,7 @@ int rseq_offset_deref_addv(intptr_t *ptr 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" ((long)rseq_offset), /* final store input */ [ptr] "m" (*ptr), [off] "er" (off), @@ -364,14 +366,14 @@ 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) "cmpq %[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]) "cmpq %[v], %[expect]\n\t" "jnz %l[error2]\n\t" #endif @@ -385,7 +387,7 @@ 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" ((long)rseq_offset), /* try store input */ [v2] "m" (*v2), [newv2] "r" (newv2), @@ -444,8 +446,8 @@ 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) "cmpq %[v], %[expect]\n\t" "jnz %l[cmpfail]\n\t" @@ -454,7 +456,7 @@ 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]) "cmpq %[v], %[expect]\n\t" "jnz %l[error2]\n\t" "cmpq %[v2], %[expect2]\n\t" @@ -467,7 +469,7 @@ 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" ((long)rseq_offset), /* cmp2 input */ [v2] "m" (*v2), [expect2] "r" (expect2), @@ -524,14 +526,14 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_ "movq %[dst], %[rseq_scratch1]\n\t" "movq %[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) "cmpq %[v], %[expect]\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) "cmpq %[v], %[expect]\n\t" "jnz 7f\n\t" #endif @@ -579,7 +581,7 @@ 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" ((long)rseq_offset), /* final store input */ [v] "m" (*v), [expect] "r" (expect), Patches currently in stable-queue which might be from mathieu.desnoyers@xxxxxxxxxxxx are queue-5.10/selftests-rseq-fix-work-around-asm-goto-compiler-bugs.patch queue-5.10/selftests-rseq-remove-arm-mips-asm-goto-compiler-work-around.patch queue-5.10/selftests-rseq-uplift-rseq-selftests-for-compatibility-with-glibc-2.35.patch queue-5.10/selftests-rseq-introduce-thread-pointer-getters.patch queue-5.10/selftests-rseq-introduce-own-copy-of-rseq-uapi-header.patch queue-5.10/selftests-rseq-introduce-rseq_get_abi-helper.patch queue-5.10/selftests-rseq-fix-ppc32-missing-instruction-selection-u-and-x-for-load-store.patch queue-5.10/selftests-rseq-change-type-of-rseq_offset-to-ptrdiff_t.patch queue-5.10/selftests-rseq-fix-ppc32-wrong-rseq_cs-32-bit-field-pointer-on-big-endian.patch queue-5.10/selftests-rseq-x86-32-use-gs-segment-selector-for-accessing-rseq-thread-area.patch queue-5.10/selftests-rseq-remove-volatile-from-__rseq_abi.patch queue-5.10/selftests-rseq-fix-warnings-about-if-checks-of-undefined-tokens.patch queue-5.10/selftests-rseq-fix-ppc32-offsets-by-using-long-rather-than-off_t.patch queue-5.10/selftests-rseq-remove-useless-assignment-to-cpu-variable.patch queue-5.10/selftests-rseq-x86-64-use-fs-segment-selector-for-accessing-rseq-thread-area.patch