From fe22983d92c15253ea8eb854acbe863fc2313759 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Mon, 29 Apr 2019 11:27:52 -0400 Subject: rseq/selftests: x86: Work-around bogus gcc-8 optimisation gcc-8 version 8.1.0, 8.2.0, and 8.3.0 generate broken assembler with asm goto that have a thread-local storage "m" input operand on both x86-32 and x86-64. For instance: __thread int var; static int fct(void) { asm goto ( "jmp %l[testlabel]\n\t" : : [var] "m" (var) : : testlabel); return 0; testlabel: return 1; } int main() { return fct(); } % gcc-8 -O2 -o test-asm-goto test-asm-goto.c /tmp/ccAdHJbe.o: In function `main': test-asm-goto.c:(.text.startup+0x1): undefined reference to `.L2' collect2: error: ld returned 1 exit status % gcc-8 -m32 -O2 -o test-asm-goto test-asm-goto.c /tmp/ccREsVXA.o: In function `main': test-asm-goto.c:(.text.startup+0x1): undefined reference to `.L2' collect2: error: ld returned 1 exit status Work-around this compiler bug in the rseq-x86.h header by passing the address of the __rseq_abi TLS as a register operand rather than using the "m" input operand. Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90193 Signed-off-by: Mathieu Desnoyers CC: Ingo Molnar CC: Peter Zijlstra CC: Thomas Gleixner CC: Joel Fernandes CC: Catalin Marinas CC: Dave Watson CC: Will Deacon CC: Shuah Khan CC: Andi Kleen CC: linux-kselftest@vger.kernel.org CC: "H . Peter Anvin" CC: Chris Lameter CC: Russell King CC: Michael Kerrisk CC: "Paul E . McKenney" CC: Paul Turner CC: Boqun Feng CC: Josh Triplett CC: Steven Rostedt CC: Ben Maurer CC: linux-api@vger.kernel.org CC: Andy Lutomirski CC: Andrew Morton CC: Linus Torvalds Signed-off-by: Shuah Khan --- tools/testing/selftests/rseq/rseq-x86.h | 144 ++++++++++++++++---------------- 1 file changed, 70 insertions(+), 74 deletions(-) (limited to 'tools/testing/selftests/rseq/rseq-x86.h') diff --git a/tools/testing/selftests/rseq/rseq-x86.h b/tools/testing/selftests/rseq/rseq-x86.h index 089410a314e9..a5341044a2f5 100644 --- a/tools/testing/selftests/rseq/rseq-x86.h +++ b/tools/testing/selftests/rseq/rseq-x86.h @@ -9,6 +9,16 @@ #define RSEQ_SIG 0x53053053 +/* + * Due to a compiler optimization bug in gcc-8 with asm goto and TLS asm input + * operands, we cannot use "m" input operands, and rather pass the __rseq_abi + * address through a "r" input operand. + */ + +/* Offset of cpu_id and rseq_cs fields in struct rseq. */ +#define RSEQ_CPU_ID_OFFSET 4 +#define RSEQ_CS_OFFSET 8 + #ifdef __x86_64__ #define rseq_smp_mb() \ @@ -51,12 +61,12 @@ do { \ #define RSEQ_ASM_STORE_RSEQ_CS(label, cs_label, rseq_cs) \ RSEQ_INJECT_ASM(1) \ "leaq " __rseq_str(cs_label) "(%%rip), %%rax\n\t" \ - "movq %%rax, %[" __rseq_str(rseq_cs) "]\n\t" \ + "movq %%rax, " __rseq_str(rseq_cs) "\n\t" \ __rseq_str(label) ":\n\t" #define RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, label) \ RSEQ_INJECT_ASM(2) \ - "cmpl %[" __rseq_str(cpu_id) "], %[" __rseq_str(current_cpu_id) "]\n\t" \ + "cmpl %[" __rseq_str(cpu_id) "], " __rseq_str(current_cpu_id) "\n\t" \ "jnz " __rseq_str(label) "\n\t" #define RSEQ_ASM_DEFINE_ABORT(label, teardown, abort_label) \ @@ -84,14 +94,14 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu) __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */ /* Start rseq by storing table entry pointer into rseq_cs. */ - RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs) - RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) + 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_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, current_cpu_id, %l[error1]) + RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1]) "cmpq %[v], %[expect]\n\t" "jnz %l[error2]\n\t" #endif @@ -102,8 +112,7 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu) RSEQ_ASM_DEFINE_ABORT(4, "", abort) : /* gcc asm goto does not allow outputs */ : [cpu_id] "r" (cpu), - [current_cpu_id] "m" (__rseq_abi.cpu_id), - [rseq_cs] "m" (__rseq_abi.rseq_cs), + [rseq_abi] "r" (&__rseq_abi), [v] "m" (*v), [expect] "r" (expect), [newv] "r" (newv) @@ -141,15 +150,15 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot, __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */ /* Start rseq by storing table entry pointer into rseq_cs. */ - RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs) - RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) + 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_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, current_cpu_id, %l[error1]) + RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1]) "movq %[v], %%rbx\n\t" "cmpq %%rbx, %[expectnot]\n\t" "je %l[error2]\n\t" @@ -164,8 +173,7 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot, RSEQ_ASM_DEFINE_ABORT(4, "", abort) : /* gcc asm goto does not allow outputs */ : [cpu_id] "r" (cpu), - [current_cpu_id] "m" (__rseq_abi.cpu_id), - [rseq_cs] "m" (__rseq_abi.rseq_cs), + [rseq_abi] "r" (&__rseq_abi), /* final store input */ [v] "m" (*v), [expectnot] "r" (expectnot), @@ -200,11 +208,11 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu) __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */ /* Start rseq by storing table entry pointer into rseq_cs. */ - RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs) - RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) + 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_INJECT_ASM(3) #ifdef RSEQ_COMPARE_TWICE - RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1]) + RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1]) #endif /* final store */ "addq %[count], %[v]\n\t" @@ -213,8 +221,7 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu) RSEQ_ASM_DEFINE_ABORT(4, "", abort) : /* gcc asm goto does not allow outputs */ : [cpu_id] "r" (cpu), - [current_cpu_id] "m" (__rseq_abi.cpu_id), - [rseq_cs] "m" (__rseq_abi.rseq_cs), + [rseq_abi] "r" (&__rseq_abi), /* final store input */ [v] "m" (*v), [count] "er" (count) @@ -245,14 +252,14 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect, __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */ /* Start rseq by storing table entry pointer into rseq_cs. */ - RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs) - RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) + 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_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, current_cpu_id, %l[error1]) + RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1]) "cmpq %[v], %[expect]\n\t" "jnz %l[error2]\n\t" #endif @@ -266,8 +273,7 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect, RSEQ_ASM_DEFINE_ABORT(4, "", abort) : /* gcc asm goto does not allow outputs */ : [cpu_id] "r" (cpu), - [current_cpu_id] "m" (__rseq_abi.cpu_id), - [rseq_cs] "m" (__rseq_abi.rseq_cs), + [rseq_abi] "r" (&__rseq_abi), /* try store input */ [v2] "m" (*v2), [newv2] "r" (newv2), @@ -315,8 +321,8 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect, __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */ /* Start rseq by storing table entry pointer into rseq_cs. */ - RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs) - RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) + 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_INJECT_ASM(3) "cmpq %[v], %[expect]\n\t" "jnz %l[cmpfail]\n\t" @@ -325,7 +331,7 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect, "jnz %l[cmpfail]\n\t" RSEQ_INJECT_ASM(5) #ifdef RSEQ_COMPARE_TWICE - RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1]) + RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1]) "cmpq %[v], %[expect]\n\t" "jnz %l[error2]\n\t" "cmpq %[v2], %[expect2]\n\t" @@ -338,8 +344,7 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect, RSEQ_ASM_DEFINE_ABORT(4, "", abort) : /* gcc asm goto does not allow outputs */ : [cpu_id] "r" (cpu), - [current_cpu_id] "m" (__rseq_abi.cpu_id), - [rseq_cs] "m" (__rseq_abi.rseq_cs), + [rseq_abi] "r" (&__rseq_abi), /* cmp2 input */ [v2] "m" (*v2), [expect2] "r" (expect2), @@ -385,14 +390,14 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect, "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) - RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) + 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_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, current_cpu_id, 6f) + RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 6f) "cmpq %[v], %[expect]\n\t" "jnz 7f\n\t" #endif @@ -440,8 +445,7 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect, #endif : /* gcc asm goto does not allow outputs */ : [cpu_id] "r" (cpu), - [current_cpu_id] "m" (__rseq_abi.cpu_id), - [rseq_cs] "m" (__rseq_abi.rseq_cs), + [rseq_abi] "r" (&__rseq_abi), /* final store input */ [v] "m" (*v), [expect] "r" (expect), @@ -533,12 +537,12 @@ do { \ #define RSEQ_ASM_STORE_RSEQ_CS(label, cs_label, rseq_cs) \ RSEQ_INJECT_ASM(1) \ - "movl $" __rseq_str(cs_label) ", %[rseq_cs]\n\t" \ + "movl $" __rseq_str(cs_label) ", " __rseq_str(rseq_cs) "\n\t" \ __rseq_str(label) ":\n\t" #define RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, label) \ RSEQ_INJECT_ASM(2) \ - "cmpl %[" __rseq_str(cpu_id) "], %[" __rseq_str(current_cpu_id) "]\n\t" \ + "cmpl %[" __rseq_str(cpu_id) "], " __rseq_str(current_cpu_id) "\n\t" \ "jnz " __rseq_str(label) "\n\t" #define RSEQ_ASM_DEFINE_ABORT(label, teardown, abort_label) \ @@ -566,14 +570,14 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu) __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */ /* Start rseq by storing table entry pointer into rseq_cs. */ - RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs) - RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) + 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_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, current_cpu_id, %l[error1]) + RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1]) "cmpl %[v], %[expect]\n\t" "jnz %l[error2]\n\t" #endif @@ -584,8 +588,7 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu) RSEQ_ASM_DEFINE_ABORT(4, "", abort) : /* gcc asm goto does not allow outputs */ : [cpu_id] "r" (cpu), - [current_cpu_id] "m" (__rseq_abi.cpu_id), - [rseq_cs] "m" (__rseq_abi.rseq_cs), + [rseq_abi] "r" (&__rseq_abi), [v] "m" (*v), [expect] "r" (expect), [newv] "r" (newv) @@ -623,15 +626,15 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot, __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */ /* Start rseq by storing table entry pointer into rseq_cs. */ - RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs) - RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) + 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_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, current_cpu_id, %l[error1]) + RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1]) "movl %[v], %%ebx\n\t" "cmpl %%ebx, %[expectnot]\n\t" "je %l[error2]\n\t" @@ -646,8 +649,7 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot, RSEQ_ASM_DEFINE_ABORT(4, "", abort) : /* gcc asm goto does not allow outputs */ : [cpu_id] "r" (cpu), - [current_cpu_id] "m" (__rseq_abi.cpu_id), - [rseq_cs] "m" (__rseq_abi.rseq_cs), + [rseq_abi] "r" (&__rseq_abi), /* final store input */ [v] "m" (*v), [expectnot] "r" (expectnot), @@ -682,11 +684,11 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu) __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */ /* Start rseq by storing table entry pointer into rseq_cs. */ - RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs) - RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) + 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_INJECT_ASM(3) #ifdef RSEQ_COMPARE_TWICE - RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1]) + RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1]) #endif /* final store */ "addl %[count], %[v]\n\t" @@ -695,8 +697,7 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu) RSEQ_ASM_DEFINE_ABORT(4, "", abort) : /* gcc asm goto does not allow outputs */ : [cpu_id] "r" (cpu), - [current_cpu_id] "m" (__rseq_abi.cpu_id), - [rseq_cs] "m" (__rseq_abi.rseq_cs), + [rseq_abi] "r" (&__rseq_abi), /* final store input */ [v] "m" (*v), [count] "ir" (count) @@ -727,14 +728,14 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect, __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */ /* Start rseq by storing table entry pointer into rseq_cs. */ - RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs) - RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) + 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_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, current_cpu_id, %l[error1]) + RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1]) "cmpl %[v], %[expect]\n\t" "jnz %l[error2]\n\t" #endif @@ -749,8 +750,7 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect, RSEQ_ASM_DEFINE_ABORT(4, "", abort) : /* gcc asm goto does not allow outputs */ : [cpu_id] "r" (cpu), - [current_cpu_id] "m" (__rseq_abi.cpu_id), - [rseq_cs] "m" (__rseq_abi.rseq_cs), + [rseq_abi] "r" (&__rseq_abi), /* try store input */ [v2] "m" (*v2), [newv2] "m" (newv2), @@ -789,15 +789,15 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect, __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */ /* Start rseq by storing table entry pointer into rseq_cs. */ - RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs) - RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) + 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_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, current_cpu_id, %l[error1]) + RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1]) "movl %[expect], %%eax\n\t" "cmpl %[v], %%eax\n\t" "jnz %l[error2]\n\t" @@ -813,8 +813,7 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect, RSEQ_ASM_DEFINE_ABORT(4, "", abort) : /* gcc asm goto does not allow outputs */ : [cpu_id] "r" (cpu), - [current_cpu_id] "m" (__rseq_abi.cpu_id), - [rseq_cs] "m" (__rseq_abi.rseq_cs), + [rseq_abi] "r" (&__rseq_abi), /* try store input */ [v2] "m" (*v2), [newv2] "r" (newv2), @@ -854,8 +853,8 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect, __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */ /* Start rseq by storing table entry pointer into rseq_cs. */ - RSEQ_ASM_STORE_RSEQ_CS(1, 3b, rseq_cs) - RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) + 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_INJECT_ASM(3) "cmpl %[v], %[expect]\n\t" "jnz %l[cmpfail]\n\t" @@ -864,7 +863,7 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect, "jnz %l[cmpfail]\n\t" RSEQ_INJECT_ASM(5) #ifdef RSEQ_COMPARE_TWICE - RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1]) + RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1]) "cmpl %[v], %[expect]\n\t" "jnz %l[error2]\n\t" "cmpl %[expect2], %[v2]\n\t" @@ -878,8 +877,7 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect, RSEQ_ASM_DEFINE_ABORT(4, "", abort) : /* gcc asm goto does not allow outputs */ : [cpu_id] "r" (cpu), - [current_cpu_id] "m" (__rseq_abi.cpu_id), - [rseq_cs] "m" (__rseq_abi.rseq_cs), + [rseq_abi] "r" (&__rseq_abi), /* cmp2 input */ [v2] "m" (*v2), [expect2] "r" (expect2), @@ -926,15 +924,15 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect, "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) - RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) + 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_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, current_cpu_id, 6f) + RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 6f) "movl %[expect], %%eax\n\t" "cmpl %%eax, %[v]\n\t" "jnz 7f\n\t" @@ -984,8 +982,7 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect, #endif : /* gcc asm goto does not allow outputs */ : [cpu_id] "r" (cpu), - [current_cpu_id] "m" (__rseq_abi.cpu_id), - [rseq_cs] "m" (__rseq_abi.rseq_cs), + [rseq_abi] "r" (&__rseq_abi), /* final store input */ [v] "m" (*v), [expect] "m" (expect), @@ -1034,15 +1031,15 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect, "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) - RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) + 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_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, current_cpu_id, 6f) + RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 6f) "movl %[expect], %%eax\n\t" "cmpl %%eax, %[v]\n\t" "jnz 7f\n\t" @@ -1093,8 +1090,7 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect, #endif : /* gcc asm goto does not allow outputs */ : [cpu_id] "r" (cpu), - [current_cpu_id] "m" (__rseq_abi.cpu_id), - [rseq_cs] "m" (__rseq_abi.rseq_cs), + [rseq_abi] "r" (&__rseq_abi), /* final store input */ [v] "m" (*v), [expect] "m" (expect), -- cgit From 4fe2088e164d2ec44530fe2840f6be5906fbc650 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Mon, 29 Apr 2019 11:27:53 -0400 Subject: rseq/selftests: Add __rseq_exit_point_array section for debuggers Knowing all exit points is useful to assist debuggers stepping over the rseq critical sections without requiring them to disassemble the content of the critical section to figure out the exit points. Signed-off-by: Mathieu Desnoyers CC: Thomas Gleixner CC: Joel Fernandes CC: Peter Zijlstra CC: Catalin Marinas CC: Dave Watson CC: Will Deacon CC: Shuah Khan CC: Andi Kleen CC: linux-kselftest@vger.kernel.org CC: "H . Peter Anvin" CC: Chris Lameter CC: Russell King CC: Michael Kerrisk CC: "Paul E . McKenney" CC: Paul Turner CC: Boqun Feng CC: Josh Triplett CC: Steven Rostedt CC: Ben Maurer CC: linux-api@vger.kernel.org CC: Andy Lutomirski CC: Andrew Morton CC: Linus Torvalds Signed-off-by: Shuah Khan --- tools/testing/selftests/rseq/rseq-x86.h | 94 +++++++++++++++++++++++++++++++++ 1 file changed, 94 insertions(+) (limited to 'tools/testing/selftests/rseq/rseq-x86.h') diff --git a/tools/testing/selftests/rseq/rseq-x86.h b/tools/testing/selftests/rseq/rseq-x86.h index a5341044a2f5..0668608d3674 100644 --- a/tools/testing/selftests/rseq/rseq-x86.h +++ b/tools/testing/selftests/rseq/rseq-x86.h @@ -58,6 +58,19 @@ do { \ __RSEQ_ASM_DEFINE_TABLE(label, 0x0, 0x0, start_ip, \ (post_commit_ip - start_ip), abort_ip) +/* + * Exit points of a rseq critical section consist of all instructions outside + * of the critical section where a critical section can either branch to or + * reach through the normal course of its execution. The abort IP and the + * post-commit IP are already part of the __rseq_table section and should not + * be explicitly defined as additional exit points. Knowing all exit points is + * useful to assist debuggers stepping over the critical section. + */ +#define RSEQ_ASM_DEFINE_EXIT_POINT(start_ip, exit_ip) \ + ".pushsection __rseq_exit_point_array, \"aw\"\n\t" \ + ".quad " __rseq_str(start_ip) ", " __rseq_str(exit_ip) "\n\t" \ + ".popsection\n\t" + #define RSEQ_ASM_STORE_RSEQ_CS(label, cs_label, rseq_cs) \ RSEQ_INJECT_ASM(1) \ "leaq " __rseq_str(cs_label) "(%%rip), %%rax\n\t" \ @@ -93,6 +106,11 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu) __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */ + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) +#ifdef RSEQ_COMPARE_TWICE + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1]) + 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) @@ -149,6 +167,11 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot, __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */ + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) +#ifdef RSEQ_COMPARE_TWICE + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1]) + 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) @@ -207,6 +230,9 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu) __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */ +#ifdef RSEQ_COMPARE_TWICE + 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) @@ -251,6 +277,11 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect, __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */ + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) +#ifdef RSEQ_COMPARE_TWICE + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1]) + 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) @@ -320,6 +351,12 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect, __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */ + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) +#ifdef RSEQ_COMPARE_TWICE + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1]) + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2]) + 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) @@ -386,6 +423,11 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect, __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */ + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) +#ifdef RSEQ_COMPARE_TWICE + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1]) + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2]) +#endif "movq %[src], %[rseq_scratch0]\n\t" "movq %[dst], %[rseq_scratch1]\n\t" "movq %[len], %[rseq_scratch2]\n\t" @@ -535,6 +577,19 @@ do { \ __RSEQ_ASM_DEFINE_TABLE(label, 0x0, 0x0, start_ip, \ (post_commit_ip - start_ip), abort_ip) +/* + * Exit points of a rseq critical section consist of all instructions outside + * of the critical section where a critical section can either branch to or + * reach through the normal course of its execution. The abort IP and the + * post-commit IP are already part of the __rseq_table section and should not + * be explicitly defined as additional exit points. Knowing all exit points is + * useful to assist debuggers stepping over the critical section. + */ +#define RSEQ_ASM_DEFINE_EXIT_POINT(start_ip, exit_ip) \ + ".pushsection __rseq_exit_point_array, \"aw\"\n\t" \ + ".long " __rseq_str(start_ip) ", 0x0, " __rseq_str(exit_ip) ", 0x0\n\t" \ + ".popsection\n\t" + #define RSEQ_ASM_STORE_RSEQ_CS(label, cs_label, rseq_cs) \ RSEQ_INJECT_ASM(1) \ "movl $" __rseq_str(cs_label) ", " __rseq_str(rseq_cs) "\n\t" \ @@ -569,6 +624,11 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu) __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */ + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) +#ifdef RSEQ_COMPARE_TWICE + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1]) + 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) @@ -625,6 +685,11 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot, __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */ + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) +#ifdef RSEQ_COMPARE_TWICE + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1]) + 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) @@ -683,6 +748,9 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu) __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */ +#ifdef RSEQ_COMPARE_TWICE + 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) @@ -727,6 +795,11 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect, __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */ + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) +#ifdef RSEQ_COMPARE_TWICE + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1]) + 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) @@ -788,6 +861,11 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect, __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */ + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) +#ifdef RSEQ_COMPARE_TWICE + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1]) + 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) @@ -852,6 +930,12 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect, __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */ + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) +#ifdef RSEQ_COMPARE_TWICE + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1]) + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2]) + 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) @@ -920,6 +1004,11 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect, __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */ + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) +#ifdef RSEQ_COMPARE_TWICE + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1]) + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2]) +#endif "movl %[src], %[rseq_scratch0]\n\t" "movl %[dst], %[rseq_scratch1]\n\t" "movl %[len], %[rseq_scratch2]\n\t" @@ -1027,6 +1116,11 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect, __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(3, 1f, 2f, 4f) /* start, commit, abort */ + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) +#ifdef RSEQ_COMPARE_TWICE + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1]) + RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2]) +#endif "movl %[src], %[rseq_scratch0]\n\t" "movl %[dst], %[rseq_scratch1]\n\t" "movl %[len], %[rseq_scratch2]\n\t" -- cgit From a3e3131f94aa1daeb978ed66d0b4e61156ef2c2a Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Mon, 29 Apr 2019 11:27:54 -0400 Subject: rseq/selftests: Introduce __rseq_cs_ptr_array, rename __rseq_table to __rseq_cs The entries within __rseq_table are aligned on 32 bytes due to linux/rseq.h struct rseq_cs uapi requirements, but the start of the __rseq_table section is not guaranteed to be 32-byte aligned. It can cause padding to be added at the start of the section, which makes it hard to use as an array of items by debuggers. Considering that __rseq_table does not really consist of a table due to the presence of padding, rename this section to __rseq_cs. Create a new __rseq_cs_ptr_array section which contains 64-bit packed pointers to entries within the __rseq_cs section. Signed-off-by: Mathieu Desnoyers CC: Thomas Gleixner CC: Joel Fernandes CC: Peter Zijlstra CC: Catalin Marinas CC: Dave Watson CC: Will Deacon CC: Shuah Khan CC: Andi Kleen CC: linux-kselftest@vger.kernel.org CC: "H . Peter Anvin" CC: Chris Lameter CC: Russell King CC: Michael Kerrisk CC: "Paul E . McKenney" CC: Paul Turner CC: Boqun Feng CC: Josh Triplett CC: Steven Rostedt CC: Ben Maurer CC: linux-api@vger.kernel.org CC: Andy Lutomirski CC: Andrew Morton CC: Linus Torvalds Signed-off-by: Shuah Khan --- tools/testing/selftests/rseq/rseq-x86.h | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) (limited to 'tools/testing/selftests/rseq/rseq-x86.h') diff --git a/tools/testing/selftests/rseq/rseq-x86.h b/tools/testing/selftests/rseq/rseq-x86.h index 0668608d3674..03095236f6fa 100644 --- a/tools/testing/selftests/rseq/rseq-x86.h +++ b/tools/testing/selftests/rseq/rseq-x86.h @@ -47,13 +47,17 @@ do { \ #define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, \ start_ip, post_commit_offset, abort_ip) \ - ".pushsection __rseq_table, \"aw\"\n\t" \ + ".pushsection __rseq_cs, \"aw\"\n\t" \ ".balign 32\n\t" \ __rseq_str(label) ":\n\t" \ ".long " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \ ".quad " __rseq_str(start_ip) ", " __rseq_str(post_commit_offset) ", " __rseq_str(abort_ip) "\n\t" \ + ".popsection\n\t" \ + ".pushsection __rseq_cs_ptr_array, \"aw\"\n\t" \ + ".quad " __rseq_str(label) "b\n\t" \ ".popsection\n\t" + #define RSEQ_ASM_DEFINE_TABLE(label, start_ip, post_commit_ip, abort_ip) \ __RSEQ_ASM_DEFINE_TABLE(label, 0x0, 0x0, start_ip, \ (post_commit_ip - start_ip), abort_ip) @@ -62,8 +66,8 @@ do { \ * Exit points of a rseq critical section consist of all instructions outside * of the critical section where a critical section can either branch to or * reach through the normal course of its execution. The abort IP and the - * post-commit IP are already part of the __rseq_table section and should not - * be explicitly defined as additional exit points. Knowing all exit points is + * post-commit IP are already part of the __rseq_cs section and should not be + * explicitly defined as additional exit points. Knowing all exit points is * useful to assist debuggers stepping over the critical section. */ #define RSEQ_ASM_DEFINE_EXIT_POINT(start_ip, exit_ip) \ @@ -566,11 +570,14 @@ do { \ */ #define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, \ start_ip, post_commit_offset, abort_ip) \ - ".pushsection __rseq_table, \"aw\"\n\t" \ + ".pushsection __rseq_cs, \"aw\"\n\t" \ ".balign 32\n\t" \ __rseq_str(label) ":\n\t" \ ".long " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \ ".long " __rseq_str(start_ip) ", 0x0, " __rseq_str(post_commit_offset) ", 0x0, " __rseq_str(abort_ip) ", 0x0\n\t" \ + ".popsection\n\t" \ + ".pushsection __rseq_cs_ptr_array, \"aw\"\n\t" \ + ".long " __rseq_str(label) "b, 0x0\n\t" \ ".popsection\n\t" #define RSEQ_ASM_DEFINE_TABLE(label, start_ip, post_commit_ip, abort_ip) \ @@ -581,8 +588,8 @@ do { \ * Exit points of a rseq critical section consist of all instructions outside * of the critical section where a critical section can either branch to or * reach through the normal course of its execution. The abort IP and the - * post-commit IP are already part of the __rseq_table section and should not - * be explicitly defined as additional exit points. Knowing all exit points is + * post-commit IP are already part of the __rseq_cs section and should not be + * explicitly defined as additional exit points. Knowing all exit points is * useful to assist debuggers stepping over the critical section. */ #define RSEQ_ASM_DEFINE_EXIT_POINT(start_ip, exit_ip) \ -- cgit From 24fa5d1efe98bc09a96ba41fdba96ef715aede77 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Mon, 29 Apr 2019 11:27:57 -0400 Subject: rseq/selftests: x86: use ud1 instruction as RSEQ_SIG opcode Use ud1 as the guard instruction for the restartable sequence abort handler. Its benefit compared to nopl is to trap execution if the program ends up trying to execute it by mistake, which makes debugging easier. The 4-byte signature per se is unchanged (it is the instruction operand). Only the opcode is changed from nopl to ud1. Signed-off-by: Mathieu Desnoyers Suggested-by: Peter Zijlstra CC: Peter Zijlstra CC: Thomas Gleixner CC: Joel Fernandes CC: Catalin Marinas CC: Dave Watson CC: Will Deacon CC: Shuah Khan CC: Andi Kleen CC: linux-kselftest@vger.kernel.org CC: "H . Peter Anvin" CC: Chris Lameter CC: Russell King CC: Michael Kerrisk CC: "Paul E . McKenney" CC: Paul Turner CC: Boqun Feng CC: Josh Triplett CC: Steven Rostedt CC: Ben Maurer CC: linux-api@vger.kernel.org CC: Andy Lutomirski CC: Andrew Morton CC: Linus Torvalds Signed-off-by: Shuah Khan --- tools/testing/selftests/rseq/rseq-x86.h | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) (limited to 'tools/testing/selftests/rseq/rseq-x86.h') diff --git a/tools/testing/selftests/rseq/rseq-x86.h b/tools/testing/selftests/rseq/rseq-x86.h index 03095236f6fa..b2da6004fe30 100644 --- a/tools/testing/selftests/rseq/rseq-x86.h +++ b/tools/testing/selftests/rseq/rseq-x86.h @@ -7,6 +7,13 @@ #include +/* + * RSEQ_SIG is used with the following reserved undefined instructions, which + * trap in user-space: + * + * x86-32: 0f b9 3d 53 30 05 53 ud1 0x53053053,%edi + * x86-64: 0f b9 3d 53 30 05 53 ud1 0x53053053(%rip),%edi + */ #define RSEQ_SIG 0x53053053 /* @@ -88,8 +95,8 @@ do { \ #define RSEQ_ASM_DEFINE_ABORT(label, teardown, abort_label) \ ".pushsection __rseq_failure, \"ax\"\n\t" \ - /* Disassembler-friendly signature: nopl (%rip). */\ - ".byte 0x0f, 0x1f, 0x05\n\t" \ + /* Disassembler-friendly signature: ud1 (%rip),%edi. */ \ + ".byte 0x0f, 0xb9, 0x3d\n\t" \ ".long " __rseq_str(RSEQ_SIG) "\n\t" \ __rseq_str(label) ":\n\t" \ teardown \ @@ -609,8 +616,8 @@ do { \ #define RSEQ_ASM_DEFINE_ABORT(label, teardown, abort_label) \ ".pushsection __rseq_failure, \"ax\"\n\t" \ - /* Disassembler-friendly signature: nopl . */ \ - ".byte 0x0f, 0x1f, 0x05\n\t" \ + /* Disassembler-friendly signature: ud1 ,%edi. */ \ + ".byte 0x0f, 0xb9, 0x3d\n\t" \ ".long " __rseq_str(RSEQ_SIG) "\n\t" \ __rseq_str(label) ":\n\t" \ teardown \ -- cgit