diff options
Diffstat (limited to 'tools/testing/selftests/rseq')
-rw-r--r-- | tools/testing/selftests/rseq/Makefile | 8 | ||||
-rw-r--r-- | tools/testing/selftests/rseq/rseq-arm.h | 132 | ||||
-rw-r--r-- | tools/testing/selftests/rseq/rseq-arm64.h | 74 | ||||
-rw-r--r-- | tools/testing/selftests/rseq/rseq-mips.h | 115 | ||||
-rw-r--r-- | tools/testing/selftests/rseq/rseq-ppc.h | 90 | ||||
-rw-r--r-- | tools/testing/selftests/rseq/rseq-s390.h | 69 | ||||
-rw-r--r-- | tools/testing/selftests/rseq/rseq-x86.h | 264 | ||||
-rw-r--r-- | tools/testing/selftests/rseq/rseq.c | 55 | ||||
-rw-r--r-- | tools/testing/selftests/rseq/rseq.h | 1 |
9 files changed, 680 insertions, 128 deletions
diff --git a/tools/testing/selftests/rseq/Makefile b/tools/testing/selftests/rseq/Makefile index c30c52e1d0d2..d6469535630a 100644 --- a/tools/testing/selftests/rseq/Makefile +++ b/tools/testing/selftests/rseq/Makefile @@ -1,5 +1,11 @@ # SPDX-License-Identifier: GPL-2.0+ OR MIT -CFLAGS += -O2 -Wall -g -I./ -I../../../../usr/include/ -L./ -Wl,-rpath=./ + +ifneq ($(shell $(CC) --version 2>&1 | head -n 1 | grep clang),) +CLANG_FLAGS += -no-integrated-as +endif + +CFLAGS += -O2 -Wall -g -I./ -I../../../../usr/include/ -L./ -Wl,-rpath=./ \ + $(CLANG_FLAGS) LDLIBS += -lpthread # Own dependencies because we only want to build against 1st prerequisite, but diff --git a/tools/testing/selftests/rseq/rseq-arm.h b/tools/testing/selftests/rseq/rseq-arm.h index 3cea19877227..84f28f147fb6 100644 --- a/tools/testing/selftests/rseq/rseq-arm.h +++ b/tools/testing/selftests/rseq/rseq-arm.h @@ -5,7 +5,54 @@ * (C) Copyright 2016-2018 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> */ -#define RSEQ_SIG 0x53053053 +/* + * RSEQ_SIG uses the udf A32 instruction with an uncommon immediate operand + * value 0x5de3. This traps if user-space reaches this instruction by mistake, + * and the uncommon operand ensures the kernel does not move the instruction + * pointer to attacker-controlled code on rseq abort. + * + * The instruction pattern in the A32 instruction set is: + * + * e7f5def3 udf #24035 ; 0x5de3 + * + * This translates to the following instruction pattern in the T16 instruction + * set: + * + * little endian: + * def3 udf #243 ; 0xf3 + * e7f5 b.n <7f5> + * + * pre-ARMv6 big endian code: + * e7f5 b.n <7f5> + * def3 udf #243 ; 0xf3 + * + * ARMv6+ -mbig-endian generates mixed endianness code vs data: little-endian + * code and big-endian data. Ensure the RSEQ_SIG data signature matches code + * endianness. Prior to ARMv6, -mbig-endian generates big-endian code and data + * (which match), so there is no need to reverse the endianness of the data + * representation of the signature. However, the choice between BE32 and BE8 + * is done by the linker, so we cannot know whether code and data endianness + * will be mixed before the linker is invoked. + */ + +#define RSEQ_SIG_CODE 0xe7f5def3 + +#ifndef __ASSEMBLER__ + +#define RSEQ_SIG_DATA \ + ({ \ + int sig; \ + asm volatile ("b 2f\n\t" \ + "1: .inst " __rseq_str(RSEQ_SIG_CODE) "\n\t" \ + "2:\n\t" \ + "ldr %[sig], 1b\n\t" \ + : [sig] "=r" (sig)); \ + sig; \ + }) + +#define RSEQ_SIG RSEQ_SIG_DATA + +#endif #define rseq_smp_mb() __asm__ __volatile__ ("dmb" ::: "memory", "cc") #define rseq_smp_rmb() __asm__ __volatile__ ("dmb" ::: "memory", "cc") @@ -30,18 +77,35 @@ do { \ #include "rseq-skip.h" #else /* !RSEQ_SKIP_FASTPATH */ -#define __RSEQ_ASM_DEFINE_TABLE(version, flags, start_ip, \ +#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" \ ".word " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \ ".word " __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" \ + ".word " __rseq_str(label) "b, 0x0\n\t" \ ".popsection\n\t" -#define RSEQ_ASM_DEFINE_TABLE(start_ip, post_commit_ip, abort_ip) \ - __RSEQ_ASM_DEFINE_TABLE(0x0, 0x0, start_ip, \ +#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) +/* + * 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_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) \ + ".pushsection __rseq_exit_point_array, \"aw\"\n\t" \ + ".word " __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) \ "adr r0, " __rseq_str(cs_label) "\n\t" \ @@ -61,7 +125,8 @@ do { \ __rseq_str(table_label) ":\n\t" \ ".word " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \ ".word " __rseq_str(start_ip) ", 0x0, " __rseq_str(post_commit_offset) ", 0x0, " __rseq_str(abort_ip) ", 0x0\n\t" \ - ".word " __rseq_str(RSEQ_SIG) "\n\t" \ + ".arm\n\t" \ + ".inst " __rseq_str(RSEQ_SIG_CODE) "\n\t" \ __rseq_str(label) ":\n\t" \ teardown \ "b %l[" __rseq_str(abort_label) "]\n\t" @@ -86,7 +151,12 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu) rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( - RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */ + RSEQ_ASM_DEFINE_TABLE(9, 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, 3f, rseq_cs) RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) @@ -148,7 +218,12 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot, rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( - RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */ + RSEQ_ASM_DEFINE_TABLE(9, 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, 3f, rseq_cs) RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) @@ -214,7 +289,10 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu) rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( - RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */ + RSEQ_ASM_DEFINE_TABLE(9, 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, 3f, rseq_cs) RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) @@ -266,7 +344,12 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect, rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( - RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */ + RSEQ_ASM_DEFINE_TABLE(9, 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, 3f, rseq_cs) RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) @@ -336,7 +419,12 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect, rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( - RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */ + RSEQ_ASM_DEFINE_TABLE(9, 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, 3f, rseq_cs) RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) @@ -407,7 +495,13 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect, rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( - RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */ + RSEQ_ASM_DEFINE_TABLE(9, 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, 3f, rseq_cs) RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) @@ -485,7 +579,12 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect, rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( - RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */ + RSEQ_ASM_DEFINE_TABLE(9, 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 "str %[src], %[rseq_scratch0]\n\t" "str %[dst], %[rseq_scratch1]\n\t" "str %[len], %[rseq_scratch2]\n\t" @@ -604,7 +703,12 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect, rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( - RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */ + RSEQ_ASM_DEFINE_TABLE(9, 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 "str %[src], %[rseq_scratch0]\n\t" "str %[dst], %[rseq_scratch1]\n\t" "str %[len], %[rseq_scratch2]\n\t" diff --git a/tools/testing/selftests/rseq/rseq-arm64.h b/tools/testing/selftests/rseq/rseq-arm64.h index 954f34671ca6..200dae9e4208 100644 --- a/tools/testing/selftests/rseq/rseq-arm64.h +++ b/tools/testing/selftests/rseq/rseq-arm64.h @@ -6,7 +6,20 @@ * (C) Copyright 2018 - Will Deacon <will.deacon@arm.com> */ -#define RSEQ_SIG 0xd428bc00 /* BRK #0x45E0 */ +/* + * aarch64 -mbig-endian generates mixed endianness code vs data: + * little-endian code and big-endian data. Ensure the RSEQ_SIG signature + * matches code endianness. + */ +#define RSEQ_SIG_CODE 0xd428bc00 /* BRK #0x45E0. */ + +#ifdef __AARCH64EB__ +#define RSEQ_SIG_DATA 0x00bc28d4 /* BRK #0x45E0. */ +#else +#define RSEQ_SIG_DATA RSEQ_SIG_CODE +#endif + +#define RSEQ_SIG RSEQ_SIG_DATA #define rseq_smp_mb() __asm__ __volatile__ ("dmb ish" ::: "memory") #define rseq_smp_rmb() __asm__ __volatile__ ("dmb ishld" ::: "memory") @@ -82,19 +95,35 @@ do { \ #define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, start_ip, \ post_commit_offset, abort_ip) \ - " .pushsection __rseq_table, \"aw\"\n" \ + " .pushsection __rseq_cs, \"aw\"\n" \ " .balign 32\n" \ __rseq_str(label) ":\n" \ " .long " __rseq_str(version) ", " __rseq_str(flags) "\n" \ " .quad " __rseq_str(start_ip) ", " \ __rseq_str(post_commit_offset) ", " \ __rseq_str(abort_ip) "\n" \ + " .popsection\n\t" \ + " .pushsection __rseq_cs_ptr_array, \"aw\"\n" \ + " .quad " __rseq_str(label) "b\n" \ " .popsection\n" #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) +/* + * 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_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) \ + " .pushsection __rseq_exit_point_array, \"aw\"\n" \ + " .quad " __rseq_str(start_ip) ", " __rseq_str(exit_ip) "\n" \ + " .popsection\n" + #define RSEQ_ASM_STORE_RSEQ_CS(label, cs_label, rseq_cs) \ RSEQ_INJECT_ASM(1) \ " adrp " RSEQ_ASM_TMP_REG ", " __rseq_str(cs_label) "\n" \ @@ -105,7 +134,7 @@ do { \ #define RSEQ_ASM_DEFINE_ABORT(label, abort_label) \ " b 222f\n" \ - " .inst " __rseq_str(RSEQ_SIG) "\n" \ + " .inst " __rseq_str(RSEQ_SIG_CODE) "\n" \ __rseq_str(label) ":\n" \ " b %l[" __rseq_str(abort_label) "]\n" \ "222:\n" @@ -182,6 +211,11 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu) __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(1, 2f, 3f, 4f) + RSEQ_ASM_DEFINE_EXIT_POINT(2f, %l[cmpfail]) +#ifdef RSEQ_COMPARE_TWICE + RSEQ_ASM_DEFINE_EXIT_POINT(2f, %l[error1]) + RSEQ_ASM_DEFINE_EXIT_POINT(2f, %l[error2]) +#endif RSEQ_ASM_STORE_RSEQ_CS(2, 1b, rseq_cs) RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) RSEQ_INJECT_ASM(3) @@ -231,6 +265,11 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot, __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(1, 2f, 3f, 4f) + RSEQ_ASM_DEFINE_EXIT_POINT(2f, %l[cmpfail]) +#ifdef RSEQ_COMPARE_TWICE + RSEQ_ASM_DEFINE_EXIT_POINT(2f, %l[error1]) + RSEQ_ASM_DEFINE_EXIT_POINT(2f, %l[error2]) +#endif RSEQ_ASM_STORE_RSEQ_CS(2, 1b, rseq_cs) RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) RSEQ_INJECT_ASM(3) @@ -282,6 +321,9 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu) __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(1, 2f, 3f, 4f) +#ifdef RSEQ_COMPARE_TWICE + RSEQ_ASM_DEFINE_EXIT_POINT(2f, %l[error1]) +#endif RSEQ_ASM_STORE_RSEQ_CS(2, 1b, rseq_cs) RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) RSEQ_INJECT_ASM(3) @@ -325,6 +367,11 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect, __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(1, 2f, 3f, 4f) + RSEQ_ASM_DEFINE_EXIT_POINT(2f, %l[cmpfail]) +#ifdef RSEQ_COMPARE_TWICE + RSEQ_ASM_DEFINE_EXIT_POINT(2f, %l[error1]) + RSEQ_ASM_DEFINE_EXIT_POINT(2f, %l[error2]) +#endif RSEQ_ASM_STORE_RSEQ_CS(2, 1b, rseq_cs) RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) RSEQ_INJECT_ASM(3) @@ -379,6 +426,11 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect, __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(1, 2f, 3f, 4f) + RSEQ_ASM_DEFINE_EXIT_POINT(2f, %l[cmpfail]) +#ifdef RSEQ_COMPARE_TWICE + RSEQ_ASM_DEFINE_EXIT_POINT(2f, %l[error1]) + RSEQ_ASM_DEFINE_EXIT_POINT(2f, %l[error2]) +#endif RSEQ_ASM_STORE_RSEQ_CS(2, 1b, rseq_cs) RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) RSEQ_INJECT_ASM(3) @@ -433,6 +485,12 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect, __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(1, 2f, 3f, 4f) + RSEQ_ASM_DEFINE_EXIT_POINT(2f, %l[cmpfail]) +#ifdef RSEQ_COMPARE_TWICE + RSEQ_ASM_DEFINE_EXIT_POINT(2f, %l[error1]) + RSEQ_ASM_DEFINE_EXIT_POINT(2f, %l[error2]) + RSEQ_ASM_DEFINE_EXIT_POINT(2f, %l[error3]) +#endif RSEQ_ASM_STORE_RSEQ_CS(2, 1b, rseq_cs) RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) RSEQ_INJECT_ASM(3) @@ -490,6 +548,11 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect, __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(1, 2f, 3f, 4f) + RSEQ_ASM_DEFINE_EXIT_POINT(2f, %l[cmpfail]) +#ifdef RSEQ_COMPARE_TWICE + RSEQ_ASM_DEFINE_EXIT_POINT(2f, %l[error1]) + RSEQ_ASM_DEFINE_EXIT_POINT(2f, %l[error2]) +#endif RSEQ_ASM_STORE_RSEQ_CS(2, 1b, rseq_cs) RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) RSEQ_INJECT_ASM(3) @@ -545,6 +608,11 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect, __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(1, 2f, 3f, 4f) + RSEQ_ASM_DEFINE_EXIT_POINT(2f, %l[cmpfail]) +#ifdef RSEQ_COMPARE_TWICE + RSEQ_ASM_DEFINE_EXIT_POINT(2f, %l[error1]) + RSEQ_ASM_DEFINE_EXIT_POINT(2f, %l[error2]) +#endif RSEQ_ASM_STORE_RSEQ_CS(2, 1b, rseq_cs) RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) RSEQ_INJECT_ASM(3) diff --git a/tools/testing/selftests/rseq/rseq-mips.h b/tools/testing/selftests/rseq/rseq-mips.h index 7f48ecf46994..e989e7c14b09 100644 --- a/tools/testing/selftests/rseq/rseq-mips.h +++ b/tools/testing/selftests/rseq/rseq-mips.h @@ -7,7 +7,39 @@ * (C) Copyright 2016-2018 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> */ -#define RSEQ_SIG 0x53053053 +/* + * RSEQ_SIG uses the break instruction. The instruction pattern is: + * + * On MIPS: + * 0350000d break 0x350 + * + * On nanoMIPS: + * 00100350 break 0x350 + * + * On microMIPS: + * 0000d407 break 0x350 + * + * For nanoMIPS32 and microMIPS, the instruction stream is encoded as 16-bit + * halfwords, so the signature halfwords need to be swapped accordingly for + * little-endian. + */ +#if defined(__nanomips__) +# ifdef __MIPSEL__ +# define RSEQ_SIG 0x03500010 +# else +# define RSEQ_SIG 0x00100350 +# endif +#elif defined(__mips_micromips) +# ifdef __MIPSEL__ +# define RSEQ_SIG 0xd4070000 +# else +# define RSEQ_SIG 0x0000d407 +# endif +#elif defined(__mips__) +# define RSEQ_SIG 0x0350000d +#else +/* Unknown MIPS architecture. */ +#endif #define rseq_smp_mb() __asm__ __volatile__ ("sync" ::: "memory") #define rseq_smp_rmb() rseq_smp_mb() @@ -54,20 +86,38 @@ do { \ # error unsupported _MIPS_SZLONG #endif -#define __RSEQ_ASM_DEFINE_TABLE(version, flags, start_ip, \ +#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" \ ".word " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \ LONG " " U32_U64_PAD(__rseq_str(start_ip)) "\n\t" \ LONG " " U32_U64_PAD(__rseq_str(post_commit_offset)) "\n\t" \ LONG " " U32_U64_PAD(__rseq_str(abort_ip)) "\n\t" \ + ".popsection\n\t" \ + ".pushsection __rseq_cs_ptr_array, \"aw\"\n\t" \ + LONG " " U32_U64_PAD(__rseq_str(label) "b") "\n\t" \ ".popsection\n\t" -#define RSEQ_ASM_DEFINE_TABLE(start_ip, post_commit_ip, abort_ip) \ - __RSEQ_ASM_DEFINE_TABLE(0x0, 0x0, start_ip, \ +#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) +/* + * 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_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) \ + ".pushsection __rseq_exit_point_array, \"aw\"\n\t" \ + LONG " " U32_U64_PAD(__rseq_str(start_ip)) "\n\t" \ + LONG " " U32_U64_PAD(__rseq_str(exit_ip)) "\n\t" \ + ".popsection\n\t" + #define RSEQ_ASM_STORE_RSEQ_CS(label, cs_label, rseq_cs) \ RSEQ_INJECT_ASM(1) \ LONG_LA " $4, " __rseq_str(cs_label) "\n\t" \ @@ -113,7 +163,12 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu) rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( - RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */ + RSEQ_ASM_DEFINE_TABLE(9, 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, 3f, rseq_cs) RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) @@ -173,7 +228,12 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot, rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( - RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */ + RSEQ_ASM_DEFINE_TABLE(9, 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, 3f, rseq_cs) RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) @@ -237,7 +297,10 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu) rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( - RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */ + RSEQ_ASM_DEFINE_TABLE(9, 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, 3f, rseq_cs) RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) @@ -289,7 +352,12 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect, rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( - RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */ + RSEQ_ASM_DEFINE_TABLE(9, 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, 3f, rseq_cs) RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) @@ -357,7 +425,12 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect, rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( - RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */ + RSEQ_ASM_DEFINE_TABLE(9, 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, 3f, rseq_cs) RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) @@ -426,7 +499,13 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect, rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( - RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */ + RSEQ_ASM_DEFINE_TABLE(9, 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, 3f, rseq_cs) RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) @@ -500,7 +579,12 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect, rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( - RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */ + RSEQ_ASM_DEFINE_TABLE(9, 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 LONG_S " %[src], %[rseq_scratch0]\n\t" LONG_S " %[dst], %[rseq_scratch1]\n\t" LONG_S " %[len], %[rseq_scratch2]\n\t" @@ -616,7 +700,12 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect, rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( - RSEQ_ASM_DEFINE_TABLE(1f, 2f, 4f) /* start, commit, abort */ + RSEQ_ASM_DEFINE_TABLE(9, 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 LONG_S " %[src], %[rseq_scratch0]\n\t" LONG_S " %[dst], %[rseq_scratch1]\n\t" LONG_S " %[len], %[rseq_scratch2]\n\t" diff --git a/tools/testing/selftests/rseq/rseq-ppc.h b/tools/testing/selftests/rseq/rseq-ppc.h index 52630c9f42be..76be90196fe4 100644 --- a/tools/testing/selftests/rseq/rseq-ppc.h +++ b/tools/testing/selftests/rseq/rseq-ppc.h @@ -6,7 +6,15 @@ * (C) Copyright 2016-2018 - Boqun Feng <boqun.feng@gmail.com> */ -#define RSEQ_SIG 0x53053053 +/* + * RSEQ_SIG is used with the following trap instruction: + * + * powerpc-be: 0f e5 00 0b twui r5,11 + * powerpc64-le: 0b 00 e5 0f twui r5,11 + * powerpc64-be: 0f e5 00 0b twui r5,11 + */ + +#define RSEQ_SIG 0x0fe5000b #define rseq_smp_mb() __asm__ __volatile__ ("sync" ::: "memory", "cc") #define rseq_smp_lwsync() __asm__ __volatile__ ("lwsync" ::: "memory", "cc") @@ -33,8 +41,8 @@ do { \ #else /* !RSEQ_SKIP_FASTPATH */ /* - * The __rseq_table section can be used by debuggers to better handle - * single-stepping through the restartable critical sections. + * The __rseq_cs_ptr_array and __rseq_cs sections can be used by debuggers to + * better handle single-stepping through the restartable critical sections. */ #ifdef __PPC64__ @@ -46,11 +54,14 @@ 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" \ ".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_STORE_RSEQ_CS(label, cs_label, rseq_cs) \ @@ -63,6 +74,19 @@ do { \ "std %%r17, %[" __rseq_str(rseq_cs) "]\n\t" \ __rseq_str(label) ":\n\t" +/* + * 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_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) \ + ".pushsection __rseq_exit_point_array, \"aw\"\n\t" \ + ".quad " __rseq_str(start_ip) ", " __rseq_str(exit_ip) "\n\t" \ + ".popsection\n\t" + #else /* #ifdef __PPC64__ */ #define STORE_WORD "stw " @@ -72,12 +96,29 @@ 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" \ /* 32-bit only supported on BE */ \ ".long 0x0, " __rseq_str(start_ip) ", 0x0, " __rseq_str(post_commit_offset) ", 0x0, " __rseq_str(abort_ip) "\n\t" \ + ".popsection\n\t" \ + ".pushsection __rseq_cs_ptr_array, \"aw\"\n\t" \ + ".long 0x0, " __rseq_str(label) "b\n\t" \ + ".popsection\n\t" + +/* + * 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_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) \ + ".pushsection __rseq_exit_point_array, \"aw\"\n\t" \ + /* 32-bit only supported on BE */ \ + ".long 0x0, " __rseq_str(start_ip) ", 0x0, " __rseq_str(exit_ip) "\n\t" \ ".popsection\n\t" #define RSEQ_ASM_STORE_RSEQ_CS(label, cs_label, rseq_cs) \ @@ -169,6 +210,11 @@ 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) /* cmp cpuid */ @@ -224,6 +270,11 @@ 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) /* cmp cpuid */ @@ -286,6 +337,9 @@ 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) /* cmp cpuid */ @@ -337,6 +391,11 @@ 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) /* cmp cpuid */ @@ -400,6 +459,11 @@ 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) /* cmp cpuid */ @@ -465,6 +529,12 @@ 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) /* cmp cpuid */ @@ -532,6 +602,11 @@ 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 /* setup for mempcy */ "mr %%r19, %[len]\n\t" "mr %%r20, %[src]\n\t" @@ -601,6 +676,11 @@ 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 /* setup for mempcy */ "mr %%r19, %[len]\n\t" "mr %%r20, %[src]\n\t" diff --git a/tools/testing/selftests/rseq/rseq-s390.h b/tools/testing/selftests/rseq/rseq-s390.h index 0afdf7957974..8ef94ad1cbb4 100644 --- a/tools/testing/selftests/rseq/rseq-s390.h +++ b/tools/testing/selftests/rseq/rseq-s390.h @@ -44,22 +44,54 @@ 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" + +/* + * 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_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) \ + ".pushsection __rseq_exit_point_array, \"aw\"\n\t" \ + ".quad " __rseq_str(start_ip) ", " __rseq_str(exit_ip) "\n\t" \ ".popsection\n\t" #elif __s390__ #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 0x0, " __rseq_str(start_ip) ", 0x0, " __rseq_str(post_commit_offset) ", 0x0, " __rseq_str(abort_ip) "\n\t" \ + ".popsection\n\t" \ + ".pushsection __rseq_cs_ptr_array, \"aw\"\n\t" \ + ".long 0x0, " __rseq_str(label) "b\n\t" \ + ".popsection\n\t" + +/* + * 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_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) \ + ".pushsection __rseq_exit_point_array, \"aw\"\n\t" \ + ".long 0x0, " __rseq_str(start_ip) ", 0x0, " __rseq_str(exit_ip) "\n\t" \ ".popsection\n\t" #define LONG_L "l" @@ -92,14 +124,14 @@ do { \ ".long " __rseq_str(RSEQ_SIG) "\n\t" \ __rseq_str(label) ":\n\t" \ teardown \ - "j %l[" __rseq_str(abort_label) "]\n\t" \ + "jg %l[" __rseq_str(abort_label) "]\n\t" \ ".popsection\n\t" #define RSEQ_ASM_DEFINE_CMPFAIL(label, teardown, cmpfail_label) \ ".pushsection __rseq_failure, \"ax\"\n\t" \ __rseq_str(label) ":\n\t" \ teardown \ - "j %l[" __rseq_str(cmpfail_label) "]\n\t" \ + "jg %l[" __rseq_str(cmpfail_label) "]\n\t" \ ".popsection\n\t" static inline __attribute__((always_inline)) @@ -109,6 +141,11 @@ 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) RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) @@ -167,6 +204,11 @@ 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) RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) @@ -227,6 +269,9 @@ 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) RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) @@ -275,6 +320,11 @@ 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) RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) @@ -346,6 +396,12 @@ 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) RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 4f) @@ -414,6 +470,11 @@ 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 LONG_S " %[src], %[rseq_scratch0]\n\t" LONG_S " %[dst], %[rseq_scratch1]\n\t" LONG_S " %[len], %[rseq_scratch2]\n\t" diff --git a/tools/testing/selftests/rseq/rseq-x86.h b/tools/testing/selftests/rseq/rseq-x86.h index 089410a314e9..b2da6004fe30 100644 --- a/tools/testing/selftests/rseq/rseq-x86.h +++ b/tools/testing/selftests/rseq/rseq-x86.h @@ -7,8 +7,25 @@ #include <stdint.h> +/* + * 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 +/* + * 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() \ @@ -37,32 +54,49 @@ 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) +/* + * 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_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) \ + ".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" \ - "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) \ ".pushsection __rseq_failure, \"ax\"\n\t" \ - /* Disassembler-friendly signature: nopl <sig>(%rip). */\ - ".byte 0x0f, 0x1f, 0x05\n\t" \ + /* Disassembler-friendly signature: ud1 <sig>(%rip),%edi. */ \ + ".byte 0x0f, 0xb9, 0x3d\n\t" \ ".long " __rseq_str(RSEQ_SIG) "\n\t" \ __rseq_str(label) ":\n\t" \ teardown \ @@ -83,15 +117,20 @@ 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) - 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 +141,7 @@ 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) @@ -140,16 +178,21 @@ 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) - 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 +207,7 @@ 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), @@ -199,12 +241,15 @@ 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) - 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 +258,7 @@ 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) @@ -244,15 +288,20 @@ 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) - 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 +315,7 @@ 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), @@ -314,9 +362,15 @@ 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) - 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 +379,7 @@ 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 +392,7 @@ 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), @@ -381,18 +434,23 @@ 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" /* 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 +498,7 @@ 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), @@ -520,31 +577,47 @@ 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) \ __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_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) \ + ".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_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) \ ".pushsection __rseq_failure, \"ax\"\n\t" \ - /* Disassembler-friendly signature: nopl <sig>. */ \ - ".byte 0x0f, 0x1f, 0x05\n\t" \ + /* Disassembler-friendly signature: ud1 <sig>,%edi. */ \ + ".byte 0x0f, 0xb9, 0x3d\n\t" \ ".long " __rseq_str(RSEQ_SIG) "\n\t" \ __rseq_str(label) ":\n\t" \ teardown \ @@ -565,15 +638,20 @@ 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) - 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 +662,7 @@ 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) @@ -622,16 +699,21 @@ 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) - 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 +728,7 @@ 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), @@ -681,12 +762,15 @@ 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) - 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 +779,7 @@ 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) @@ -726,15 +809,20 @@ 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) - 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 +837,7 @@ 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), @@ -788,16 +875,21 @@ 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) - 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 +905,7 @@ 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), @@ -853,9 +944,15 @@ 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) - 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 +961,7 @@ 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 +975,7 @@ 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), @@ -922,19 +1018,24 @@ 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" /* 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 +1085,7 @@ 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), @@ -1030,19 +1130,24 @@ 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" /* 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 +1198,7 @@ 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), diff --git a/tools/testing/selftests/rseq/rseq.c b/tools/testing/selftests/rseq/rseq.c index 4847e97ed049..7159eb777fd3 100644 --- a/tools/testing/selftests/rseq/rseq.c +++ b/tools/testing/selftests/rseq/rseq.c @@ -25,18 +25,27 @@ #include <syscall.h> #include <assert.h> #include <signal.h> +#include <limits.h> #include "rseq.h" #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0])) -__attribute__((tls_model("initial-exec"))) __thread -volatile struct rseq __rseq_abi = { +__thread volatile struct rseq __rseq_abi = { .cpu_id = RSEQ_CPU_ID_UNINITIALIZED, }; -static __attribute__((tls_model("initial-exec"))) __thread -volatile int refcount; +/* + * Shared with other libraries. This library may take rseq ownership if it is + * still 0 when executing the library constructor. Set to 1 by library + * constructor when handling rseq. Set to 0 in destructor if handling rseq. + */ +int __rseq_handled; + +/* Whether this library have ownership of rseq registration. */ +static int rseq_ownership; + +static __thread volatile uint32_t __rseq_refcount; static void signal_off_save(sigset_t *oldset) { @@ -69,8 +78,14 @@ int rseq_register_current_thread(void) int rc, ret = 0; sigset_t oldset; + if (!rseq_ownership) + return 0; signal_off_save(&oldset); - if (refcount++) + if (__rseq_refcount == UINT_MAX) { + ret = -1; + goto end; + } + if (__rseq_refcount++) goto end; rc = sys_rseq(&__rseq_abi, sizeof(struct rseq), 0, RSEQ_SIG); if (!rc) { @@ -78,9 +93,9 @@ int rseq_register_current_thread(void) goto end; } if (errno != EBUSY) - __rseq_abi.cpu_id = -2; + __rseq_abi.cpu_id = RSEQ_CPU_ID_REGISTRATION_FAILED; ret = -1; - refcount--; + __rseq_refcount--; end: signal_restore(oldset); return ret; @@ -91,13 +106,20 @@ int rseq_unregister_current_thread(void) int rc, ret = 0; sigset_t oldset; + if (!rseq_ownership) + return 0; signal_off_save(&oldset); - if (--refcount) + if (!__rseq_refcount) { + ret = -1; + goto end; + } + if (--__rseq_refcount) goto end; rc = sys_rseq(&__rseq_abi, sizeof(struct rseq), RSEQ_FLAG_UNREGISTER, RSEQ_SIG); if (!rc) goto end; + __rseq_refcount = 1; ret = -1; end: signal_restore(oldset); @@ -115,3 +137,20 @@ int32_t rseq_fallback_current_cpu(void) } return cpu; } + +void __attribute__((constructor)) rseq_init(void) +{ + /* Check whether rseq is handled by another library. */ + if (__rseq_handled) + return; + __rseq_handled = 1; + rseq_ownership = 1; +} + +void __attribute__((destructor)) rseq_fini(void) +{ + if (!rseq_ownership) + return; + __rseq_handled = 0; + rseq_ownership = 0; +} diff --git a/tools/testing/selftests/rseq/rseq.h b/tools/testing/selftests/rseq/rseq.h index 6c1126e7f685..d40d60e7499e 100644 --- a/tools/testing/selftests/rseq/rseq.h +++ b/tools/testing/selftests/rseq/rseq.h @@ -44,6 +44,7 @@ #endif extern __thread volatile struct rseq __rseq_abi; +extern int __rseq_handled; #define rseq_likely(x) __builtin_expect(!!(x), 1) #define rseq_unlikely(x) __builtin_expect(!!(x), 0) |