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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> * * - ARMv6+ big endian (BE8): * * ARMv6+ -mbig-endian generates mixed endianness code vs data: little-endian * code and big-endian data. The data value of the signature needs to have its * byte order reversed to generate the trap instruction: * * Data: 0xf3def5e7 * * Translates to this A32 instruction pattern: * * e7f5def3 udf #24035 ; 0x5de3 * * Translates to this T16 instruction pattern: * * def3 udf #243 ; 0xf3 * e7f5 b.n <7f5> * * - Prior to ARMv6 big endian (BE32): * * Prior to ARMv6, -mbig-endian generates big-endian code and data * (which match), so the endianness of the data representation of the * signature should not be reversed. 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. So rather * than try to play tricks with the linker, the rseq signature is simply * data (not a trap instruction) prior to ARMv6 on big endian. This is * why the signature is expressed as data (.word) rather than as * instruction (.inst) in assembler. */ #ifdef __ARMEB__ #define RSEQ_SIG 0xf3def5e7 /* udf #24035 ; 0x5de3 (ARMv6+) */ #else #define RSEQ_SIG 0xe7f5def3 /* udf #24035 ; 0x5de3 */ #endif #define rseq_smp_mb() __asm__ __volatile__ ("dmb" ::: "memory", "cc") #define rseq_smp_rmb() __asm__ __volatile__ ("dmb" ::: "memory", "cc") #define rseq_smp_wmb() __asm__ __volatile__ ("dmb" ::: "memory", "cc") #define rseq_smp_load_acquire(p) \ __extension__ ({ \ __typeof(*p) ____p1 = RSEQ_READ_ONCE(*p); \ rseq_smp_mb(); \ ____p1; \ }) #define rseq_smp_acquire__after_ctrl_dep() rseq_smp_rmb() #define rseq_smp_store_release(p, v) \ do { \ rseq_smp_mb(); \ RSEQ_WRITE_ONCE(*p, v); \ } while (0) #ifdef RSEQ_SKIP_FASTPATH #include "rseq-skip.h" #else /* !RSEQ_SKIP_FASTPATH */ #define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, start_ip, \ post_commit_offset, abort_ip) \ ".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(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" \ "str r0, %[" __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) \ "ldr r0, %[" __rseq_str(current_cpu_id) "]\n\t" \ "cmp %[" __rseq_str(cpu_id) "], r0\n\t" \ "bne " __rseq_str(label) "\n\t" #define __RSEQ_ASM_DEFINE_ABORT(table_label, label, teardown, \ abort_label, version, flags, \ start_ip, post_commit_offset, abort_ip) \ ".balign 32\n\t" \ __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" \ __rseq_str(label) ":\n\t" \ teardown \ "b %l[" __rseq_str(abort_label) "]\n\t" #define RSEQ_ASM_DEFINE_ABORT(table_label, label, teardown, abort_label, \ start_ip, post_commit_ip, abort_ip) \ __RSEQ_ASM_DEFINE_ABORT(table_label, label, teardown, \ abort_label, 0x0, 0x0, start_ip, \ (post_commit_ip - start_ip), abort_ip) #define RSEQ_ASM_DEFINE_CMPFAIL(label, teardown, cmpfail_label) \ __rseq_str(label) ":\n\t" \ teardown \ "b %l[" __rseq_str(cmpfail_label) "]\n\t" #define rseq_workaround_gcc_asm_size_guess() __asm__ __volatile__("") static inline __attribute__((always_inline)) int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu) { RSEQ_INJECT_C(9) rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) #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) RSEQ_INJECT_ASM(3) "ldr r0, %[v]\n\t" "cmp %[expect], r0\n\t" "bne %l[cmpfail]\n\t" RSEQ_INJECT_ASM(4) #ifdef RSEQ_COMPARE_TWICE RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1]) "ldr r0, %[v]\n\t" "cmp %[expect], r0\n\t" "bne %l[error2]\n\t" #endif /* final store */ "str %[newv], %[v]\n\t" "2:\n\t" RSEQ_INJECT_ASM(5) "b 5f\n\t" RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f) "5:\n\t" : /* 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), [v] "m" (*v), [expect] "r" (expect), [newv] "r" (newv) RSEQ_INJECT_INPUT : "r0", "memory", "cc" RSEQ_INJECT_CLOBBER : abort, cmpfail #ifdef RSEQ_COMPARE_TWICE , error1, error2 #endif ); rseq_workaround_gcc_asm_size_guess(); return 0; abort: rseq_workaround_gcc_asm_size_guess(); RSEQ_INJECT_FAILED return -1; cmpfail: rseq_workaround_gcc_asm_size_guess(); return 1; #ifdef RSEQ_COMPARE_TWICE error1: rseq_bug("cpu_id comparison failed"); error2: rseq_bug("expected value comparison failed"); #endif } static inline __attribute__((always_inline)) int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot, off_t voffp, intptr_t *load, int cpu) { RSEQ_INJECT_C(9) rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) #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) RSEQ_INJECT_ASM(3) "ldr r0, %[v]\n\t" "cmp %[expectnot], r0\n\t" "beq %l[cmpfail]\n\t" RSEQ_INJECT_ASM(4) #ifdef RSEQ_COMPARE_TWICE RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1]) "ldr r0, %[v]\n\t" "cmp %[expectnot], r0\n\t" "beq %l[error2]\n\t" #endif "str r0, %[load]\n\t" "add r0, %[voffp]\n\t" "ldr r0, [r0]\n\t" /* final store */ "str r0, %[v]\n\t" "2:\n\t" RSEQ_INJECT_ASM(5) "b 5f\n\t" RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f) "5:\n\t" : /* 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), /* final store input */ [v] "m" (*v), [expectnot] "r" (expectnot), [voffp] "Ir" (voffp), [load] "m" (*load) RSEQ_INJECT_INPUT : "r0", "memory", "cc" RSEQ_INJECT_CLOBBER : abort, cmpfail #ifdef RSEQ_COMPARE_TWICE , error1, error2 #endif ); rseq_workaround_gcc_asm_size_guess(); return 0; abort: rseq_workaround_gcc_asm_size_guess(); RSEQ_INJECT_FAILED return -1; cmpfail: rseq_workaround_gcc_asm_size_guess(); return 1; #ifdef RSEQ_COMPARE_TWICE error1: rseq_bug("cpu_id comparison failed"); error2: rseq_bug("expected value comparison failed"); #endif } static inline __attribute__((always_inline)) int rseq_addv(intptr_t *v, intptr_t count, int cpu) { RSEQ_INJECT_C(9) rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */ #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) RSEQ_INJECT_ASM(3) #ifdef RSEQ_COMPARE_TWICE RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1]) #endif "ldr r0, %[v]\n\t" "add r0, %[count]\n\t" /* final store */ "str r0, %[v]\n\t" "2:\n\t" RSEQ_INJECT_ASM(4) "b 5f\n\t" RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f) "5:\n\t" : /* 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), [v] "m" (*v), [count] "Ir" (count) RSEQ_INJECT_INPUT : "r0", "memory", "cc" RSEQ_INJECT_CLOBBER : abort #ifdef RSEQ_COMPARE_TWICE , error1 #endif ); rseq_workaround_gcc_asm_size_guess(); return 0; abort: rseq_workaround_gcc_asm_size_guess(); RSEQ_INJECT_FAILED return -1; #ifdef RSEQ_COMPARE_TWICE error1: rseq_bug("cpu_id comparison failed"); #endif } static inline __attribute__((always_inline)) int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect, intptr_t *v2, intptr_t newv2, intptr_t newv, int cpu) { RSEQ_INJECT_C(9) rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) #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) RSEQ_INJECT_ASM(3) "ldr r0, %[v]\n\t" "cmp %[expect], r0\n\t" "bne %l[cmpfail]\n\t" RSEQ_INJECT_ASM(4) #ifdef RSEQ_COMPARE_TWICE RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1]) "ldr r0, %[v]\n\t" "cmp %[expect], r0\n\t" "bne %l[error2]\n\t" #endif /* try store */ "str %[newv2], %[v2]\n\t" RSEQ_INJECT_ASM(5) /* final store */ "str %[newv], %[v]\n\t" "2:\n\t" RSEQ_INJECT_ASM(6) "b 5f\n\t" RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f) "5:\n\t" : /* 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), /* try store input */ [v2] "m" (*v2), [newv2] "r" (newv2), /* final store input */ [v] "m" (*v), [expect] "r" (expect), [newv] "r" (newv) RSEQ_INJECT_INPUT : "r0", "memory", "cc" RSEQ_INJECT_CLOBBER : abort, cmpfail #ifdef RSEQ_COMPARE_TWICE , error1, error2 #endif ); rseq_workaround_gcc_asm_size_guess(); return 0; abort: rseq_workaround_gcc_asm_size_guess(); RSEQ_INJECT_FAILED return -1; cmpfail: rseq_workaround_gcc_asm_size_guess(); return 1; #ifdef RSEQ_COMPARE_TWICE error1: rseq_bug("cpu_id comparison failed"); error2: rseq_bug("expected value comparison failed"); #endif } static inline __attribute__((always_inline)) int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect, intptr_t *v2, intptr_t newv2, intptr_t newv, int cpu) { RSEQ_INJECT_C(9) rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) #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) RSEQ_INJECT_ASM(3) "ldr r0, %[v]\n\t" "cmp %[expect], r0\n\t" "bne %l[cmpfail]\n\t" RSEQ_INJECT_ASM(4) #ifdef RSEQ_COMPARE_TWICE RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1]) "ldr r0, %[v]\n\t" "cmp %[expect], r0\n\t" "bne %l[error2]\n\t" #endif /* try store */ "str %[newv2], %[v2]\n\t" RSEQ_INJECT_ASM(5) "dmb\n\t" /* full mb provides store-release */ /* final store */ "str %[newv], %[v]\n\t" "2:\n\t" RSEQ_INJECT_ASM(6) "b 5f\n\t" RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f) "5:\n\t" : /* 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), /* try store input */ [v2] "m" (*v2), [newv2] "r" (newv2), /* final store input */ [v] "m" (*v), [expect] "r" (expect), [newv] "r" (newv) RSEQ_INJECT_INPUT : "r0", "memory", "cc" RSEQ_INJECT_CLOBBER : abort, cmpfail #ifdef RSEQ_COMPARE_TWICE , error1, error2 #endif ); rseq_workaround_gcc_asm_size_guess(); return 0; abort: rseq_workaround_gcc_asm_size_guess(); RSEQ_INJECT_FAILED return -1; cmpfail: rseq_workaround_gcc_asm_size_guess(); return 1; #ifdef RSEQ_COMPARE_TWICE error1: rseq_bug("cpu_id comparison failed"); error2: rseq_bug("expected value comparison failed"); #endif } static inline __attribute__((always_inline)) int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t *v2, intptr_t expect2, intptr_t newv, int cpu) { RSEQ_INJECT_C(9) rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) #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) RSEQ_INJECT_ASM(3) "ldr r0, %[v]\n\t" "cmp %[expect], r0\n\t" "bne %l[cmpfail]\n\t" RSEQ_INJECT_ASM(4) "ldr r0, %[v2]\n\t" "cmp %[expect2], r0\n\t" "bne %l[cmpfail]\n\t" RSEQ_INJECT_ASM(5) #ifdef RSEQ_COMPARE_TWICE RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1]) "ldr r0, %[v]\n\t" "cmp %[expect], r0\n\t" "bne %l[error2]\n\t" "ldr r0, %[v2]\n\t" "cmp %[expect2], r0\n\t" "bne %l[error3]\n\t" #endif /* final store */ "str %[newv], %[v]\n\t" "2:\n\t" RSEQ_INJECT_ASM(6) "b 5f\n\t" RSEQ_ASM_DEFINE_ABORT(3, 4, "", abort, 1b, 2b, 4f) "5:\n\t" : /* 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), /* cmp2 input */ [v2] "m" (*v2), [expect2] "r" (expect2), /* final store input */ [v] "m" (*v), [expect] "r" (expect), [newv] "r" (newv) RSEQ_INJECT_INPUT : "r0", "memory", "cc" RSEQ_INJECT_CLOBBER : abort, cmpfail #ifdef RSEQ_COMPARE_TWICE , error1, error2, error3 #endif ); rseq_workaround_gcc_asm_size_guess(); return 0; abort: rseq_workaround_gcc_asm_size_guess(); RSEQ_INJECT_FAILED return -1; cmpfail: rseq_workaround_gcc_asm_size_guess(); return 1; #ifdef RSEQ_COMPARE_TWICE error1: rseq_bug("cpu_id comparison failed"); error2: rseq_bug("1st expected value comparison failed"); error3: rseq_bug("2nd expected value comparison failed"); #endif } static inline __attribute__((always_inline)) int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect, void *dst, void *src, size_t len, intptr_t newv, int cpu) { uint32_t rseq_scratch[3]; RSEQ_INJECT_C(9) rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) #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" /* 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) RSEQ_INJECT_ASM(3) "ldr r0, %[v]\n\t" "cmp %[expect], r0\n\t" "bne 5f\n\t" RSEQ_INJECT_ASM(4) #ifdef RSEQ_COMPARE_TWICE RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 6f) "ldr r0, %[v]\n\t" "cmp %[expect], r0\n\t" "bne 7f\n\t" #endif /* try memcpy */ "cmp %[len], #0\n\t" \ "beq 333f\n\t" \ "222:\n\t" \ "ldrb %%r0, [%[src]]\n\t" \ "strb %%r0, [%[dst]]\n\t" \ "adds %[src], #1\n\t" \ "adds %[dst], #1\n\t" \ "subs %[len], #1\n\t" \ "bne 222b\n\t" \ "333:\n\t" \ RSEQ_INJECT_ASM(5) /* final store */ "str %[newv], %[v]\n\t" "2:\n\t" RSEQ_INJECT_ASM(6) /* teardown */ "ldr %[len], %[rseq_scratch2]\n\t" "ldr %[dst], %[rseq_scratch1]\n\t" "ldr %[src], %[rseq_scratch0]\n\t" "b 8f\n\t" RSEQ_ASM_DEFINE_ABORT(3, 4, /* teardown */ "ldr %[len], %[rseq_scratch2]\n\t" "ldr %[dst], %[rseq_scratch1]\n\t" "ldr %[src], %[rseq_scratch0]\n\t", abort, 1b, 2b, 4f) RSEQ_ASM_DEFINE_CMPFAIL(5, /* teardown */ "ldr %[len], %[rseq_scratch2]\n\t" "ldr %[dst], %[rseq_scratch1]\n\t" "ldr %[src], %[rseq_scratch0]\n\t", cmpfail) #ifdef RSEQ_COMPARE_TWICE RSEQ_ASM_DEFINE_CMPFAIL(6, /* teardown */ "ldr %[len], %[rseq_scratch2]\n\t" "ldr %[dst], %[rseq_scratch1]\n\t" "ldr %[src], %[rseq_scratch0]\n\t", error1) RSEQ_ASM_DEFINE_CMPFAIL(7, /* teardown */ "ldr %[len], %[rseq_scratch2]\n\t" "ldr %[dst], %[rseq_scratch1]\n\t" "ldr %[src], %[rseq_scratch0]\n\t", error2) #endif "8:\n\t" : /* 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), /* final store input */ [v] "m" (*v), [expect] "r" (expect), [newv] "r" (newv), /* try memcpy input */ [dst] "r" (dst), [src] "r" (src), [len] "r" (len), [rseq_scratch0] "m" (rseq_scratch[0]), [rseq_scratch1] "m" (rseq_scratch[1]), [rseq_scratch2] "m" (rseq_scratch[2]) RSEQ_INJECT_INPUT : "r0", "memory", "cc" RSEQ_INJECT_CLOBBER : abort, cmpfail #ifdef RSEQ_COMPARE_TWICE , error1, error2 #endif ); rseq_workaround_gcc_asm_size_guess(); return 0; abort: rseq_workaround_gcc_asm_size_guess(); RSEQ_INJECT_FAILED return -1; cmpfail: rseq_workaround_gcc_asm_size_guess(); return 1; #ifdef RSEQ_COMPARE_TWICE error1: rseq_workaround_gcc_asm_size_guess(); rseq_bug("cpu_id comparison failed"); error2: rseq_workaround_gcc_asm_size_guess(); rseq_bug("expected value comparison failed"); #endif } static inline __attribute__((always_inline)) int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect, void *dst, void *src, size_t len, intptr_t newv, int cpu) { uint32_t rseq_scratch[3]; RSEQ_INJECT_C(9) rseq_workaround_gcc_asm_size_guess(); __asm__ __volatile__ goto ( RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */ RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail]) #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" /* 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) RSEQ_INJECT_ASM(3) "ldr r0, %[v]\n\t" "cmp %[expect], r0\n\t" "bne 5f\n\t" RSEQ_INJECT_ASM(4) #ifdef RSEQ_COMPARE_TWICE RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, 6f) "ldr r0, %[v]\n\t" "cmp %[expect], r0\n\t" "bne 7f\n\t" #endif /* try memcpy */ "cmp %[len], #0\n\t" \ "beq 333f\n\t" \ "222:\n\t" \ "ldrb %%r0, [%[src]]\n\t" \ "strb %%r0, [%[dst]]\n\t" \ "adds %[src], #1\n\t" \ "adds %[dst], #1\n\t" \ "subs %[len], #1\n\t" \ "bne 222b\n\t" \ "333:\n\t" \ RSEQ_INJECT_ASM(5) "dmb\n\t" /* full mb provides store-release */ /* final store */ "str %[newv], %[v]\n\t" "2:\n\t" RSEQ_INJECT_ASM(6) /* teardown */ "ldr %[len], %[rseq_scratch2]\n\t" "ldr %[dst], %[rseq_scratch1]\n\t" "ldr %[src], %[rseq_scratch0]\n\t" "b 8f\n\t" RSEQ_ASM_DEFINE_ABORT(3, 4, /* teardown */ "ldr %[len], %[rseq_scratch2]\n\t" "ldr %[dst], %[rseq_scratch1]\n\t" "ldr %[src], %[rseq_scratch0]\n\t", abort, 1b, 2b, 4f) RSEQ_ASM_DEFINE_CMPFAIL(5, /* teardown */ "ldr %[len], %[rseq_scratch2]\n\t" "ldr %[dst], %[rseq_scratch1]\n\t" "ldr %[src], %[rseq_scratch0]\n\t", cmpfail) #ifdef RSEQ_COMPARE_TWICE RSEQ_ASM_DEFINE_CMPFAIL(6, /* teardown */ "ldr %[len], %[rseq_scratch2]\n\t" "ldr %[dst], %[rseq_scratch1]\n\t" "ldr %[src], %[rseq_scratch0]\n\t", error1) RSEQ_ASM_DEFINE_CMPFAIL(7, /* teardown */ "ldr %[len], %[rseq_scratch2]\n\t" "ldr %[dst], %[rseq_scratch1]\n\t" "ldr %[src], %[rseq_scratch0]\n\t", error2) #endif "8:\n\t" : /* 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), /* final store input */ [v] "m" (*v), [expect] "r" (expect), [newv] "r" (newv), /* try memcpy input */ [dst] "r" (dst), [src] "r" (src), [len] "r" (len), [rseq_scratch0] "m" (rseq_scratch[0]), [rseq_scratch1] "m" (rseq_scratch[1]), [rseq_scratch2] "m" (rseq_scratch[2]) RSEQ_INJECT_INPUT : "r0", "memory", "cc" RSEQ_INJECT_CLOBBER : abort, cmpfail #ifdef RSEQ_COMPARE_TWICE , error1, error2 #endif ); rseq_workaround_gcc_asm_size_guess(); return 0; abort: rseq_workaround_gcc_asm_size_guess(); RSEQ_INJECT_FAILED return -1; cmpfail: rseq_workaround_gcc_asm_size_guess(); return 1; #ifdef RSEQ_COMPARE_TWICE error1: rseq_workaround_gcc_asm_size_guess(); rseq_bug("cpu_id comparison failed"); error2: rseq_workaround_gcc_asm_size_guess(); rseq_bug("expected value comparison failed"); #endif } #endif /* !RSEQ_SKIP_FASTPATH */ |