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linuxdebug/tools/testing/selftests/rseq/rseq-arm.h

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null pointer error
2024-07-16 15:50:57 +02:00
/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
/*
* rseq-arm.h
*
* (C) Copyright 2016-2018 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
*/
/*
* - ARM little endian
*
* 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>
*
* - 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"
static inline __attribute__((always_inline))
int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
{
RSEQ_INJECT_C(9)
__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_get_abi()->cpu_id),
[rseq_cs] "m" (rseq_get_abi()->rseq_cs.arch.ptr),
[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_after_asm_goto();
return 0;
abort:
rseq_after_asm_goto();
RSEQ_INJECT_FAILED
return -1;
cmpfail:
rseq_after_asm_goto();
return 1;
#ifdef RSEQ_COMPARE_TWICE
error1:
rseq_after_asm_goto();
rseq_bug("cpu_id comparison failed");
error2:
rseq_after_asm_goto();
rseq_bug("expected value comparison failed");
#endif
}
static inline __attribute__((always_inline))
int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
long voffp, intptr_t *load, int cpu)
{
RSEQ_INJECT_C(9)
__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_get_abi()->cpu_id),
[rseq_cs] "m" (rseq_get_abi()->rseq_cs.arch.ptr),
/* 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_after_asm_goto();
return 0;
abort:
rseq_after_asm_goto();
RSEQ_INJECT_FAILED
return -1;
cmpfail:
rseq_after_asm_goto();
return 1;
#ifdef RSEQ_COMPARE_TWICE
error1:
rseq_after_asm_goto();
rseq_bug("cpu_id comparison failed");
error2:
rseq_after_asm_goto();
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)
__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_get_abi()->cpu_id),
[rseq_cs] "m" (rseq_get_abi()->rseq_cs.arch.ptr),
[v] "m" (*v),
[count] "Ir" (count)
RSEQ_INJECT_INPUT
: "r0", "memory", "cc"
RSEQ_INJECT_CLOBBER
: abort
#ifdef RSEQ_COMPARE_TWICE
, error1
#endif
);
rseq_after_asm_goto();
return 0;
abort:
rseq_after_asm_goto();
RSEQ_INJECT_FAILED
return -1;
#ifdef RSEQ_COMPARE_TWICE
error1:
rseq_after_asm_goto();
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)
__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_get_abi()->cpu_id),
[rseq_cs] "m" (rseq_get_abi()->rseq_cs.arch.ptr),
/* 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_after_asm_goto();
return 0;
abort:
rseq_after_asm_goto();
RSEQ_INJECT_FAILED
return -1;
cmpfail:
rseq_after_asm_goto();
return 1;
#ifdef RSEQ_COMPARE_TWICE
error1:
rseq_after_asm_goto();
rseq_bug("cpu_id comparison failed");
error2:
rseq_after_asm_goto();
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)
__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_get_abi()->cpu_id),
[rseq_cs] "m" (rseq_get_abi()->rseq_cs.arch.ptr),
/* 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_after_asm_goto();
return 0;
abort:
rseq_after_asm_goto();
RSEQ_INJECT_FAILED
return -1;
cmpfail:
rseq_after_asm_goto();
return 1;
#ifdef RSEQ_COMPARE_TWICE
error1:
rseq_after_asm_goto();
rseq_bug("cpu_id comparison failed");
error2:
rseq_after_asm_goto();
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)
__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_get_abi()->cpu_id),
[rseq_cs] "m" (rseq_get_abi()->rseq_cs.arch.ptr),
/* 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_after_asm_goto();
return 0;
abort:
rseq_after_asm_goto();
RSEQ_INJECT_FAILED
return -1;
cmpfail:
rseq_after_asm_goto();
return 1;
#ifdef RSEQ_COMPARE_TWICE
error1:
rseq_after_asm_goto();
rseq_bug("cpu_id comparison failed");
error2:
rseq_after_asm_goto();
rseq_bug("1st expected value comparison failed");
error3:
rseq_after_asm_goto();
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)
__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_get_abi()->cpu_id),
[rseq_cs] "m" (rseq_get_abi()->rseq_cs.arch.ptr),
/* 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_after_asm_goto();
return 0;
abort:
rseq_after_asm_goto();
RSEQ_INJECT_FAILED
return -1;
cmpfail:
rseq_after_asm_goto();
return 1;
#ifdef RSEQ_COMPARE_TWICE
error1:
rseq_after_asm_goto();
rseq_bug("cpu_id comparison failed");
error2:
rseq_after_asm_goto();
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)
__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_get_abi()->cpu_id),
[rseq_cs] "m" (rseq_get_abi()->rseq_cs.arch.ptr),
/* 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_after_asm_goto();
return 0;
abort:
rseq_after_asm_goto();
RSEQ_INJECT_FAILED
return -1;
cmpfail:
rseq_after_asm_goto();
return 1;
#ifdef RSEQ_COMPARE_TWICE
error1:
rseq_after_asm_goto();
rseq_bug("cpu_id comparison failed");
error2:
rseq_after_asm_goto();
rseq_bug("expected value comparison failed");
#endif
}
#endif /* !RSEQ_SKIP_FASTPATH */