/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
/*
* RSEQ_SIG uses the trap4 instruction. As Linux does not make use of the
* access-register mode nor the linkage stack this instruction will always
* cause a special-operation exception (the trap-enabled bit in the DUCT
* is and will stay 0). The instruction pattern is
* b2 ff 0f ff trap4 4095(%r0)
*/
#define RSEQ_SIG 0xB2FF0FFF
#define rseq_smp_mb() __asm__ __volatile__ ("bcr 15,0" ::: "memory")
#define rseq_smp_rmb() rseq_smp_mb()
#define rseq_smp_wmb() rseq_smp_mb()
#define rseq_smp_load_acquire(p) \
__extension__ ({ \
__typeof(*p) ____p1 = RSEQ_READ_ONCE(*p); \
rseq_barrier(); \
____p1; \
})
#define rseq_smp_acquire__after_ctrl_dep() rseq_smp_rmb()
#define rseq_smp_store_release(p, v) \
do { \
rseq_barrier(); \
RSEQ_WRITE_ONCE(*p, v); \
} while (0)
#ifdef RSEQ_SKIP_FASTPATH
#include "rseq-skip.h"
#else /* !RSEQ_SKIP_FASTPATH */
#ifdef __s390x__
#define LONG_L "lg"
#define LONG_S "stg"
#define LONG_LT_R "ltgr"
#define LONG_CMP "cg"
#define LONG_CMP_R "cgr"
#define LONG_ADDI "aghi"
#define LONG_ADD_R "agr"
#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" \
".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_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"
#define LONG_S "st"
#define LONG_LT_R "ltr"
#define LONG_CMP "c"
#define LONG_CMP_R "cr"
#define LONG_ADDI "ahi"
#define LONG_ADD_R "ar"
#endif
#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)
#define RSEQ_ASM_STORE_RSEQ_CS(label, cs_label, rseq_cs) \
RSEQ_INJECT_ASM(1) \
"larl %%r0, " __rseq_str(cs_label) "\n\t" \
LONG_S " %%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) \
"c %[" __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" \
".long " __rseq_str(RSEQ_SIG) "\n\t" \
__rseq_str(label) ":\n\t" \
teardown \
"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 \
"jg %l[" __rseq_str(cmpfail_label) "]\n\t" \
".popsection\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(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_INJECT_ASM(3)
LONG_CMP " %[expect], %[v]\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])
LONG_CMP " %[expect], %[v]\n\t"
"jnz %l[error2]\n\t"
#endif
/* final store */
LONG_S " %[newv], %[v]\n\t"
"2:\n\t"
RSEQ_INJECT_ASM(5)
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),
[v] "m" (*v),
[expect] "r" (expect),
[newv] "r" (newv)
RSEQ_INJECT_INPUT
: "memory", "cc", "r0"
RSEQ_INJECT_CLOBBER
: abort, cmpfail
#ifdef RSEQ_COMPARE_TWICE
, error1, error2
#endif
);
return 0;
abort:
RSEQ_INJECT_FAILED
return -1;
cmpfail:
return 1;
#ifdef RSEQ_COMPARE_TWICE
error1:
rseq_bug("cpu_id comparison failed");
error2:
rseq_bug("expected value comparison failed");
#endif
}
/*
* Compare @v against @expectnot. When it does _not_ match, load @v
* into @load, and store the content of *@v + voffp into @v.
*/
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)
__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_INJECT_ASM(3)
LONG_L " %%r1, %[v]\n\t"
LONG_CMP_R " %%r1, %[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])
LONG_L " %%r1, %[v]\n\t"
LONG_CMP_R " %%r1, %[expectnot]\n\t"
"je %l[error2]\n\t"
#endif
LONG_S " %%r1, %[load]\n\t"
LONG_ADD_R " %%r1, %[voffp]\n\t"
LONG_L " %%r1, 0(%%r1)\n\t"
/* final store */
LONG_S " %%r1, %[v]\n\t"
"2:\n\t"
RSEQ_INJECT_ASM(5)
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),
/* final store input */
[v] "m" (*v),
[expectnot] "r" (expectnot),
[voffp] "r" (voffp),
[load] "m" (*load)
RSEQ_INJECT_INPUT
: "memory", "cc", "r0", "r1"
RSEQ_INJECT_CLOBBER
: abort, cmpfail
#ifdef RSEQ_COMPARE_TWICE
, error1, error2
#endif
);
return 0;
abort:
RSEQ_INJECT_FAILED
return -1;
cmpfail:
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)
__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_INJECT_ASM(3)
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, %l[error1])
#endif
LONG_L " %%r0, %[v]\n\t"
LONG_ADD_R " %%r0, %[count]\n\t"
/* final store */
LONG_S " %%r0, %[v]\n\t"
"2:\n\t"
RSEQ_INJECT_ASM(4)
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),
/* final store input */
[v] "m" (*v),
[count] "r" (count)
RSEQ_INJECT_INPUT
: "memory", "cc", "r0"
RSEQ_INJECT_CLOBBER
: abort
#ifdef RSEQ_COMPARE_TWICE
, error1
#endif
);
return 0;
abort:
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)
__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_INJECT_ASM(3)
LONG_CMP " %[expect], %[v]\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])
LONG_CMP " %[expect], %[v]\n\t"
"jnz %l[error2]\n\t"
#endif
/* try store */
LONG_S " %[newv2], %[v2]\n\t"
RSEQ_INJECT_ASM(5)
/* final store */
LONG_S " %[newv], %[v]\n\t"
"2:\n\t"
RSEQ_INJECT_ASM(6)
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),
/* try store input */
[v2] "m" (*v2),
[newv2] "r" (newv2),
/* final store input */
[v] "m" (*v),
[expect] "r" (expect),
[newv] "r" (newv)
RSEQ_INJECT_INPUT
: "memory", "cc", "r0"
RSEQ_INJECT_CLOBBER
: abort, cmpfail
#ifdef RSEQ_COMPARE_TWICE
, error1, error2
#endif
);
return 0;
abort:
RSEQ_INJECT_FAILED
return -1;
cmpfail:
return 1;
#ifdef RSEQ_COMPARE_TWICE
error1:
rseq_bug("cpu_id comparison failed");
error2:
rseq_bug("expected value comparison failed");
#endif
}
/* s390 is TSO. */
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)
{
return rseq_cmpeqv_trystorev_storev(v, expect, v2, newv2, newv, cpu);
}
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(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_INJECT_ASM(3)
LONG_CMP " %[expect], %[v]\n\t"
"jnz %l[cmpfail]\n\t"
RSEQ_INJECT_ASM(4)
LONG_CMP " %[expect2], %[v2]\n\t"
"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])
LONG_CMP " %[expect], %[v]\n\t"
"jnz %l[error2]\n\t"
LONG_CMP " %[expect2], %[v2]\n\t"
"jnz %l[error3]\n\t"
#endif
/* final store */
LONG_S " %[newv], %[v]\n\t"
"2:\n\t"
RSEQ_INJECT_ASM(6)
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),
/* cmp2 input */
[v2] "m" (*v2),
[expect2] "r" (expect2),
/* final store input */
[v] "m" (*v),
[expect] "r" (expect),
[newv] "r" (newv)
RSEQ_INJECT_INPUT
: "memory", "cc", "r0"
RSEQ_INJECT_CLOBBER
: abort, cmpfail
#ifdef RSEQ_COMPARE_TWICE
, error1, error2, error3
#endif
);
return 0;
abort:
RSEQ_INJECT_FAILED
return -1;
cmpfail:
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)
{
uint64_t rseq_scratch[3];
RSEQ_INJECT_C(9)
__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"
/* 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_INJECT_ASM(3)
LONG_CMP " %[expect], %[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)
LONG_CMP " %[expect], %[v]\n\t"
"jnz 7f\n\t"
#endif
/* try memcpy */
LONG_LT_R " %[len], %[len]\n\t"
"jz 333f\n\t"
"222:\n\t"
"ic %%r0,0(%[src])\n\t"
"stc %%r0,0(%[dst])\n\t"
LONG_ADDI " %[src], 1\n\t"
LONG_ADDI " %[dst], 1\n\t"
LONG_ADDI " %[len], -1\n\t"
"jnz 222b\n\t"
"333:\n\t"
RSEQ_INJECT_ASM(5)
/* final store */
LONG_S " %[newv], %[v]\n\t"
"2:\n\t"
RSEQ_INJECT_ASM(6)
/* teardown */
LONG_L " %[len], %[rseq_scratch2]\n\t"
LONG_L " %[dst], %[rseq_scratch1]\n\t"
LONG_L " %[src], %[rseq_scratch0]\n\t"
RSEQ_ASM_DEFINE_ABORT(4,
LONG_L " %[len], %[rseq_scratch2]\n\t"
LONG_L " %[dst], %[rseq_scratch1]\n\t"
LONG_L " %[src], %[rseq_scratch0]\n\t",
abort)
RSEQ_ASM_DEFINE_CMPFAIL(5,
LONG_L " %[len], %[rseq_scratch2]\n\t"
LONG_L " %[dst], %[rseq_scratch1]\n\t"
LONG_L " %[src], %[rseq_scratch0]\n\t",
cmpfail)
#ifdef RSEQ_COMPARE_TWICE
RSEQ_ASM_DEFINE_CMPFAIL(6,
LONG_L " %[len], %[rseq_scratch2]\n\t"
LONG_L " %[dst], %[rseq_scratch1]\n\t"
LONG_L " %[src], %[rseq_scratch0]\n\t",
error1)
RSEQ_ASM_DEFINE_CMPFAIL(7,
LONG_L " %[len], %[rseq_scratch2]\n\t"
LONG_L " %[dst], %[rseq_scratch1]\n\t"
LONG_L " %[src], %[rseq_scratch0]\n\t",
error2)
#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),
/* 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
: "memory", "cc", "r0"
RSEQ_INJECT_CLOBBER
: abort, cmpfail
#ifdef RSEQ_COMPARE_TWICE
, error1, error2
#endif
);
return 0;
abort:
RSEQ_INJECT_FAILED
return -1;
cmpfail:
return 1;
#ifdef RSEQ_COMPARE_TWICE
error1:
rseq_bug("cpu_id comparison failed");
error2:
rseq_bug("expected value comparison failed");
#endif
}
/* s390 is TSO. */
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)
{
return rseq_cmpeqv_trymemcpy_storev(v, expect, dst, src, len,
newv, cpu);
}
#endif /* !RSEQ_SKIP_FASTPATH */
