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Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
1/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
2
3/*
4 * RSEQ_SIG uses the trap4 instruction. As Linux does not make use of the
5 * access-register mode nor the linkage stack this instruction will always
6 * cause a special-operation exception (the trap-enabled bit in the DUCT
7 * is and will stay 0). The instruction pattern is
8 * b2 ff 0f ff trap4 4095(%r0)
9 */
10#define RSEQ_SIG 0xB2FF0FFF
11
12#define rseq_smp_mb() __asm__ __volatile__ ("bcr 15,0" ::: "memory")
13#define rseq_smp_rmb() rseq_smp_mb()
14#define rseq_smp_wmb() rseq_smp_mb()
15
16#define rseq_smp_load_acquire(p) \
17__extension__ ({ \
18 rseq_unqual_scalar_typeof(*(p)) ____p1 = RSEQ_READ_ONCE(*(p)); \
19 rseq_barrier(); \
20 ____p1; \
21})
22
23#define rseq_smp_acquire__after_ctrl_dep() rseq_smp_rmb()
24
25#define rseq_smp_store_release(p, v) \
26do { \
27 rseq_barrier(); \
28 RSEQ_WRITE_ONCE(*(p), v); \
29} while (0)
30
31#define LONG_L "lg"
32#define LONG_S "stg"
33#define LONG_LT_R "ltgr"
34#define LONG_CMP "cg"
35#define LONG_CMP_R "cgr"
36#define LONG_ADDI "aghi"
37#define LONG_ADD_R "agr"
38
39#define __RSEQ_ASM_DEFINE_TABLE(label, version, flags, \
40 start_ip, post_commit_offset, abort_ip) \
41 ".pushsection __rseq_cs, \"aw\"\n\t" \
42 ".balign 32\n\t" \
43 __rseq_str(label) ":\n\t" \
44 ".long " __rseq_str(version) ", " __rseq_str(flags) "\n\t" \
45 ".quad " __rseq_str(start_ip) ", " __rseq_str(post_commit_offset) ", " __rseq_str(abort_ip) "\n\t" \
46 ".popsection\n\t" \
47 ".pushsection __rseq_cs_ptr_array, \"aw\"\n\t" \
48 ".quad " __rseq_str(label) "b\n\t" \
49 ".popsection\n\t"
50
51/*
52 * Exit points of a rseq critical section consist of all instructions outside
53 * of the critical section where a critical section can either branch to or
54 * reach through the normal course of its execution. The abort IP and the
55 * post-commit IP are already part of the __rseq_cs section and should not be
56 * explicitly defined as additional exit points. Knowing all exit points is
57 * useful to assist debuggers stepping over the critical section.
58 */
59#define RSEQ_ASM_DEFINE_EXIT_POINT(start_ip, exit_ip) \
60 ".pushsection __rseq_exit_point_array, \"aw\"\n\t" \
61 ".quad " __rseq_str(start_ip) ", " __rseq_str(exit_ip) "\n\t" \
62 ".popsection\n\t"
63
64#define RSEQ_ASM_DEFINE_TABLE(label, start_ip, post_commit_ip, abort_ip) \
65 __RSEQ_ASM_DEFINE_TABLE(label, 0x0, 0x0, start_ip, \
66 (post_commit_ip - start_ip), abort_ip)
67
68#define RSEQ_ASM_STORE_RSEQ_CS(label, cs_label, rseq_cs) \
69 RSEQ_INJECT_ASM(1) \
70 "larl %%r0, " __rseq_str(cs_label) "\n\t" \
71 LONG_S " %%r0, %[" __rseq_str(rseq_cs) "]\n\t" \
72 __rseq_str(label) ":\n\t"
73
74#define RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, label) \
75 RSEQ_INJECT_ASM(2) \
76 "c %[" __rseq_str(cpu_id) "], %[" __rseq_str(current_cpu_id) "]\n\t" \
77 "jnz " __rseq_str(label) "\n\t"
78
79#define RSEQ_ASM_DEFINE_ABORT(label, teardown, abort_label) \
80 ".pushsection __rseq_failure, \"ax\"\n\t" \
81 ".long " __rseq_str(RSEQ_SIG) "\n\t" \
82 __rseq_str(label) ":\n\t" \
83 teardown \
84 "jg %l[" __rseq_str(abort_label) "]\n\t" \
85 ".popsection\n\t"
86
87#define RSEQ_ASM_DEFINE_CMPFAIL(label, teardown, cmpfail_label) \
88 ".pushsection __rseq_failure, \"ax\"\n\t" \
89 __rseq_str(label) ":\n\t" \
90 teardown \
91 "jg %l[" __rseq_str(cmpfail_label) "]\n\t" \
92 ".popsection\n\t"
93
94/* Per-cpu-id indexing. */
95
96#define RSEQ_TEMPLATE_CPU_ID
97#define RSEQ_TEMPLATE_MO_RELAXED
98#include "rseq-s390-bits.h"
99#undef RSEQ_TEMPLATE_MO_RELAXED
100
101#define RSEQ_TEMPLATE_MO_RELEASE
102#include "rseq-s390-bits.h"
103#undef RSEQ_TEMPLATE_MO_RELEASE
104#undef RSEQ_TEMPLATE_CPU_ID
105
106/* Per-mm-cid indexing. */
107
108#define RSEQ_TEMPLATE_MM_CID
109#define RSEQ_TEMPLATE_MO_RELAXED
110#include "rseq-s390-bits.h"
111#undef RSEQ_TEMPLATE_MO_RELAXED
112
113#define RSEQ_TEMPLATE_MO_RELEASE
114#include "rseq-s390-bits.h"
115#undef RSEQ_TEMPLATE_MO_RELEASE
116#undef RSEQ_TEMPLATE_MM_CID
117
118/* APIs which are not based on cpu ids. */
119
120#define RSEQ_TEMPLATE_CPU_ID_NONE
121#define RSEQ_TEMPLATE_MO_RELAXED
122#include "rseq-s390-bits.h"
123#undef RSEQ_TEMPLATE_MO_RELAXED
124#undef RSEQ_TEMPLATE_CPU_ID_NONE