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189af465 AB |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | ||
3 | #include "gcc-common.h" | |
4 | ||
5 | __visible int plugin_is_GPL_compatible; | |
6 | ||
7 | static unsigned int sp_mask, canary_offset; | |
8 | ||
9 | static unsigned int arm_pertask_ssp_rtl_execute(void) | |
10 | { | |
11 | rtx_insn *insn; | |
12 | ||
13 | for (insn = get_insns(); insn; insn = NEXT_INSN(insn)) { | |
14 | const char *sym; | |
15 | rtx body; | |
560706d5 | 16 | rtx mask, masked_sp; |
189af465 AB |
17 | |
18 | /* | |
19 | * Find a SET insn involving a SYMBOL_REF to __stack_chk_guard | |
20 | */ | |
21 | if (!INSN_P(insn)) | |
22 | continue; | |
23 | body = PATTERN(insn); | |
24 | if (GET_CODE(body) != SET || | |
25 | GET_CODE(SET_SRC(body)) != SYMBOL_REF) | |
26 | continue; | |
27 | sym = XSTR(SET_SRC(body), 0); | |
28 | if (strcmp(sym, "__stack_chk_guard")) | |
29 | continue; | |
30 | ||
31 | /* | |
32 | * Replace the source of the SET insn with an expression that | |
33 | * produces the address of the copy of the stack canary value | |
34 | * stored in struct thread_info | |
35 | */ | |
560706d5 | 36 | mask = GEN_INT(sext_hwi(sp_mask, GET_MODE_PRECISION(Pmode))); |
189af465 AB |
37 | masked_sp = gen_reg_rtx(Pmode); |
38 | ||
259799ea | 39 | emit_insn_before(gen_rtx_set(masked_sp, |
189af465 AB |
40 | gen_rtx_AND(Pmode, |
41 | stack_pointer_rtx, | |
560706d5 | 42 | mask)), |
189af465 AB |
43 | insn); |
44 | ||
45 | SET_SRC(body) = gen_rtx_PLUS(Pmode, masked_sp, | |
46 | GEN_INT(canary_offset)); | |
47 | } | |
48 | return 0; | |
49 | } | |
50 | ||
51 | #define PASS_NAME arm_pertask_ssp_rtl | |
52 | ||
53 | #define NO_GATE | |
54 | #include "gcc-generate-rtl-pass.h" | |
55 | ||
2c88c742 AB |
56 | #if BUILDING_GCC_VERSION >= 9000 |
57 | static bool no(void) | |
58 | { | |
59 | return false; | |
60 | } | |
61 | ||
62 | static void arm_pertask_ssp_start_unit(void *gcc_data, void *user_data) | |
63 | { | |
64 | targetm.have_stack_protect_combined_set = no; | |
65 | targetm.have_stack_protect_combined_test = no; | |
66 | } | |
67 | #endif | |
68 | ||
189af465 AB |
69 | __visible int plugin_init(struct plugin_name_args *plugin_info, |
70 | struct plugin_gcc_version *version) | |
71 | { | |
72 | const char * const plugin_name = plugin_info->base_name; | |
73 | const int argc = plugin_info->argc; | |
74 | const struct plugin_argument *argv = plugin_info->argv; | |
75 | int tso = 0; | |
76 | int i; | |
77 | ||
78 | if (!plugin_default_version_check(version, &gcc_version)) { | |
79 | error(G_("incompatible gcc/plugin versions")); | |
80 | return 1; | |
81 | } | |
82 | ||
83 | for (i = 0; i < argc; ++i) { | |
84 | if (!strcmp(argv[i].key, "disable")) | |
85 | return 0; | |
86 | ||
87 | /* all remaining options require a value */ | |
88 | if (!argv[i].value) { | |
89 | error(G_("no value supplied for option '-fplugin-arg-%s-%s'"), | |
90 | plugin_name, argv[i].key); | |
91 | return 1; | |
92 | } | |
93 | ||
94 | if (!strcmp(argv[i].key, "tso")) { | |
95 | tso = atoi(argv[i].value); | |
96 | continue; | |
97 | } | |
98 | ||
99 | if (!strcmp(argv[i].key, "offset")) { | |
100 | canary_offset = atoi(argv[i].value); | |
101 | continue; | |
102 | } | |
103 | error(G_("unknown option '-fplugin-arg-%s-%s'"), | |
104 | plugin_name, argv[i].key); | |
105 | return 1; | |
106 | } | |
107 | ||
108 | /* create the mask that produces the base of the stack */ | |
109 | sp_mask = ~((1U << (12 + tso)) - 1); | |
110 | ||
111 | PASS_INFO(arm_pertask_ssp_rtl, "expand", 1, PASS_POS_INSERT_AFTER); | |
112 | ||
113 | register_callback(plugin_info->base_name, PLUGIN_PASS_MANAGER_SETUP, | |
114 | NULL, &arm_pertask_ssp_rtl_pass_info); | |
115 | ||
2c88c742 AB |
116 | #if BUILDING_GCC_VERSION >= 9000 |
117 | register_callback(plugin_info->base_name, PLUGIN_START_UNIT, | |
118 | arm_pertask_ssp_start_unit, NULL); | |
119 | #endif | |
120 | ||
189af465 AB |
121 | return 0; |
122 | } |