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 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; |
16 | rtx current; |
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 current task's stack canary value |
34 | */ |
35 | current = gen_reg_rtx(Pmode); |
36 | |
37 | emit_insn_before(gen_load_tp_hard(current), insn); |
38 | |
39 | SET_SRC(body) = gen_rtx_PLUS(Pmode, current, |
40 | GEN_INT(canary_offset)); |
41 | } |
42 | return 0; |
43 | } |
44 | |
45 | #define PASS_NAME arm_pertask_ssp_rtl |
46 | |
47 | #define NO_GATE |
48 | #include "gcc-generate-rtl-pass.h" |
49 | |
50 | #if BUILDING_GCC_VERSION >= 9000 |
51 | static bool no(void) |
52 | { |
53 | return false; |
54 | } |
55 | |
56 | static void arm_pertask_ssp_start_unit(void *gcc_data, void *user_data) |
57 | { |
58 | targetm.have_stack_protect_combined_set = no; |
59 | targetm.have_stack_protect_combined_test = no; |
60 | } |
61 | #endif |
62 | |
63 | __visible int plugin_init(struct plugin_name_args *plugin_info, |
64 | struct plugin_gcc_version *version) |
65 | { |
66 | const char * const plugin_name = plugin_info->base_name; |
67 | const int argc = plugin_info->argc; |
68 | const struct plugin_argument *argv = plugin_info->argv; |
69 | int i; |
70 | |
71 | if (!plugin_default_version_check(version, &gcc_version)) { |
72 | error(G_("incompatible gcc/plugin versions" )); |
73 | return 1; |
74 | } |
75 | |
76 | for (i = 0; i < argc; ++i) { |
77 | if (!strcmp(argv[i].key, "disable" )) |
78 | return 0; |
79 | |
80 | /* all remaining options require a value */ |
81 | if (!argv[i].value) { |
82 | error(G_("no value supplied for option '-fplugin-arg-%s-%s'" ), |
83 | plugin_name, argv[i].key); |
84 | return 1; |
85 | } |
86 | |
87 | if (!strcmp(argv[i].key, "offset" )) { |
88 | canary_offset = atoi(argv[i].value); |
89 | continue; |
90 | } |
91 | error(G_("unknown option '-fplugin-arg-%s-%s'" ), |
92 | plugin_name, argv[i].key); |
93 | return 1; |
94 | } |
95 | |
96 | PASS_INFO(arm_pertask_ssp_rtl, "expand" , 1, PASS_POS_INSERT_AFTER); |
97 | |
98 | register_callback(plugin_info->base_name, PLUGIN_PASS_MANAGER_SETUP, |
99 | NULL, &arm_pertask_ssp_rtl_pass_info); |
100 | |
101 | #if BUILDING_GCC_VERSION >= 9000 |
102 | register_callback(plugin_info->base_name, PLUGIN_START_UNIT, |
103 | arm_pertask_ssp_start_unit, NULL); |
104 | #endif |
105 | |
106 | return 0; |
107 | } |
108 | |