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// SPDX-License-Identifier: GPL-2.0
#include "gcc-common.h"
__visible int plugin_is_GPL_compatible;
static unsigned int sp_mask, canary_offset;
static unsigned int arm_pertask_ssp_rtl_execute(void)
{
rtx_insn *insn;
for (insn = get_insns(); insn; insn = NEXT_INSN(insn)) {
const char *sym;
rtx body;
rtx mask, masked_sp;
/*
* Find a SET insn involving a SYMBOL_REF to __stack_chk_guard
*/
if (!INSN_P(insn))
continue;
body = PATTERN(insn);
if (GET_CODE(body) != SET ||
GET_CODE(SET_SRC(body)) != SYMBOL_REF)
continue;
sym = XSTR(SET_SRC(body), 0);
if (strcmp(sym, "__stack_chk_guard"))
continue;
/*
* Replace the source of the SET insn with an expression that
* produces the address of the copy of the stack canary value
* stored in struct thread_info
*/
mask = GEN_INT(sext_hwi(sp_mask, GET_MODE_PRECISION(Pmode)));
masked_sp = gen_reg_rtx(Pmode);
emit_insn_before(gen_rtx_SET(masked_sp,
gen_rtx_AND(Pmode,
stack_pointer_rtx,
mask)),
insn);
SET_SRC(body) = gen_rtx_PLUS(Pmode, masked_sp,
GEN_INT(canary_offset));
}
return 0;
}
#define PASS_NAME arm_pertask_ssp_rtl
#define NO_GATE
#include "gcc-generate-rtl-pass.h"
#if BUILDING_GCC_VERSION >= 9000
static bool no(void)
{
return false;
}
static void arm_pertask_ssp_start_unit(void *gcc_data, void *user_data)
{
targetm.have_stack_protect_combined_set = no;
targetm.have_stack_protect_combined_test = no;
}
#endif
__visible int plugin_init(struct plugin_name_args *plugin_info,
struct plugin_gcc_version *version)
{
const char * const plugin_name = plugin_info->base_name;
const int argc = plugin_info->argc;
const struct plugin_argument *argv = plugin_info->argv;
int tso = 0;
int i;
if (!plugin_default_version_check(version, &gcc_version)) {
error(G_("incompatible gcc/plugin versions"));
return 1;
}
for (i = 0; i < argc; ++i) {
if (!strcmp(argv[i].key, "disable"))
return 0;
/* all remaining options require a value */
if (!argv[i].value) {
error(G_("no value supplied for option '-fplugin-arg-%s-%s'"),
plugin_name, argv[i].key);
return 1;
}
if (!strcmp(argv[i].key, "tso")) {
tso = atoi(argv[i].value);
continue;
}
if (!strcmp(argv[i].key, "offset")) {
canary_offset = atoi(argv[i].value);
continue;
}
error(G_("unknown option '-fplugin-arg-%s-%s'"),
plugin_name, argv[i].key);
return 1;
}
/* create the mask that produces the base of the stack */
sp_mask = ~((1U << (12 + tso)) - 1);
PASS_INFO(arm_pertask_ssp_rtl, "expand", 1, PASS_POS_INSERT_AFTER);
register_callback(plugin_info->base_name, PLUGIN_PASS_MANAGER_SETUP,
NULL, &arm_pertask_ssp_rtl_pass_info);
#if BUILDING_GCC_VERSION >= 9000
register_callback(plugin_info->base_name, PLUGIN_START_UNIT,
arm_pertask_ssp_start_unit, NULL);
#endif
return 0;
}
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