mirror of
https://github.com/torvalds/linux.git
synced 2024-12-01 16:41:39 +00:00
dfbdcda280
We will be enabling THREAD_INFO_IN_TASK support for ARM, which means that we can no longer load the stack canary value by masking the stack pointer and taking the copy that lives in thread_info. Instead, we will be able to load it from the task_struct directly, by using the TPIDRURO register which will hold the current task pointer when THREAD_INFO_IN_TASK is in effect. This is much more straight-forward, and allows us to declutter this code a bit while at it. Note that this means that ARMv6 (non-v6K) SMP systems can no longer use this feature, but those are quite rare to begin with, so this is a reasonable trade off. Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
108 lines
2.4 KiB
C
108 lines
2.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
|
|
#include "gcc-common.h"
|
|
|
|
__visible int plugin_is_GPL_compatible;
|
|
|
|
static unsigned int 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 current;
|
|
|
|
/*
|
|
* 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 current task's stack canary value
|
|
*/
|
|
current = gen_reg_rtx(Pmode);
|
|
|
|
emit_insn_before(gen_load_tp_hard(current), insn);
|
|
|
|
SET_SRC(body) = gen_rtx_PLUS(Pmode, current,
|
|
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 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, "offset")) {
|
|
canary_offset = atoi(argv[i].value);
|
|
continue;
|
|
}
|
|
error(G_("unknown option '-fplugin-arg-%s-%s'"),
|
|
plugin_name, argv[i].key);
|
|
return 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;
|
|
}
|