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-rw-r--r--arch/arm/Kconfig8
-rw-r--r--arch/arm/Makefile9
-rw-r--r--arch/arm/include/asm/assembler.h29
-rw-r--r--arch/arm/include/asm/current.h50
-rw-r--r--arch/arm/include/asm/smp.h3
-rw-r--r--arch/arm/include/asm/stackprotector.h2
-rw-r--r--arch/arm/include/asm/switch_to.h16
-rw-r--r--arch/arm/include/asm/thread_info.h15
-rw-r--r--arch/arm/include/asm/tls.h10
-rw-r--r--arch/arm/kernel/asm-offsets.c6
-rw-r--r--arch/arm/kernel/entry-armv.S5
-rw-r--r--arch/arm/kernel/entry-common.S1
-rw-r--r--arch/arm/kernel/entry-header.S8
-rw-r--r--arch/arm/kernel/head-common.S5
-rw-r--r--arch/arm/kernel/head-nommu.S1
-rw-r--r--arch/arm/kernel/head.S5
-rw-r--r--arch/arm/kernel/process.c8
-rw-r--r--arch/arm/kernel/smp.c13
-rw-r--r--arch/arm/mm/proc-macros.S3
-rw-r--r--scripts/gcc-plugins/arm_ssp_per_task_plugin.c27
20 files changed, 174 insertions, 50 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index fc196421b2ce..4f61c9789e7f 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -125,6 +125,7 @@ config ARM
select PERF_USE_VMALLOC
select RTC_LIB
select SYS_SUPPORTS_APM_EMULATION
+ select THREAD_INFO_IN_TASK if CURRENT_POINTER_IN_TPIDRURO
select TRACE_IRQFLAGS_SUPPORT if !CPU_V7M
# Above selects are sorted alphabetically; please add new ones
# according to that. Thanks.
@@ -1157,6 +1158,11 @@ config SMP_ON_UP
If you don't know what to do here, say Y.
+
+config CURRENT_POINTER_IN_TPIDRURO
+ def_bool y
+ depends on SMP && CPU_32v6K && !CPU_V6
+
config ARM_CPU_TOPOLOGY
bool "Support cpu topology definition"
depends on SMP && CPU_V7
@@ -1600,7 +1606,7 @@ config XEN
config STACKPROTECTOR_PER_TASK
bool "Use a unique stack canary value for each task"
- depends on GCC_PLUGINS && STACKPROTECTOR && SMP && !XIP_DEFLATED_DATA
+ depends on GCC_PLUGINS && STACKPROTECTOR && THREAD_INFO_IN_TASK && !XIP_DEFLATED_DATA
select GCC_PLUGIN_ARM_SSP_PER_TASK
default y
help
diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index 847c31e7c368..1c540157e283 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -113,6 +113,10 @@ ifeq ($(CONFIG_CC_IS_CLANG),y)
CFLAGS_ABI += -meabi gnu
endif
+ifeq ($(CONFIG_CURRENT_POINTER_IN_TPIDRURO),y)
+CFLAGS_ABI += -mtp=cp15
+endif
+
# Accept old syntax despite ".syntax unified"
AFLAGS_NOWARN :=$(call as-option,-Wa$(comma)-mno-warn-deprecated,-Wa$(comma)-W)
@@ -273,11 +277,8 @@ ifeq ($(CONFIG_STACKPROTECTOR_PER_TASK),y)
prepare: stack_protector_prepare
stack_protector_prepare: prepare0
$(eval SSP_PLUGIN_CFLAGS := \
- -fplugin-arg-arm_ssp_per_task_plugin-tso=$(shell \
- awk '{if ($$2 == "THREAD_SZ_ORDER") print $$3;}'\
- include/generated/asm-offsets.h) \
-fplugin-arg-arm_ssp_per_task_plugin-offset=$(shell \
- awk '{if ($$2 == "TI_STACK_CANARY") print $$3;}'\
+ awk '{if ($$2 == "TSK_STACK_CANARY") print $$3;}'\
include/generated/asm-offsets.h))
$(eval KBUILD_CFLAGS += $(SSP_PLUGIN_CFLAGS))
$(eval GCC_PLUGINS_CFLAGS += $(SSP_PLUGIN_CFLAGS))
diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h
index e2b1fd558bf3..7d23d4bb2168 100644
--- a/arch/arm/include/asm/assembler.h
+++ b/arch/arm/include/asm/assembler.h
@@ -199,14 +199,43 @@
.endm
.endr
+ .macro get_current, rd
+#ifdef CONFIG_CURRENT_POINTER_IN_TPIDRURO
+ mrc p15, 0, \rd, c13, c0, 3 @ get TPIDRURO register
+#else
+ get_thread_info \rd
+ ldr \rd, [\rd, #TI_TASK]
+#endif
+ .endm
+
+ .macro set_current, rn
+#ifdef CONFIG_CURRENT_POINTER_IN_TPIDRURO
+ mcr p15, 0, \rn, c13, c0, 3 @ set TPIDRURO register
+#endif
+ .endm
+
+ .macro reload_current, t1:req, t2:req
+#ifdef CONFIG_CURRENT_POINTER_IN_TPIDRURO
+ adr_l \t1, __entry_task @ get __entry_task base address
+ mrc p15, 0, \t2, c13, c0, 4 @ get per-CPU offset
+ ldr \t1, [\t1, \t2] @ load variable
+ mcr p15, 0, \t1, c13, c0, 3 @ store in TPIDRURO
+#endif
+ .endm
+
/*
* Get current thread_info.
*/
.macro get_thread_info, rd
+#ifdef CONFIG_THREAD_INFO_IN_TASK
+ /* thread_info is the first member of struct task_struct */
+ get_current \rd
+#else
ARM( mov \rd, sp, lsr #THREAD_SIZE_ORDER + PAGE_SHIFT )
THUMB( mov \rd, sp )
THUMB( lsr \rd, \rd, #THREAD_SIZE_ORDER + PAGE_SHIFT )
mov \rd, \rd, lsl #THREAD_SIZE_ORDER + PAGE_SHIFT
+#endif
.endm
/*
diff --git a/arch/arm/include/asm/current.h b/arch/arm/include/asm/current.h
new file mode 100644
index 000000000000..1d472fa7697b
--- /dev/null
+++ b/arch/arm/include/asm/current.h
@@ -0,0 +1,50 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2021 Keith Packard <keithp@keithp.com>
+ * Copyright (c) 2021 Google, LLC <ardb@kernel.org>
+ */
+
+#ifndef _ASM_ARM_CURRENT_H
+#define _ASM_ARM_CURRENT_H
+
+#ifndef __ASSEMBLY__
+
+struct task_struct;
+
+static inline void set_current(struct task_struct *cur)
+{
+ if (!IS_ENABLED(CONFIG_CURRENT_POINTER_IN_TPIDRURO))
+ return;
+
+ /* Set TPIDRURO */
+ asm("mcr p15, 0, %0, c13, c0, 3" :: "r"(cur) : "memory");
+}
+
+#ifdef CONFIG_CURRENT_POINTER_IN_TPIDRURO
+
+static inline struct task_struct *get_current(void)
+{
+ struct task_struct *cur;
+
+#if __has_builtin(__builtin_thread_pointer)
+ /*
+ * Use the __builtin helper when available - this results in better
+ * code, especially when using GCC in combination with the per-task
+ * stack protector, as the compiler will recognize that it needs to
+ * load the TLS register only once in every function.
+ */
+ cur = __builtin_thread_pointer();
+#else
+ asm("mrc p15, 0, %0, c13, c0, 3" : "=r"(cur));
+#endif
+ return cur;
+}
+
+#define current get_current()
+#else
+#include <asm-generic/current.h>
+#endif /* CONFIG_CURRENT_POINTER_IN_TPIDRURO */
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* _ASM_ARM_CURRENT_H */
diff --git a/arch/arm/include/asm/smp.h b/arch/arm/include/asm/smp.h
index 5d508f5d56c4..f16cbbd5cda4 100644
--- a/arch/arm/include/asm/smp.h
+++ b/arch/arm/include/asm/smp.h
@@ -48,7 +48,7 @@ extern void set_smp_ipi_range(int ipi_base, int nr_ipi);
* Called from platform specific assembly code, this is the
* secondary CPU entry point.
*/
-asmlinkage void secondary_start_kernel(void);
+asmlinkage void secondary_start_kernel(struct task_struct *task);
/*
@@ -61,6 +61,7 @@ struct secondary_data {
};
unsigned long swapper_pg_dir;
void *stack;
+ struct task_struct *task;
};
extern struct secondary_data secondary_data;
extern void secondary_startup(void);
diff --git a/arch/arm/include/asm/stackprotector.h b/arch/arm/include/asm/stackprotector.h
index 72a20c3a0a90..088d03161be5 100644
--- a/arch/arm/include/asm/stackprotector.h
+++ b/arch/arm/include/asm/stackprotector.h
@@ -39,8 +39,6 @@ static __always_inline void boot_init_stack_canary(void)
current->stack_canary = canary;
#ifndef CONFIG_STACKPROTECTOR_PER_TASK
__stack_chk_guard = current->stack_canary;
-#else
- current_thread_info()->stack_canary = current->stack_canary;
#endif
}
diff --git a/arch/arm/include/asm/switch_to.h b/arch/arm/include/asm/switch_to.h
index 007d8fea7157..b55c7b2755e4 100644
--- a/arch/arm/include/asm/switch_to.h
+++ b/arch/arm/include/asm/switch_to.h
@@ -23,9 +23,25 @@
*/
extern struct task_struct *__switch_to(struct task_struct *, struct thread_info *, struct thread_info *);
+static inline void set_ti_cpu(struct task_struct *p)
+{
+#ifdef CONFIG_THREAD_INFO_IN_TASK
+ /*
+ * The core code no longer maintains the thread_info::cpu field once
+ * CONFIG_THREAD_INFO_IN_TASK is in effect, but we rely on it for
+ * raw_smp_processor_id(), which cannot access struct task_struct*
+ * directly for reasons of circular #inclusion hell.
+ */
+ task_thread_info(p)->cpu = task_cpu(p);
+#endif
+}
+
#define switch_to(prev,next,last) \
do { \
__complete_pending_tlbi(); \
+ set_ti_cpu(next); \
+ if (IS_ENABLED(CONFIG_CURRENT_POINTER_IN_TPIDRURO)) \
+ __this_cpu_write(__entry_task, next); \
last = __switch_to(prev,task_thread_info(prev), task_thread_info(next)); \
} while (0)
diff --git a/arch/arm/include/asm/thread_info.h b/arch/arm/include/asm/thread_info.h
index 9a18da3e10cc..787511396f3f 100644
--- a/arch/arm/include/asm/thread_info.h
+++ b/arch/arm/include/asm/thread_info.h
@@ -29,6 +29,8 @@
struct task_struct;
+DECLARE_PER_CPU(struct task_struct *, __entry_task);
+
#include <asm/types.h>
struct cpu_context_save {
@@ -52,12 +54,11 @@ struct cpu_context_save {
struct thread_info {
unsigned long flags; /* low level flags */
int preempt_count; /* 0 => preemptable, <0 => bug */
+#ifndef CONFIG_THREAD_INFO_IN_TASK
struct task_struct *task; /* main task structure */
+#endif
__u32 cpu; /* cpu */
__u32 cpu_domain; /* cpu domain */
-#ifdef CONFIG_STACKPROTECTOR_PER_TASK
- unsigned long stack_canary;
-#endif
struct cpu_context_save cpu_context; /* cpu context */
__u32 abi_syscall; /* ABI type and syscall nr */
__u8 used_cp[16]; /* thread used copro */
@@ -71,11 +72,16 @@ struct thread_info {
#define INIT_THREAD_INFO(tsk) \
{ \
- .task = &tsk, \
+ INIT_THREAD_INFO_TASK(tsk) \
.flags = 0, \
.preempt_count = INIT_PREEMPT_COUNT, \
}
+#ifdef CONFIG_THREAD_INFO_IN_TASK
+#define INIT_THREAD_INFO_TASK(tsk)
+#else
+#define INIT_THREAD_INFO_TASK(tsk) .task = &(tsk),
+
/*
* how to get the thread information struct from C
*/
@@ -86,6 +92,7 @@ static inline struct thread_info *current_thread_info(void)
return (struct thread_info *)
(current_stack_pointer & ~(THREAD_SIZE - 1));
}
+#endif
#define thread_saved_pc(tsk) \
((unsigned long)(task_thread_info(tsk)->cpu_context.pc))
diff --git a/arch/arm/include/asm/tls.h b/arch/arm/include/asm/tls.h
index 5a66c3b13c92..c3296499176c 100644
--- a/arch/arm/include/asm/tls.h
+++ b/arch/arm/include/asm/tls.h
@@ -12,8 +12,8 @@
.macro switch_tls_v6k, base, tp, tpuser, tmp1, tmp2
mrc p15, 0, \tmp2, c13, c0, 2 @ get the user r/w register
- mcr p15, 0, \tp, c13, c0, 3 @ set TLS register
- mcr p15, 0, \tpuser, c13, c0, 2 @ and the user r/w register
+ @ TLS register update is deferred until return to user space
+ mcr p15, 0, \tpuser, c13, c0, 2 @ set the user r/w register
str \tmp2, [\base, #TI_TP_VALUE + 4] @ save it
.endm
@@ -38,18 +38,22 @@
#ifdef CONFIG_TLS_REG_EMUL
#define tls_emu 1
#define has_tls_reg 1
+#define defer_tls_reg_update 0
#define switch_tls switch_tls_none
#elif defined(CONFIG_CPU_V6)
#define tls_emu 0
#define has_tls_reg (elf_hwcap & HWCAP_TLS)
+#define defer_tls_reg_update 0
#define switch_tls switch_tls_v6
#elif defined(CONFIG_CPU_32v6K)
#define tls_emu 0
#define has_tls_reg 1
+#define defer_tls_reg_update 1
#define switch_tls switch_tls_v6k
#else
#define tls_emu 0
#define has_tls_reg 0
+#define defer_tls_reg_update 0
#define switch_tls switch_tls_software
#endif
@@ -77,7 +81,7 @@ static inline void set_tls(unsigned long val)
*/
barrier();
- if (!tls_emu) {
+ if (!tls_emu && !defer_tls_reg_update) {
if (has_tls_reg) {
asm("mcr p15, 0, %0, c13, c0, 3"
: : "r" (val));
diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c
index a646a3f6440f..645845e4982a 100644
--- a/arch/arm/kernel/asm-offsets.c
+++ b/arch/arm/kernel/asm-offsets.c
@@ -43,7 +43,9 @@ int main(void)
BLANK();
DEFINE(TI_FLAGS, offsetof(struct thread_info, flags));
DEFINE(TI_PREEMPT, offsetof(struct thread_info, preempt_count));
+#ifndef CONFIG_THREAD_INFO_IN_TASK
DEFINE(TI_TASK, offsetof(struct thread_info, task));
+#endif
DEFINE(TI_CPU, offsetof(struct thread_info, cpu));
DEFINE(TI_CPU_DOMAIN, offsetof(struct thread_info, cpu_domain));
DEFINE(TI_CPU_SAVE, offsetof(struct thread_info, cpu_context));
@@ -63,10 +65,6 @@ int main(void)
#ifdef CONFIG_IWMMXT
DEFINE(TI_IWMMXT_STATE, offsetof(struct thread_info, fpstate.iwmmxt));
#endif
-#ifdef CONFIG_STACKPROTECTOR_PER_TASK
- DEFINE(TI_STACK_CANARY, offsetof(struct thread_info, stack_canary));
-#endif
- DEFINE(THREAD_SZ_ORDER, THREAD_SIZE_ORDER);
BLANK();
DEFINE(S_R0, offsetof(struct pt_regs, ARM_r0));
DEFINE(S_R1, offsetof(struct pt_regs, ARM_r1));
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index 241b73d64df7..a54b5044d406 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -384,6 +384,8 @@ ENDPROC(__fiq_abt)
ATRAP( teq r8, r7)
ATRAP( mcrne p15, 0, r8, c1, c0, 0)
+ reload_current r7, r8
+
@
@ Clear FP to mark the first stack frame
@
@@ -762,6 +764,8 @@ ENTRY(__switch_to)
add r7, r7, #TSK_STACK_CANARY & ~IMM12_MASK
.endif
ldr r7, [r7, #TSK_STACK_CANARY & IMM12_MASK]
+#elif defined(CONFIG_CURRENT_POINTER_IN_TPIDRURO)
+ mov r7, r2 @ Preserve 'next'
#endif
#ifdef CONFIG_CPU_USE_DOMAINS
mcr p15, 0, r6, c3, c0, 0 @ Set domain register
@@ -776,6 +780,7 @@ ENTRY(__switch_to)
#endif
THUMB( mov ip, r4 )
mov r0, r5
+ set_current r7
ARM( ldmia r4, {r4 - sl, fp, sp, pc} ) @ Load all regs saved previously
THUMB( ldmia ip!, {r4 - sl, fp} ) @ Load all regs saved previously
THUMB( ldr sp, [ip], #4 )
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index d9c99db50243..ac86c34682bb 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -170,6 +170,7 @@ ENTRY(vector_swi)
str saved_psr, [sp, #S_PSR] @ Save CPSR
str r0, [sp, #S_OLD_R0] @ Save OLD_R0
#endif
+ reload_current r10, ip
zero_fp
alignment_trap r10, ip, __cr_alignment
asm_trace_hardirqs_on save=0
diff --git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S
index 40db0f9188b6..ae24dd54e9ef 100644
--- a/arch/arm/kernel/entry-header.S
+++ b/arch/arm/kernel/entry-header.S
@@ -292,6 +292,14 @@
.macro restore_user_regs, fast = 0, offset = 0
+#if defined(CONFIG_CPU_32v6K) && !defined(CONFIG_CPU_V6)
+ @ The TLS register update is deferred until return to user space so we
+ @ can use it for other things while running in the kernel
+ get_thread_info r1
+ ldr r1, [r1, #TI_TP_VALUE]
+ mcr p15, 0, r1, c13, c0, 3 @ set TLS register
+#endif
+
uaccess_enable r1, isb=0
#ifndef CONFIG_THUMB2_KERNEL
@ ARM mode restore
diff --git a/arch/arm/kernel/head-common.S b/arch/arm/kernel/head-common.S
index 29b2eda136bb..da18e0a17dc2 100644
--- a/arch/arm/kernel/head-common.S
+++ b/arch/arm/kernel/head-common.S
@@ -105,6 +105,11 @@ __mmap_switched:
mov r1, #0
bl __memset @ clear .bss
+#ifdef CONFIG_CURRENT_POINTER_IN_TPIDRURO
+ adr_l r0, init_task @ get swapper task_struct
+ set_current r0
+#endif
+
ldmia r4, {r0, r1, r2, r3}
str r9, [r0] @ Save processor ID
str r7, [r1] @ Save machine type
diff --git a/arch/arm/kernel/head-nommu.S b/arch/arm/kernel/head-nommu.S
index 0fc814bbc34b..fadfee9e2b45 100644
--- a/arch/arm/kernel/head-nommu.S
+++ b/arch/arm/kernel/head-nommu.S
@@ -115,6 +115,7 @@ ENTRY(secondary_startup)
ret r12
1: bl __after_proc_init
ldr sp, [r7, #12] @ set up the stack pointer
+ ldr r0, [r7, #16] @ set up task pointer
mov fp, #0
b secondary_start_kernel
ENDPROC(secondary_startup)
diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index 29070eb8df7d..fa44e2d9f0b0 100644
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -424,8 +424,9 @@ ENDPROC(secondary_startup)
ENDPROC(secondary_startup_arm)
ENTRY(__secondary_switched)
- ldr_l r7, secondary_data + 12 @ get secondary_data.stack
- mov sp, r7
+ adr_l r7, secondary_data + 12 @ get secondary_data.stack
+ ldr sp, [r7]
+ ldr r0, [r7, #4] @ get secondary_data.task
mov fp, #0
b secondary_start_kernel
ENDPROC(__secondary_switched)
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 0e2d3051741e..30428d756515 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -36,6 +36,10 @@
#include "signal.h"
+#ifdef CONFIG_CURRENT_POINTER_IN_TPIDRURO
+DEFINE_PER_CPU(struct task_struct *, __entry_task);
+#endif
+
#if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_STACKPROTECTOR_PER_TASK)
#include <linux/stackprotector.h>
unsigned long __stack_chk_guard __read_mostly;
@@ -269,10 +273,6 @@ int copy_thread(unsigned long clone_flags, unsigned long stack_start,
thread_notify(THREAD_NOTIFY_COPY, thread);
-#ifdef CONFIG_STACKPROTECTOR_PER_TASK
- thread->stack_canary = p->stack_canary;
-#endif
-
return 0;
}
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 842427ff2b3c..cde5b6d8bac5 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -153,6 +153,10 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle)
secondary_data.pgdir = virt_to_phys(idmap_pgd);
secondary_data.swapper_pg_dir = get_arch_pgd(swapper_pg_dir);
#endif
+ secondary_data.task = idle;
+ if (IS_ENABLED(CONFIG_THREAD_INFO_IN_TASK))
+ task_thread_info(idle)->cpu = cpu;
+
sync_cache_w(&secondary_data);
/*
@@ -375,9 +379,12 @@ void arch_cpu_idle_dead(void)
*/
__asm__("mov sp, %0\n"
" mov fp, #0\n"
+ " mov r0, %1\n"
" b secondary_start_kernel"
:
- : "r" (task_stack_page(current) + THREAD_SIZE - 8));
+ : "r" (task_stack_page(current) + THREAD_SIZE - 8),
+ "r" (current)
+ : "r0");
}
#endif /* CONFIG_HOTPLUG_CPU */
@@ -400,11 +407,13 @@ static void smp_store_cpu_info(unsigned int cpuid)
* This is the secondary CPU boot entry. We're using this CPUs
* idle thread stack, but a set of temporary page tables.
*/
-asmlinkage void secondary_start_kernel(void)
+asmlinkage void secondary_start_kernel(struct task_struct *task)
{
struct mm_struct *mm = &init_mm;
unsigned int cpu;
+ set_current(task);
+
secondary_biglittle_init();
/*
diff --git a/arch/arm/mm/proc-macros.S b/arch/arm/mm/proc-macros.S
index e2c743aa2eb2..d48ba99d739c 100644
--- a/arch/arm/mm/proc-macros.S
+++ b/arch/arm/mm/proc-macros.S
@@ -30,8 +30,7 @@
* act_mm - get current->active_mm
*/
.macro act_mm, rd
- get_thread_info \rd
- ldr \rd, [\rd, #TI_TASK]
+ get_current \rd
.if (TSK_ACTIVE_MM > IMM12_MASK)
add \rd, \rd, #TSK_ACTIVE_MM & ~IMM12_MASK
.endif
diff --git a/scripts/gcc-plugins/arm_ssp_per_task_plugin.c b/scripts/gcc-plugins/arm_ssp_per_task_plugin.c
index 8c1af9bdcb1b..7328d037f975 100644
--- a/scripts/gcc-plugins/arm_ssp_per_task_plugin.c
+++ b/scripts/gcc-plugins/arm_ssp_per_task_plugin.c
@@ -4,7 +4,7 @@
__visible int plugin_is_GPL_compatible;
-static unsigned int sp_mask, canary_offset;
+static unsigned int canary_offset;
static unsigned int arm_pertask_ssp_rtl_execute(void)
{
@@ -13,7 +13,7 @@ static unsigned int arm_pertask_ssp_rtl_execute(void)
for (insn = get_insns(); insn; insn = NEXT_INSN(insn)) {
const char *sym;
rtx body;
- rtx mask, masked_sp;
+ rtx current;
/*
* Find a SET insn involving a SYMBOL_REF to __stack_chk_guard
@@ -30,19 +30,13 @@ static unsigned int arm_pertask_ssp_rtl_execute(void)
/*
* 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
+ * produces the address of the current task's stack canary value
*/
- mask = GEN_INT(sext_hwi(sp_mask, GET_MODE_PRECISION(Pmode)));
- masked_sp = gen_reg_rtx(Pmode);
+ current = gen_reg_rtx(Pmode);
- emit_insn_before(gen_rtx_set(masked_sp,
- gen_rtx_AND(Pmode,
- stack_pointer_rtx,
- mask)),
- insn);
+ emit_insn_before(gen_load_tp_hard(current), insn);
- SET_SRC(body) = gen_rtx_PLUS(Pmode, masked_sp,
+ SET_SRC(body) = gen_rtx_PLUS(Pmode, current,
GEN_INT(canary_offset));
}
return 0;
@@ -72,7 +66,6 @@ __visible int plugin_init(struct plugin_name_args *plugin_info,
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)) {
@@ -91,11 +84,6 @@ __visible int plugin_init(struct plugin_name_args *plugin_info,
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;
@@ -105,9 +93,6 @@ __visible int plugin_init(struct plugin_name_args *plugin_info,
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,