diff options
| -rw-r--r-- | arch/riscv/Kconfig | 6 | ||||
| -rw-r--r-- | arch/riscv/Makefile | 4 | ||||
| -rw-r--r-- | arch/riscv/include/asm/asm.h | 6 | ||||
| -rw-r--r-- | arch/riscv/include/asm/scs.h | 47 | ||||
| -rw-r--r-- | arch/riscv/include/asm/thread_info.h | 13 | ||||
| -rw-r--r-- | arch/riscv/kernel/asm-offsets.c | 3 | ||||
| -rw-r--r-- | arch/riscv/kernel/entry.S | 11 | ||||
| -rw-r--r-- | arch/riscv/kernel/head.S | 4 | ||||
| -rw-r--r-- | arch/riscv/kernel/vdso/Makefile | 2 | ||||
| -rw-r--r-- | arch/riscv/purgatory/Makefile | 4 |
10 files changed, 99 insertions, 1 deletions
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index d607ab0f7c6d..2f14ccb5fb01 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -48,6 +48,7 @@ config RISCV select ARCH_SUPPORTS_HUGETLBFS if MMU select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU select ARCH_SUPPORTS_PER_VMA_LOCK if MMU + select ARCH_SUPPORTS_SHADOW_CALL_STACK if HAVE_SHADOW_CALL_STACK select ARCH_USE_MEMTEST select ARCH_USE_QUEUED_RWLOCKS select ARCH_USES_CFI_TRAPS if CFI_CLANG @@ -174,6 +175,11 @@ config GCC_SUPPORTS_DYNAMIC_FTRACE def_bool CC_IS_GCC depends on $(cc-option,-fpatchable-function-entry=8) +config HAVE_SHADOW_CALL_STACK + def_bool $(cc-option,-fsanitize=shadow-call-stack) + # https://github.com/riscv-non-isa/riscv-elf-psabi-doc/commit/a484e843e6eeb51f0cb7b8819e50da6d2444d769 + depends on $(ld-option,--no-relax-gp) + config ARCH_MMAP_RND_BITS_MIN default 18 if 64BIT default 8 diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile index 1329e060c548..304b94446507 100644 --- a/arch/riscv/Makefile +++ b/arch/riscv/Makefile @@ -55,6 +55,10 @@ endif endif endif +ifeq ($(CONFIG_SHADOW_CALL_STACK),y) + KBUILD_LDFLAGS += --no-relax-gp +endif + # ISA string setting riscv-march-$(CONFIG_ARCH_RV32I) := rv32ima riscv-march-$(CONFIG_ARCH_RV64I) := rv64ima diff --git a/arch/riscv/include/asm/asm.h b/arch/riscv/include/asm/asm.h index f34dd1a526a1..b0487b39e674 100644 --- a/arch/riscv/include/asm/asm.h +++ b/arch/riscv/include/asm/asm.h @@ -109,6 +109,11 @@ REG_L \dst, 0(\dst) .endm +#ifdef CONFIG_SHADOW_CALL_STACK +/* gp is used as the shadow call stack pointer instead */ +.macro load_global_pointer +.endm +#else /* load __global_pointer to gp */ .macro load_global_pointer .option push @@ -116,6 +121,7 @@ la gp, __global_pointer$ .option pop .endm +#endif /* CONFIG_SHADOW_CALL_STACK */ /* save all GPs except x1 ~ x5 */ .macro save_from_x6_to_x31 diff --git a/arch/riscv/include/asm/scs.h b/arch/riscv/include/asm/scs.h new file mode 100644 index 000000000000..94726ea773e3 --- /dev/null +++ b/arch/riscv/include/asm/scs.h @@ -0,0 +1,47 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_SCS_H +#define _ASM_SCS_H + +#ifdef __ASSEMBLY__ +#include <asm/asm-offsets.h> + +#ifdef CONFIG_SHADOW_CALL_STACK + +/* Load init_shadow_call_stack to gp. */ +.macro scs_load_init_stack + la gp, init_shadow_call_stack + XIP_FIXUP_OFFSET gp +.endm + +/* Load task_scs_sp(current) to gp. */ +.macro scs_load_current + REG_L gp, TASK_TI_SCS_SP(tp) +.endm + +/* Load task_scs_sp(current) to gp, but only if tp has changed. */ +.macro scs_load_current_if_task_changed prev + beq \prev, tp, _skip_scs + scs_load_current +_skip_scs: +.endm + +/* Save gp to task_scs_sp(current). */ +.macro scs_save_current + REG_S gp, TASK_TI_SCS_SP(tp) +.endm + +#else /* CONFIG_SHADOW_CALL_STACK */ + +.macro scs_load_init_stack +.endm +.macro scs_load_current +.endm +.macro scs_load_current_if_task_changed prev +.endm +.macro scs_save_current +.endm + +#endif /* CONFIG_SHADOW_CALL_STACK */ +#endif /* __ASSEMBLY__ */ + +#endif /* _ASM_SCS_H */ diff --git a/arch/riscv/include/asm/thread_info.h b/arch/riscv/include/asm/thread_info.h index d18ce0113ca1..574779900bfb 100644 --- a/arch/riscv/include/asm/thread_info.h +++ b/arch/riscv/include/asm/thread_info.h @@ -57,8 +57,20 @@ struct thread_info { long user_sp; /* User stack pointer */ int cpu; unsigned long syscall_work; /* SYSCALL_WORK_ flags */ +#ifdef CONFIG_SHADOW_CALL_STACK + void *scs_base; + void *scs_sp; +#endif }; +#ifdef CONFIG_SHADOW_CALL_STACK +#define INIT_SCS \ + .scs_base = init_shadow_call_stack, \ + .scs_sp = init_shadow_call_stack, +#else +#define INIT_SCS +#endif + /* * macros/functions for gaining access to the thread information structure * @@ -68,6 +80,7 @@ struct thread_info { { \ .flags = 0, \ .preempt_count = INIT_PREEMPT_COUNT, \ + INIT_SCS \ } void arch_release_task_struct(struct task_struct *tsk); diff --git a/arch/riscv/kernel/asm-offsets.c b/arch/riscv/kernel/asm-offsets.c index 0af8860f9d68..a03129f40c46 100644 --- a/arch/riscv/kernel/asm-offsets.c +++ b/arch/riscv/kernel/asm-offsets.c @@ -39,6 +39,9 @@ void asm_offsets(void) OFFSET(TASK_TI_PREEMPT_COUNT, task_struct, thread_info.preempt_count); OFFSET(TASK_TI_KERNEL_SP, task_struct, thread_info.kernel_sp); OFFSET(TASK_TI_USER_SP, task_struct, thread_info.user_sp); +#ifdef CONFIG_SHADOW_CALL_STACK + OFFSET(TASK_TI_SCS_SP, task_struct, thread_info.scs_sp); +#endif OFFSET(TASK_TI_CPU_NUM, task_struct, thread_info.cpu); OFFSET(TASK_THREAD_F0, task_struct, thread.fstate.f[0]); diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S index 6215dcf2e83b..52793193a763 100644 --- a/arch/riscv/kernel/entry.S +++ b/arch/riscv/kernel/entry.S @@ -9,6 +9,7 @@ #include <asm/asm.h> #include <asm/csr.h> +#include <asm/scs.h> #include <asm/unistd.h> #include <asm/page.h> #include <asm/thread_info.h> @@ -77,6 +78,9 @@ _save_context: /* Load the global pointer */ load_global_pointer + /* Load the kernel shadow call stack pointer if coming from userspace */ + scs_load_current_if_task_changed s5 + move a0, sp /* pt_regs */ la ra, ret_from_exception @@ -123,6 +127,9 @@ SYM_CODE_START_NOALIGN(ret_from_exception) addi s0, sp, PT_SIZE_ON_STACK REG_S s0, TASK_TI_KERNEL_SP(tp) + /* Save the kernel shadow call stack pointer */ + scs_save_current + /* * Save TP into the scratch register , so we can find the kernel data * structures again. @@ -275,6 +282,8 @@ SYM_FUNC_START(__switch_to) REG_S s9, TASK_THREAD_S9_RA(a3) REG_S s10, TASK_THREAD_S10_RA(a3) REG_S s11, TASK_THREAD_S11_RA(a3) + /* Save the kernel shadow call stack pointer */ + scs_save_current /* Restore context from next->thread */ REG_L ra, TASK_THREAD_RA_RA(a4) REG_L sp, TASK_THREAD_SP_RA(a4) @@ -292,6 +301,8 @@ SYM_FUNC_START(__switch_to) REG_L s11, TASK_THREAD_S11_RA(a4) /* The offset of thread_info in task_struct is zero. */ move tp, a1 + /* Switch to the next shadow call stack */ + scs_load_current ret SYM_FUNC_END(__switch_to) diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S index a0484d95d8fb..18f97ec0f7ed 100644 --- a/arch/riscv/kernel/head.S +++ b/arch/riscv/kernel/head.S @@ -14,6 +14,7 @@ #include <asm/cpu_ops_sbi.h> #include <asm/hwcap.h> #include <asm/image.h> +#include <asm/scs.h> #include <asm/xip_fixup.h> #include "efi-header.S" @@ -153,6 +154,7 @@ secondary_start_sbi: XIP_FIXUP_OFFSET a3 add a3, a3, a1 REG_L sp, (a3) + scs_load_current .Lsecondary_start_common: @@ -289,6 +291,7 @@ clear_bss_done: la sp, init_thread_union + THREAD_SIZE XIP_FIXUP_OFFSET sp addi sp, sp, -PT_SIZE_ON_STACK + scs_load_init_stack #ifdef CONFIG_BUILTIN_DTB la a0, __dtb_start XIP_FIXUP_OFFSET a0 @@ -307,6 +310,7 @@ clear_bss_done: la tp, init_task la sp, init_thread_union + THREAD_SIZE addi sp, sp, -PT_SIZE_ON_STACK + scs_load_current #ifdef CONFIG_KASAN call kasan_early_init diff --git a/arch/riscv/kernel/vdso/Makefile b/arch/riscv/kernel/vdso/Makefile index 6b1dba11bf6d..48c362c0cb3d 100644 --- a/arch/riscv/kernel/vdso/Makefile +++ b/arch/riscv/kernel/vdso/Makefile @@ -36,7 +36,7 @@ CPPFLAGS_vdso.lds += -DHAS_VGETTIMEOFDAY endif # Disable -pg to prevent insert call site -CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) +CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) $(CC_FLAGS_SCS) # Disable profiling and instrumentation for VDSO code GCOV_PROFILE := n diff --git a/arch/riscv/purgatory/Makefile b/arch/riscv/purgatory/Makefile index 9e6476719abb..6a3c16bd5ca3 100644 --- a/arch/riscv/purgatory/Makefile +++ b/arch/riscv/purgatory/Makefile @@ -81,6 +81,10 @@ ifdef CONFIG_CFI_CLANG PURGATORY_CFLAGS_REMOVE += $(CC_FLAGS_CFI) endif +ifdef CONFIG_SHADOW_CALL_STACK +PURGATORY_CFLAGS_REMOVE += $(CC_FLAGS_SCS) +endif + CFLAGS_REMOVE_purgatory.o += $(PURGATORY_CFLAGS_REMOVE) CFLAGS_purgatory.o += $(PURGATORY_CFLAGS) |