diff options
| -rw-r--r-- | arch/arm64/kernel/entry.S | 2 | ||||
| -rw-r--r-- | arch/arm64/kernel/head.S | 25 | ||||
| -rw-r--r-- | arch/arm64/kernel/process.c | 5 | ||||
| -rw-r--r-- | arch/arm64/kernel/stacktrace.c | 16 |
4 files changed, 32 insertions, 16 deletions
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 3513984a88bd..294f24e16fee 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -285,7 +285,7 @@ alternative_else_nop_endif stp lr, x21, [sp, #S_LR] /* - * For exceptions from EL0, create a terminal frame record. + * For exceptions from EL0, create a final frame record. * For exceptions from EL1, create a synthetic frame record so the * interrupted code shows up in the backtrace. */ diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index 96873dfa67fd..cc2d45d54838 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -16,6 +16,7 @@ #include <asm/asm_pointer_auth.h> #include <asm/assembler.h> #include <asm/boot.h> +#include <asm/bug.h> #include <asm/ptrace.h> #include <asm/asm-offsets.h> #include <asm/cache.h> @@ -393,6 +394,18 @@ SYM_FUNC_START_LOCAL(__create_page_tables) ret x28 SYM_FUNC_END(__create_page_tables) + /* + * Create a final frame record at task_pt_regs(current)->stackframe, so + * that the unwinder can identify the final frame record of any task by + * its location in the task stack. We reserve the entire pt_regs space + * for consistency with user tasks and kthreads. + */ + .macro setup_final_frame + sub sp, sp, #PT_REGS_SIZE + stp xzr, xzr, [sp, #S_STACKFRAME] + add x29, sp, #S_STACKFRAME + .endm + /* * The following fragment of code is executed with the MMU enabled. * @@ -447,9 +460,9 @@ SYM_FUNC_START_LOCAL(__primary_switched) #endif bl switch_to_vhe // Prefer VHE if possible add sp, sp, #16 - mov x29, #0 - mov x30, #0 - b start_kernel + setup_final_frame + bl start_kernel + ASM_BUG() SYM_FUNC_END(__primary_switched) .pushsection ".rodata", "a" @@ -639,14 +652,14 @@ SYM_FUNC_START_LOCAL(__secondary_switched) cbz x2, __secondary_too_slow msr sp_el0, x2 scs_load x2, x3 - mov x29, #0 - mov x30, #0 + setup_final_frame #ifdef CONFIG_ARM64_PTR_AUTH ptrauth_keys_init_cpu x2, x3, x4, x5 #endif - b secondary_start_kernel + bl secondary_start_kernel + ASM_BUG() SYM_FUNC_END(__secondary_switched) SYM_FUNC_START_LOCAL(__secondary_too_slow) diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index b4bb67f17a2c..8928fba54e4b 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -435,6 +435,11 @@ int copy_thread(unsigned long clone_flags, unsigned long stack_start, } p->thread.cpu_context.pc = (unsigned long)ret_from_fork; p->thread.cpu_context.sp = (unsigned long)childregs; + /* + * For the benefit of the unwinder, set up childregs->stackframe + * as the final frame for the new task. + */ + p->thread.cpu_context.fp = (unsigned long)childregs->stackframe; ptrace_hw_copy_thread(p); diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c index de07147a7926..36cf05d5eb9e 100644 --- a/arch/arm64/kernel/stacktrace.c +++ b/arch/arm64/kernel/stacktrace.c @@ -68,12 +68,16 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame) unsigned long fp = frame->fp; struct stack_info info; - if (fp & 0xf) - return -EINVAL; - if (!tsk) tsk = current; + /* Final frame; nothing to unwind */ + if (fp == (unsigned long)task_pt_regs(tsk)->stackframe) + return -ENOENT; + + if (fp & 0xf) + return -EINVAL; + if (!on_accessible_stack(tsk, fp, &info)) return -EINVAL; @@ -128,12 +132,6 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame) frame->pc = ptrauth_strip_insn_pac(frame->pc); - /* - * This is a terminal record, so we have finished unwinding. - */ - if (!frame->fp && !frame->pc) - return -ENOENT; - return 0; } NOKPROBE_SYMBOL(unwind_frame); |