Commit 06a8c353 authored by Yong Cong Sin's avatar Yong Cong Sin Committed by Anas Nashif
Browse files

arch: x86: implement `arch_stack_walk()` 



Currently it supports `esf` based unwinding only.

Then, update the exception stack unwinding to use
`arch_stack_walk()`, and update the Kconfigs & testcase
accordingly.

Signed-off-by: default avatarYong Cong Sin <ycsin@meta.com>
Signed-off-by: default avatarYong Cong Sin <yongcong.sin@gmail.com>
parent 6fae891c

arch/x86/core/Kconfig.ia32

+3 −2
Original line number Diff line number Diff line
@@ -163,14 +163,15 @@ config X86_DYNAMIC_IRQ_STUBS 


endmenu



config X86_EXCEPTION_STACK_TRACE

config ARCH_HAS_STACKWALK

	bool

	default y

	select DEBUG_INFO

	select THREAD_STACK_INFO

	depends on !OMIT_FRAME_POINTER

	help

	  Internal config to enable runtime stack traces on fatal exceptions.

	  Internal config to indicate that the arch_stack_walk() API is implemented

	  and it can be enabled.



config X86_USE_THREAD_LOCAL_STORAGE

	bool

arch/x86/core/Kconfig.intel64

+3 −2
Original line number Diff line number Diff line
@@ -29,7 +29,7 @@ config X86_EXCEPTION_STACK_SIZE 
	  support limited call-tree depth and must fit into the low core,

	  so they are typically smaller than the ISR stacks.



config X86_EXCEPTION_STACK_TRACE

config ARCH_HAS_STACKWALK

	bool

	default y

	select DEBUG_INFO
@@ -37,7 +37,8 @@ config X86_EXCEPTION_STACK_TRACE 
	depends on !OMIT_FRAME_POINTER

	depends on NO_OPTIMIZATIONS

	help

	  Internal config to enable runtime stack traces on fatal exceptions.

	  Internal config to indicate that the arch_stack_walk() API is implemented

	  and it can be enabled.



config SCHED_IPI_VECTOR

	int "IDT vector to use for scheduler IPI"

arch/x86/core/fatal.c

+70 −33
Original line number Diff line number Diff line
@@ -84,7 +84,7 @@ bool z_x86_check_stack_bounds(uintptr_t addr, size_t size, uint16_t cs) 


	return (addr <= start) || (addr + size > end);

}

#endif

#endif /* CONFIG_THREAD_STACK_INFO */



#ifdef CONFIG_THREAD_STACK_MEM_MAPPED

/**
@@ -120,18 +120,9 @@ bool z_x86_check_guard_page(uintptr_t addr) 
}

#endif /* CONFIG_THREAD_STACK_MEM_MAPPED */



#ifdef CONFIG_EXCEPTION_DEBUG

#if defined(CONFIG_ARCH_STACKWALK)

typedef bool (*x86_stacktrace_cb)(void *cookie, unsigned long addr, unsigned long arg);



static inline uintptr_t esf_get_code(const struct arch_esf *esf)

{

#ifdef CONFIG_X86_64

	return esf->code;

#else

	return esf->errorCode;

#endif

}



#if defined(CONFIG_EXCEPTION_STACK_TRACE)

struct stack_frame {

	uintptr_t next;

	uintptr_t ret_addr;
@@ -140,20 +131,31 @@ struct stack_frame { 
#endif

};



#define MAX_STACK_FRAMES CONFIG_EXCEPTION_STACK_TRACE_MAX_FRAMES



__pinned_func

static void unwind_stack(uintptr_t base_ptr, uint16_t cs)

__pinned_func static void walk_stackframe(x86_stacktrace_cb cb, void *cookie,

					  const struct arch_esf *esf, int max_frames)

{

	uintptr_t base_ptr;

	uint16_t cs;

	struct stack_frame *frame;

	int i;



	if (esf != NULL) {

#ifdef CONFIG_X86_64

		base_ptr = esf->rbp;

#else /* x86 32-bit */

		base_ptr = esf->ebp;

#endif /* CONFIG_X86_64 */

		cs = esf->cs;

	} else {

		return;

	}



	if (base_ptr == 0U) {

		LOG_ERR("NULL base ptr");

		return;

	}



	for (i = 0; i < MAX_STACK_FRAMES; i++) {

	for (i = 0; i < max_frames; i++) {

		if (base_ptr % sizeof(base_ptr) != 0U) {

			LOG_ERR("unaligned frame ptr");

			return;
@@ -178,16 +180,59 @@ static void unwind_stack(uintptr_t base_ptr, uint16_t cs) 
		if (frame->ret_addr == 0U) {

			break;

		}



		if (!cb(cookie, frame->ret_addr,

			COND_CODE_1(CONFIG_X86_64, (0), (frame->args)))) {

			break;

		}



		base_ptr = frame->next;

	}

}



void arch_stack_walk(stack_trace_callback_fn callback_fn, void *cookie,

		     const struct k_thread *thread, const struct arch_esf *esf)

{

	ARG_UNUSED(thread);



	walk_stackframe((x86_stacktrace_cb)callback_fn, cookie, esf,

			CONFIG_ARCH_STACKWALK_MAX_FRAMES);

}

#endif /* CONFIG_ARCH_STACKWALK */



#if defined(CONFIG_EXCEPTION_STACK_TRACE)

static bool print_trace_address(void *arg, unsigned long addr, unsigned long args)

{

	int *i = arg;



#ifdef CONFIG_X86_64

		LOG_ERR("     0x%016lx", frame->ret_addr);

	LOG_ERR("     %d: 0x%016lx", (*i)++, addr);

#else

		LOG_ERR("     0x%08lx (0x%lx)", frame->ret_addr, frame->args);

	LOG_ERR("     %d: 0x%08lx (0x%lx)", (*i)++, addr, args);

#endif

		base_ptr = frame->next;



	return true;

}



__pinned_func

static void unwind_stack(const struct arch_esf *esf)

{

	int i = 0;



	walk_stackframe(print_trace_address, &i, esf, CONFIG_ARCH_STACKWALK_MAX_FRAMES);

}

#endif /* CONFIG_EXCEPTION_STACK_TRACE */



#ifdef CONFIG_EXCEPTION_DEBUG

static inline uintptr_t esf_get_code(const struct arch_esf *esf)

{

#ifdef CONFIG_X86_64

	return esf->code;

#else

	return esf->errorCode;

#endif

}



static inline uintptr_t get_cr3(const struct arch_esf *esf)

{

#if defined(CONFIG_USERSPACE) && defined(CONFIG_X86_KPTI)
@@ -226,13 +271,7 @@ static void dump_regs(const struct arch_esf *esf) 
	LOG_ERR("RSP: 0x%016lx RFLAGS: 0x%016lx CS: 0x%04lx CR3: 0x%016lx",

		esf->rsp, esf->rflags, esf->cs & 0xFFFFU, get_cr3(esf));



#ifdef CONFIG_EXCEPTION_STACK_TRACE

	LOG_ERR("call trace:");

#endif

	LOG_ERR("RIP: 0x%016lx", esf->rip);

#ifdef CONFIG_EXCEPTION_STACK_TRACE

	unwind_stack(esf->rbp, esf->cs);

#endif

}

#else /* 32-bit */

__pinned_func
@@ -245,13 +284,7 @@ static void dump_regs(const struct arch_esf *esf) 
	LOG_ERR("EFLAGS: 0x%08x CS: 0x%04x CR3: 0x%08lx", esf->eflags,

		esf->cs & 0xFFFFU, get_cr3(esf));



#ifdef CONFIG_EXCEPTION_STACK_TRACE

	LOG_ERR("call trace:");

#endif

	LOG_ERR("EIP: 0x%08x", esf->eip);

#ifdef CONFIG_EXCEPTION_STACK_TRACE

	unwind_stack(esf->ebp, esf->cs);

#endif

}

#endif /* CONFIG_X86_64 */
@@ -368,6 +401,10 @@ FUNC_NORETURN void z_x86_fatal_error(unsigned int reason, 
#ifdef CONFIG_EXCEPTION_DEBUG

		dump_regs(esf);

#endif

#ifdef CONFIG_EXCEPTION_STACK_TRACE

		LOG_ERR("call trace:");

		unwind_stack(esf);

#endif /* CONFIG_EXCEPTION_STACK_TRACE */

#if defined(CONFIG_ASSERT) && defined(CONFIG_X86_64)

		if (esf->rip == 0xb9) {

			/* See implementation of __resume in locore.S. This is

subsys/debug/Kconfig

+1 −2
Original line number Diff line number Diff line
@@ -381,8 +381,7 @@ config DEBUG_INFO 
config EXCEPTION_STACK_TRACE

	bool "Attempt to print stack traces upon exceptions"

	default y

	depends on (X86_EXCEPTION_STACK_TRACE || \

		    ARM64_EXCEPTION_STACK_TRACE) || ARCH_STACKWALK

	depends on ARM64_EXCEPTION_STACK_TRACE || ARCH_STACKWALK

	help

	  If the architecture fatal handling code supports it, attempt to

	  print a stack trace of function memory addresses when an

tests/arch/common/stack_unwind/testcase.yaml

+2 −1
Original line number Diff line number Diff line
@@ -42,7 +42,8 @@ tests: 
      type: multi_line

      regex:

        - "E: call trace:"

        - "E: (E|R)IP: \\w+"

        - "E:      0: \\w+"

        - "E:      1: \\w+"

  arch.common.stack_unwind.arm64:

    arch_allow:

      - arm64

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