.. code-block:: none
SYM_CODE_START(return_to_handler)
- UNWIND_HINT_EMPTY
+ UNWIND_HINT_UNDEFINED
subq $24, %rsp
/* Save the return values */
*/
movq %rsp, %rdi
movq PER_CPU_VAR(cpu_tss_rw + TSS_sp0), %rsp
- UNWIND_HINT_EMPTY
+ UNWIND_HINT_END_OF_STACK
pushq RSP-RDI(%rdi) /* RSP */
pushq (%rdi) /* RDI */
.pushsection .text, "ax"
__FUNC_ALIGN
SYM_CODE_START_NOALIGN(ret_from_fork)
- UNWIND_HINT_EMPTY
+ UNWIND_HINT_END_OF_STACK
ANNOTATE_NOENDBR // copy_thread
CALL_DEPTH_ACCOUNT
movq %rax, %rdi
1:
/* kernel thread */
- UNWIND_HINT_EMPTY
+ UNWIND_HINT_END_OF_STACK
movq %r12, %rdi
CALL_NOSPEC rbx
/*
*/
movq %rsp, %rdi
movq PER_CPU_VAR(cpu_tss_rw + TSS_sp0), %rsp
- UNWIND_HINT_EMPTY
+ UNWIND_HINT_END_OF_STACK
/* Copy the IRET frame to the trampoline stack. */
pushq 6*8(%rdi) /* SS */
*/
__FUNC_ALIGN
SYM_CODE_START_NOALIGN(xen_failsafe_callback)
- UNWIND_HINT_EMPTY
+ UNWIND_HINT_UNDEFINED
ENDBR
movl %ds, %ecx
cmpw %cx, 0x10(%rsp)
* MSRs to fully disable 32-bit SYSCALL.
*/
SYM_CODE_START(ignore_sysret)
- UNWIND_HINT_EMPTY
+ UNWIND_HINT_END_OF_STACK
ENDBR
mov $-ENOSYS, %eax
sysretl
#define ORC_REG_SP_INDIRECT 9
#define ORC_REG_MAX 15
-#define ORC_TYPE_CALL 0
-#define ORC_TYPE_REGS 1
-#define ORC_TYPE_REGS_PARTIAL 2
+#define ORC_TYPE_UNDEFINED 0
+#define ORC_TYPE_END_OF_STACK 1
+#define ORC_TYPE_CALL 2
+#define ORC_TYPE_REGS 3
+#define ORC_TYPE_REGS_PARTIAL 4
#ifndef __ASSEMBLY__
#include <asm/byteorder.h>
#if defined(__LITTLE_ENDIAN_BITFIELD)
unsigned sp_reg:4;
unsigned bp_reg:4;
- unsigned type:2;
+ unsigned type:3;
unsigned signal:1;
- unsigned end:1;
#elif defined(__BIG_ENDIAN_BITFIELD)
unsigned bp_reg:4;
unsigned sp_reg:4;
unsigned unused:4;
- unsigned end:1;
unsigned signal:1;
- unsigned type:2;
+ unsigned type:3;
#endif
} __packed;
#ifdef __ASSEMBLY__
-.macro UNWIND_HINT_EMPTY
- UNWIND_HINT type=UNWIND_HINT_TYPE_CALL end=1
+.macro UNWIND_HINT_END_OF_STACK
+ UNWIND_HINT type=UNWIND_HINT_TYPE_END_OF_STACK
+.endm
+
+.macro UNWIND_HINT_UNDEFINED
+ UNWIND_HINT type=UNWIND_HINT_TYPE_UNDEFINED
.endm
.macro UNWIND_HINT_ENTRY
VALIDATE_UNRET_BEGIN
- UNWIND_HINT_EMPTY
+ UNWIND_HINT_END_OF_STACK
.endm
.macro UNWIND_HINT_REGS base=%rsp offset=0 indirect=0 extra=1 partial=0 signal=1
#else
#define UNWIND_HINT_FUNC \
- UNWIND_HINT(UNWIND_HINT_TYPE_FUNC, ORC_REG_SP, 8, 0, 0)
+ UNWIND_HINT(UNWIND_HINT_TYPE_FUNC, ORC_REG_SP, 8, 0)
#endif /* __ASSEMBLY__ */
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
SYM_CODE_START(return_to_handler)
- UNWIND_HINT_EMPTY
+ UNWIND_HINT_UNDEFINED
ANNOTATE_NOENDBR
subq $16, %rsp
__HEAD
.code64
SYM_CODE_START_NOALIGN(startup_64)
- UNWIND_HINT_EMPTY
+ UNWIND_HINT_END_OF_STACK
/*
* At this point the CPU runs in 64bit mode CS.L = 1 CS.D = 0,
* and someone has loaded an identity mapped page table
lretq
.Lon_kernel_cs:
- UNWIND_HINT_EMPTY
+ UNWIND_HINT_END_OF_STACK
/* Sanitize CPU configuration */
call verify_cpu
SYM_CODE_END(startup_64)
SYM_CODE_START(secondary_startup_64)
- UNWIND_HINT_EMPTY
+ UNWIND_HINT_END_OF_STACK
ANNOTATE_NOENDBR
/*
* At this point the CPU runs in 64bit mode CS.L = 1 CS.D = 0,
* verify_cpu() above to make sure NX is enabled.
*/
SYM_INNER_LABEL(secondary_startup_64_no_verify, SYM_L_GLOBAL)
- UNWIND_HINT_EMPTY
+ UNWIND_HINT_END_OF_STACK
ANNOTATE_NOENDBR
/*
ANNOTATE_RETPOLINE_SAFE
jmp *%rax
1:
- UNWIND_HINT_EMPTY
+ UNWIND_HINT_END_OF_STACK
ANNOTATE_NOENDBR // above
/*
*/
SYM_CODE_START(start_cpu0)
ANNOTATE_NOENDBR
- UNWIND_HINT_EMPTY
+ UNWIND_HINT_END_OF_STACK
movq initial_stack(%rip), %rsp
jmp .Ljump_to_C_code
SYM_CODE_END(start_cpu0)
.code64
SYM_CODE_START_NOALIGN(relocate_range)
SYM_CODE_START_NOALIGN(relocate_kernel)
- UNWIND_HINT_EMPTY
+ UNWIND_HINT_END_OF_STACK
ANNOTATE_NOENDBR
/*
* %rdi indirection_page
SYM_CODE_END(relocate_kernel)
SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
- UNWIND_HINT_EMPTY
+ UNWIND_HINT_END_OF_STACK
/* set return address to 0 if not preserving context */
pushq $0
/* store the start address on the stack */
SYM_CODE_END(identity_mapped)
SYM_CODE_START_LOCAL_NOALIGN(virtual_mapped)
- UNWIND_HINT_EMPTY
+ UNWIND_HINT_END_OF_STACK
ANNOTATE_NOENDBR // RET target, above
movq RSP(%r8), %rsp
movq CR4(%r8), %rax
/* Do the copies */
SYM_CODE_START_LOCAL_NOALIGN(swap_pages)
- UNWIND_HINT_EMPTY
- movq %rdi, %rcx /* Put the page_list in %rcx */
+ UNWIND_HINT_END_OF_STACK
+ movq %rdi, %rcx /* Put the page_list in %rcx */
xorl %edi, %edi
xorl %esi, %esi
jmp 1f
.sp_offset = 16,
.bp_reg = ORC_REG_PREV_SP,
.bp_offset = -16,
- .end = 0,
};
static struct orc_entry *orc_find(unsigned long ip)
return -1;
/*
- * The "weak" section terminator entries need to always be on the left
+ * The "weak" section terminator entries need to always be first
* to ensure the lookup code skips them in favor of real entries.
* These terminator entries exist to handle any gaps created by
* whitelisted .o files which didn't get objtool generation.
*/
orc_a = cur_orc_table + (a - cur_orc_ip_table);
- return orc_a->sp_reg == ORC_REG_UNDEFINED && !orc_a->end ? -1 : 1;
+ return orc_a->type == ORC_TYPE_UNDEFINED ? -1 : 1;
}
void unwind_module_init(struct module *mod, void *_orc_ip, size_t orc_ip_size,
*/
orc = &orc_fp_entry;
state->error = true;
- }
-
- /* End-of-stack check for kernel threads: */
- if (orc->sp_reg == ORC_REG_UNDEFINED) {
- if (!orc->end)
+ } else {
+ if (orc->type == ORC_TYPE_UNDEFINED)
goto err;
- goto the_end;
+ if (orc->type == ORC_TYPE_END_OF_STACK)
+ goto the_end;
}
state->signal = orc->signal;
.align RETPOLINE_THUNK_SIZE
SYM_INNER_LABEL(__x86_indirect_thunk_\reg, SYM_L_GLOBAL)
- UNWIND_HINT_EMPTY
+ UNWIND_HINT_UNDEFINED
ANNOTATE_NOENDBR
ALTERNATIVE_2 __stringify(RETPOLINE \reg), \
.align RETPOLINE_THUNK_SIZE
SYM_INNER_LABEL(__x86_indirect_call_thunk_\reg, SYM_L_GLOBAL)
- UNWIND_HINT_EMPTY
+ UNWIND_HINT_UNDEFINED
ANNOTATE_NOENDBR
CALL_DEPTH_ACCOUNT
.align RETPOLINE_THUNK_SIZE
SYM_INNER_LABEL(__x86_indirect_jump_thunk_\reg, SYM_L_GLOBAL)
- UNWIND_HINT_EMPTY
+ UNWIND_HINT_UNDEFINED
ANNOTATE_NOENDBR
POLINE \reg
ANNOTATE_UNRET_SAFE
#define PVH_DS_SEL (PVH_GDT_ENTRY_DS * 8)
SYM_CODE_START_LOCAL(pvh_start_xen)
- UNWIND_HINT_EMPTY
+ UNWIND_HINT_END_OF_STACK
cld
lgdt (_pa(gdt))
SYM_CODE_START(xen_early_idt_handler_array)
i = 0
.rept NUM_EXCEPTION_VECTORS
- UNWIND_HINT_EMPTY
+ UNWIND_HINT_UNDEFINED
ENDBR
pop %rcx
pop %r11
* rsp->rax }
*/
SYM_CODE_START(xen_iret)
- UNWIND_HINT_EMPTY
+ UNWIND_HINT_UNDEFINED
ANNOTATE_NOENDBR
pushq $0
jmp hypercall_iret
#ifdef CONFIG_XEN_PV
__INIT
SYM_CODE_START(startup_xen)
- UNWIND_HINT_EMPTY
+ UNWIND_HINT_END_OF_STACK
ANNOTATE_NOENDBR
cld
#ifdef CONFIG_XEN_PV_SMP
.pushsection .text
SYM_CODE_START(asm_cpu_bringup_and_idle)
- UNWIND_HINT_EMPTY
+ UNWIND_HINT_END_OF_STACK
ENDBR
call cpu_bringup_and_idle
#ifndef __ASSEMBLY__
-#define UNWIND_HINT(type, sp_reg, sp_offset, signal, end) \
+#define UNWIND_HINT(type, sp_reg, sp_offset, signal) \
"987: \n\t" \
".pushsection .discard.unwind_hints\n\t" \
/* struct unwind_hint */ \
".byte " __stringify(sp_reg) "\n\t" \
".byte " __stringify(type) "\n\t" \
".byte " __stringify(signal) "\n\t" \
- ".byte " __stringify(end) "\n\t" \
".balign 4 \n\t" \
".popsection\n\t"
* the debuginfo as necessary. It will also warn if it sees any
* inconsistencies.
*/
-.macro UNWIND_HINT type:req sp_reg=0 sp_offset=0 signal=0 end=0
+.macro UNWIND_HINT type:req sp_reg=0 sp_offset=0 signal=0
.Lhere_\@:
.pushsection .discard.unwind_hints
/* struct unwind_hint */
.byte \sp_reg
.byte \type
.byte \signal
- .byte \end
.balign 4
.popsection
.endm
#ifndef __ASSEMBLY__
-#define UNWIND_HINT(type, sp_reg, sp_offset, signal, end) "\n\t"
+#define UNWIND_HINT(type, sp_reg, sp_offset, signal) "\n\t"
#define STACK_FRAME_NON_STANDARD(func)
#define STACK_FRAME_NON_STANDARD_FP(func)
#define ANNOTATE_NOENDBR
#define ASM_REACHABLE
#else
#define ANNOTATE_INTRA_FUNCTION_CALL
-.macro UNWIND_HINT type:req sp_reg=0 sp_offset=0 signal=0 end=0
+.macro UNWIND_HINT type:req sp_reg=0 sp_offset=0 signal=0
.endm
.macro STACK_FRAME_NON_STANDARD func:req
.endm
u8 sp_reg;
u8 type;
u8 signal;
- u8 end;
};
#endif /* __ASSEMBLY__ */
/*
+ * UNWIND_HINT_TYPE_UNDEFINED: A blind spot in ORC coverage which can result in
+ * a truncated and unreliable stack unwind.
+ *
+ * UNWIND_HINT_TYPE_END_OF_STACK: The end of the kernel stack unwind before
+ * hitting user entry, boot code, or fork entry (when there are no pt_regs
+ * available).
+ *
* UNWIND_HINT_TYPE_CALL: Indicates that sp_reg+sp_offset resolves to PREV_SP
* (the caller's SP right before it made the call). Used for all callable
* functions, i.e. all C code and all callable asm functions.
* UNWIND_HINT_TYPE_REGS_PARTIAL: Used in entry code to indicate that
* sp_reg+sp_offset points to the iret return frame.
*
- * UNWIND_HINT_FUNC: Generate the unwind metadata of a callable function.
+ * UNWIND_HINT_TYPE_FUNC: Generate the unwind metadata of a callable function.
* Useful for code which doesn't have an ELF function annotation.
*
- * UNWIND_HINT_ENTRY: machine entry without stack, SYSCALL/SYSENTER etc.
+ * UNWIND_HINT_TYPE_{SAVE,RESTORE}: Save the unwind metadata at a certain
+ * location so that it can be restored later.
*/
-#define UNWIND_HINT_TYPE_CALL 0
-#define UNWIND_HINT_TYPE_REGS 1
-#define UNWIND_HINT_TYPE_REGS_PARTIAL 2
+#define UNWIND_HINT_TYPE_UNDEFINED 0
+#define UNWIND_HINT_TYPE_END_OF_STACK 1
+#define UNWIND_HINT_TYPE_CALL 2
+#define UNWIND_HINT_TYPE_REGS 3
+#define UNWIND_HINT_TYPE_REGS_PARTIAL 4
/* The below hint types don't have corresponding ORC types */
-#define UNWIND_HINT_TYPE_FUNC 3
-#define UNWIND_HINT_TYPE_SAVE 4
-#define UNWIND_HINT_TYPE_RESTORE 5
+#define UNWIND_HINT_TYPE_FUNC 5
+#define UNWIND_HINT_TYPE_SAVE 6
+#define UNWIND_HINT_TYPE_RESTORE 7
#endif /* _LINUX_OBJTOOL_TYPES_H */
* whitelisted .o files which didn't get objtool generation.
*/
orc_a = g_orc_table + (a - g_orc_ip_table);
- return orc_a->sp_reg == ORC_REG_UNDEFINED && !orc_a->end ? -1 : 1;
+ return orc_a->type == ORC_TYPE_UNDEFINED ? -1 : 1;
}
static void *sort_orctable(void *arg)
#define ORC_REG_SP_INDIRECT 9
#define ORC_REG_MAX 15
-#define ORC_TYPE_CALL 0
-#define ORC_TYPE_REGS 1
-#define ORC_TYPE_REGS_PARTIAL 2
+#define ORC_TYPE_UNDEFINED 0
+#define ORC_TYPE_END_OF_STACK 1
+#define ORC_TYPE_CALL 2
+#define ORC_TYPE_REGS 3
+#define ORC_TYPE_REGS_PARTIAL 4
#ifndef __ASSEMBLY__
#include <asm/byteorder.h>
#if defined(__LITTLE_ENDIAN_BITFIELD)
unsigned sp_reg:4;
unsigned bp_reg:4;
- unsigned type:2;
+ unsigned type:3;
unsigned signal:1;
- unsigned end:1;
#elif defined(__BIG_ENDIAN_BITFIELD)
unsigned bp_reg:4;
unsigned sp_reg:4;
unsigned unused:4;
- unsigned end:1;
unsigned signal:1;
- unsigned type:2;
+ unsigned type:3;
#endif
} __packed;
u8 sp_reg;
u8 type;
u8 signal;
- u8 end;
};
#endif /* __ASSEMBLY__ */
/*
+ * UNWIND_HINT_TYPE_UNDEFINED: A blind spot in ORC coverage which can result in
+ * a truncated and unreliable stack unwind.
+ *
+ * UNWIND_HINT_TYPE_END_OF_STACK: The end of the kernel stack unwind before
+ * hitting user entry, boot code, or fork entry (when there are no pt_regs
+ * available).
+ *
* UNWIND_HINT_TYPE_CALL: Indicates that sp_reg+sp_offset resolves to PREV_SP
* (the caller's SP right before it made the call). Used for all callable
* functions, i.e. all C code and all callable asm functions.
* UNWIND_HINT_TYPE_REGS_PARTIAL: Used in entry code to indicate that
* sp_reg+sp_offset points to the iret return frame.
*
- * UNWIND_HINT_FUNC: Generate the unwind metadata of a callable function.
+ * UNWIND_HINT_TYPE_FUNC: Generate the unwind metadata of a callable function.
* Useful for code which doesn't have an ELF function annotation.
*
- * UNWIND_HINT_ENTRY: machine entry without stack, SYSCALL/SYSENTER etc.
+ * UNWIND_HINT_TYPE_{SAVE,RESTORE}: Save the unwind metadata at a certain
+ * location so that it can be restored later.
*/
-#define UNWIND_HINT_TYPE_CALL 0
-#define UNWIND_HINT_TYPE_REGS 1
-#define UNWIND_HINT_TYPE_REGS_PARTIAL 2
+#define UNWIND_HINT_TYPE_UNDEFINED 0
+#define UNWIND_HINT_TYPE_END_OF_STACK 1
+#define UNWIND_HINT_TYPE_CALL 2
+#define UNWIND_HINT_TYPE_REGS 3
+#define UNWIND_HINT_TYPE_REGS_PARTIAL 4
/* The below hint types don't have corresponding ORC types */
-#define UNWIND_HINT_TYPE_FUNC 3
-#define UNWIND_HINT_TYPE_SAVE 4
-#define UNWIND_HINT_TYPE_RESTORE 5
+#define UNWIND_HINT_TYPE_FUNC 5
+#define UNWIND_HINT_TYPE_SAVE 6
+#define UNWIND_HINT_TYPE_RESTORE 7
#endif /* _LINUX_OBJTOOL_TYPES_H */
memcpy(&state->regs, &initial_func_cfi.regs,
CFI_NUM_REGS * sizeof(struct cfi_reg));
state->stack_size = initial_func_cfi.cfa.offset;
+ state->type = UNWIND_HINT_TYPE_CALL;
}
static int read_unwind_hints(struct objtool_file *file)
cfi.cfa.offset = bswap_if_needed(file->elf, hint->sp_offset);
cfi.type = hint->type;
cfi.signal = hint->signal;
- cfi.end = hint->end;
insn->cfi = cfi_hash_find_or_add(&cfi);
}
static const char *orc_type_name(unsigned int type)
{
switch (type) {
+ case ORC_TYPE_UNDEFINED:
+ return "(und)";
+ case ORC_TYPE_END_OF_STACK:
+ return "end";
case ORC_TYPE_CALL:
return "call";
case ORC_TYPE_REGS:
printf("%llx:", (unsigned long long)(orc_ip_addr + (i * sizeof(int)) + orc_ip[i]));
}
+ printf("type:%s", orc_type_name(orc[i].type));
printf(" sp:");
print_reg(orc[i].bp_reg, bswap_if_needed(&dummy_elf, orc[i].bp_offset));
- printf(" type:%s signal:%d end:%d\n",
- orc_type_name(orc[i].type), orc[i].signal, orc[i].end);
+ printf(" signal:%d\n", orc[i].signal);
}
elf_end(elf);
memset(orc, 0, sizeof(*orc));
if (!cfi) {
- orc->end = 0;
- orc->sp_reg = ORC_REG_UNDEFINED;
+ /*
+ * This is usually either unreachable nops/traps (which don't
+ * trigger unreachable instruction warnings), or
+ * STACK_FRAME_NON_STANDARD functions.
+ */
+ orc->type = ORC_TYPE_UNDEFINED;
return 0;
}
switch (cfi->type) {
+ case UNWIND_HINT_TYPE_UNDEFINED:
+ orc->type = ORC_TYPE_UNDEFINED;
+ return 0;
+ case UNWIND_HINT_TYPE_END_OF_STACK:
+ orc->type = ORC_TYPE_END_OF_STACK;
+ return 0;
case UNWIND_HINT_TYPE_CALL:
orc->type = ORC_TYPE_CALL;
break;
return -1;
}
- orc->end = cfi->end;
orc->signal = cfi->signal;
- if (cfi->cfa.base == CFI_UNDEFINED) {
- orc->sp_reg = ORC_REG_UNDEFINED;
- return 0;
- }
-
switch (cfi->cfa.base) {
case CFI_SP:
orc->sp_reg = ORC_REG_SP;
struct orc_list_entry *entry;
struct list_head orc_list;
- struct orc_entry null = {
- .sp_reg = ORC_REG_UNDEFINED,
- .bp_reg = ORC_REG_UNDEFINED,
- .type = ORC_TYPE_CALL,
- };
+ struct orc_entry null = { .type = ORC_TYPE_UNDEFINED };
/* Build a deduplicated list of ORC entries: */
INIT_LIST_HEAD(&orc_list);
projects / users / hch / xfs.git / commitdiff