mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-23 04:04:26 +08:00
x86,objtool: Split UNWIND_HINT_EMPTY in two
Mark reported that the ORC unwinder incorrectly marks an unwind as reliable when the unwind terminates prematurely in the dark corners of return_to_handler() due to lack of information about the next frame. The problem is UNWIND_HINT_EMPTY is used in two different situations: 1) The end of the kernel stack unwind before hitting user entry, boot code, or fork entry 2) A blind spot in ORC coverage where the unwinder has to bail due to lack of information about the next frame The ORC unwinder has no way to tell the difference between the two. When it encounters an undefined stack state with 'end=1', it blindly marks the stack reliable, which can break the livepatch consistency model. Fix it by splitting UNWIND_HINT_EMPTY into UNWIND_HINT_UNDEFINED and UNWIND_HINT_END_OF_STACK. Reported-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/fd6212c8b450d3564b855e1cb48404d6277b4d9f.1677683419.git.jpoimboe@kernel.org
This commit is contained in:
parent
4708ea14be
commit
fb799447ae
@ -183,7 +183,7 @@ trampoline or return trampoline. For example, considering the x86_64
|
||||
.. code-block:: none
|
||||
|
||||
SYM_CODE_START(return_to_handler)
|
||||
UNWIND_HINT_EMPTY
|
||||
UNWIND_HINT_UNDEFINED
|
||||
subq $24, %rsp
|
||||
|
||||
/* Save the return values */
|
||||
|
@ -205,7 +205,7 @@ syscall_return_via_sysret:
|
||||
*/
|
||||
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 */
|
||||
@ -286,7 +286,7 @@ SYM_FUNC_END(__switch_to_asm)
|
||||
.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
|
||||
@ -303,7 +303,7 @@ SYM_CODE_START_NOALIGN(ret_from_fork)
|
||||
|
||||
1:
|
||||
/* kernel thread */
|
||||
UNWIND_HINT_EMPTY
|
||||
UNWIND_HINT_END_OF_STACK
|
||||
movq %r12, %rdi
|
||||
CALL_NOSPEC rbx
|
||||
/*
|
||||
@ -643,7 +643,7 @@ SYM_INNER_LABEL(swapgs_restore_regs_and_return_to_usermode, SYM_L_GLOBAL)
|
||||
*/
|
||||
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 */
|
||||
@ -869,7 +869,7 @@ SYM_CODE_END(exc_xen_hypervisor_callback)
|
||||
*/
|
||||
__FUNC_ALIGN
|
||||
SYM_CODE_START_NOALIGN(xen_failsafe_callback)
|
||||
UNWIND_HINT_EMPTY
|
||||
UNWIND_HINT_UNDEFINED
|
||||
ENDBR
|
||||
movl %ds, %ecx
|
||||
cmpw %cx, 0x10(%rsp)
|
||||
@ -1520,7 +1520,7 @@ SYM_CODE_END(asm_exc_nmi)
|
||||
* 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
|
||||
|
@ -39,9 +39,11 @@
|
||||
#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>
|
||||
@ -60,16 +62,14 @@ struct orc_entry {
|
||||
#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;
|
||||
|
||||
|
@ -7,13 +7,17 @@
|
||||
|
||||
#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
|
||||
@ -73,7 +77,7 @@
|
||||
#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__ */
|
||||
|
||||
|
@ -340,7 +340,7 @@ STACK_FRAME_NON_STANDARD_FP(__fentry__)
|
||||
|
||||
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
||||
SYM_CODE_START(return_to_handler)
|
||||
UNWIND_HINT_EMPTY
|
||||
UNWIND_HINT_UNDEFINED
|
||||
ANNOTATE_NOENDBR
|
||||
subq $16, %rsp
|
||||
|
||||
|
@ -42,7 +42,7 @@ L3_START_KERNEL = pud_index(__START_KERNEL_map)
|
||||
__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
|
||||
@ -105,7 +105,7 @@ SYM_CODE_START_NOALIGN(startup_64)
|
||||
lretq
|
||||
|
||||
.Lon_kernel_cs:
|
||||
UNWIND_HINT_EMPTY
|
||||
UNWIND_HINT_END_OF_STACK
|
||||
|
||||
/* Sanitize CPU configuration */
|
||||
call verify_cpu
|
||||
@ -127,7 +127,7 @@ SYM_CODE_START_NOALIGN(startup_64)
|
||||
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,
|
||||
@ -156,7 +156,7 @@ SYM_CODE_START(secondary_startup_64)
|
||||
* 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
|
||||
|
||||
/*
|
||||
@ -238,7 +238,7 @@ SYM_INNER_LABEL(secondary_startup_64_no_verify, SYM_L_GLOBAL)
|
||||
ANNOTATE_RETPOLINE_SAFE
|
||||
jmp *%rax
|
||||
1:
|
||||
UNWIND_HINT_EMPTY
|
||||
UNWIND_HINT_END_OF_STACK
|
||||
ANNOTATE_NOENDBR // above
|
||||
|
||||
/*
|
||||
@ -371,7 +371,7 @@ SYM_CODE_END(secondary_startup_64)
|
||||
*/
|
||||
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)
|
||||
|
@ -43,7 +43,7 @@
|
||||
.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
|
||||
@ -113,7 +113,7 @@ SYM_CODE_START_NOALIGN(relocate_kernel)
|
||||
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 */
|
||||
@ -231,7 +231,7 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
|
||||
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
|
||||
@ -256,8 +256,8 @@ SYM_CODE_END(virtual_mapped)
|
||||
|
||||
/* 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
|
||||
|
@ -158,7 +158,6 @@ static struct orc_entry orc_fp_entry = {
|
||||
.sp_offset = 16,
|
||||
.bp_reg = ORC_REG_PREV_SP,
|
||||
.bp_offset = -16,
|
||||
.end = 0,
|
||||
};
|
||||
|
||||
static struct orc_entry *orc_find(unsigned long ip)
|
||||
@ -250,13 +249,13 @@ static int orc_sort_cmp(const void *_a, const void *_b)
|
||||
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,
|
||||
@ -474,14 +473,12 @@ bool unwind_next_frame(struct unwind_state *state)
|
||||
*/
|
||||
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;
|
||||
|
@ -33,7 +33,7 @@
|
||||
|
||||
.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), \
|
||||
@ -75,7 +75,7 @@ SYM_CODE_END(__x86_indirect_thunk_array)
|
||||
.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
|
||||
@ -103,7 +103,7 @@ SYM_CODE_END(__x86_indirect_call_thunk_array)
|
||||
.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
|
||||
|
@ -50,7 +50,7 @@
|
||||
#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))
|
||||
|
@ -165,7 +165,7 @@ xen_pv_trap asm_exc_xen_hypervisor_callback
|
||||
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
|
||||
@ -193,7 +193,7 @@ hypercall_iret = hypercall_page + __HYPERVISOR_iret * 32
|
||||
* rsp->rax }
|
||||
*/
|
||||
SYM_CODE_START(xen_iret)
|
||||
UNWIND_HINT_EMPTY
|
||||
UNWIND_HINT_UNDEFINED
|
||||
ANNOTATE_NOENDBR
|
||||
pushq $0
|
||||
jmp hypercall_iret
|
||||
|
@ -45,7 +45,7 @@ SYM_CODE_END(hypercall_page)
|
||||
#ifdef CONFIG_XEN_PV
|
||||
__INIT
|
||||
SYM_CODE_START(startup_xen)
|
||||
UNWIND_HINT_EMPTY
|
||||
UNWIND_HINT_END_OF_STACK
|
||||
ANNOTATE_NOENDBR
|
||||
cld
|
||||
|
||||
@ -71,7 +71,7 @@ SYM_CODE_END(startup_xen)
|
||||
#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
|
||||
|
@ -10,7 +10,7 @@
|
||||
|
||||
#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 */ \
|
||||
@ -19,7 +19,6 @@
|
||||
".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"
|
||||
|
||||
@ -91,7 +90,7 @@
|
||||
* 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 */
|
||||
@ -100,7 +99,6 @@
|
||||
.byte \sp_reg
|
||||
.byte \type
|
||||
.byte \signal
|
||||
.byte \end
|
||||
.balign 4
|
||||
.popsection
|
||||
.endm
|
||||
@ -153,14 +151,14 @@
|
||||
|
||||
#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
|
||||
|
@ -16,12 +16,18 @@ struct unwind_hint {
|
||||
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.
|
||||
@ -32,17 +38,20 @@ struct unwind_hint {
|
||||
* 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 */
|
||||
|
@ -128,7 +128,7 @@ static int orc_sort_cmp(const void *_a, const void *_b)
|
||||
* 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)
|
||||
|
@ -39,9 +39,11 @@
|
||||
#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>
|
||||
@ -60,16 +62,14 @@ struct orc_entry {
|
||||
#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;
|
||||
|
||||
|
@ -16,12 +16,18 @@ struct unwind_hint {
|
||||
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.
|
||||
@ -32,17 +38,20 @@ struct unwind_hint {
|
||||
* 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 */
|
||||
|
@ -2243,6 +2243,7 @@ static void set_func_state(struct cfi_state *state)
|
||||
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)
|
||||
@ -2327,7 +2328,6 @@ 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);
|
||||
}
|
||||
|
@ -38,6 +38,10 @@ static const char *reg_name(unsigned int reg)
|
||||
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:
|
||||
@ -201,6 +205,7 @@ int orc_dump(const char *_objname)
|
||||
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:");
|
||||
|
||||
@ -210,8 +215,7 @@ int orc_dump(const char *_objname)
|
||||
|
||||
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);
|
||||
|
@ -21,12 +21,22 @@ static int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi,
|
||||
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;
|
||||
@ -42,14 +52,8 @@ static int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi,
|
||||
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;
|
||||
@ -163,11 +167,7 @@ int orc_create(struct objtool_file *file)
|
||||
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);
|
||||
|
Loading…
Reference in New Issue
Block a user