x86/unwind: Add the ORC unwinder
Add the new ORC unwinder which is enabled by CONFIG_ORC_UNWINDER=y. It plugs into the existing x86 unwinder framework. It relies on objtool to generate the needed .orc_unwind and .orc_unwind_ip sections. For more details on why ORC is used instead of DWARF, see Documentation/x86/orc-unwinder.txt - but the short version is that it's a simplified, fundamentally more robust debugninfo data structure, which also allows up to two orders of magnitude faster lookups than the DWARF unwinder - which matters to profiling workloads like perf. Thanks to Andy Lutomirski for the performance improvement ideas: splitting the ORC unwind table into two parallel arrays and creating a fast lookup table to search a subset of the unwind table. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/0a6cbfb40f8da99b7a45a1a8302dc6aef16ec812.1500938583.git.jpoimboe@redhat.com [ Extended the changelog. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Josh Poimboeuf
Ingo Molnar
Родитель
1ee6f00d11
Коммит
ee9f8fce99
|
|
@ -0,0 +1,179 @@
|
|||
ORC unwinder
|
||||
============
|
||||
|
||||
Overview
|
||||
--------
|
||||
|
||||
The kernel CONFIG_ORC_UNWINDER option enables the ORC unwinder, which is
|
||||
similar in concept to a DWARF unwinder. The difference is that the
|
||||
format of the ORC data is much simpler than DWARF, which in turn allows
|
||||
the ORC unwinder to be much simpler and faster.
|
||||
|
||||
The ORC data consists of unwind tables which are generated by objtool.
|
||||
They contain out-of-band data which is used by the in-kernel ORC
|
||||
unwinder. Objtool generates the ORC data by first doing compile-time
|
||||
stack metadata validation (CONFIG_STACK_VALIDATION). After analyzing
|
||||
all the code paths of a .o file, it determines information about the
|
||||
stack state at each instruction address in the file and outputs that
|
||||
information to the .orc_unwind and .orc_unwind_ip sections.
|
||||
|
||||
The per-object ORC sections are combined at link time and are sorted and
|
||||
post-processed at boot time. The unwinder uses the resulting data to
|
||||
correlate instruction addresses with their stack states at run time.
|
||||
|
||||
|
||||
ORC vs frame pointers
|
||||
---------------------
|
||||
|
||||
With frame pointers enabled, GCC adds instrumentation code to every
|
||||
function in the kernel. The kernel's .text size increases by about
|
||||
3.2%, resulting in a broad kernel-wide slowdown. Measurements by Mel
|
||||
Gorman [1] have shown a slowdown of 5-10% for some workloads.
|
||||
|
||||
In contrast, the ORC unwinder has no effect on text size or runtime
|
||||
performance, because the debuginfo is out of band. So if you disable
|
||||
frame pointers and enable the ORC unwinder, you get a nice performance
|
||||
improvement across the board, and still have reliable stack traces.
|
||||
|
||||
Ingo Molnar says:
|
||||
|
||||
"Note that it's not just a performance improvement, but also an
|
||||
instruction cache locality improvement: 3.2% .text savings almost
|
||||
directly transform into a similarly sized reduction in cache
|
||||
footprint. That can transform to even higher speedups for workloads
|
||||
whose cache locality is borderline."
|
||||
|
||||
Another benefit of ORC compared to frame pointers is that it can
|
||||
reliably unwind across interrupts and exceptions. Frame pointer based
|
||||
unwinds can sometimes skip the caller of the interrupted function, if it
|
||||
was a leaf function or if the interrupt hit before the frame pointer was
|
||||
saved.
|
||||
|
||||
The main disadvantage of the ORC unwinder compared to frame pointers is
|
||||
that it needs more memory to store the ORC unwind tables: roughly 2-4MB
|
||||
depending on the kernel config.
|
||||
|
||||
|
||||
ORC vs DWARF
|
||||
------------
|
||||
|
||||
ORC debuginfo's advantage over DWARF itself is that it's much simpler.
|
||||
It gets rid of the complex DWARF CFI state machine and also gets rid of
|
||||
the tracking of unnecessary registers. This allows the unwinder to be
|
||||
much simpler, meaning fewer bugs, which is especially important for
|
||||
mission critical oops code.
|
||||
|
||||
The simpler debuginfo format also enables the unwinder to be much faster
|
||||
than DWARF, which is important for perf and lockdep. In a basic
|
||||
performance test by Jiri Slaby [2], the ORC unwinder was about 20x
|
||||
faster than an out-of-tree DWARF unwinder. (Note: That measurement was
|
||||
taken before some performance tweaks were added, which doubled
|
||||
performance, so the speedup over DWARF may be closer to 40x.)
|
||||
|
||||
The ORC data format does have a few downsides compared to DWARF. ORC
|
||||
unwind tables take up ~50% more RAM (+1.3MB on an x86 defconfig kernel)
|
||||
than DWARF-based eh_frame tables.
|
||||
|
||||
Another potential downside is that, as GCC evolves, it's conceivable
|
||||
that the ORC data may end up being *too* simple to describe the state of
|
||||
the stack for certain optimizations. But IMO this is unlikely because
|
||||
GCC saves the frame pointer for any unusual stack adjustments it does,
|
||||
so I suspect we'll really only ever need to keep track of the stack
|
||||
pointer and the frame pointer between call frames. But even if we do
|
||||
end up having to track all the registers DWARF tracks, at least we will
|
||||
still be able to control the format, e.g. no complex state machines.
|
||||
|
||||
|
||||
ORC unwind table generation
|
||||
---------------------------
|
||||
|
||||
The ORC data is generated by objtool. With the existing compile-time
|
||||
stack metadata validation feature, objtool already follows all code
|
||||
paths, and so it already has all the information it needs to be able to
|
||||
generate ORC data from scratch. So it's an easy step to go from stack
|
||||
validation to ORC data generation.
|
||||
|
||||
It should be possible to instead generate the ORC data with a simple
|
||||
tool which converts DWARF to ORC data. However, such a solution would
|
||||
be incomplete due to the kernel's extensive use of asm, inline asm, and
|
||||
special sections like exception tables.
|
||||
|
||||
That could be rectified by manually annotating those special code paths
|
||||
using GNU assembler .cfi annotations in .S files, and homegrown
|
||||
annotations for inline asm in .c files. But asm annotations were tried
|
||||
in the past and were found to be unmaintainable. They were often
|
||||
incorrect/incomplete and made the code harder to read and keep updated.
|
||||
And based on looking at glibc code, annotating inline asm in .c files
|
||||
might be even worse.
|
||||
|
||||
Objtool still needs a few annotations, but only in code which does
|
||||
unusual things to the stack like entry code. And even then, far fewer
|
||||
annotations are needed than what DWARF would need, so they're much more
|
||||
maintainable than DWARF CFI annotations.
|
||||
|
||||
So the advantages of using objtool to generate ORC data are that it
|
||||
gives more accurate debuginfo, with very few annotations. It also
|
||||
insulates the kernel from toolchain bugs which can be very painful to
|
||||
deal with in the kernel since we often have to workaround issues in
|
||||
older versions of the toolchain for years.
|
||||
|
||||
The downside is that the unwinder now becomes dependent on objtool's
|
||||
ability to reverse engineer GCC code flow. If GCC optimizations become
|
||||
too complicated for objtool to follow, the ORC data generation might
|
||||
stop working or become incomplete. (It's worth noting that livepatch
|
||||
already has such a dependency on objtool's ability to follow GCC code
|
||||
flow.)
|
||||
|
||||
If newer versions of GCC come up with some optimizations which break
|
||||
objtool, we may need to revisit the current implementation. Some
|
||||
possible solutions would be asking GCC to make the optimizations more
|
||||
palatable, or having objtool use DWARF as an additional input, or
|
||||
creating a GCC plugin to assist objtool with its analysis. But for now,
|
||||
objtool follows GCC code quite well.
|
||||
|
||||
|
||||
Unwinder implementation details
|
||||
-------------------------------
|
||||
|
||||
Objtool generates the ORC data by integrating with the compile-time
|
||||
stack metadata validation feature, which is described in detail in
|
||||
tools/objtool/Documentation/stack-validation.txt. After analyzing all
|
||||
the code paths of a .o file, it creates an array of orc_entry structs,
|
||||
and a parallel array of instruction addresses associated with those
|
||||
structs, and writes them to the .orc_unwind and .orc_unwind_ip sections
|
||||
respectively.
|
||||
|
||||
The ORC data is split into the two arrays for performance reasons, to
|
||||
make the searchable part of the data (.orc_unwind_ip) more compact. The
|
||||
arrays are sorted in parallel at boot time.
|
||||
|
||||
Performance is further improved by the use of a fast lookup table which
|
||||
is created at runtime. The fast lookup table associates a given address
|
||||
with a range of indices for the .orc_unwind table, so that only a small
|
||||
subset of the table needs to be searched.
|
||||
|
||||
|
||||
Etymology
|
||||
---------
|
||||
|
||||
Orcs, fearsome creatures of medieval folklore, are the Dwarves' natural
|
||||
enemies. Similarly, the ORC unwinder was created in opposition to the
|
||||
complexity and slowness of DWARF.
|
||||
|
||||
"Although Orcs rarely consider multiple solutions to a problem, they do
|
||||
excel at getting things done because they are creatures of action, not
|
||||
thought." [3] Similarly, unlike the esoteric DWARF unwinder, the
|
||||
veracious ORC unwinder wastes no time or siloconic effort decoding
|
||||
variable-length zero-extended unsigned-integer byte-coded
|
||||
state-machine-based debug information entries.
|
||||
|
||||
Similar to how Orcs frequently unravel the well-intentioned plans of
|
||||
their adversaries, the ORC unwinder frequently unravels stacks with
|
||||
brutal, unyielding efficiency.
|
||||
|
||||
ORC stands for Oops Rewind Capability.
|
||||
|
||||
|
||||
[1] https://lkml.kernel.org/r/20170602104048.jkkzssljsompjdwy@suse.de
|
||||
[2] https://lkml.kernel.org/r/d2ca5435-6386-29b8-db87-7f227c2b713a@suse.cz
|
||||
[3] http://dustin.wikidot.com/half-orcs-and-orcs
|
||||
|
|
@ -0,0 +1,8 @@
|
|||
#ifndef _ASM_UML_UNWIND_H
|
||||
#define _ASM_UML_UNWIND_H
|
||||
|
||||
static inline void
|
||||
unwind_module_init(struct module *mod, void *orc_ip, size_t orc_ip_size,
|
||||
void *orc, size_t orc_size) {}
|
||||
|
||||
#endif /* _ASM_UML_UNWIND_H */
|
||||
|
|
@ -157,6 +157,7 @@ config X86
|
|||
select HAVE_MEMBLOCK
|
||||
select HAVE_MEMBLOCK_NODE_MAP
|
||||
select HAVE_MIXED_BREAKPOINTS_REGS
|
||||
select HAVE_MOD_ARCH_SPECIFIC
|
||||
select HAVE_NMI
|
||||
select HAVE_OPROFILE
|
||||
select HAVE_OPTPROBES
|
||||
|
|
|
|||
|
|
@ -355,4 +355,29 @@ config PUNIT_ATOM_DEBUG
|
|||
The current power state can be read from
|
||||
/sys/kernel/debug/punit_atom/dev_power_state
|
||||
|
||||
config ORC_UNWINDER
|
||||
bool "ORC unwinder"
|
||||
depends on X86_64
|
||||
select STACK_VALIDATION
|
||||
---help---
|
||||
This option enables the ORC (Oops Rewind Capability) unwinder for
|
||||
unwinding kernel stack traces. It uses a custom data format which is
|
||||
a simplified version of the DWARF Call Frame Information standard.
|
||||
|
||||
This unwinder is more accurate across interrupt entry frames than the
|
||||
frame pointer unwinder. It can also enable a 5-10% performance
|
||||
improvement across the entire kernel if CONFIG_FRAME_POINTER is
|
||||
disabled.
|
||||
|
||||
Enabling this option will increase the kernel's runtime memory usage
|
||||
by roughly 2-4MB, depending on your kernel config.
|
||||
|
||||
config FRAME_POINTER_UNWINDER
|
||||
def_bool y
|
||||
depends on !ORC_UNWINDER && FRAME_POINTER
|
||||
|
||||
config GUESS_UNWINDER
|
||||
def_bool y
|
||||
depends on !ORC_UNWINDER && !FRAME_POINTER
|
||||
|
||||
endmenu
|
||||
|
|
|
|||
|
|
@ -2,6 +2,15 @@
|
|||
#define _ASM_X86_MODULE_H
|
||||
|
||||
#include <asm-generic/module.h>
|
||||
#include <asm/orc_types.h>
|
||||
|
||||
struct mod_arch_specific {
|
||||
#ifdef CONFIG_ORC_UNWINDER
|
||||
unsigned int num_orcs;
|
||||
int *orc_unwind_ip;
|
||||
struct orc_entry *orc_unwind;
|
||||
#endif
|
||||
};
|
||||
|
||||
#ifdef CONFIG_X86_64
|
||||
/* X86_64 does not define MODULE_PROC_FAMILY */
|
||||
|
|
|
|||
|
|
@ -0,0 +1,46 @@
|
|||
/*
|
||||
* Copyright (C) 2017 Josh Poimboeuf <jpoimboe@redhat.com>
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or
|
||||
* modify it under the terms of the GNU General Public License
|
||||
* as published by the Free Software Foundation; either version 2
|
||||
* of the License, or (at your option) any later version.
|
||||
*
|
||||
* This program is distributed in the hope that it will be useful,
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
* GNU General Public License for more details.
|
||||
*
|
||||
* You should have received a copy of the GNU General Public License
|
||||
* along with this program; if not, see <http://www.gnu.org/licenses/>.
|
||||
*/
|
||||
#ifndef _ORC_LOOKUP_H
|
||||
#define _ORC_LOOKUP_H
|
||||
|
||||
/*
|
||||
* This is a lookup table for speeding up access to the .orc_unwind table.
|
||||
* Given an input address offset, the corresponding lookup table entry
|
||||
* specifies a subset of the .orc_unwind table to search.
|
||||
*
|
||||
* Each block represents the end of the previous range and the start of the
|
||||
* next range. An extra block is added to give the last range an end.
|
||||
*
|
||||
* The block size should be a power of 2 to avoid a costly 'div' instruction.
|
||||
*
|
||||
* A block size of 256 was chosen because it roughly doubles unwinder
|
||||
* performance while only adding ~5% to the ORC data footprint.
|
||||
*/
|
||||
#define LOOKUP_BLOCK_ORDER 8
|
||||
#define LOOKUP_BLOCK_SIZE (1 << LOOKUP_BLOCK_ORDER)
|
||||
|
||||
#ifndef LINKER_SCRIPT
|
||||
|
||||
extern unsigned int orc_lookup[];
|
||||
extern unsigned int orc_lookup_end[];
|
||||
|
||||
#define LOOKUP_START_IP (unsigned long)_stext
|
||||
#define LOOKUP_STOP_IP (unsigned long)_etext
|
||||
|
||||
#endif /* LINKER_SCRIPT */
|
||||
|
||||
#endif /* _ORC_LOOKUP_H */
|
||||
|
|
@ -88,7 +88,7 @@ struct orc_entry {
|
|||
unsigned sp_reg:4;
|
||||
unsigned bp_reg:4;
|
||||
unsigned type:2;
|
||||
};
|
||||
} __packed;
|
||||
|
||||
/*
|
||||
* This struct is used by asm and inline asm code to manually annotate the
|
||||
|
|
|
|||
|
|
@ -12,11 +12,14 @@ struct unwind_state {
|
|||
struct task_struct *task;
|
||||
int graph_idx;
|
||||
bool error;
|
||||
#ifdef CONFIG_FRAME_POINTER
|
||||
bool got_irq;
|
||||
unsigned long *bp, *orig_sp;
|
||||
#if defined(CONFIG_ORC_UNWINDER)
|
||||
bool signal, full_regs;
|
||||
unsigned long sp, bp, ip;
|
||||
struct pt_regs *regs;
|
||||
#elif defined(CONFIG_FRAME_POINTER)
|
||||
bool got_irq;
|
||||
unsigned long *bp, *orig_sp, ip;
|
||||
struct pt_regs *regs;
|
||||
unsigned long ip;
|
||||
#else
|
||||
unsigned long *sp;
|
||||
#endif
|
||||
|
|
@ -24,16 +27,20 @@ struct unwind_state {
|
|||
|
||||
void __unwind_start(struct unwind_state *state, struct task_struct *task,
|
||||
struct pt_regs *regs, unsigned long *first_frame);
|
||||
|
||||
bool unwind_next_frame(struct unwind_state *state);
|
||||
|
||||
unsigned long unwind_get_return_address(struct unwind_state *state);
|
||||
unsigned long *unwind_get_return_address_ptr(struct unwind_state *state);
|
||||
|
||||
static inline bool unwind_done(struct unwind_state *state)
|
||||
{
|
||||
return state->stack_info.type == STACK_TYPE_UNKNOWN;
|
||||
}
|
||||
|
||||
static inline bool unwind_error(struct unwind_state *state)
|
||||
{
|
||||
return state->error;
|
||||
}
|
||||
|
||||
static inline
|
||||
void unwind_start(struct unwind_state *state, struct task_struct *task,
|
||||
struct pt_regs *regs, unsigned long *first_frame)
|
||||
|
|
@ -43,22 +50,7 @@ void unwind_start(struct unwind_state *state, struct task_struct *task,
|
|||
__unwind_start(state, task, regs, first_frame);
|
||||
}
|
||||
|
||||
static inline bool unwind_error(struct unwind_state *state)
|
||||
{
|
||||
return state->error;
|
||||
}
|
||||
|
||||
#ifdef CONFIG_FRAME_POINTER
|
||||
|
||||
static inline
|
||||
unsigned long *unwind_get_return_address_ptr(struct unwind_state *state)
|
||||
{
|
||||
if (unwind_done(state))
|
||||
return NULL;
|
||||
|
||||
return state->regs ? &state->regs->ip : state->bp + 1;
|
||||
}
|
||||
|
||||
#if defined(CONFIG_ORC_UNWINDER) || defined(CONFIG_FRAME_POINTER)
|
||||
static inline struct pt_regs *unwind_get_entry_regs(struct unwind_state *state)
|
||||
{
|
||||
if (unwind_done(state))
|
||||
|
|
@ -66,20 +58,46 @@ static inline struct pt_regs *unwind_get_entry_regs(struct unwind_state *state)
|
|||
|
||||
return state->regs;
|
||||
}
|
||||
|
||||
#else /* !CONFIG_FRAME_POINTER */
|
||||
|
||||
static inline
|
||||
unsigned long *unwind_get_return_address_ptr(struct unwind_state *state)
|
||||
{
|
||||
return NULL;
|
||||
}
|
||||
|
||||
#else
|
||||
static inline struct pt_regs *unwind_get_entry_regs(struct unwind_state *state)
|
||||
{
|
||||
return NULL;
|
||||
}
|
||||
#endif
|
||||
|
||||
#endif /* CONFIG_FRAME_POINTER */
|
||||
#ifdef CONFIG_ORC_UNWINDER
|
||||
void unwind_init(void);
|
||||
void unwind_module_init(struct module *mod, void *orc_ip, size_t orc_ip_size,
|
||||
void *orc, size_t orc_size);
|
||||
#else
|
||||
static inline void unwind_init(void) {}
|
||||
static inline
|
||||
void unwind_module_init(struct module *mod, void *orc_ip, size_t orc_ip_size,
|
||||
void *orc, size_t orc_size) {}
|
||||
#endif
|
||||
|
||||
/*
|
||||
* This disables KASAN checking when reading a value from another task's stack,
|
||||
* since the other task could be running on another CPU and could have poisoned
|
||||
* the stack in the meantime.
|
||||
*/
|
||||
#define READ_ONCE_TASK_STACK(task, x) \
|
||||
({ \
|
||||
unsigned long val; \
|
||||
if (task == current) \
|
||||
val = READ_ONCE(x); \
|
||||
else \
|
||||
val = READ_ONCE_NOCHECK(x); \
|
||||
val; \
|
||||
})
|
||||
|
||||
static inline bool task_on_another_cpu(struct task_struct *task)
|
||||
{
|
||||
#ifdef CONFIG_SMP
|
||||
return task != current && task->on_cpu;
|
||||
#else
|
||||
return false;
|
||||
#endif
|
||||
}
|
||||
|
||||
#endif /* _ASM_X86_UNWIND_H */
|
||||
|
|
|
|||
|
|
@ -126,11 +126,9 @@ obj-$(CONFIG_PERF_EVENTS) += perf_regs.o
|
|||
obj-$(CONFIG_TRACING) += tracepoint.o
|
||||
obj-$(CONFIG_SCHED_MC_PRIO) += itmt.o
|
||||
|
||||
ifdef CONFIG_FRAME_POINTER
|
||||
obj-y += unwind_frame.o
|
||||
else
|
||||
obj-y += unwind_guess.o
|
||||
endif
|
||||
obj-$(CONFIG_ORC_UNWINDER) += unwind_orc.o
|
||||
obj-$(CONFIG_FRAME_POINTER_UNWINDER) += unwind_frame.o
|
||||
obj-$(CONFIG_GUESS_UNWINDER) += unwind_guess.o
|
||||
|
||||
###
|
||||
# 64 bit specific files
|
||||
|
|
|
|||
|
|
@ -35,6 +35,7 @@
|
|||
#include <asm/page.h>
|
||||
#include <asm/pgtable.h>
|
||||
#include <asm/setup.h>
|
||||
#include <asm/unwind.h>
|
||||
|
||||
#if 0
|
||||
#define DEBUGP(fmt, ...) \
|
||||
|
|
@ -213,7 +214,7 @@ int module_finalize(const Elf_Ehdr *hdr,
|
|||
struct module *me)
|
||||
{
|
||||
const Elf_Shdr *s, *text = NULL, *alt = NULL, *locks = NULL,
|
||||
*para = NULL;
|
||||
*para = NULL, *orc = NULL, *orc_ip = NULL;
|
||||
char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
|
||||
|
||||
for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
|
||||
|
|
@ -225,6 +226,10 @@ int module_finalize(const Elf_Ehdr *hdr,
|
|||
locks = s;
|
||||
if (!strcmp(".parainstructions", secstrings + s->sh_name))
|
||||
para = s;
|
||||
if (!strcmp(".orc_unwind", secstrings + s->sh_name))
|
||||
orc = s;
|
||||
if (!strcmp(".orc_unwind_ip", secstrings + s->sh_name))
|
||||
orc_ip = s;
|
||||
}
|
||||
|
||||
if (alt) {
|
||||
|
|
@ -248,6 +253,10 @@ int module_finalize(const Elf_Ehdr *hdr,
|
|||
/* make jump label nops */
|
||||
jump_label_apply_nops(me);
|
||||
|
||||
if (orc && orc_ip)
|
||||
unwind_module_init(me, (void *)orc_ip->sh_addr, orc_ip->sh_size,
|
||||
(void *)orc->sh_addr, orc->sh_size);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
|
|
|
|||
|
|
@ -115,6 +115,7 @@
|
|||
#include <asm/microcode.h>
|
||||
#include <asm/mmu_context.h>
|
||||
#include <asm/kaslr.h>
|
||||
#include <asm/unwind.h>
|
||||
|
||||
/*
|
||||
* max_low_pfn_mapped: highest direct mapped pfn under 4GB
|
||||
|
|
@ -1310,6 +1311,8 @@ void __init setup_arch(char **cmdline_p)
|
|||
if (efi_enabled(EFI_BOOT))
|
||||
efi_apply_memmap_quirks();
|
||||
#endif
|
||||
|
||||
unwind_init();
|
||||
}
|
||||
|
||||
#ifdef CONFIG_X86_32
|
||||
|
|
|
|||
|
|
@ -10,20 +10,22 @@
|
|||
|
||||
#define FRAME_HEADER_SIZE (sizeof(long) * 2)
|
||||
|
||||
/*
|
||||
* This disables KASAN checking when reading a value from another task's stack,
|
||||
* since the other task could be running on another CPU and could have poisoned
|
||||
* the stack in the meantime.
|
||||
*/
|
||||
#define READ_ONCE_TASK_STACK(task, x) \
|
||||
({ \
|
||||
unsigned long val; \
|
||||
if (task == current) \
|
||||
val = READ_ONCE(x); \
|
||||
else \
|
||||
val = READ_ONCE_NOCHECK(x); \
|
||||
val; \
|
||||
})
|
||||
unsigned long unwind_get_return_address(struct unwind_state *state)
|
||||
{
|
||||
if (unwind_done(state))
|
||||
return 0;
|
||||
|
||||
return __kernel_text_address(state->ip) ? state->ip : 0;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(unwind_get_return_address);
|
||||
|
||||
unsigned long *unwind_get_return_address_ptr(struct unwind_state *state)
|
||||
{
|
||||
if (unwind_done(state))
|
||||
return NULL;
|
||||
|
||||
return state->regs ? &state->regs->ip : state->bp + 1;
|
||||
}
|
||||
|
||||
static void unwind_dump(struct unwind_state *state)
|
||||
{
|
||||
|
|
@ -66,15 +68,6 @@ static void unwind_dump(struct unwind_state *state)
|
|||
}
|
||||
}
|
||||
|
||||
unsigned long unwind_get_return_address(struct unwind_state *state)
|
||||
{
|
||||
if (unwind_done(state))
|
||||
return 0;
|
||||
|
||||
return __kernel_text_address(state->ip) ? state->ip : 0;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(unwind_get_return_address);
|
||||
|
||||
static size_t regs_size(struct pt_regs *regs)
|
||||
{
|
||||
/* x86_32 regs from kernel mode are two words shorter: */
|
||||
|
|
|
|||
|
|
@ -19,6 +19,11 @@ unsigned long unwind_get_return_address(struct unwind_state *state)
|
|||
}
|
||||
EXPORT_SYMBOL_GPL(unwind_get_return_address);
|
||||
|
||||
unsigned long *unwind_get_return_address_ptr(struct unwind_state *state)
|
||||
{
|
||||
return NULL;
|
||||
}
|
||||
|
||||
bool unwind_next_frame(struct unwind_state *state)
|
||||
{
|
||||
struct stack_info *info = &state->stack_info;
|
||||
|
|
|
|||
|
|
@ -0,0 +1,582 @@
|
|||
#include <linux/module.h>
|
||||
#include <linux/sort.h>
|
||||
#include <asm/ptrace.h>
|
||||
#include <asm/stacktrace.h>
|
||||
#include <asm/unwind.h>
|
||||
#include <asm/orc_types.h>
|
||||
#include <asm/orc_lookup.h>
|
||||
#include <asm/sections.h>
|
||||
|
||||
#define orc_warn(fmt, ...) \
|
||||
printk_deferred_once(KERN_WARNING pr_fmt("WARNING: " fmt), ##__VA_ARGS__)
|
||||
|
||||
extern int __start_orc_unwind_ip[];
|
||||
extern int __stop_orc_unwind_ip[];
|
||||
extern struct orc_entry __start_orc_unwind[];
|
||||
extern struct orc_entry __stop_orc_unwind[];
|
||||
|
||||
static DEFINE_MUTEX(sort_mutex);
|
||||
int *cur_orc_ip_table = __start_orc_unwind_ip;
|
||||
struct orc_entry *cur_orc_table = __start_orc_unwind;
|
||||
|
||||
unsigned int lookup_num_blocks;
|
||||
bool orc_init;
|
||||
|
||||
static inline unsigned long orc_ip(const int *ip)
|
||||
{
|
||||
return (unsigned long)ip + *ip;
|
||||
}
|
||||
|
||||
static struct orc_entry *__orc_find(int *ip_table, struct orc_entry *u_table,
|
||||
unsigned int num_entries, unsigned long ip)
|
||||
{
|
||||
int *first = ip_table;
|
||||
int *last = ip_table + num_entries - 1;
|
||||
int *mid = first, *found = first;
|
||||
|
||||
if (!num_entries)
|
||||
return NULL;
|
||||
|
||||
/*
|
||||
* Do a binary range search to find the rightmost duplicate of a given
|
||||
* starting address. Some entries are section terminators which are
|
||||
* "weak" entries for ensuring there are no gaps. They should be
|
||||
* ignored when they conflict with a real entry.
|
||||
*/
|
||||
while (first <= last) {
|
||||
mid = first + ((last - first) / 2);
|
||||
|
||||
if (orc_ip(mid) <= ip) {
|
||||
found = mid;
|
||||
first = mid + 1;
|
||||
} else
|
||||
last = mid - 1;
|
||||
}
|
||||
|
||||
return u_table + (found - ip_table);
|
||||
}
|
||||
|
||||
#ifdef CONFIG_MODULES
|
||||
static struct orc_entry *orc_module_find(unsigned long ip)
|
||||
{
|
||||
struct module *mod;
|
||||
|
||||
mod = __module_address(ip);
|
||||
if (!mod || !mod->arch.orc_unwind || !mod->arch.orc_unwind_ip)
|
||||
return NULL;
|
||||
return __orc_find(mod->arch.orc_unwind_ip, mod->arch.orc_unwind,
|
||||
mod->arch.num_orcs, ip);
|
||||
}
|
||||
#else
|
||||
static struct orc_entry *orc_module_find(unsigned long ip)
|
||||
{
|
||||
return NULL;
|
||||
}
|
||||
#endif
|
||||
|
||||
static struct orc_entry *orc_find(unsigned long ip)
|
||||
{
|
||||
if (!orc_init)
|
||||
return NULL;
|
||||
|
||||
/* For non-init vmlinux addresses, use the fast lookup table: */
|
||||
if (ip >= LOOKUP_START_IP && ip < LOOKUP_STOP_IP) {
|
||||
unsigned int idx, start, stop;
|
||||
|
||||
idx = (ip - LOOKUP_START_IP) / LOOKUP_BLOCK_SIZE;
|
||||
|
||||
if (unlikely((idx >= lookup_num_blocks-1))) {
|
||||
orc_warn("WARNING: bad lookup idx: idx=%u num=%u ip=%lx\n",
|
||||
idx, lookup_num_blocks, ip);
|
||||
return NULL;
|
||||
}
|
||||
|
||||
start = orc_lookup[idx];
|
||||
stop = orc_lookup[idx + 1] + 1;
|
||||
|
||||
if (unlikely((__start_orc_unwind + start >= __stop_orc_unwind) ||
|
||||
(__start_orc_unwind + stop > __stop_orc_unwind))) {
|
||||
orc_warn("WARNING: bad lookup value: idx=%u num=%u start=%u stop=%u ip=%lx\n",
|
||||
idx, lookup_num_blocks, start, stop, ip);
|
||||
return NULL;
|
||||
}
|
||||
|
||||
return __orc_find(__start_orc_unwind_ip + start,
|
||||
__start_orc_unwind + start, stop - start, ip);
|
||||
}
|
||||
|
||||
/* vmlinux .init slow lookup: */
|
||||
if (ip >= (unsigned long)_sinittext && ip < (unsigned long)_einittext)
|
||||
return __orc_find(__start_orc_unwind_ip, __start_orc_unwind,
|
||||
__stop_orc_unwind_ip - __start_orc_unwind_ip, ip);
|
||||
|
||||
/* Module lookup: */
|
||||
return orc_module_find(ip);
|
||||
}
|
||||
|
||||
static void orc_sort_swap(void *_a, void *_b, int size)
|
||||
{
|
||||
struct orc_entry *orc_a, *orc_b;
|
||||
struct orc_entry orc_tmp;
|
||||
int *a = _a, *b = _b, tmp;
|
||||
int delta = _b - _a;
|
||||
|
||||
/* Swap the .orc_unwind_ip entries: */
|
||||
tmp = *a;
|
||||
*a = *b + delta;
|
||||
*b = tmp - delta;
|
||||
|
||||
/* Swap the corresponding .orc_unwind entries: */
|
||||
orc_a = cur_orc_table + (a - cur_orc_ip_table);
|
||||
orc_b = cur_orc_table + (b - cur_orc_ip_table);
|
||||
orc_tmp = *orc_a;
|
||||
*orc_a = *orc_b;
|
||||
*orc_b = orc_tmp;
|
||||
}
|
||||
|
||||
static int orc_sort_cmp(const void *_a, const void *_b)
|
||||
{
|
||||
struct orc_entry *orc_a;
|
||||
const int *a = _a, *b = _b;
|
||||
unsigned long a_val = orc_ip(a);
|
||||
unsigned long b_val = orc_ip(b);
|
||||
|
||||
if (a_val > b_val)
|
||||
return 1;
|
||||
if (a_val < b_val)
|
||||
return -1;
|
||||
|
||||
/*
|
||||
* The "weak" section terminator entries need to always be on the left
|
||||
* 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 ? -1 : 1;
|
||||
}
|
||||
|
||||
#ifdef CONFIG_MODULES
|
||||
void unwind_module_init(struct module *mod, void *_orc_ip, size_t orc_ip_size,
|
||||
void *_orc, size_t orc_size)
|
||||
{
|
||||
int *orc_ip = _orc_ip;
|
||||
struct orc_entry *orc = _orc;
|
||||
unsigned int num_entries = orc_ip_size / sizeof(int);
|
||||
|
||||
WARN_ON_ONCE(orc_ip_size % sizeof(int) != 0 ||
|
||||
orc_size % sizeof(*orc) != 0 ||
|
||||
num_entries != orc_size / sizeof(*orc));
|
||||
|
||||
/*
|
||||
* The 'cur_orc_*' globals allow the orc_sort_swap() callback to
|
||||
* associate an .orc_unwind_ip table entry with its corresponding
|
||||
* .orc_unwind entry so they can both be swapped.
|
||||
*/
|
||||
mutex_lock(&sort_mutex);
|
||||
cur_orc_ip_table = orc_ip;
|
||||
cur_orc_table = orc;
|
||||
sort(orc_ip, num_entries, sizeof(int), orc_sort_cmp, orc_sort_swap);
|
||||
mutex_unlock(&sort_mutex);
|
||||
|
||||
mod->arch.orc_unwind_ip = orc_ip;
|
||||
mod->arch.orc_unwind = orc;
|
||||
mod->arch.num_orcs = num_entries;
|
||||
}
|
||||
#endif
|
||||
|
||||
void __init unwind_init(void)
|
||||
{
|
||||
size_t orc_ip_size = (void *)__stop_orc_unwind_ip - (void *)__start_orc_unwind_ip;
|
||||
size_t orc_size = (void *)__stop_orc_unwind - (void *)__start_orc_unwind;
|
||||
size_t num_entries = orc_ip_size / sizeof(int);
|
||||
struct orc_entry *orc;
|
||||
int i;
|
||||
|
||||
if (!num_entries || orc_ip_size % sizeof(int) != 0 ||
|
||||
orc_size % sizeof(struct orc_entry) != 0 ||
|
||||
num_entries != orc_size / sizeof(struct orc_entry)) {
|
||||
orc_warn("WARNING: Bad or missing .orc_unwind table. Disabling unwinder.\n");
|
||||
return;
|
||||
}
|
||||
|
||||
/* Sort the .orc_unwind and .orc_unwind_ip tables: */
|
||||
sort(__start_orc_unwind_ip, num_entries, sizeof(int), orc_sort_cmp,
|
||||
orc_sort_swap);
|
||||
|
||||
/* Initialize the fast lookup table: */
|
||||
lookup_num_blocks = orc_lookup_end - orc_lookup;
|
||||
for (i = 0; i < lookup_num_blocks-1; i++) {
|
||||
orc = __orc_find(__start_orc_unwind_ip, __start_orc_unwind,
|
||||
num_entries,
|
||||
LOOKUP_START_IP + (LOOKUP_BLOCK_SIZE * i));
|
||||
if (!orc) {
|
||||
orc_warn("WARNING: Corrupt .orc_unwind table. Disabling unwinder.\n");
|
||||
return;
|
||||
}
|
||||
|
||||
orc_lookup[i] = orc - __start_orc_unwind;
|
||||
}
|
||||
|
||||
/* Initialize the ending block: */
|
||||
orc = __orc_find(__start_orc_unwind_ip, __start_orc_unwind, num_entries,
|
||||
LOOKUP_STOP_IP);
|
||||
if (!orc) {
|
||||
orc_warn("WARNING: Corrupt .orc_unwind table. Disabling unwinder.\n");
|
||||
return;
|
||||
}
|
||||
orc_lookup[lookup_num_blocks-1] = orc - __start_orc_unwind;
|
||||
|
||||
orc_init = true;
|
||||
}
|
||||
|
||||
unsigned long unwind_get_return_address(struct unwind_state *state)
|
||||
{
|
||||
if (unwind_done(state))
|
||||
return 0;
|
||||
|
||||
return __kernel_text_address(state->ip) ? state->ip : 0;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(unwind_get_return_address);
|
||||
|
||||
unsigned long *unwind_get_return_address_ptr(struct unwind_state *state)
|
||||
{
|
||||
if (unwind_done(state))
|
||||
return NULL;
|
||||
|
||||
if (state->regs)
|
||||
return &state->regs->ip;
|
||||
|
||||
if (state->sp)
|
||||
return (unsigned long *)state->sp - 1;
|
||||
|
||||
return NULL;
|
||||
}
|
||||
|
||||
static bool stack_access_ok(struct unwind_state *state, unsigned long addr,
|
||||
size_t len)
|
||||
{
|
||||
struct stack_info *info = &state->stack_info;
|
||||
|
||||
/*
|
||||
* If the address isn't on the current stack, switch to the next one.
|
||||
*
|
||||
* We may have to traverse multiple stacks to deal with the possibility
|
||||
* that info->next_sp could point to an empty stack and the address
|
||||
* could be on a subsequent stack.
|
||||
*/
|
||||
while (!on_stack(info, (void *)addr, len))
|
||||
if (get_stack_info(info->next_sp, state->task, info,
|
||||
&state->stack_mask))
|
||||
return false;
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
static bool deref_stack_reg(struct unwind_state *state, unsigned long addr,
|
||||
unsigned long *val)
|
||||
{
|
||||
if (!stack_access_ok(state, addr, sizeof(long)))
|
||||
return false;
|
||||
|
||||
*val = READ_ONCE_TASK_STACK(state->task, *(unsigned long *)addr);
|
||||
return true;
|
||||
}
|
||||
|
||||
#define REGS_SIZE (sizeof(struct pt_regs))
|
||||
#define SP_OFFSET (offsetof(struct pt_regs, sp))
|
||||
#define IRET_REGS_SIZE (REGS_SIZE - offsetof(struct pt_regs, ip))
|
||||
#define IRET_SP_OFFSET (SP_OFFSET - offsetof(struct pt_regs, ip))
|
||||
|
||||
static bool deref_stack_regs(struct unwind_state *state, unsigned long addr,
|
||||
unsigned long *ip, unsigned long *sp, bool full)
|
||||
{
|
||||
size_t regs_size = full ? REGS_SIZE : IRET_REGS_SIZE;
|
||||
size_t sp_offset = full ? SP_OFFSET : IRET_SP_OFFSET;
|
||||
struct pt_regs *regs = (struct pt_regs *)(addr + regs_size - REGS_SIZE);
|
||||
|
||||
if (IS_ENABLED(CONFIG_X86_64)) {
|
||||
if (!stack_access_ok(state, addr, regs_size))
|
||||
return false;
|
||||
|
||||
*ip = regs->ip;
|
||||
*sp = regs->sp;
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
if (!stack_access_ok(state, addr, sp_offset))
|
||||
return false;
|
||||
|
||||
*ip = regs->ip;
|
||||
|
||||
if (user_mode(regs)) {
|
||||
if (!stack_access_ok(state, addr + sp_offset,
|
||||
REGS_SIZE - SP_OFFSET))
|
||||
return false;
|
||||
|
||||
*sp = regs->sp;
|
||||
} else
|
||||
*sp = (unsigned long)®s->sp;
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
bool unwind_next_frame(struct unwind_state *state)
|
||||
{
|
||||
unsigned long ip_p, sp, orig_ip, prev_sp = state->sp;
|
||||
enum stack_type prev_type = state->stack_info.type;
|
||||
struct orc_entry *orc;
|
||||
struct pt_regs *ptregs;
|
||||
bool indirect = false;
|
||||
|
||||
if (unwind_done(state))
|
||||
return false;
|
||||
|
||||
/* Don't let modules unload while we're reading their ORC data. */
|
||||
preempt_disable();
|
||||
|
||||
/* Have we reached the end? */
|
||||
if (state->regs && user_mode(state->regs))
|
||||
goto done;
|
||||
|
||||
/*
|
||||
* Find the orc_entry associated with the text address.
|
||||
*
|
||||
* Decrement call return addresses by one so they work for sibling
|
||||
* calls and calls to noreturn functions.
|
||||
*/
|
||||
orc = orc_find(state->signal ? state->ip : state->ip - 1);
|
||||
if (!orc || orc->sp_reg == ORC_REG_UNDEFINED)
|
||||
goto done;
|
||||
orig_ip = state->ip;
|
||||
|
||||
/* Find the previous frame's stack: */
|
||||
switch (orc->sp_reg) {
|
||||
case ORC_REG_SP:
|
||||
sp = state->sp + orc->sp_offset;
|
||||
break;
|
||||
|
||||
case ORC_REG_BP:
|
||||
sp = state->bp + orc->sp_offset;
|
||||
break;
|
||||
|
||||
case ORC_REG_SP_INDIRECT:
|
||||
sp = state->sp + orc->sp_offset;
|
||||
indirect = true;
|
||||
break;
|
||||
|
||||
case ORC_REG_BP_INDIRECT:
|
||||
sp = state->bp + orc->sp_offset;
|
||||
indirect = true;
|
||||
break;
|
||||
|
||||
case ORC_REG_R10:
|
||||
if (!state->regs || !state->full_regs) {
|
||||
orc_warn("missing regs for base reg R10 at ip %p\n",
|
||||
(void *)state->ip);
|
||||
goto done;
|
||||
}
|
||||
sp = state->regs->r10;
|
||||
break;
|
||||
|
||||
case ORC_REG_R13:
|
||||
if (!state->regs || !state->full_regs) {
|
||||
orc_warn("missing regs for base reg R13 at ip %p\n",
|
||||
(void *)state->ip);
|
||||
goto done;
|
||||
}
|
||||
sp = state->regs->r13;
|
||||
break;
|
||||
|
||||
case ORC_REG_DI:
|
||||
if (!state->regs || !state->full_regs) {
|
||||
orc_warn("missing regs for base reg DI at ip %p\n",
|
||||
(void *)state->ip);
|
||||
goto done;
|
||||
}
|
||||
sp = state->regs->di;
|
||||
break;
|
||||
|
||||
case ORC_REG_DX:
|
||||
if (!state->regs || !state->full_regs) {
|
||||
orc_warn("missing regs for base reg DX at ip %p\n",
|
||||
(void *)state->ip);
|
||||
goto done;
|
||||
}
|
||||
sp = state->regs->dx;
|
||||
break;
|
||||
|
||||
default:
|
||||
orc_warn("unknown SP base reg %d for ip %p\n",
|
||||
orc->sp_reg, (void *)state->ip);
|
||||
goto done;
|
||||
}
|
||||
|
||||
if (indirect) {
|
||||
if (!deref_stack_reg(state, sp, &sp))
|
||||
goto done;
|
||||
}
|
||||
|
||||
/* Find IP, SP and possibly regs: */
|
||||
switch (orc->type) {
|
||||
case ORC_TYPE_CALL:
|
||||
ip_p = sp - sizeof(long);
|
||||
|
||||
if (!deref_stack_reg(state, ip_p, &state->ip))
|
||||
goto done;
|
||||
|
||||
state->ip = ftrace_graph_ret_addr(state->task, &state->graph_idx,
|
||||
state->ip, (void *)ip_p);
|
||||
|
||||
state->sp = sp;
|
||||
state->regs = NULL;
|
||||
state->signal = false;
|
||||
break;
|
||||
|
||||
case ORC_TYPE_REGS:
|
||||
if (!deref_stack_regs(state, sp, &state->ip, &state->sp, true)) {
|
||||
orc_warn("can't dereference registers at %p for ip %p\n",
|
||||
(void *)sp, (void *)orig_ip);
|
||||
goto done;
|
||||
}
|
||||
|
||||
state->regs = (struct pt_regs *)sp;
|
||||
state->full_regs = true;
|
||||
state->signal = true;
|
||||
break;
|
||||
|
||||
case ORC_TYPE_REGS_IRET:
|
||||
if (!deref_stack_regs(state, sp, &state->ip, &state->sp, false)) {
|
||||
orc_warn("can't dereference iret registers at %p for ip %p\n",
|
||||
(void *)sp, (void *)orig_ip);
|
||||
goto done;
|
||||
}
|
||||
|
||||
ptregs = container_of((void *)sp, struct pt_regs, ip);
|
||||
if ((unsigned long)ptregs >= prev_sp &&
|
||||
on_stack(&state->stack_info, ptregs, REGS_SIZE)) {
|
||||
state->regs = ptregs;
|
||||
state->full_regs = false;
|
||||
} else
|
||||
state->regs = NULL;
|
||||
|
||||
state->signal = true;
|
||||
break;
|
||||
|
||||
default:
|
||||
orc_warn("unknown .orc_unwind entry type %d\n", orc->type);
|
||||
break;
|
||||
}
|
||||
|
||||
/* Find BP: */
|
||||
switch (orc->bp_reg) {
|
||||
case ORC_REG_UNDEFINED:
|
||||
if (state->regs && state->full_regs)
|
||||
state->bp = state->regs->bp;
|
||||
break;
|
||||
|
||||
case ORC_REG_PREV_SP:
|
||||
if (!deref_stack_reg(state, sp + orc->bp_offset, &state->bp))
|
||||
goto done;
|
||||
break;
|
||||
|
||||
case ORC_REG_BP:
|
||||
if (!deref_stack_reg(state, state->bp + orc->bp_offset, &state->bp))
|
||||
goto done;
|
||||
break;
|
||||
|
||||
default:
|
||||
orc_warn("unknown BP base reg %d for ip %p\n",
|
||||
orc->bp_reg, (void *)orig_ip);
|
||||
goto done;
|
||||
}
|
||||
|
||||
/* Prevent a recursive loop due to bad ORC data: */
|
||||
if (state->stack_info.type == prev_type &&
|
||||
on_stack(&state->stack_info, (void *)state->sp, sizeof(long)) &&
|
||||
state->sp <= prev_sp) {
|
||||
orc_warn("stack going in the wrong direction? ip=%p\n",
|
||||
(void *)orig_ip);
|
||||
goto done;
|
||||
}
|
||||
|
||||
preempt_enable();
|
||||
return true;
|
||||
|
||||
done:
|
||||
preempt_enable();
|
||||
state->stack_info.type = STACK_TYPE_UNKNOWN;
|
||||
return false;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(unwind_next_frame);
|
||||
|
||||
void __unwind_start(struct unwind_state *state, struct task_struct *task,
|
||||
struct pt_regs *regs, unsigned long *first_frame)
|
||||
{
|
||||
memset(state, 0, sizeof(*state));
|
||||
state->task = task;
|
||||
|
||||
/*
|
||||
* Refuse to unwind the stack of a task while it's executing on another
|
||||
* CPU. This check is racy, but that's ok: the unwinder has other
|
||||
* checks to prevent it from going off the rails.
|
||||
*/
|
||||
if (task_on_another_cpu(task))
|
||||
goto done;
|
||||
|
||||
if (regs) {
|
||||
if (user_mode(regs))
|
||||
goto done;
|
||||
|
||||
state->ip = regs->ip;
|
||||
state->sp = kernel_stack_pointer(regs);
|
||||
state->bp = regs->bp;
|
||||
state->regs = regs;
|
||||
state->full_regs = true;
|
||||
state->signal = true;
|
||||
|
||||
} else if (task == current) {
|
||||
asm volatile("lea (%%rip), %0\n\t"
|
||||
"mov %%rsp, %1\n\t"
|
||||
"mov %%rbp, %2\n\t"
|
||||
: "=r" (state->ip), "=r" (state->sp),
|
||||
"=r" (state->bp));
|
||||
|
||||
} else {
|
||||
struct inactive_task_frame *frame = (void *)task->thread.sp;
|
||||
|
||||
state->sp = task->thread.sp;
|
||||
state->bp = READ_ONCE_NOCHECK(frame->bp);
|
||||
state->ip = READ_ONCE_NOCHECK(frame->ret_addr);
|
||||
}
|
||||
|
||||
if (get_stack_info((unsigned long *)state->sp, state->task,
|
||||
&state->stack_info, &state->stack_mask))
|
||||
return;
|
||||
|
||||
/*
|
||||
* The caller can provide the address of the first frame directly
|
||||
* (first_frame) or indirectly (regs->sp) to indicate which stack frame
|
||||
* to start unwinding at. Skip ahead until we reach it.
|
||||
*/
|
||||
|
||||
/* When starting from regs, skip the regs frame: */
|
||||
if (regs) {
|
||||
unwind_next_frame(state);
|
||||
return;
|
||||
}
|
||||
|
||||
/* Otherwise, skip ahead to the user-specified starting frame: */
|
||||
while (!unwind_done(state) &&
|
||||
(!on_stack(&state->stack_info, first_frame, sizeof(long)) ||
|
||||
state->sp <= (unsigned long)first_frame))
|
||||
unwind_next_frame(state);
|
||||
|
||||
return;
|
||||
|
||||
done:
|
||||
state->stack_info.type = STACK_TYPE_UNKNOWN;
|
||||
return;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(__unwind_start);
|
||||
|
|
@ -24,6 +24,7 @@
|
|||
#include <asm/asm-offsets.h>
|
||||
#include <asm/thread_info.h>
|
||||
#include <asm/page_types.h>
|
||||
#include <asm/orc_lookup.h>
|
||||
#include <asm/cache.h>
|
||||
#include <asm/boot.h>
|
||||
|
||||
|
|
@ -148,6 +149,8 @@ SECTIONS
|
|||
|
||||
BUG_TABLE
|
||||
|
||||
ORC_UNWIND_TABLE
|
||||
|
||||
. = ALIGN(PAGE_SIZE);
|
||||
__vvar_page = .;
|
||||
|
||||
|
|
|
|||
|
|
@ -680,6 +680,31 @@
|
|||
#define BUG_TABLE
|
||||
#endif
|
||||
|
||||
#ifdef CONFIG_ORC_UNWINDER
|
||||
#define ORC_UNWIND_TABLE \
|
||||
. = ALIGN(4); \
|
||||
.orc_unwind_ip : AT(ADDR(.orc_unwind_ip) - LOAD_OFFSET) { \
|
||||
VMLINUX_SYMBOL(__start_orc_unwind_ip) = .; \
|
||||
KEEP(*(.orc_unwind_ip)) \
|
||||
VMLINUX_SYMBOL(__stop_orc_unwind_ip) = .; \
|
||||
} \
|
||||
. = ALIGN(6); \
|
||||
.orc_unwind : AT(ADDR(.orc_unwind) - LOAD_OFFSET) { \
|
||||
VMLINUX_SYMBOL(__start_orc_unwind) = .; \
|
||||
KEEP(*(.orc_unwind)) \
|
||||
VMLINUX_SYMBOL(__stop_orc_unwind) = .; \
|
||||
} \
|
||||
. = ALIGN(4); \
|
||||
.orc_lookup : AT(ADDR(.orc_lookup) - LOAD_OFFSET) { \
|
||||
VMLINUX_SYMBOL(orc_lookup) = .; \
|
||||
. += (((SIZEOF(.text) + LOOKUP_BLOCK_SIZE - 1) / \
|
||||
LOOKUP_BLOCK_SIZE) + 1) * 4; \
|
||||
VMLINUX_SYMBOL(orc_lookup_end) = .; \
|
||||
}
|
||||
#else
|
||||
#define ORC_UNWIND_TABLE
|
||||
#endif
|
||||
|
||||
#ifdef CONFIG_PM_TRACE
|
||||
#define TRACEDATA \
|
||||
. = ALIGN(4); \
|
||||
|
|
@ -866,7 +891,7 @@
|
|||
DATA_DATA \
|
||||
CONSTRUCTORS \
|
||||
} \
|
||||
BUG_TABLE
|
||||
BUG_TABLE \
|
||||
|
||||
#define INIT_TEXT_SECTION(inittext_align) \
|
||||
. = ALIGN(inittext_align); \
|
||||
|
|
|
|||
|
|
@ -374,6 +374,9 @@ config STACK_VALIDATION
|
|||
pointers (if CONFIG_FRAME_POINTER is enabled). This helps ensure
|
||||
that runtime stack traces are more reliable.
|
||||
|
||||
This is also a prerequisite for generation of ORC unwind data, which
|
||||
is needed for CONFIG_ORC_UNWINDER.
|
||||
|
||||
For more information, see
|
||||
tools/objtool/Documentation/stack-validation.txt.
|
||||
|
||||
|
|
|
|||
|
|
@ -258,7 +258,8 @@ ifneq ($(SKIP_STACK_VALIDATION),1)
|
|||
|
||||
__objtool_obj := $(objtree)/tools/objtool/objtool
|
||||
|
||||
objtool_args = check
|
||||
objtool_args = $(if $(CONFIG_ORC_UNWINDER),orc generate,check)
|
||||
|
||||
ifndef CONFIG_FRAME_POINTER
|
||||
objtool_args += --no-fp
|
||||
endif
|
||||
|
|
@ -279,6 +280,11 @@ objtool_obj = $(if $(patsubst y%,, \
|
|||
endif # SKIP_STACK_VALIDATION
|
||||
endif # CONFIG_STACK_VALIDATION
|
||||
|
||||
# Rebuild all objects when objtool changes, or is enabled/disabled.
|
||||
objtool_dep = $(objtool_obj) \
|
||||
$(wildcard include/config/orc/unwinder.h \
|
||||
include/config/stack/validation.h)
|
||||
|
||||
define rule_cc_o_c
|
||||
$(call echo-cmd,checksrc) $(cmd_checksrc) \
|
||||
$(call cmd_and_fixdep,cc_o_c) \
|
||||
|
|
@ -301,13 +307,13 @@ cmd_undef_syms = echo
|
|||
endif
|
||||
|
||||
# Built-in and composite module parts
|
||||
$(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_obj) FORCE
|
||||
$(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE
|
||||
$(call cmd,force_checksrc)
|
||||
$(call if_changed_rule,cc_o_c)
|
||||
|
||||
# Single-part modules are special since we need to mark them in $(MODVERDIR)
|
||||
|
||||
$(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_obj) FORCE
|
||||
$(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE
|
||||
$(call cmd,force_checksrc)
|
||||
$(call if_changed_rule,cc_o_c)
|
||||
@{ echo $(@:.o=.ko); echo $@; \
|
||||
|
|
@ -402,7 +408,7 @@ cmd_modversions_S = \
|
|||
endif
|
||||
endif
|
||||
|
||||
$(obj)/%.o: $(src)/%.S $(objtool_obj) FORCE
|
||||
$(obj)/%.o: $(src)/%.S $(objtool_dep) FORCE
|
||||
$(call if_changed_rule,as_o_S)
|
||||
|
||||
targets += $(real-objs-y) $(real-objs-m) $(lib-y)
|
||||
|
|
|
|||
Загрузка…
Ссылка в новой задаче