Pull x86 fixes from Ingo Molnar:
"Misc fixes:
- fix the s2ram regression related to confusion around segment
register restoration, plus related cleanups that make the code more
robust
- a guess-unwinder Kconfig dependency fix
- an isoimage build target fix for certain tool chain combinations
- instruction decoder opcode map fixes+updates, and the syncing of
the kernel decoder headers to the objtool headers
- a kmmio tracing fix
- two 5-level paging related fixes
- a topology enumeration fix on certain SMP systems"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
objtool: Resync objtool's instruction decoder source code copy with the kernel's latest version
x86/decoder: Fix and update the opcodes map
x86/power: Make restore_processor_context() sane
x86/power/32: Move SYSENTER MSR restoration to fix_processor_context()
x86/power/64: Use struct desc_ptr for the IDT in struct saved_context
x86/unwinder/guess: Prevent using CONFIG_UNWINDER_GUESS=y with CONFIG_STACKDEPOT=y
x86/build: Don't verify mtools configuration file for isoimage
x86/mm/kmmio: Fix mmiotrace for page unaligned addresses
x86/boot/compressed/64: Print error if 5-level paging is not supported
x86/boot/compressed/64: Detect and handle 5-level paging at boot-time
x86/smpboot: Do not use smp_num_siblings in __max_logical_packages calculation
objtool grew this new warning:
Warning: synced file at 'tools/objtool/arch/x86/include/asm/inat.h' differs from latest kernel version at 'arch/x86/include/asm/inat.h'
which upstream header grew new INAT_SEG_* definitions.
Sync up the tooling version of the header.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Arnd Bergmann reported a bunch of warnings like:
crypto/jitterentropy.o: warning: objtool: jent_fold_time()+0x3b: call without frame pointer save/setup
crypto/jitterentropy.o: warning: objtool: jent_stuck()+0x1d: call without frame pointer save/setup
crypto/jitterentropy.o: warning: objtool: jent_unbiased_bit()+0x15: call without frame pointer save/setup
crypto/jitterentropy.o: warning: objtool: jent_read_entropy()+0x32: call without frame pointer save/setup
crypto/jitterentropy.o: warning: objtool: jent_entropy_collector_free()+0x19: call without frame pointer save/setup
and
arch/x86/events/core.o: warning: objtool: collect_events uses BP as a scratch register
arch/x86/events/core.o: warning: objtool: events_ht_sysfs_show()+0x22: call without frame pointer save/setup
With certain rare configurations, GCC sometimes sets up the frame
pointer with:
lea (%rsp),%rbp
instead of:
mov %rsp,%rbp
The instructions are equivalent, so treat the former like the latter.
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/a468af8b28a69b83fffc6d7668be9b6fcc873699.1506526584.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The kbuild bot reported the following warning with GCC 4.4 and a
randconfig:
net/socket.o: warning: objtool: compat_sock_ioctl()+0x1083: stack state mismatch: cfa1=7+160 cfa2=-1+0
This is caused by another GCC non-optimization, where it backs up and
restores the stack pointer for no apparent reason:
2f91: 48 89 e0 mov %rsp,%rax
2f94: 4c 89 e7 mov %r12,%rdi
2f97: 4c 89 f6 mov %r14,%rsi
2f9a: ba 20 00 00 00 mov $0x20,%edx
2f9f: 48 89 c4 mov %rax,%rsp
This issue would have been happily ignored before the following commit:
dd88a0a0c8 ("objtool: Handle GCC stack pointer adjustment bug")
But now that objtool is paying attention to such stack pointer writes
to/from a register, it needs to understand them properly. In this case
that means recognizing that the "mov %rsp, %rax" instruction is
potentially a backup of the stack pointer.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Miguel Bernal Marin <miguel.bernal.marin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: dd88a0a0c8 ("objtool: Handle GCC stack pointer adjustment bug")
Link: http://lkml.kernel.org/r/8c7aa8e9a36fbbb6655d9d8e7cea58958c912da8.1505942196.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Arnd Bergmann reported the following warning with GCC 7.1.1:
fs/fs_pin.o: warning: objtool: pin_kill()+0x139: stack state mismatch: cfa1=7+88 cfa2=7+96
And the kbuild robot reported the following warnings with GCC 5.4.1:
fs/fs_pin.o: warning: objtool: pin_kill()+0x182: return with modified stack frame
fs/quota/dquot.o: warning: objtool: dquot_alloc_inode()+0x140: stack state mismatch: cfa1=7+120 cfa2=7+128
fs/quota/dquot.o: warning: objtool: dquot_free_inode()+0x11a: stack state mismatch: cfa1=7+112 cfa2=7+120
Those warnings are caused by an unusual GCC non-optimization where it
uses an intermediate register to adjust the stack pointer. It does:
lea 0x8(%rsp), %rcx
...
mov %rcx, %rsp
Instead of the obvious:
add $0x8, %rsp
It makes no sense to use an intermediate register, so I opened a GCC bug
to track it:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81813
But it's not exactly a high-priority bug and it looks like we'll be
stuck with this issue for a while. So for now we have to track register
values when they're loaded with stack pointer offsets.
This is kind of a big workaround for a tiny problem, but c'est la vie.
I hope to eventually create a GCC plugin to implement a big chunk of
objtool's functionality. Hopefully at that point we'll be able to
remove of a lot of these GCC-isms from the objtool code.
Reported-by: Arnd Bergmann <arnd@arndb.de>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/6a41a96884c725e7f05413bb7df40cfe824b2444.1504028945.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Arnd reported some false positive warnings with GCC 7:
drivers/hid/wacom_wac.o: warning: objtool: wacom_bpt3_touch()+0x2a5: stack state mismatch: cfa1=7+8 cfa2=6+16
drivers/iio/adc/vf610_adc.o: warning: objtool: vf610_adc_calculate_rates() falls through to next function vf610_adc_sample_set()
drivers/pwm/pwm-hibvt.o: warning: objtool: hibvt_pwm_get_state() falls through to next function hibvt_pwm_remove()
drivers/pwm/pwm-mediatek.o: warning: objtool: mtk_pwm_config() falls through to next function mtk_pwm_enable()
drivers/spi/spi-bcm2835.o: warning: objtool: .text: unexpected end of section
drivers/spi/spi-bcm2835aux.o: warning: objtool: .text: unexpected end of section
drivers/watchdog/digicolor_wdt.o: warning: objtool: dc_wdt_get_timeleft() falls through to next function dc_wdt_restart()
When GCC 7 detects a potential divide-by-zero condition, it sometimes
inserts a UD2 instruction for the case where the divisor is zero,
instead of letting the hardware trap on the divide instruction.
Objtool doesn't consider UD2 to be fatal unless it's annotated with
unreachable(). So it considers the GCC-generated UD2 to be non-fatal,
and it tries to follow the control flow past the UD2 and gets
confused.
Previously, objtool *did* assume UD2 was always a dead end. That
changed with the following commit:
d1091c7fa3 ("objtool: Improve detection of BUG() and other dead ends")
The motivation behind that change was that Peter was planning on using
UD2 for __WARN(), which is *not* a dead end. However, it turns out
that some emulators rely on UD2 being fatal, so he ended up using
'ud0' instead:
9a93848fe7 ("x86/debug: Implement __WARN() using UD0")
For GCC 4.5+, it should be safe to go back to the previous assumption
that UD2 is fatal, even when it's not annotated with unreachable().
But for pre-4.5 versions of GCC, the unreachable() macro isn't
supported, so such cases of UD2 need to be explicitly annotated as
reachable.
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: d1091c7fa3 ("objtool: Improve detection of BUG() and other dead ends")
Link: http://lkml.kernel.org/r/e57fa9dfede25f79487da8126ee9cdf7b856db65.1501188854.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull perf updates from Ingo Molnar:
"Most of the changes are for tooling, the main changes in this cycle were:
- Improve Intel-PT hardware tracing support, both on the kernel and
on the tooling side: PTWRITE instruction support, power events for
C-state tracing, etc. (Adrian Hunter)
- Add support to measure SMI cost to the x86 architecture, with
tooling support in 'perf stat' (Kan Liang)
- Support function filtering in 'perf ftrace', plus related
improvements (Namhyung Kim)
- Allow adding and removing fields to the default 'perf script'
columns, using + or - as field prefixes to do so (Andi Kleen)
- Allow resolving the DSO name with 'perf script -F brstack{sym,off},dso'
(Mark Santaniello)
- Add perf tooling unwind support for PowerPC (Paolo Bonzini)
- ... and various other improvements as well"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (84 commits)
perf auxtrace: Add CPU filter support
perf intel-pt: Do not use TSC packets for calculating CPU cycles to TSC
perf intel-pt: Update documentation to include new ptwrite and power events
perf intel-pt: Add example script for power events and PTWRITE
perf intel-pt: Synthesize new power and "ptwrite" events
perf intel-pt: Move code in intel_pt_synth_events() to simplify attr setting
perf intel-pt: Factor out intel_pt_set_event_name()
perf intel-pt: Tidy messages into called function intel_pt_synth_event()
perf intel-pt: Tidy Intel PT evsel lookup into separate function
perf intel-pt: Join needlessly wrapped lines
perf intel-pt: Remove unused instructions_sample_period
perf intel-pt: Factor out common code synthesizing event samples
perf script: Add synthesized Intel PT power and ptwrite events
perf/x86/intel: Constify the 'lbr_desc[]' array and make a function static
perf script: Add 'synth' field for synthesized event payloads
perf auxtrace: Add itrace option to output power events
perf auxtrace: Add itrace option to output ptwrite events
tools include: Add byte-swapping macros to kernel.h
perf script: Add 'synth' event type for synthesized events
x86/insn: perf tools: Add new ptwrite instruction
...
Add ptwrite to the op code map and the perf tools new instructions test.
To run the test:
$ tools/perf/perf test "x86 ins"
39: Test x86 instruction decoder - new instructions : Ok
Or to see the details:
$ tools/perf/perf test -v "x86 ins" 2>&1 | grep ptwrite
For information about ptwrite, refer the Intel SDM.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: http://lkml.kernel.org/r/1495180230-19367-1-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The BUG() macro's use of __builtin_unreachable() via the unreachable()
macro tells gcc that the instruction is a dead end, and that it's safe
to assume the current code path will not execute past the previous
instruction.
On x86, the BUG() macro is implemented with the 'ud2' instruction. When
objtool's branch analysis sees that instruction, it knows the current
code path has come to a dead end.
Peter Zijlstra has been working on a patch to change the WARN macros to
use 'ud2'. That patch will break objtool's assumption that 'ud2' is
always a dead end.
Generally it's best for objtool to avoid making those kinds of
assumptions anyway. The more ignorant it is of kernel code internals,
the better.
So create a more generic way for objtool to detect dead ends by adding
an annotation to the unreachable() macro. The annotation stores a
pointer to the end of the unreachable code path in an '__unreachable'
section. Objtool can read that section to find the dead ends.
Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/41a6d33971462ebd944a1c60ad4bf5be86c17b77.1487712920.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Arnd reported that enabling CONFIG_MATOM results in a bunch of objtool
false positive frame pointer warnings:
arch/x86/events/intel/ds.o: warning: objtool: intel_pmu_pebs_del()+0x43: call without frame pointer save/setup
security/keys/keyring.o: warning: objtool: keyring_read()+0x59: call without frame pointer save/setup
kernel/signal.o: warning: objtool: __dequeue_signal()+0xd8: call without frame pointer save/setup
...
objtool gets confused by the fact that the '-mtune=atom' GCC option
sometimes uses 'lea (%rsp),%rbp' instead of 'mov %rsp,%rbp'. The
instructions are effectively the same, but objtool doesn't know about
the 'lea' variant.
Fix the false warnings by adding support for 'lea (%rsp),%rbp' in the
objtool decoder.
Reported-by: Arnd Bergmann <arnd@arndb.de>
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: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull misc fixes from Thomas Gleixner:
"This update contains:
- a fix for stomp-machine so the nmi_watchdog wont trigger on the cpu
waiting for the others to execute the callback
- various fixes and updates to objtool including an resync of the
instruction decoder to match the kernel's decoder"
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
objtool: Un-capitalize "Warning" for out-of-sync instruction decoder
objtool: Resync x86 instruction decoder with the kernel's
objtool: Support new GCC 6 switch jump table pattern
stop_machine: Touch_nmi_watchdog() after MULTI_STOP_PREPARE
objtool: Add 'fixdep' to objtool/.gitignore
When running objtool on a ppc64le host to analyze x86 binaries, it
reports a lot of false warnings like:
ipc/compat_mq.o: warning: objtool: compat_SyS_mq_open()+0x91: can't find jump dest instruction at .text+0x3a5
The warnings are caused by the x86 instruction decoder setting the wrong
value for the jump instruction's immediate field because it assumes that
"char == signed char", which isn't true for all architectures. When
converting char to int, gcc sign-extends on x86 but doesn't sign-extend
on ppc64le.
According to the gcc man page, that's a feature, not a bug:
> Each kind of machine has a default for what "char" should be. It is
> either like "unsigned char" by default or like "signed char" by
> default.
>
> Ideally, a portable program should always use "signed char" or
> "unsigned char" when it depends on the signedness of an object.
Conform to the "standards" by changing the "char" casts to "signed
char". This results in no actual changes to the object code on x86.
Note: the x86 decoder now lives in three different locations in the
kernel tree, which are all kept in sync via makefile checks and
warnings: in-kernel, perf, and objtool. This fixes all three locations.
Eventually we should probably try to at least converge the two separate
"tools" locations into a single shared location.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/9dd4161719b20e6def9564646d68bfbe498c549f.1456962210.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
