- Have recordmcount work with > 64K sections (to support LTO)
- kprobe RCU fixes
- Correct a kprobe critical section with missing mutex
- Remove redundant arch_disarm_kprobe() call
- Fix lockup when kretprobe triggers within kprobe_flush_task()
- Fix memory leak in fetch_op_data operations
- Fix sleep in atomic in ftrace trace array sample code
- Free up memory on failure in sample trace array code
- Fix incorrect reporting of function_graph fields in format file
- Fix quote within quote parsing in bootconfig
- Fix return value of bootconfig tool
- Add testcases for bootconfig tool
- Fix maybe uninitialized warning in ftrace pid file code
- Remove unused variable in tracing_iter_reset()
- Fix some typos
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Merge tag 'trace-v5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
- Have recordmcount work with > 64K sections (to support LTO)
- kprobe RCU fixes
- Correct a kprobe critical section with missing mutex
- Remove redundant arch_disarm_kprobe() call
- Fix lockup when kretprobe triggers within kprobe_flush_task()
- Fix memory leak in fetch_op_data operations
- Fix sleep in atomic in ftrace trace array sample code
- Free up memory on failure in sample trace array code
- Fix incorrect reporting of function_graph fields in format file
- Fix quote within quote parsing in bootconfig
- Fix return value of bootconfig tool
- Add testcases for bootconfig tool
- Fix maybe uninitialized warning in ftrace pid file code
- Remove unused variable in tracing_iter_reset()
- Fix some typos
* tag 'trace-v5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
ftrace: Fix maybe-uninitialized compiler warning
tools/bootconfig: Add testcase for show-command and quotes test
tools/bootconfig: Fix to return 0 if succeeded to show the bootconfig
tools/bootconfig: Fix to use correct quotes for value
proc/bootconfig: Fix to use correct quotes for value
tracing: Remove unused event variable in tracing_iter_reset
tracing/probe: Fix memleak in fetch_op_data operations
trace: Fix typo in allocate_ftrace_ops()'s comment
tracing: Make ftrace packed events have align of 1
sample-trace-array: Remove trace_array 'sample-instance'
sample-trace-array: Fix sleeping function called from invalid context
kretprobe: Prevent triggering kretprobe from within kprobe_flush_task
kprobes: Remove redundant arch_disarm_kprobe() call
kprobes: Fix to protect kick_kprobe_optimizer() by kprobe_mutex
kprobes: Use non RCU traversal APIs on kprobe_tables if possible
kprobes: Suppress the suspicious RCU warning on kprobes
recordmcount: support >64k sections
Ziqian reported lockup when adding retprobe on _raw_spin_lock_irqsave.
My test was also able to trigger lockdep output:
============================================
WARNING: possible recursive locking detected
5.6.0-rc6+ #6 Not tainted
--------------------------------------------
sched-messaging/2767 is trying to acquire lock:
ffffffff9a492798 (&(kretprobe_table_locks[i].lock)){-.-.}, at: kretprobe_hash_lock+0x52/0xa0
but task is already holding lock:
ffffffff9a491a18 (&(kretprobe_table_locks[i].lock)){-.-.}, at: kretprobe_trampoline+0x0/0x50
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&(kretprobe_table_locks[i].lock));
lock(&(kretprobe_table_locks[i].lock));
*** DEADLOCK ***
May be due to missing lock nesting notation
1 lock held by sched-messaging/2767:
#0: ffffffff9a491a18 (&(kretprobe_table_locks[i].lock)){-.-.}, at: kretprobe_trampoline+0x0/0x50
stack backtrace:
CPU: 3 PID: 2767 Comm: sched-messaging Not tainted 5.6.0-rc6+ #6
Call Trace:
dump_stack+0x96/0xe0
__lock_acquire.cold.57+0x173/0x2b7
? native_queued_spin_lock_slowpath+0x42b/0x9e0
? lockdep_hardirqs_on+0x590/0x590
? __lock_acquire+0xf63/0x4030
lock_acquire+0x15a/0x3d0
? kretprobe_hash_lock+0x52/0xa0
_raw_spin_lock_irqsave+0x36/0x70
? kretprobe_hash_lock+0x52/0xa0
kretprobe_hash_lock+0x52/0xa0
trampoline_handler+0xf8/0x940
? kprobe_fault_handler+0x380/0x380
? find_held_lock+0x3a/0x1c0
kretprobe_trampoline+0x25/0x50
? lock_acquired+0x392/0xbc0
? _raw_spin_lock_irqsave+0x50/0x70
? __get_valid_kprobe+0x1f0/0x1f0
? _raw_spin_unlock_irqrestore+0x3b/0x40
? finish_task_switch+0x4b9/0x6d0
? __switch_to_asm+0x34/0x70
? __switch_to_asm+0x40/0x70
The code within the kretprobe handler checks for probe reentrancy,
so we won't trigger any _raw_spin_lock_irqsave probe in there.
The problem is in outside kprobe_flush_task, where we call:
kprobe_flush_task
kretprobe_table_lock
raw_spin_lock_irqsave
_raw_spin_lock_irqsave
where _raw_spin_lock_irqsave triggers the kretprobe and installs
kretprobe_trampoline handler on _raw_spin_lock_irqsave return.
The kretprobe_trampoline handler is then executed with already
locked kretprobe_table_locks, and first thing it does is to
lock kretprobe_table_locks ;-) the whole lockup path like:
kprobe_flush_task
kretprobe_table_lock
raw_spin_lock_irqsave
_raw_spin_lock_irqsave ---> probe triggered, kretprobe_trampoline installed
---> kretprobe_table_locks locked
kretprobe_trampoline
trampoline_handler
kretprobe_hash_lock(current, &head, &flags); <--- deadlock
Adding kprobe_busy_begin/end helpers that mark code with fake
probe installed to prevent triggering of another kprobe within
this code.
Using these helpers in kprobe_flush_task, so the probe recursion
protection check is hit and the probe is never set to prevent
above lockup.
Link: http://lkml.kernel.org/r/158927059835.27680.7011202830041561604.stgit@devnote2
Fixes: ef53d9c5e4 ("kprobes: improve kretprobe scalability with hashed locking")
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "Gustavo A . R . Silva" <gustavoars@kernel.org>
Cc: Anders Roxell <anders.roxell@linaro.org>
Cc: "Naveen N . Rao" <naveen.n.rao@linux.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David Miller <davem@davemloft.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Reported-by: "Ziqian SUN (Zamir)" <zsun@redhat.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Add perf text poke events for kprobes. That includes:
- the replaced instruction(s) which are executed out-of-line
i.e. arch_copy_kprobe() and arch_remove_kprobe()
- the INT3 that activates the kprobe
i.e. arch_arm_kprobe() and arch_disarm_kprobe()
- optimised kprobe function
i.e. arch_prepare_optimized_kprobe() and
__arch_remove_optimized_kprobe()
- optimised kprobe
i.e. arch_optimize_kprobes() and arch_unoptimize_kprobe()
Resulting in 8 possible text_poke events:
0: NULL -> probe.ainsn.insn (if ainsn.boostable && !kp.post_handler)
arch_copy_kprobe()
1: old0 -> INT3 arch_arm_kprobe()
// boosted kprobe active
2: NULL -> optprobe_trampoline arch_prepare_optimized_kprobe()
3: INT3,old1,old2,old3,old4 -> JMP32 arch_optimize_kprobes()
// optprobe active
4: JMP32 -> INT3,old1,old2,old3,old4
// optprobe disabled and kprobe active (this sometimes goes back to 3)
arch_unoptimize_kprobe()
5: optprobe_trampoline -> NULL arch_remove_optimized_kprobe()
// boosted kprobe active
6: INT3 -> old0 arch_disarm_kprobe()
7: probe.ainsn.insn -> NULL (if ainsn.boostable && !kp.post_handler)
arch_remove_kprobe()
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lkml.kernel.org/r/20200512121922.8997-6-adrian.hunter@intel.com
The entry rework moved interrupt entry code from the irqentry to the
noinstr section which made the irqentry section empty.
This breaks boundary checks which rely on the __irqentry_text_start/end
markers to find out whether a function in a stack trace is
interrupt/exception entry code. This affects the function graph tracer and
filter_irq_stacks().
As the IDT entry points are all sequentialy emitted this is rather simple
to unbreak by injecting __irqentry_text_start/end as global labels.
To make this work correctly:
- Remove the IRQENTRY_TEXT section from the x86 linker script
- Define __irqentry so it breaks the build if it's used
- Adjust the entry mirroring in PTI
- Remove the redundant kprobes and unwinder bound checks
Reported-by: Qian Cai <cai@lca.pw>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The replacement of <asm/pgrable.h> with <linux/pgtable.h> made the include
of the latter in the middle of asm includes. Fix this up with the aid of
the below script and manual adjustments here and there.
import sys
import re
if len(sys.argv) is not 3:
print "USAGE: %s <file> <header>" % (sys.argv[0])
sys.exit(1)
hdr_to_move="#include <linux/%s>" % sys.argv[2]
moved = False
in_hdrs = False
with open(sys.argv[1], "r") as f:
lines = f.readlines()
for _line in lines:
line = _line.rstrip('
')
if line == hdr_to_move:
continue
if line.startswith("#include <linux/"):
in_hdrs = True
elif not moved and in_hdrs:
moved = True
print hdr_to_move
print line
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200514170327.31389-4-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The include/linux/pgtable.h is going to be the home of generic page table
manipulation functions.
Start with moving asm-generic/pgtable.h to include/linux/pgtable.h and
make the latter include asm/pgtable.h.
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200514170327.31389-3-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
While looking at an objtool UACCESS warning, it suddenly occurred to me
that it is entirely possible to have an OPTPROBE right in the middle of
an UACCESS region.
In this case we must of course clear FLAGS.AC while running the KPROBE.
Luckily the trampoline already saves/restores [ER]FLAGS, so all we need
to do is inject a CLAC. Unfortunately we cannot use ALTERNATIVE() in the
trampoline text, so we have to frob that manually.
Fixes: ca0bbc70f147 ("sched/x86_64: Don't save flags on context switch")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lkml.kernel.org/r/20200305092130.GU2596@hirez.programming.kicks-ass.net
Pull perf updates from Ingo Molnar:
"Kernel side changes:
- Ftrace is one of the last W^X violators (after this only KLP is
left). These patches move it over to the generic text_poke()
interface and thereby get rid of this oddity. This requires a
surprising amount of surgery, by Peter Zijlstra.
- x86/AMD PMUs: add support for 'Large Increment per Cycle Events' to
count certain types of events that have a special, quirky hw ABI
(by Kim Phillips)
- kprobes fixes by Masami Hiramatsu
Lots of tooling updates as well, the following subcommands were
updated: annotate/report/top, c2c, clang, record, report/top TUI,
sched timehist, tests; plus updates were done to the gtk ui, libperf,
headers and the parser"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (57 commits)
perf/x86/amd: Add support for Large Increment per Cycle Events
perf/x86/amd: Constrain Large Increment per Cycle events
perf/x86/intel/rapl: Add Comet Lake support
tracing: Initialize ret in syscall_enter_define_fields()
perf header: Use last modification time for timestamp
perf c2c: Fix return type for histogram sorting comparision functions
perf beauty sockaddr: Fix augmented syscall format warning
perf/ui/gtk: Fix gtk2 build
perf ui gtk: Add missing zalloc object
perf tools: Use %define api.pure full instead of %pure-parser
libperf: Setup initial evlist::all_cpus value
perf report: Fix no libunwind compiled warning break s390 issue
perf tools: Support --prefix/--prefix-strip
perf report: Clarify in help that --children is default
tools build: Fix test-clang.cpp with Clang 8+
perf clang: Fix build with Clang 9
kprobes: Fix optimize_kprobe()/unoptimize_kprobe() cancellation logic
tools lib: Fix builds when glibc contains strlcpy()
perf report/top: Make 'e' visible in the help and make it toggle showing callchains
perf report/top: Do not offer annotation for symbols without samples
...
The inclusion of linux/vmalloc.h, which is required for its definition
of set_vm_flush_reset_perms(), is somehow dependent on asm/realmode.h
being included by asm/acpi.h. Explicitly include linux/vmalloc.h so
that a future patch can drop the realmode.h include from asm/acpi.h
without breaking the build.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lkml.kernel.org/r/20191126165417.22423-5-sean.j.christopherson@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add a few words describing how it is safe to overwrite the 4 bytes
after a kprobe. In specific it is possible the JMP.d32 required for
the optimized kprobe overwrites multiple instructions.
Tested-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
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>
Link: https://lkml.kernel.org/r/20191111132458.401696663@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Kprobes does something like:
register:
arch_arm_kprobe()
text_poke(INT3)
/* guarantees nothing, INT3 will become visible at some point, maybe */
kprobe_optimizer()
/* guarantees the bytes after INT3 are unused */
synchronize_rcu_tasks();
text_poke_bp(JMP32);
/* implies IPI-sync, kprobe really is enabled */
unregister:
__disarm_kprobe()
unoptimize_kprobe()
text_poke_bp(INT3 + tail);
/* implies IPI-sync, so tail is guaranteed visible */
arch_disarm_kprobe()
text_poke(old);
/* guarantees nothing, old will maybe become visible */
synchronize_rcu()
free-stuff
Now the problem is that on register, the synchronize_rcu_tasks() does
not imply sufficient to guarantee all CPUs have already observed INT3
(although in practice this is exceedingly unlikely not to have
happened) (similar to how MEMBARRIER_CMD_PRIVATE_EXPEDITED does not
imply MEMBARRIER_CMD_PRIVATE_EXPEDITED_SYNC_CORE).
Worse, even if it did, we'd have to do 2 synchronize calls to provide
the guarantee we're looking for, the first to ensure INT3 is visible,
the second to guarantee nobody is then still using the instruction
bytes after INT3.
Similar on unregister; the synchronize_rcu() between
__unregister_kprobe_top() and __unregister_kprobe_bottom() does not
guarantee all CPUs are free of the INT3 (and observe the old text).
Therefore, sprinkle some IPI-sync love around. This guarantees that
all CPUs agree on the text and RCU once again provides the required
guaranteed.
Tested-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
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>
Link: https://lkml.kernel.org/r/20191111132458.162172862@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull perf updates from Ingo Molnar:
"The main kernel side changes in this cycle were:
- Various Intel-PT updates and optimizations (Alexander Shishkin)
- Prohibit kprobes on Xen/KVM emulate prefixes (Masami Hiramatsu)
- Add support for LSM and SELinux checks to control access to the
perf syscall (Joel Fernandes)
- Misc other changes, optimizations, fixes and cleanups - see the
shortlog for details.
There were numerous tooling changes as well - 254 non-merge commits.
Here are the main changes - too many to list in detail:
- Enhancements to core tooling infrastructure, perf.data, libperf,
libtraceevent, event parsing, vendor events, Intel PT, callchains,
BPF support and instruction decoding.
- There were updates to the following tools:
perf annotate
perf diff
perf inject
perf kvm
perf list
perf maps
perf parse
perf probe
perf record
perf report
perf script
perf stat
perf test
perf trace
- And a lot of other changes: please see the shortlog and Git log for
more details"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (279 commits)
perf parse: Fix potential memory leak when handling tracepoint errors
perf probe: Fix spelling mistake "addrees" -> "address"
libtraceevent: Fix memory leakage in copy_filter_type
libtraceevent: Fix header installation
perf intel-bts: Does not support AUX area sampling
perf intel-pt: Add support for decoding AUX area samples
perf intel-pt: Add support for recording AUX area samples
perf pmu: When using default config, record which bits of config were changed by the user
perf auxtrace: Add support for queuing AUX area samples
perf session: Add facility to peek at all events
perf auxtrace: Add support for dumping AUX area samples
perf inject: Cut AUX area samples
perf record: Add aux-sample-size config term
perf record: Add support for AUX area sampling
perf auxtrace: Add support for AUX area sample recording
perf auxtrace: Move perf_evsel__find_pmu()
perf record: Add a function to test for kernel support for AUX area sampling
perf tools: Add kernel AUX area sampling definitions
perf/core: Make the mlock accounting simple again
perf report: Jump to symbol source view from total cycles view
...
In preparation for static_call and variable size jump_label support,
teach text_poke_bp() to emulate instructions, namely:
JMP32, JMP8, CALL, NOP2, NOP_ATOMIC5, INT3
The current text_poke_bp() takes a @handler argument which is used as
a jump target when the temporary INT3 is hit by a different CPU.
When patching CALL instructions, this doesn't work because we'd miss
the PUSH of the return address. Instead, teach poke_int3_handler() to
emulate an instruction, typically the instruction we're patching in.
This fits almost all text_poke_bp() users, except
arch_unoptimize_kprobe() which restores random text, and for that site
we have to build an explicit emulate instruction.
Tested-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20191111132457.529086974@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
(cherry picked from commit 8c7eebc10687af45ac8e40ad1bac0cf7893dba9f)
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Prohibit probing on instruction which has XEN_EMULATE_PREFIX
or KVM's emulate prefix. Since that prefix is a marker for Xen
and KVM, if we modify the marker by kprobe's int3, that doesn't
work as expected.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Juergen Gross <jgross@suse.com>
Cc: x86@kernel.org
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: xen-devel@lists.xenproject.org
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/156777566048.25081.6296162369492175325.stgit@devnote2
Pull x86 cpu-feature updates from Ingo Molnar:
- Rework the Intel model names symbols/macros, which were decades of
ad-hoc extensions and added random noise. It's now a coherent, easy
to follow nomenclature.
- Add new Intel CPU model IDs:
- "Tiger Lake" desktop and mobile models
- "Elkhart Lake" model ID
- and the "Lightning Mountain" variant of Airmont, plus support code
- Add the new AVX512_VP2INTERSECT instruction to cpufeatures
- Remove Intel MPX user-visible APIs and the self-tests, because the
toolchain (gcc) is not supporting it going forward. This is the
first, lowest-risk phase of MPX removal.
- Remove X86_FEATURE_MFENCE_RDTSC
- Various smaller cleanups and fixes
* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (25 commits)
x86/cpu: Update init data for new Airmont CPU model
x86/cpu: Add new Airmont variant to Intel family
x86/cpu: Add Elkhart Lake to Intel family
x86/cpu: Add Tiger Lake to Intel family
x86: Correct misc typos
x86/intel: Add common OPTDIFFs
x86/intel: Aggregate microserver naming
x86/intel: Aggregate big core graphics naming
x86/intel: Aggregate big core mobile naming
x86/intel: Aggregate big core client naming
x86/cpufeature: Explain the macro duplication
x86/ftrace: Remove mcount() declaration
x86/PCI: Remove superfluous returns from void functions
x86/msr-index: Move AMD MSRs where they belong
x86/cpu: Use constant definitions for CPU models
lib: Remove redundant ftrace flag removal
x86/crash: Remove unnecessary comparison
x86/bitops: Use __builtin_constant_p() directly instead of IS_IMMEDIATE()
x86: Remove X86_FEATURE_MFENCE_RDTSC
x86/mpx: Remove MPX APIs
...
CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by
CONFIG_PREEMPT_RT. Both PREEMPT and PREEMPT_RT require the same
functionality which today depends on CONFIG_PREEMPT.
Switch the entry code, preempt and kprobes conditionals over to
CONFIG_PREEMPTION.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20190726212124.608488448@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
- A fair pile of RST conversions, many from Mauro. These create more
than the usual number of simple but annoying merge conflicts with other
trees, unfortunately. He has a lot more of these waiting on the wings
that, I think, will go to you directly later on.
- A new document on how to use merges and rebases in kernel repos, and one
on Spectre vulnerabilities.
- Various improvements to the build system, including automatic markup of
function() references because some people, for reasons I will never
understand, were of the opinion that :c:func:``function()`` is
unattractive and not fun to type.
- We now recommend using sphinx 1.7, but still support back to 1.4.
- Lots of smaller improvements, warning fixes, typo fixes, etc.
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Merge tag 'docs-5.3' of git://git.lwn.net/linux
Pull Documentation updates from Jonathan Corbet:
"It's been a relatively busy cycle for docs:
- A fair pile of RST conversions, many from Mauro. These create more
than the usual number of simple but annoying merge conflicts with
other trees, unfortunately. He has a lot more of these waiting on
the wings that, I think, will go to you directly later on.
- A new document on how to use merges and rebases in kernel repos,
and one on Spectre vulnerabilities.
- Various improvements to the build system, including automatic
markup of function() references because some people, for reasons I
will never understand, were of the opinion that
:c:func:``function()`` is unattractive and not fun to type.
- We now recommend using sphinx 1.7, but still support back to 1.4.
- Lots of smaller improvements, warning fixes, typo fixes, etc"
* tag 'docs-5.3' of git://git.lwn.net/linux: (129 commits)
docs: automarkup.py: ignore exceptions when seeking for xrefs
docs: Move binderfs to admin-guide
Disable Sphinx SmartyPants in HTML output
doc: RCU callback locks need only _bh, not necessarily _irq
docs: format kernel-parameters -- as code
Doc : doc-guide : Fix a typo
platform: x86: get rid of a non-existent document
Add the RCU docs to the core-api manual
Documentation: RCU: Add TOC tree hooks
Documentation: RCU: Rename txt files to rst
Documentation: RCU: Convert RCU UP systems to reST
Documentation: RCU: Convert RCU linked list to reST
Documentation: RCU: Convert RCU basic concepts to reST
docs: filesystems: Remove uneeded .rst extension on toctables
scripts/sphinx-pre-install: fix out-of-tree build
docs: zh_CN: submitting-drivers.rst: Remove a duplicated Documentation/
Documentation: PGP: update for newer HW devices
Documentation: Add section about CPU vulnerabilities for Spectre
Documentation: platform: Delete x86-laptop-drivers.txt
docs: Note that :c:func: should no longer be used
...
Pull x86 paravirt updates from Ingo Molnar:
"A handful of paravirt patching code enhancements to make it more
robust against patching failures, and related cleanups and not so
related cleanups - by Thomas Gleixner and myself"
* 'x86-paravirt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/paravirt: Rename paravirt_patch_site::instrtype to paravirt_patch_site::type
x86/paravirt: Standardize 'insn_buff' variable names
x86/paravirt: Match paravirt patchlet field definition ordering to initialization ordering
x86/paravirt: Replace the paravirt patch asm magic
x86/paravirt: Unify the 32/64 bit paravirt patching code
x86/paravirt: Detect over-sized patching bugs in paravirt_patch_call()
x86/paravirt: Detect over-sized patching bugs in paravirt_patch_insns()
x86/paravirt: Remove bogus extern declarations
Currently pt_regs on x86_32 has an oddity in that kernel regs
(!user_mode(regs)) are short two entries (esp/ss). This means that any
code trying to use them (typically: regs->sp) needs to jump through
some unfortunate hoops.
Change the entry code to fix this up and create a full pt_regs frame.
This then simplifies various trampolines in ftrace and kprobes, the
stack unwinder, ptrace, kdump and kgdb.
Much thanks to Josh for help with the cleanups!
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The kprobe trampolines have a FRAME_POINTER annotation that makes no
sense. It marks the frame in the middle of pt_regs, at the place of
saving BP.
Change it to mark the pt_regs frame as per the ENCODE_FRAME_POINTER
from the respective entry_*.S.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'v5.2-rc4' into mauro
We need to pick up post-rc1 changes to various document files so they don't
get lost in Mauro's massive RST conversion push.
Fix a couple of s/poped/popped/ typos.
Signed-off-by: George G. Davis <george_davis@mentor.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Based on 1 normalized pattern(s):
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 write to the free software foundation inc
59 temple place suite 330 boston ma 02111 1307 usa
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 1334 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add SPDX license identifiers to all Make/Kconfig files which:
- Have no license information of any form
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:
GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This function is referenced from assembler, so in LTO
it needs to be global and visible to not be optimized away.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lkml.kernel.org/r/20190330004743.29541-7-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 mm updates from Ingo Molnar:
"The changes in here are:
- text_poke() fixes and an extensive set of executability lockdowns,
to (hopefully) eliminate the last residual circumstances under
which we are using W|X mappings even temporarily on x86 kernels.
This required a broad range of surgery in text patching facilities,
module loading, trampoline handling and other bits.
- tweak page fault messages to be more informative and more
structured.
- remove DISCONTIGMEM support on x86-32 and make SPARSEMEM the
default.
- reduce KASLR granularity on 5-level paging kernels from 512 GB to
1 GB.
- misc other changes and updates"
* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits)
x86/mm: Initialize PGD cache during mm initialization
x86/alternatives: Add comment about module removal races
x86/kprobes: Use vmalloc special flag
x86/ftrace: Use vmalloc special flag
bpf: Use vmalloc special flag
modules: Use vmalloc special flag
mm/vmalloc: Add flag for freeing of special permsissions
mm/hibernation: Make hibernation handle unmapped pages
x86/mm/cpa: Add set_direct_map_*() functions
x86/alternatives: Remove the return value of text_poke_*()
x86/jump-label: Remove support for custom text poker
x86/modules: Avoid breaking W^X while loading modules
x86/kprobes: Set instruction page as executable
x86/ftrace: Set trampoline pages as executable
x86/kgdb: Avoid redundant comparison of patched code
x86/alternatives: Use temporary mm for text poking
x86/alternatives: Initialize temporary mm for patching
fork: Provide a function for copying init_mm
uprobes: Initialize uprobes earlier
x86/mm: Save debug registers when loading a temporary mm
...
Pull x86 asm updates from Ingo Molnar:
"This includes the following changes:
- cpu_has() cleanups
- sync_bitops.h modernization to the rmwcc.h facility, similarly to
bitops.h
- continued LTO annotations/fixes
- misc cleanups and smaller cleanups"
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/um/vdso: Drop unnecessary cc-ldoption
x86/vdso: Rename variable to fix -Wshadow warning
x86/cpu/amd: Exclude 32bit only assembler from 64bit build
x86/asm: Mark all top level asm statements as .text
x86/build/vdso: Add FORCE to the build rule of %.so
x86/asm: Modernize sync_bitops.h
x86/mm: Convert some slow-path static_cpu_has() callers to boot_cpu_has()
x86: Convert some slow-path static_cpu_has() callers to boot_cpu_has()
x86/asm: Clarify static_cpu_has()'s intended use
x86/uaccess: Fix implicit cast of __user pointer
x86/cpufeature: Remove __pure attribute to _static_cpu_has()
Use new flag VM_FLUSH_RESET_PERMS for handling freeing of special
permissioned memory in vmalloc and remove places where memory was set NX
and RW before freeing which is no longer needed.
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <akpm@linux-foundation.org>
Cc: <ard.biesheuvel@linaro.org>
Cc: <deneen.t.dock@intel.com>
Cc: <kernel-hardening@lists.openwall.com>
Cc: <kristen@linux.intel.com>
Cc: <linux_dti@icloud.com>
Cc: <will.deacon@arm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190426001143.4983-21-namit@vmware.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Set the page as executable after allocation. This patch is a
preparatory patch for a following patch that makes module allocated
pages non-executable.
While at it, do some small cleanup of what appears to be unnecessary
masking.
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <akpm@linux-foundation.org>
Cc: <ard.biesheuvel@linaro.org>
Cc: <deneen.t.dock@intel.com>
Cc: <kernel-hardening@lists.openwall.com>
Cc: <kristen@linux.intel.com>
Cc: <linux_dti@icloud.com>
Cc: <will.deacon@arm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190426001143.4983-11-namit@vmware.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We currently have 6 (!) separate naming variants to name temporary instruction
buffers that are used for code patching:
- insnbuf
- insnbuff
- insn_buff
- insn_buffer
- ibuf
- ibuffer
These are used as local variables, percpu fields and function parameters.
Standardize all the names to a single variant: 'insn_buff'.
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
With gcc toplevel assembler statements that do not mark themselves as .text
may end up in other sections. This causes LTO boot crashes because various
assembler statements ended up in the middle of the initcall section. It's
also a latent problem without LTO, although it's currently not known to
cause any real problems.
According to the gcc team it's expected behavior.
Always mark all the top level assembler statements as text so that they
switch to the right section.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190330004743.29541-1-andi@firstfloor.org
Avoid kretprobe recursion loop bg by setting a dummy
kprobes to current_kprobe per-CPU variable.
This bug has been introduced with the asm-coded trampoline
code, since previously it used another kprobe for hooking
the function return placeholder (which only has a nop) and
trampoline handler was called from that kprobe.
This revives the old lost kprobe again.
With this fix, we don't see deadlock anymore.
And you can see that all inner-called kretprobe are skipped.
event_1 235 0
event_2 19375 19612
The 1st column is recorded count and the 2nd is missed count.
Above shows (event_1 rec) + (event_2 rec) ~= (event_2 missed)
(some difference are here because the counter is racy)
Reported-by: Andrea Righi <righi.andrea@gmail.com>
Tested-by: Andrea Righi <righi.andrea@gmail.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Fixes: c9becf58d9 ("[PATCH] kretprobe: kretprobe-booster")
Link: http://lkml.kernel.org/r/155094064889.6137.972160690963039.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Verify the stack frame pointer on kretprobe trampoline handler,
If the stack frame pointer does not match, it skips the wrong
entry and tries to find correct one.
This can happen if user puts the kretprobe on the function
which can be used in the path of ftrace user-function call.
Such functions should not be probed, so this adds a warning
message that reports which function should be blacklisted.
Tested-by: Andrea Righi <righi.andrea@gmail.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/155094059185.6137.15527904013362842072.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Move optprobe trampoline code into RODATA since it is
not executed, but copied and modified to be used on
a trampoline buffer.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrea Righi <righi.andrea@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/154998790744.31052.3016106262944915510.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Prohibit probing on optprobe template code, since it is not
a code but a template instruction sequence. If we modify
this template, copied template must be broken.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrea Righi <righi.andrea@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Fixes: 9326638cbe ("kprobes, x86: Use NOKPROBE_SYMBOL() instead of __kprobes annotation")
Link: http://lkml.kernel.org/r/154998787911.31052.15274376330136234452.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Remove x86 specific arch_within_kprobe_blacklist().
Since we have already added all blacklisted symbols to the
kprobe blacklist by arch_populate_kprobe_blacklist(),
we don't need arch_within_kprobe_blacklist() on x86
anymore.
Tested-by: Andrea Righi <righi.andrea@gmail.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: David S. Miller <davem@davemloft.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yonghong Song <yhs@fb.com>
Link: http://lkml.kernel.org/r/154503491354.26176.13903264647254766066.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Show x86-64 specific blacklisted symbols in debugfs.
Since x86-64 prohibits probing on symbols which are in
entry text, those should be shown.
Tested-by: Andrea Righi <righi.andrea@gmail.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: David S. Miller <davem@davemloft.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yonghong Song <yhs@fb.com>
Link: http://lkml.kernel.org/r/154503488425.26176.17136784384033608516.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
... and make it static. It is called only by the kretprobe_trampoline()
from asm.
It was marked __visible so that it is visible outside of the current
compilation unit but that is not needed as it is used only in this
compilation unit.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lkml.kernel.org/r/20181205162526.GB109259@gmail.com
... with the goal of eventually enabling -Wmissing-prototypes by
default. At least on x86.
Make functions static where possible, otherwise add prototypes or make
them visible through includes.
asm/trace/ changes courtesy of Steven Rostedt <rostedt@goodmis.org>.
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> # ACPI + cpufreq bits
Cc: Andrew Banman <andrew.banman@hpe.com>
Cc: Dimitri Sivanich <dimitri.sivanich@hpe.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mike Travis <mike.travis@hpe.com>
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yi Wang <wang.yi59@zte.com.cn>
Cc: linux-acpi@vger.kernel.org
After copy_optimized_instructions() copies several instructions
to the working buffer it tries to fix up the real RIP address, but it
adjusts the RIP-relative instruction with an incorrect RIP address
for the 2nd and subsequent instructions due to a bug in the logic.
This will break the kernel pretty badly (with likely outcomes such as
a kernel freeze, a crash, or worse) because probed instructions can refer
to the wrong data.
For example putting kprobes on cpumask_next() typically hits this bug.
cpumask_next() is normally like below if CONFIG_CPUMASK_OFFSTACK=y
(in this case nr_cpumask_bits is an alias of nr_cpu_ids):
<cpumask_next>:
48 89 f0 mov %rsi,%rax
8b 35 7b fb e2 00 mov 0xe2fb7b(%rip),%esi # ffffffff82db9e64 <nr_cpu_ids>
55 push %rbp
...
If we put a kprobe on it and it gets jump-optimized, it gets
patched by the kprobes code like this:
<cpumask_next>:
e9 95 7d 07 1e jmpq 0xffffffffa000207a
7b fb jnp 0xffffffff81f8a2e2 <cpumask_next+2>
e2 00 loop 0xffffffff81f8a2e9 <cpumask_next+9>
55 push %rbp
This shows that the first two MOV instructions were copied to a
trampoline buffer at 0xffffffffa000207a.
Here is the disassembled result of the trampoline, skipping
the optprobe template instructions:
# Dump of assembly code from 0xffffffffa000207a to 0xffffffffa00020ea:
54 push %rsp
...
48 83 c4 08 add $0x8,%rsp
9d popfq
48 89 f0 mov %rsi,%rax
8b 35 82 7d db e2 mov -0x1d24827e(%rip),%esi # 0xffffffff82db9e67 <nr_cpu_ids+3>
This dump shows that the second MOV accesses *(nr_cpu_ids+3) instead of
the original *nr_cpu_ids. This leads to a kernel freeze because
cpumask_next() always returns 0 and for_each_cpu() never ends.
Fix this by adding 'len' correctly to the real RIP address while
copying.
[ mingo: Improved the changelog. ]
Reported-by: Michael Rodin <michael@rodin.online>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org # v4.15+
Fixes: 63fef14fc9 ("kprobes/x86: Make insn buffer always ROX and use text_poke()")
Link: http://lkml.kernel.org/r/153504457253.22602.1314289671019919596.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 pti updates from Ingo Molnar:
"The main changes:
- Make the IBPB barrier more strict and add STIBP support (Jiri
Kosina)
- Micro-optimize and clean up the entry code (Andy Lutomirski)
- ... plus misc other fixes"
* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/speculation: Propagate information about RSB filling mitigation to sysfs
x86/speculation: Enable cross-hyperthread spectre v2 STIBP mitigation
x86/speculation: Apply IBPB more strictly to avoid cross-process data leak
x86/speculation: Add RETPOLINE_AMD support to the inline asm CALL_NOSPEC variant
x86/CPU: Fix unused variable warning when !CONFIG_IA32_EMULATION
x86/pti/64: Remove the SYSCALL64 entry trampoline
x86/entry/64: Use the TSS sp2 slot for SYSCALL/SYSRET scratch space
x86/entry/64: Document idtentry
Pull perf updates from Ingo Molnar:
"The main updates in this cycle were:
- Lots of perf tooling changes too voluminous to list (big perf trace
and perf stat improvements, lots of libtraceevent reorganization,
etc.), so I'll list the authors and refer to the changelog for
details:
Benjamin Peterson, Jérémie Galarneau, Kim Phillips, Peter
Zijlstra, Ravi Bangoria, Sangwon Hong, Sean V Kelley, Steven
Rostedt, Thomas Gleixner, Ding Xiang, Eduardo Habkost, Thomas
Richter, Andi Kleen, Sanskriti Sharma, Adrian Hunter, Tzvetomir
Stoyanov, Arnaldo Carvalho de Melo, Jiri Olsa.
... with the bulk of the changes written by Jiri Olsa, Tzvetomir
Stoyanov and Arnaldo Carvalho de Melo.
- Continued intel_rdt work with a focus on playing well with perf
events. This also imported some non-perf RDT work due to
dependencies. (Reinette Chatre)
- Implement counter freezing for Arch Perfmon v4 (Skylake and newer).
This allows to speed up the PMI handler by avoiding unnecessary MSR
writes and make it more accurate. (Andi Kleen)
- kprobes cleanups and simplification (Masami Hiramatsu)
- Intel Goldmont PMU updates (Kan Liang)
- ... plus misc other fixes and updates"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (155 commits)
kprobes/x86: Use preempt_enable() in optimized_callback()
x86/intel_rdt: Prevent pseudo-locking from using stale pointers
kprobes, x86/ptrace.h: Make regs_get_kernel_stack_nth() not fault on bad stack
perf/x86/intel: Export mem events only if there's PEBS support
x86/cpu: Drop pointless static qualifier in punit_dev_state_show()
x86/intel_rdt: Fix initial allocation to consider CDP
x86/intel_rdt: CBM overlap should also check for overlap with CDP peer
x86/intel_rdt: Introduce utility to obtain CDP peer
tools lib traceevent, perf tools: Move struct tep_handler definition in a local header file
tools lib traceevent: Separate out tep_strerror() for strerror_r() issues
perf python: More portable way to make CFLAGS work with clang
perf python: Make clang_has_option() work on Python 3
perf tools: Free temporary 'sys' string in read_event_files()
perf tools: Avoid double free in read_event_file()
perf tools: Free 'printk' string in parse_ftrace_printk()
perf tools: Cleanup trace-event-info 'tdata' leak
perf strbuf: Match va_{add,copy} with va_end
perf test: S390 does not support watchpoints in test 22
perf auxtrace: Include missing asm/bitsperlong.h to get BITS_PER_LONG
tools include: Adopt linux/bits.h
...
The following commit:
a19b2e3d78 ("kprobes/x86: Remove IRQ disabling from ftrace-based/optimized kprobes”)
removed local_irq_save/restore() from optimized_callback(), the handler
might be interrupted by the rescheduling interrupt and might be
rescheduled - so we must not use the preempt_enable_no_resched() macro.
Use preempt_enable() instead, to not lose preemption events.
[ mingo: Improved the changelog. ]
Reported-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dwmw@amazon.co.uk
Fixes: a19b2e3d78 ("kprobes/x86: Remove IRQ disabling from ftrace-based/optimized kprobes”)
Link: http://lkml.kernel.org/r/154002887331.7627.10194920925792947001.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
