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2020-12-14ring-buffer: Add rb_check_bpage in __rb_allocate_pagesQiujun Huang
It may be better to check each page is aligned by 4 bytes. The 2 least significant bits of the address will be used as flags. Link: https://lkml.kernel.org/r/20201015113842.2921-1-hqjagain@gmail.com Signed-off-by: Qiujun Huang <hqjagain@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-12-14ring-buffer: Fix two typos in commentsQiujun Huang
s/inerrupting/interrupting/ s/beween/between/ Link: https://lkml.kernel.org/r/20201014152749.29986-1-hqjagain@gmail.com Signed-off-by: Qiujun Huang <hqjagain@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-12-14tracing: Drop unneeded assignment in ring_buffer_resize()Lukas Bulwahn
Since commit 0a1754b2a97e ("ring-buffer: Return 0 on success from ring_buffer_resize()"), computing the size is not needed anymore. Drop unneeded assignment in ring_buffer_resize(). Link: https://lkml.kernel.org/r/20201214084503.3079-1-lukas.bulwahn@gmail.com Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-12-14tracing: Disable ftrace selftests when any tracer is runningMasami Hiramatsu
Disable ftrace selftests when any tracer (kernel command line options like ftrace=, trace_events=, kprobe_events=, and boot-time tracing) starts running because selftest can disturb it. Currently ftrace= and trace_events= are checked, but kprobe_events has a different flag, and boot-time tracing didn't checked. This unifies the disabled flag and all of those boot-time tracing features sets the flag. This also fixes warnings on kprobe-event selftest (CONFIG_FTRACE_STARTUP_TEST=y and CONFIG_KPROBE_EVENTS=y) with boot-time tracing (ftrace.event.kprobes.EVENT.probes) like below; [ 59.803496] trace_kprobe: Testing kprobe tracing: [ 59.804258] ------------[ cut here ]------------ [ 59.805682] WARNING: CPU: 3 PID: 1 at kernel/trace/trace_kprobe.c:1987 kprobe_trace_self_tests_ib [ 59.806944] Modules linked in: [ 59.807335] CPU: 3 PID: 1 Comm: swapper/0 Not tainted 5.10.0-rc7+ #172 [ 59.808029] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1 04/01/204 [ 59.808999] RIP: 0010:kprobe_trace_self_tests_init+0x5f/0x42b [ 59.809696] Code: e8 03 00 00 48 c7 c7 30 8e 07 82 e8 6d 3c 46 ff 48 c7 c6 00 b2 1a 81 48 c7 c7 7 [ 59.812439] RSP: 0018:ffffc90000013e78 EFLAGS: 00010282 [ 59.813038] RAX: 00000000ffffffef RBX: 0000000000000000 RCX: 0000000000049443 [ 59.813780] RDX: 0000000000049403 RSI: 0000000000049403 RDI: 000000000002deb0 [ 59.814589] RBP: ffffc90000013e90 R08: 0000000000000001 R09: 0000000000000001 [ 59.815349] R10: 0000000000000001 R11: 0000000000000000 R12: 00000000ffffffef [ 59.816138] R13: ffff888004613d80 R14: ffffffff82696940 R15: ffff888004429138 [ 59.816877] FS: 0000000000000000(0000) GS:ffff88807dcc0000(0000) knlGS:0000000000000000 [ 59.817772] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 59.818395] CR2: 0000000001a8dd38 CR3: 0000000002222000 CR4: 00000000000006a0 [ 59.819144] Call Trace: [ 59.819469] ? init_kprobe_trace+0x6b/0x6b [ 59.819948] do_one_initcall+0x5f/0x300 [ 59.820392] ? rcu_read_lock_sched_held+0x4f/0x80 [ 59.820916] kernel_init_freeable+0x22a/0x271 [ 59.821416] ? rest_init+0x241/0x241 [ 59.821841] kernel_init+0xe/0x10f [ 59.822251] ret_from_fork+0x22/0x30 [ 59.822683] irq event stamp: 16403349 [ 59.823121] hardirqs last enabled at (16403359): [<ffffffff810db81e>] console_unlock+0x48e/0x580 [ 59.824074] hardirqs last disabled at (16403368): [<ffffffff810db786>] console_unlock+0x3f6/0x580 [ 59.825036] softirqs last enabled at (16403200): [<ffffffff81c0033a>] __do_softirq+0x33a/0x484 [ 59.825982] softirqs last disabled at (16403087): [<ffffffff81a00f02>] asm_call_irq_on_stack+0x10 [ 59.827034] ---[ end trace 200c544775cdfeb3 ]--- [ 59.827635] trace_kprobe: error on probing function entry. Link: https://lkml.kernel.org/r/160741764955.3448999.3347769358299456915.stgit@devnote2 Fixes: 4d655281eb1b ("tracing/boot Add kprobe event support") Cc: Ingo Molnar <mingo@kernel.org> Cc: stable@vger.kernel.org Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-12-07seq_buf: Avoid type mismatch for seq_buf_initArnd Bergmann
Building with W=2 prints a number of warnings for one function that has a pointer type mismatch: linux/seq_buf.h: In function 'seq_buf_init': linux/seq_buf.h:35:12: warning: pointer targets in assignment from 'unsigned char *' to 'char *' differ in signedness [-Wpointer-sign] Change the type in the function prototype according to the type in the structure. Link: https://lkml.kernel.org/r/20201026161108.3707783-1-arnd@kernel.org Fixes: 9a7777935c34 ("tracing: Convert seq_buf fields to be like seq_file fields") Reviewed-by: Cezary Rojewski <cezary.rojewski@intel.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-12-07ring-buffer: Fix a typo in function descriptionQiujun Huang
s/ring_buffer_commit_discard/ring_buffer_discard_commit/ Link: https://lkml.kernel.org/r/20201112151800.14382-1-hqjagain@gmail.com Signed-off-by: Qiujun Huang <hqjagain@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-12-07ring-buffer: Remove obsolete rb_event_is_commit()Lukas Bulwahn
Commit a389d86f7fd0 ("ring-buffer: Have nested events still record running time stamp") removed the only uses of rb_event_is_commit() in rb_update_event() and rb_update_write_stamp(). Hence, since then, make CC=clang W=1 warns: kernel/trace/ring_buffer.c:2763:1: warning: unused function 'rb_event_is_commit' [-Wunused-function] Remove this obsolete function. Link: https://lkml.kernel.org/r/20201117053703.11275-1-lukas.bulwahn@gmail.com Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-12-01ring-buffer: Add test to validate the time stamp deltasSteven Rostedt (VMware)
While debugging a situation where a delta for an event was calucalted wrong, I realize there was nothing making sure that the delta of events are correct. If a single event has an incorrect delta, then all events after it will also have one. If the discrepency gets large enough, it could cause the time stamps to go backwards when crossing sub buffers, that record a full 64 bit time stamp, and the new deltas are added to that. Add a way to validate the events at most events and when crossing a buffer page. This will help make sure that the deltas are always correct. This test will detect if they are ever corrupted. The test adds a high overhead to the ring buffer recording, as it does the audit for almost every event, and should only be used for testing the ring buffer. This will catch the bug that is fixed by commit 55ea4cf40380 ("ring-buffer: Update write stamp with the correct ts"), which is not applied when this commit is applied. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-18ftrace/documentation: Fix RST C code blocksSteven Rostedt (VMware)
Some C code in the ftrace-users.rst document is missing RST C block annotation, which has to be added. Link: https://lore.kernel.org/r/20201116173502.392a769c@canb.auug.org.au Acked-by: Jonathan Corbet <corbet@lwn.net> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-16tracing: Clean up after filter logic rewritingLukas Bulwahn
The functions event_{set,clear,}_no_set_filter_flag were only used in replace_system_preds() [now, renamed to process_system_preds()]. Commit 80765597bc58 ("tracing: Rewrite filter logic to be simpler and faster") removed the use of those functions in replace_system_preds(). Since then, the functions event_{set,clear,}_no_set_filter_flag were unused. Fortunately, make CC=clang W=1 indicates this with -Wunused-function warnings on those three functions. So, clean up these obsolete unused functions. Link: https://lkml.kernel.org/r/20201115155336.20248-1-lukas.bulwahn@gmail.com Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-13tracing: Remove the useless value assignment in test_create_synth_event()Kaixu Xia
The value of variable ret is overwritten on the delete branch in the test_create_synth_event() and we care more about the above error than this delete portion. Remove it. Link: https://lkml.kernel.org/r/1605283360-6804-1-git-send-email-kaixuxia@tencent.com Reported-by: Tosk Robot <tencent_os_robot@tencent.com> Signed-off-by: Kaixu Xia <kaixuxia@tencent.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-13livepatch: Use the default ftrace_ops instead of REGS when ARGS is availableSteven Rostedt (VMware)
When CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS is available, the ftrace call will be able to set the ip of the calling function. This will improve the performance of live kernel patching where it does not need all the regs to be stored just to change the instruction pointer. If all archs that support live kernel patching also support HAVE_DYNAMIC_FTRACE_WITH_ARGS, then the architecture specific function klp_arch_set_pc() could be made generic. It is possible that an arch can support HAVE_DYNAMIC_FTRACE_WITH_ARGS but not HAVE_DYNAMIC_FTRACE_WITH_REGS and then have access to live patching. Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: live-patching@vger.kernel.org Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-13ftrace/x86: Allow for arguments to be passed in to ftrace_regs by defaultSteven Rostedt (VMware)
Currently, the only way to get access to the registers of a function via a ftrace callback is to set the "FL_SAVE_REGS" bit in the ftrace_ops. But as this saves all regs as if a breakpoint were to trigger (for use with kprobes), it is expensive. The regs are already saved on the stack for the default ftrace callbacks, as that is required otherwise a function being traced will get the wrong arguments and possibly crash. And on x86, the arguments are already stored where they would be on a pt_regs structure to use that code for both the regs version of a callback, it makes sense to pass that information always to all functions. If an architecture does this (as x86_64 now does), it is to set HAVE_DYNAMIC_FTRACE_WITH_ARGS, and this will let the generic code that it could have access to arguments without having to set the flags. This also includes having the stack pointer being saved, which could be used for accessing arguments on the stack, as well as having the function graph tracer not require its own trampoline! Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-13ftrace: Have the callbacks receive a struct ftrace_regs instead of pt_regsSteven Rostedt (VMware)
In preparation to have arguments of a function passed to callbacks attached to functions as default, change the default callback prototype to receive a struct ftrace_regs as the forth parameter instead of a pt_regs. For callbacks that set the FL_SAVE_REGS flag in their ftrace_ops flags, they will now need to get the pt_regs via a ftrace_get_regs() helper call. If this is called by a callback that their ftrace_ops did not have a FL_SAVE_REGS flag set, it that helper function will return NULL. This will allow the ftrace_regs to hold enough just to get the parameters and stack pointer, but without the worry that callbacks may have a pt_regs that is not completely filled. Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-10MAINTAINERS: assign ./fs/tracefs to TRACINGLukas Bulwahn
A check with ./scripts/get_maintainer.pl --letters -f fs/tracefs/ shows that the tracefs is not assigned to the TRACING section in MAINTAINERS. Add the file pattern for the TRACING section to rectify that. Link: https://lkml.kernel.org/r/20201109122250.31915-1-lukas.bulwahn@gmail.com Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-10tracing: Fix some typos in commentsQiujun Huang
s/detetector/detector/ s/enfoced/enforced/ s/writen/written/ s/actualy/actually/ s/bascially/basically/ s/Regarldess/Regardless/ s/zeroes/zeros/ s/followd/followed/ s/incrememented/incremented/ s/separatelly/separately/ s/accesible/accessible/ s/sythetic/synthetic/ s/enabed/enabled/ s/heurisitc/heuristic/ s/assocated/associated/ s/otherwides/otherwise/ s/specfied/specified/ s/seaching/searching/ s/hierachry/hierarchy/ s/internel/internal/ s/Thise/This/ Link: https://lkml.kernel.org/r/20201029150554.3354-1-hqjagain@gmail.com Signed-off-by: Qiujun Huang <hqjagain@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-10ftrace: Remove unused varible 'ret'Alex Shi
'ret' in 2 functions are not used. and one of them is a void function. So remove them to avoid gcc warning: kernel/trace/ftrace.c:4166:6: warning: variable ‘ret’ set but not used [-Wunused-but-set-variable] kernel/trace/ftrace.c:5571:6: warning: variable ‘ret’ set but not used [-Wunused-but-set-variable] Link: https://lkml.kernel.org/r/1604674486-52350-1-git-send-email-alex.shi@linux.alibaba.com Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-10ring-buffer: Add recording of ring buffer recursion into recursed_functionsSteven Rostedt (VMware)
Add a new config RING_BUFFER_RECORD_RECURSION that will place functions that recurse from the ring buffer into the ftrace recused_functions file. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-10ftrace: Clean up the recursion code a bitSteven Rostedt (VMware)
In trace_test_and_set_recursion(), current->trace_recursion is placed into a variable, and that variable should be used for the processing, as there's no reason to dereference current multiple times. On trace_clear_recursion(), current->trace_recursion is modified and there's no reason to copy it over to a variable. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-10fgraph: Make overruns 4 bytes in graph stack structureSteven Rostedt (VMware)
Inspecting the data structures of the function graph tracer, I found that the overrun value is unsigned long, which is 8 bytes on a 64 bit machine, and not only that, the depth is an int (4 bytes). The overrun can be simply an unsigned int (4 bytes) and pack the ftrace_graph_ret structure better. The depth is moved up next to the func, as it is used more often with func, and improves cache locality. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-06ftrace: Add recording of functions that caused recursionSteven Rostedt (VMware)
This adds CONFIG_FTRACE_RECORD_RECURSION that will record to a file "recursed_functions" all the functions that caused recursion while a callback to the function tracer was running. Link: https://lkml.kernel.org/r/20201106023548.102375687@goodmis.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Guo Ren <guoren@kernel.org> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Helge Deller <deller@gmx.de> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bp@alien8.de> Cc: x86@kernel.org Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Anton Vorontsov <anton@enomsg.org> Cc: Colin Cross <ccross@android.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Miroslav Benes <mbenes@suse.cz> Cc: Petr Mladek <pmladek@suse.com> Cc: Joe Lawrence <joe.lawrence@redhat.com> Cc: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-csky@vger.kernel.org Cc: linux-parisc@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: live-patching@vger.kernel.org Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-06ftrace: Reverse what the RECURSION flag means in the ftrace_opsSteven Rostedt (VMware)
Now that all callbacks are recursion safe, reverse the meaning of the RECURSION flag and rename it from RECURSION_SAFE to simply RECURSION. Now only callbacks that request to have recursion protecting it will have the added trampoline to do so. Also remove the outdated comment about "PER_CPU" when determining to use the ftrace_ops_assist_func. Link: https://lkml.kernel.org/r/20201028115613.742454631@goodmis.org Link: https://lkml.kernel.org/r/20201106023547.904270143@goodmis.org Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Miroslav Benes <mbenes@suse.cz> Cc: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Cc: Petr Mladek <pmladek@suse.com> Cc: linux-doc@vger.kernel.org Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-06perf/ftrace: Check for rcu_is_watching() in callback functionSteven Rostedt (VMware)
If a ftrace callback requires "rcu_is_watching", then it adds the FTRACE_OPS_FL_RCU flag and it will not be called if RCU is not "watching". But this means that it will use a trampoline when called, and this slows down the function tracing a tad. By checking rcu_is_watching() from within the callback, it no longer needs the RCU flag set in the ftrace_ops and it can be safely called directly. Link: https://lkml.kernel.org/r/20201028115613.591878956@goodmis.org Link: https://lkml.kernel.org/r/20201106023547.711035826@goodmis.org Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Miroslav Benes <mbenes@suse.cz> Cc: Petr Mladek <pmladek@suse.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-06perf/ftrace: Add recursion protection to the ftrace callbackSteven Rostedt (VMware)
If a ftrace callback does not supply its own recursion protection and does not set the RECURSION_SAFE flag in its ftrace_ops, then ftrace will make a helper trampoline to do so before calling the callback instead of just calling the callback directly. The default for ftrace_ops is going to change. It will expect that handlers provide their own recursion protection, unless its ftrace_ops states otherwise. Link: https://lkml.kernel.org/r/20201028115613.444477858@goodmis.org Link: https://lkml.kernel.org/r/20201106023547.466892083@goodmis.org Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Miroslav Benes <mbenes@suse.cz> Cc: Petr Mladek <pmladek@suse.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-06livepatch: Trigger WARNING if livepatch function fails due to recursionSteven Rostedt (VMware)
If for some reason a function is called that triggers the recursion detection of live patching, trigger a warning. By not executing the live patch code, it is possible that the old unpatched function will be called placing the system into an unknown state. Link: https://lore.kernel.org/r/20201029145709.GD16774@alley Link: https://lkml.kernel.org/r/20201106023547.312639435@goodmis.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Joe Lawrence <joe.lawrence@redhat.com> Cc: live-patching@vger.kernel.org Suggested-by: Miroslav Benes <mbenes@suse.cz> Reviewed-by: Petr Mladek <pmladek@suse.com> Acked-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-06livepatch/ftrace: Add recursion protection to the ftrace callbackSteven Rostedt (VMware)
If a ftrace callback does not supply its own recursion protection and does not set the RECURSION_SAFE flag in its ftrace_ops, then ftrace will make a helper trampoline to do so before calling the callback instead of just calling the callback directly. The default for ftrace_ops is going to change. It will expect that handlers provide their own recursion protection, unless its ftrace_ops states otherwise. Link: https://lkml.kernel.org/r/20201028115613.291169246@goodmis.org Link: https://lkml.kernel.org/r/20201106023547.122802424@goodmis.org Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Joe Lawrence <joe.lawrence@redhat.com> Cc: live-patching@vger.kernel.org Reviewed-by: Petr Mladek <pmladek@suse.com> Acked-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-06kprobes/ftrace: Add recursion protection to the ftrace callbackSteven Rostedt (VMware)
If a ftrace callback does not supply its own recursion protection and does not set the RECURSION_SAFE flag in its ftrace_ops, then ftrace will make a helper trampoline to do so before calling the callback instead of just calling the callback directly. The default for ftrace_ops is going to change. It will expect that handlers provide their own recursion protection, unless its ftrace_ops states otherwise. Link: https://lkml.kernel.org/r/20201028115613.140212174@goodmis.org Link: https://lkml.kernel.org/r/20201106023546.944907560@goodmis.org Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Miroslav Benes <mbenes@suse.cz> Cc: Petr Mladek <pmladek@suse.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Guo Ren <guoren@kernel.org> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Helge Deller <deller@gmx.de> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bp@alien8.de> Cc: x86@kernel.org Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: linux-csky@vger.kernel.org Cc: linux-parisc@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-06pstore/ftrace: Add recursion protection to the ftrace callbackSteven Rostedt (VMware)
If a ftrace callback does not supply its own recursion protection and does not set the RECURSION_SAFE flag in its ftrace_ops, then ftrace will make a helper trampoline to do so before calling the callback instead of just calling the callback directly. The default for ftrace_ops is going to change. It will expect that handlers provide their own recursion protection, unless its ftrace_ops states otherwise. Link: https://lkml.kernel.org/r/20201028115612.990886844@goodmis.org Link: https://lkml.kernel.org/r/20201106023546.720372267@goodmis.org Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Miroslav Benes <mbenes@suse.cz> Cc: Petr Mladek <pmladek@suse.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Meyer <thomas@m3y3r.de> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-06ftrace: Optimize testing what context current is inSteven Rostedt (VMware)
The preempt_count() is not a simple location in memory, it could be part of per_cpu code or more. Each access to preempt_count(), or one of its accessor functions (like in_interrupt()) takes several cycles. By reading preempt_count() once, and then doing tests to find the context against the value return is slightly faster than using in_nmi() and in_interrupt(). Link: https://lkml.kernel.org/r/20201028115612.780796355@goodmis.org Link: https://lkml.kernel.org/r/20201106023546.558881845@goodmis.org Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-06ftrace: Add ftrace_test_recursion_trylock() helper functionSteven Rostedt (VMware)
To make it easier for ftrace callbacks to have recursion protection, provide a ftrace_test_recursion_trylock() and ftrace_test_recursion_unlock() helper that tests for recursion. Link: https://lkml.kernel.org/r/20201028115612.634927593@goodmis.org Link: https://lkml.kernel.org/r/20201106023546.378584067@goodmis.org Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-06ftrace: Move the recursion testing into global headersSteven Rostedt (VMware)
Currently, if a callback is registered to a ftrace function and its ftrace_ops does not have the RECURSION flag set, it is encapsulated in a helper function that does the recursion for it. Really, all the callbacks should have their own recursion protection for performance reasons. But they should not all implement their own. Move the recursion helpers to global headers, so that all callbacks can use them. Link: https://lkml.kernel.org/r/20201028115612.460535535@goodmis.org Link: https://lkml.kernel.org/r/20201106023546.166456258@goodmis.org Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-04kprobes: Tell lockdep about kprobe nestingSteven Rostedt (VMware)
Since the kprobe handlers have protection that prohibits other handlers from executing in other contexts (like if an NMI comes in while processing a kprobe, and executes the same kprobe, it will get fail with a "busy" return). Lockdep is unaware of this protection. Use lockdep's nesting api to differentiate between locks taken in INT3 context and other context to suppress the false warnings. Link: https://lore.kernel.org/r/20201102160234.fa0ae70915ad9e2b21c08b85@kernel.org Cc: Peter Zijlstra <peterz@infradead.org> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-02tracing: Make -ENOMEM the default error for parse_synth_field()Steven Rostedt (VMware)
parse_synth_field() returns a pointer and requires that errors get surrounded by ERR_PTR(). The ret variable is initialized to zero, but should never be used as zero, and if it is, it could cause a false return code and produce a NULL pointer dereference. It makes no sense to set ret to zero. Set ret to -ENOMEM (the most common error case), and have any other errors set it to something else. This removes the need to initialize ret on *every* error branch. Fixes: 761a8c58db6b ("tracing, synthetic events: Replace buggy strcat() with seq_buf operations") Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-02ring-buffer: Fix recursion protection transitions between interrupt contextSteven Rostedt (VMware)
The recursion protection of the ring buffer depends on preempt_count() to be correct. But it is possible that the ring buffer gets called after an interrupt comes in but before it updates the preempt_count(). This will trigger a false positive in the recursion code. Use the same trick from the ftrace function callback recursion code which uses a "transition" bit that gets set, to allow for a single recursion for to handle transitions between contexts. Cc: stable@vger.kernel.org Fixes: 567cd4da54ff4 ("ring-buffer: User context bit recursion checking") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-02tracing: Fix the checking of stackidx in __ftrace_trace_stackQiujun Huang
The array size is FTRACE_KSTACK_NESTING, so the index FTRACE_KSTACK_NESTING is illegal too. And fix two typos by the way. Link: https://lkml.kernel.org/r/20201031085714.2147-1-hqjagain@gmail.com Signed-off-by: Qiujun Huang <hqjagain@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-02ftrace: Handle tracing when switching between contextSteven Rostedt (VMware)
When an interrupt or NMI comes in and switches the context, there's a delay from when the preempt_count() shows the update. As the preempt_count() is used to detect recursion having each context have its own bit get set when tracing starts, and if that bit is already set, it is considered a recursion and the function exits. But if this happens in that section where context has changed but preempt_count() has not been updated, this will be incorrectly flagged as a recursion. To handle this case, create another bit call TRANSITION and test it if the current context bit is already set. Flag the call as a recursion if the TRANSITION bit is already set, and if not, set it and continue. The TRANSITION bit will be cleared normally on the return of the function that set it, or if the current context bit is clear, set it and clear the TRANSITION bit to allow for another transition between the current context and an even higher one. Cc: stable@vger.kernel.org Fixes: edc15cafcbfa3 ("tracing: Avoid unnecessary multiple recursion checks") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-02ftrace: Fix recursion check for NMI testSteven Rostedt (VMware)
The code that checks recursion will work to only do the recursion check once if there's nested checks. The top one will do the check, the other nested checks will see recursion was already checked and return zero for its "bit". On the return side, nothing will be done if the "bit" is zero. The problem is that zero is returned for the "good" bit when in NMI context. This will set the bit for NMIs making it look like *all* NMI tracing is recursing, and prevent tracing of anything in NMI context! The simple fix is to return "bit + 1" and subtract that bit on the end to get the real bit. Cc: stable@vger.kernel.org Fixes: edc15cafcbfa3 ("tracing: Avoid unnecessary multiple recursion checks") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-02tracing: Fix out of bounds write in get_trace_bufQiujun Huang
The nesting count of trace_printk allows for 4 levels of nesting. The nesting counter starts at zero and is incremented before being used to retrieve the current context's buffer. But the index to the buffer uses the nesting counter after it was incremented, and not its original number, which in needs to do. Link: https://lkml.kernel.org/r/20201029161905.4269-1-hqjagain@gmail.com Cc: stable@vger.kernel.org Fixes: 3d9622c12c887 ("tracing: Add barrier to trace_printk() buffer nesting modification") Signed-off-by: Qiujun Huang <hqjagain@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-01Linux 5.10-rc2Linus Torvalds
2020-11-01Merge tag 'x86-urgent-2020-11-01' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: "Three fixes all related to #DB: - Handle the BTF bit correctly so it doesn't get lost due to a kernel #DB - Only clear and set the virtual DR6 value used by ptrace on user space triggered #DB. A kernel #DB must leave it alone to ensure data consistency for ptrace. - Make the bitmasking of the virtual DR6 storage correct so it does not lose DR_STEP" * tag 'x86-urgent-2020-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/debug: Fix DR_STEP vs ptrace_get_debugreg(6) x86/debug: Only clear/set ->virtual_dr6 for userspace #DB x86/debug: Fix BTF handling
2020-11-01Merge tag 'timers-urgent-2020-11-01' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fixes from Thomas Gleixner: "A few fixes for timers/timekeeping: - Prevent undefined behaviour in the timespec64_to_ns() conversion which is used for converting user supplied time input to nanoseconds. It lacked overflow protection. - Mark sched_clock_read_begin/retry() to prevent recursion in the tracer - Remove unused debug functions in the hrtimer and timerlist code" * tag 'timers-urgent-2020-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: time: Prevent undefined behaviour in timespec64_to_ns() timers: Remove unused inline funtion debug_timer_free() hrtimer: Remove unused inline function debug_hrtimer_free() time/sched_clock: Mark sched_clock_read_begin/retry() as notrace
2020-11-01Merge tag 'smp-urgent-2020-11-01' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull smp fix from Thomas Gleixner: "A single fix for stop machine. Mark functions no trace to prevent a crash caused by recursion when enabling or disabling a tracer on RISC-V (probably all architectures which patch through stop machine)" * tag 'smp-urgent-2020-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: stop_machine, rcu: Mark functions as notrace
2020-11-01Merge tag 'locking-urgent-2020-11-01' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking fixes from Thomas Gleixner: "A couple of locking fixes: - Fix incorrect failure injection handling in the fuxtex code - Prevent a preemption warning in lockdep when tracking local_irq_enable() and interrupts are already enabled - Remove more raw_cpu_read() usage from lockdep which causes state corruption on !X86 architectures. - Make the nr_unused_locks accounting in lockdep correct again" * tag 'locking-urgent-2020-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: lockdep: Fix nr_unused_locks accounting locking/lockdep: Remove more raw_cpu_read() usage futex: Fix incorrect should_fail_futex() handling lockdep: Fix preemption WARN for spurious IRQ-enable
2020-11-01Merge tag 'char-misc-5.10-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char/misc fixes/removals from Greg KH: "Here's some small fixes for 5.10-rc2 and a big driver removal. The fixes are for some reported issues in the interconnect and coresight drivers, nothing major. The "big" driver removal is the MIC drivers have been asked to be removed as the hardware never shipped and Intel no longer wants to maintain something that no one can use. This is welcomed by many as the DMA usage of these drivers was "interesting" and the security people were starting to question some issues that were starting to be found in the codebase. Note, one of the subsystems for this driver, the "VOP" code, will probably come back in future kernel versions as it was looking to potentially solve some PCIe virtualization issues that a number of other vendors were wanting to solve. But as-is, this codebase didn't work for anyone else so no actual functionality is being removed. All of these have been in linux-next with no reported issues" * tag 'char-misc-5.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: coresight: cti: Initialize dynamic sysfs attributes coresight: Fix uninitialised pointer bug in etm_setup_aux() coresight: add module license misc: mic: remove the MIC drivers interconnect: qcom: use icc_sync state for sm8[12]50 interconnect: qcom: Ensure that the floor bandwidth value is enforced interconnect: qcom: sc7180: Init BCMs before creating the nodes interconnect: qcom: sdm845: Init BCMs before creating the nodes interconnect: Aggregate before setting initial bandwidth interconnect: qcom: sdm845: Enable keepalive for the MM1 BCM
2020-11-01Merge tag 'driver-core-5.10-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core and documentation fixes from Greg KH: "Here is one tiny debugfs change to fix up an API where the last user was successfully fixed up in 5.10-rc1 (so it couldn't be merged earlier), and a much larger Documentation/ABI/ update to the files so they can be automatically parsed by our tools. The Documentation/ABI/ updates are just formatting issues, small ones to bring the files into parsable format, and have been acked by numerous subsystem maintainers and the documentation maintainer. I figured it was good to get this into 5.10-rc2 to help wih the merge issues that would arise if these were to stick in linux-next until 5.11-rc1. The debugfs change has been in linux-next for a long time, and the Documentation updates only for the last linux-next release" * tag 'driver-core-5.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (40 commits) scripts: get_abi.pl: assume ReST format by default docs: ABI: sysfs-class-led-trigger-pattern: remove hw_pattern duplication docs: ABI: sysfs-class-backlight: unify ABI documentation docs: ABI: sysfs-c2port: remove a duplicated entry docs: ABI: sysfs-class-power: unify duplicated properties docs: ABI: unify /sys/class/leds/<led>/brightness documentation docs: ABI: stable: remove a duplicated documentation docs: ABI: change read/write attributes docs: ABI: cleanup several ABI documents docs: ABI: sysfs-bus-nvdimm: use the right format for ABI docs: ABI: vdso: use the right format for ABI docs: ABI: fix syntax to be parsed using ReST notation docs: ABI: convert testing/configfs-acpi to ReST docs: Kconfig/Makefile: add a check for broken ABI files docs: abi-testing.rst: enable --rst-sources when building docs docs: ABI: don't escape ReST-incompatible chars from obsolete and removed docs: ABI: create a 2-depth index for ABI docs: ABI: make it parse ABI/stable as ReST-compatible files docs: ABI: sysfs-uevent: make it compatible with ReST output docs: ABI: testing: make the files compatible with ReST output ...
2020-11-01Merge tag 'staging-5.10-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging Pull staging driver fixes from Greg KH: "Here are some small staging driver fixes for issues that have been reported in 5.10-rc1: - octeon driver fixes - wfx driver fixes - memory leak fix in vchiq driver - fieldbus driver bugfix - comedi driver bugfix All of these have been in linux-next with no reported issues" * tag 'staging-5.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: staging: fieldbus: anybuss: jump to correct label in an error path staging: wfx: fix test on return value of gpiod_get_value() staging: wfx: fix use of uninitialized pointer staging: mmal-vchiq: Fix memory leak for vchiq_instance staging: comedi: cb_pcidas: Allow 2-channel commands for AO subdevice staging: octeon: Drop on uncorrectable alignment or FCS error staging: octeon: repair "fixed-link" support
2020-11-01Merge tag 'tty-5.10-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial fixes from Greg KH: "Here are some small TTY and Serial driver fixes for reported issues for 5.10-rc2. They include: - vt ioctl bugfix for reported problems - fsl_lpuart serial driver fix - 21285 serial driver bugfix All have been in linux-next with no reported issues" * tag 'tty-5.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: vt_ioctl: fix GIO_UNIMAP regression vt: keyboard, extend func_buf_lock to readers vt: keyboard, simplify vt_kdgkbsent tty: serial: fsl_lpuart: LS1021A has a FIFO size of 16 words, like LS1028A tty: serial: 21285: fix lockup on open
2020-11-01Merge tag 'usb-5.10-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb Pull USB driver fixes from Greg KH: "Here are a number of small bugfixes for reported issues in some USB drivers. They include: - typec bugfixes - xhci bugfixes and lockdep warning fixes - cdc-acm driver regression fix - kernel doc fixes - cdns3 driver bugfixes for a bunch of reported issues - other tiny USB driver fixes All have been in linux-next with no reported issues" * tag 'usb-5.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: usb: cdns3: gadget: own the lock wrongly at the suspend routine usb: cdns3: Fix on-chip memory overflow issue usb: cdns3: gadget: suspicious implicit sign extension xhci: Don't create stream debugfs files with spinlock held. usb: xhci: Workaround for S3 issue on AMD SNPS 3.0 xHC xhci: Fix sizeof() mismatch usb: typec: stusb160x: fix signedness comparison issue with enum variables usb: typec: add missing MODULE_DEVICE_TABLE() to stusb160x USB: apple-mfi-fastcharge: don't probe unhandled devices usbcore: Check both id_table and match() when both available usb: host: ehci-tegra: Fix error handling in tegra_ehci_probe() usb: typec: stusb160x: fix an IS_ERR() vs NULL check in probe usb: typec: tcpm: reset hard_reset_count for any disconnect usb: cdc-acm: fix cooldown mechanism usb: host: fsl-mph-dr-of: check return of dma_set_mask() usb: fix kernel-doc markups usb: typec: stusb160x: fix some signedness bugs usb: cdns3: Variable 'length' set but not used
2020-11-01Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm fixes from Paolo Bonzini: "ARM: - selftest fix - force PTE mapping on device pages provided via VFIO - fix detection of cacheable mapping at S2 - fallback to PMD/PTE mappings for composite huge pages - fix accounting of Stage-2 PGD allocation - fix AArch32 handling of some of the debug registers - simplify host HYP entry - fix stray pointer conversion on nVHE TLB invalidation - fix initialization of the nVHE code - simplify handling of capabilities exposed to HYP - nuke VCPUs caught using a forbidden AArch32 EL0 x86: - new nested virtualization selftest - miscellaneous fixes - make W=1 fixes - reserve new CPUID bit in the KVM leaves" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: vmx: remove unused variable KVM: selftests: Don't require THP to run tests KVM: VMX: eVMCS: make evmcs_sanitize_exec_ctrls() work again KVM: selftests: test behavior of unmapped L2 APIC-access address KVM: x86: Fix NULL dereference at kvm_msr_ignored_check() KVM: x86: replace static const variables with macros KVM: arm64: Handle Asymmetric AArch32 systems arm64: cpufeature: upgrade hyp caps to final arm64: cpufeature: reorder cpus_have_{const, final}_cap() KVM: arm64: Factor out is_{vhe,nvhe}_hyp_code() KVM: arm64: Force PTE mapping on fault resulting in a device mapping KVM: arm64: Use fallback mapping sizes for contiguous huge page sizes KVM: arm64: Fix masks in stage2_pte_cacheable() KVM: arm64: Fix AArch32 handling of DBGD{CCINT,SCRext} and DBGVCR KVM: arm64: Allocate stage-2 pgd pages with GFP_KERNEL_ACCOUNT KVM: arm64: Drop useless PAN setting on host EL1 to EL2 transition KVM: arm64: Remove leftover kern_hyp_va() in nVHE TLB invalidation KVM: arm64: Don't corrupt tpidr_el2 on failed HVC call x86/kvm: Reserve KVM_FEATURE_MSI_EXT_DEST_ID
2020-10-31Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhostLinus Torvalds
Pull vhost fixes from Michael Tsirkin: "Fixes all over the place. A new UAPI is borderline: can also be considered a new feature but also seems to be the only way we could come up with to fix addressing for userspace - and it seems important to switch to it now before userspace making assumptions about addressing ability of devices is set in stone" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: vdpasim: allow to assign a MAC address vdpasim: fix MAC address configuration vdpa: handle irq bypass register failure case vdpa_sim: Fix DMA mask Revert "vhost-vdpa: fix page pinning leakage in error path" vdpa/mlx5: Fix error return in map_direct_mr() vhost_vdpa: Return -EFAULT if copy_from_user() fails vdpa_sim: implement get_iova_range() vhost: vdpa: report iova range vdpa: introduce config op to get valid iova range