| Commit message (Collapse) | Author | Age | Files | Lines |
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git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
"The major changes in this tracing update includes:
- Removal of non-DYNAMIC_FTRACE from 32bit x86
- Removal of mcount support from x86
- Emulating a call from int3 on x86_64, fixes live kernel patching
- Consolidated Tracing Error logs file
Minor updates:
- Removal of klp_check_compiler_support()
- kdb ftrace dumping output changes
- Accessing and creating ftrace instances from inside the kernel
- Clean up of #define if macro
- Introduction of TRACE_EVENT_NOP() to disable trace events based on
config options
And other minor fixes and clean ups"
* tag 'trace-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (44 commits)
x86: Hide the int3_emulate_call/jmp functions from UML
livepatch: Remove klp_check_compiler_support()
ftrace/x86: Remove mcount support
ftrace/x86_32: Remove support for non DYNAMIC_FTRACE
tracing: Simplify "if" macro code
tracing: Fix documentation about disabling options using trace_options
tracing: Replace kzalloc with kcalloc
tracing: Fix partial reading of trace event's id file
tracing: Allow RCU to run between postponed startup tests
tracing: Fix white space issues in parse_pred() function
tracing: Eliminate const char[] auto variables
ring-buffer: Fix mispelling of Calculate
tracing: probeevent: Fix to make the type of $comm string
tracing: probeevent: Do not accumulate on ret variable
tracing: uprobes: Re-enable $comm support for uprobe events
ftrace/x86_64: Emulate call function while updating in breakpoint handler
x86_64: Allow breakpoints to emulate call instructions
x86_64: Add gap to int3 to allow for call emulation
tracing: kdb: Allow ftdump to skip all but the last few entries
tracing: Add trace_total_entries() / trace_total_entries_cpu()
...
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User Mode Linux does not have access to the ip or sp fields of the pt_regs,
and accessing them causes UML to fail to build. Hide the int3_emulate_jmp()
and int3_emulate_call() instructions from UML, as it doesn't need them
anyway.
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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The only purpose of klp_check_compiler_support() is to make sure that we
are not using ftrace on x86 via mcount (because that's executed only after
prologue has already happened, and that's too late for livepatching
purposes).
Now that mcount is not supported by ftrace any more, there is no need for
klp_check_compiler_support() either.
Link: http://lkml.kernel.org/r/nycvar.YFH.7.76.1905102346100.17054@cbobk.fhfr.pm
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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There's two methods of enabling function tracing in Linux on x86. One is
with just "gcc -pg" and the other is "gcc -pg -mfentry". The former will use
calls to a special function "mcount" after the frame is set up in all C
functions. The latter will add calls to a special function called "fentry"
as the very first instruction of all C functions.
At compile time, there is a check to see if gcc supports, -mfentry, and if
it does, it will use that, because it is more versatile and less error prone
for function tracing.
Starting with v4.19, the minimum gcc supported to build the Linux kernel,
was raised to version 4.6. That also happens to be the first gcc version to
support -mfentry. Since on x86, using gcc versions from 4.6 and beyond will
unconditionally enable the -mfentry, it will no longer use mcount as the
method for inserting calls into the C functions of the kernel. This means
that there is no point in continuing to maintain mcount in x86.
Remove support for using mcount. This makes the code less complex, and will
also allow it to be simplified in the future.
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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When DYNAMIC_FTRACE is enabled in the kernel, all the functions that can be
traced by the function tracer have a "nop" placeholder at the start of the
function. When function tracing is enabled, the nop is converted into a call
to the tracing infrastructure where the functions get traced. This also
allows for specifying specific functions to trace, and a lot of
infrastructure is built on top of this.
When DYNAMIC_FTRACE is not enabled, all the functions have a call to the
ftrace trampoline. A check is made to see if a function pointer is the
ftrace_stub or not, and if it is not, it calls the function pointer to trace
the code. This adds over 10% overhead to the kernel even when tracing is
disabled.
When an architecture supports DYNAMIC_FTRACE there really is no reason to
use the static tracing. I have kept non DYNAMIC_FTRACE available in x86 so
that the generic code for non DYNAMIC_FTRACE can be tested. There is no
reason to support non DYNAMIC_FTRACE for both x86_64 and x86_32. As the non
DYNAMIC_FTRACE for x86_32 does not even support fentry, and we want to
remove mcount completely, there's no reason to keep non DYNAMIC_FTRACE
around for x86_32.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Peter Zijlstra noticed that with CONFIG_PROFILE_ALL_BRANCHES, the "if"
macro converts the conditional to an array index. This can cause GCC
to create horrible code. When there are nested ifs, the generated code
uses register values to encode branching decisions.
Josh Poimboeuf found that replacing the define "if" macro from using
the condition as an array index and incrementing the branch statics
with an if statement itself, reduced the asm complexity and shrinks the
generated code quite a bit.
But this can be simplified even further by replacing the internal if
statement with a ternary operator.
Link: https://lkml.kernel.org/r/20190307174802.46fmpysxyo35hh43@treble
Link: http://lkml.kernel.org/r/CAHk-=wiALN3jRuzARpwThN62iKd476Xj-uom+YnLZ4=eqcz7xQ@mail.gmail.com
Reported-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reported-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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To disable a tracing option using the trace_options file, the option
name needs to be prefixed with 'no', and not suffixed, as the README
states. Fix it.
Link: http://lkml.kernel.org/r/154872690031.47356.5739053380942044586.stgit@srivatsa-ubuntu
Signed-off-by: Srivatsa S. Bhat (VMware) <srivatsa@csail.mit.edu>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Replace kzalloc() function with its 2-factor argument form, kcalloc().
This patch replaces cases of:
kzalloc(a * b, gfp)
with:
kcalloc(a, b, gfp)
This code was detected with the help of Coccinelle.
Link: http://lkml.kernel.org/r/20190115043408.GA23456@embeddedor
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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When reading only part of the id file, the ppos isn't tracked correctly.
This is taken care by simple_read_from_buffer.
Reading a single byte, and then the next byte would result EOF.
While this seems like not a big deal, this breaks abstractions that
reads information from files unbuffered. See for example
https://github.com/golang/go/issues/29399
This code was mentioned as problematic in
commit cd458ba9d5a5
("tracing: Do not (ab)use trace_seq in event_id_read()")
An example C code that show this bug is:
#include <stdio.h>
#include <stdint.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
int main(int argc, char **argv) {
if (argc < 2)
return 1;
int fd = open(argv[1], O_RDONLY);
char c;
read(fd, &c, 1);
printf("First %c\n", c);
read(fd, &c, 1);
printf("Second %c\n", c);
}
Then run with, e.g.
sudo ./a.out /sys/kernel/debug/tracing/events/tcp/tcp_set_state/id
You'll notice you're getting the first character twice, instead of the
first two characters in the id file.
Link: http://lkml.kernel.org/r/20181231115837.4932-1-elazar@lightbitslabs.com
Cc: Orit Wasserman <orit.was@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 23725aeeab10b ("ftrace: provide an id file for each event")
Signed-off-by: Elazar Leibovich <elazar@lightbitslabs.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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When building a allmodconfig kernel for arm64 and boot that in qemu,
CONFIG_FTRACE_STARTUP_TEST gets enabled and that takes time so the
watchdog expires and prints out a message like this:
'watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [swapper/0:1]'
Depending on what the what test gets called from init_trace_selftests()
it stays minutes in the loop.
Rework so that function cond_resched() gets called in the
init_trace_selftests loop.
Link: http://lkml.kernel.org/r/20181130145622.26334-1-anders.roxell@linaro.org
Co-developed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Trivial fix to clean up an indentation issue, a whole chunk of code
has an extra space in the indentation.
Link: http://lkml.kernel.org/r/20181109132312.20994-1-colin.king@canonical.com
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Automatic const char[] variables cause unnecessary code
generation. For example, the this_mod variable leads to
3f04: 48 b8 5f 5f 74 68 69 73 5f 6d movabs $0x6d5f736968745f5f,%rax # __this_m
3f0e: 4c 8d 44 24 02 lea 0x2(%rsp),%r8
3f13: 48 8d 7c 24 10 lea 0x10(%rsp),%rdi
3f18: 48 89 44 24 02 mov %rax,0x2(%rsp)
3f1d: 4c 89 e9 mov %r13,%rcx
3f20: b8 65 00 00 00 mov $0x65,%eax # e
3f25: 48 c7 c2 00 00 00 00 mov $0x0,%rdx
3f28: R_X86_64_32S .rodata.str1.1+0x18d
3f2c: be 48 00 00 00 mov $0x48,%esi
3f31: c7 44 24 0a 6f 64 75 6c movl $0x6c75646f,0xa(%rsp) # odul
3f39: 66 89 44 24 0e mov %ax,0xe(%rsp)
i.e., the string gets built on the stack at runtime. Similar code can be
found for the other instances I'm replacing here. Putting the string
in .rodata reduces the combined .text+.rodata size and saves time and
stack space at runtime.
The simplest fix, and what I've done for the this_mod case, is to just
make the variable static.
However, for the "<faulted>" case where the same string is used twice,
that prevents the linker from merging those two literals, so instead use
a macro - that also keeps the two instances automatically in
sync (instead of only the compile-time strlen expression).
Finally, for the two runs of spaces, it turns out that the "build
these strings on the stack" is not the worst part of what gcc does -
it turns print_func_help_header_irq() into "if (tgid) { /*
print_event_info + five seq_printf calls */ } else { /* print
event_info + another five seq_printf */}". Taking inspiration from a
suggestion from Al Viro, use %.*s to make snprintf either stop after
the first two spaces or print the whole string. As a bonus, the
seq_printfs now fit on single lines (at least, they are not longer
than the existing ones in the function just above), making it easier
to see that the ascii art lines up.
x86-64 defconfig + CONFIG_FUNCTION_TRACER:
$ scripts/stackdelta /tmp/stackusage.{0,1}
./kernel/trace/ftrace.c ftrace_mod_callback 152 136 -16
./kernel/trace/trace.c trace_default_header 56 32 -24
./kernel/trace/trace.c tracing_mark_raw_write 96 72 -24
./kernel/trace/trace.c tracing_mark_write 104 80 -24
bloat-o-meter
add/remove: 1/0 grow/shrink: 0/4 up/down: 14/-375 (-361)
Function old new delta
this_mod - 14 +14
ftrace_mod_callback 577 542 -35
tracing_mark_raw_write 444 374 -70
tracing_mark_write 616 540 -76
trace_default_header 600 406 -194
Link: http://lkml.kernel.org/r/20190320081757.6037-1-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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It's not "Caculate".
Link: http://lkml.kernel.org/r/20181101154640.23162-1-tiny.windzz@gmail.com
Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Fix to make the type of $comm "string". If we set the other type to $comm
argument, it shows meaningless value or wrong data. Currently probe events
allow us to set string array type (e.g. ":string[2]"), or other digit types
like x8 on $comm. But since clearly $comm is just a string data, it should
not be fetched by other types including array.
Link: http://lkml.kernel.org/r/155723736241.9149.14582064184468574539.stgit@devnote2
Cc: Andreas Ziegler <andreas.ziegler@fau.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 533059281ee5 ("tracing: probeevent: Introduce new argument fetching code")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Do not accumulate strlen result on "ret" local variable, because
it is accumulated on "total" local variable for array case.
Link: http://lkml.kernel.org/r/155723735237.9149.3192150444705457531.stgit@devnote2
Fixes: 40b53b771806 ("tracing: probeevent: Add array type support")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Since commit 533059281ee5 ("tracing: probeevent: Introduce new
argument fetching code") dropped the $comm support from uprobe
events, this re-enables it.
For $comm support, uses strlcpy() instead of strncpy_from_user()
to copy current task's comm. Because it is in the kernel space,
strncpy_from_user() always fails to copy the comm.
This also uses strlen() instead of strnlen_user() to measure the
length of the comm.
Note that this uses -ECOMM as a token value to fetch the comm
string. If the user-space pointer points -ECOMM, it will be
translated to task->comm.
Link: http://lkml.kernel.org/r/155723734162.9149.4042756162201097965.stgit@devnote2
Fixes: 533059281ee5 ("tracing: probeevent: Introduce new argument fetching code")
Reported-by: Andreas Ziegler <andreas.ziegler@fau.de>
Acked-by: Andreas Ziegler <andreas.ziegler@fau.de>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Nicolai Stange discovered[1] that if live kernel patching is enabled, and the
function tracer started tracing the same function that was patched, the
conversion of the fentry call site during the translation of going from
calling the live kernel patch trampoline to the iterator trampoline, would
have as slight window where it didn't call anything.
As live kernel patching depends on ftrace to always call its code (to
prevent the function being traced from being called, as it will redirect
it). This small window would allow the old buggy function to be called, and
this can cause undesirable results.
Nicolai submitted new patches[2] but these were controversial. As this is
similar to the static call emulation issues that came up a while ago[3].
But after some debate[4][5] adding a gap in the stack when entering the
breakpoint handler allows for pushing the return address onto the stack to
easily emulate a call.
[1] http://lkml.kernel.org/r/20180726104029.7736-1-nstange@suse.de
[2] http://lkml.kernel.org/r/20190427100639.15074-1-nstange@suse.de
[3] http://lkml.kernel.org/r/3cf04e113d71c9f8e4be95fb84a510f085aa4afa.1541711457.git.jpoimboe@redhat.com
[4] http://lkml.kernel.org/r/CAHk-=wh5OpheSU8Em_Q3Hg8qw_JtoijxOdPtHru6d+5K8TWM=A@mail.gmail.com
[5] http://lkml.kernel.org/r/CAHk-=wjvQxY4DvPrJ6haPgAa6b906h=MwZXO6G8OtiTGe=N7_w@mail.gmail.com
[
Live kernel patching is not implemented on x86_32, thus the emulate
calls are only for x86_64.
]
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Nicolai Stange <nstange@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: the arch/x86 maintainers <x86@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: Joe Lawrence <joe.lawrence@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Mimi Zohar <zohar@linux.ibm.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Nayna Jain <nayna@linux.ibm.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: "open list:KERNEL SELFTEST FRAMEWORK" <linux-kselftest@vger.kernel.org>
Cc: stable@vger.kernel.org
Fixes: b700e7f03df5 ("livepatch: kernel: add support for live patching")
Tested-by: Nicolai Stange <nstange@suse.de>
Reviewed-by: Nicolai Stange <nstange@suse.de>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
[ Changed to only implement emulated calls for x86_64 ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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In order to allow breakpoints to emulate call instructions, they need to push
the return address onto the stack. The x86_64 int3 handler adds a small gap
to allow the stack to grow some. Use this gap to add the return address to
be able to emulate a call instruction at the breakpoint location.
These helper functions are added:
int3_emulate_jmp(): changes the location of the regs->ip to return there.
(The next two are only for x86_64)
int3_emulate_push(): to push the address onto the gap in the stack
int3_emulate_call(): push the return address and change regs->ip
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Nicolai Stange <nstange@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: the arch/x86 maintainers <x86@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: Joe Lawrence <joe.lawrence@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Mimi Zohar <zohar@linux.ibm.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Nayna Jain <nayna@linux.ibm.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: "open list:KERNEL SELFTEST FRAMEWORK" <linux-kselftest@vger.kernel.org>
Cc: stable@vger.kernel.org
Fixes: b700e7f03df5 ("livepatch: kernel: add support for live patching")
Tested-by: Nicolai Stange <nstange@suse.de>
Reviewed-by: Nicolai Stange <nstange@suse.de>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
[ Modified to only work for x86_64 and added comment to int3_emulate_push() ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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To allow an int3 handler to emulate a call instruction, it must be able to
push a return address onto the stack. Add a gap to the stack to allow the
int3 handler to push the return address and change the return from int3 to
jump straight to the emulated called function target.
Link: http://lkml.kernel.org/r/20181130183917.hxmti5josgq4clti@treble
Link: http://lkml.kernel.org/r/20190502162133.GX2623@hirez.programming.kicks-ass.net
[
Note, this is needed to allow Live Kernel Patching to not miss calling a
patched function when tracing is enabled. -- Steven Rostedt
]
Cc: stable@vger.kernel.org
Fixes: b700e7f03df5 ("livepatch: kernel: add support for live patching")
Tested-by: Nicolai Stange <nstange@suse.de>
Reviewed-by: Nicolai Stange <nstange@suse.de>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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The 'ftdump' command in kdb is currently a bit of a last resort, at
least if you have lots of traces turned on. It's going to print a
whole boatload of data out your serial port which is probably running
at 115200. This could easily take many, many minutes.
Usually you're most interested in what's at the _end_ of the ftrace
buffer, AKA what happened most recently. That means you've got to
wait the full time for the dump. The 'ftdump' command does attempt to
help you a little bit by allowing you to skip a fixed number of
entries. Unfortunately it provides no way for you to know how many
entries you should skip.
Let's do similar to python and allow you to use a negative number to
indicate that you want to skip all entries except the last few. This
allows you to quickly see what you want.
Note that we also change the printout in ftdump to print the
(positive) number of entries actually skipped since that could be
helpful to know when you've specified a negative skip count.
Link: http://lkml.kernel.org/r/20190319171206.97107-3-dianders@chromium.org
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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These two new exported functions will be used in a future patch by
kdb_ftdump() to quickly skip all but the last few trace entries.
Link: http://lkml.kernel.org/r/20190319171206.97107-2-dianders@chromium.org
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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The things skipped by kdb's "ftdump" command when you pass it a
parameter has always been entries, not lines. The difference usually
doesn't matter but when the trace buffer has multi-line entries (like
a stack dump) it can matter.
Let's fix this both in the help text for ftdump and also in the local
variable names.
Link: http://lkml.kernel.org/r/20190319171206.97107-1-dianders@chromium.org
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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include/linux/ftrace.h
ftrace_graph_entry_stub() is defined in generic code, its prototype should
be in the generic header and not defined throughout architecture specific
code in order to use it.
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-parisc@vger.kernel.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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The function_graph boot up self test emulates the tr->init() function in
order to add a wrapper around the function graph tracer entry code to test
for lock ups and such. But it does not emulate the tr->reset(), and just
calls the function_graph tracer tr->reset() function which will use its own
fgraph_ops to unregister function tracing with. As the fgraph_ops is
becoming more meaningful with the register_ftrace_graph() and
unregister_ftrace_graph() functions, the two need to be the same. The
emulated tr->init() uses its own fgraph_ops descriptor, which means the
unregister_ftrace_graph() must use the same ftrace_ops, which the selftest
currently does not do. By emulating the tr->reset() as the selftest does
with the tr->init() it will be able to pass the same fgraph_ops descriptor
to the unregister_ftrace_graph() as it did with the register_ftrace_graph().
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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The function_graph tracer has a stub function and its ops flag has the
FTRACE_OPS_FL_STUB set. As the function graph does not use the
ftrace_ops->func pointer but instead is called by a separate part of the
ftrace trampoline. The function_graph tracer still requires to pass in a
ftrace_ops that may also hold the hash of the functions to call. But there's
no reason to test that hash in the function tracing portion. Instead of
testing to see if we should call the stub function, just test if the ops has
FTRACE_OPS_FL_STUB set, and just skip it.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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The ASSIGN_OPS_HASH() macro was moved to fgraph.c where it was used, but for
some reason it wasn't removed from ftrace.c, as it is no longer referenced
there.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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When CONFIG_RCU_TRACE is not set, all these tracepoints are defined as
do-nothing macro.
We'd better make those inline functions that take proper arguments.
As RCU_TRACE() is defined as do-nothing marco as well when
CONFIG_RCU_TRACE is not set, so we can clean it up.
Link: http://lkml.kernel.org/r/1553602391-11926-4-git-send-email-laoar.shao@gmail.com
Reviewed-by: Paul E. McKenney <paulmck@linux.ibm.com>
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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not set
The tracepoints trace_sched_stat_{iowait, blocked, wait, sleep} should
be not exposed to user if CONFIG_SCHEDSTATS is not set.
Link: http://lkml.kernel.org/r/1553602391-11926-3-git-send-email-laoar.shao@gmail.com
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Sometimes we want to define a tracepoint as a do-nothing function.
So I introduce TRACE_EVENT_NOP, DECLARE_EVENT_CLASS_NOP and
DEFINE_EVENT_NOP for this kind of usage.
Link: http://lkml.kernel.org/r/1553602391-11926-2-git-send-email-laoar.shao@gmail.com
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Add brief blurb about error_log to the 'Important files' section.
Link: http://lkml.kernel.org/r/c81e60f9aded495081231a32d2d1023c4d043a7a.1554072478.git.tom.zanussi@linux.intel.com
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Move most of the hist trigger extended error documentation to
ftrace.rst and expand on it to fully document tracing/error_log.
Link: http://lkml.kernel.org/r/c5d53c8f643ef6844d6ad8d0200c116936730b01.1554072478.git.tom.zanussi@linux.intel.com
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Add a testcase verifying basic tracing/error_log functionality.
Link: http://lkml.kernel.org/r/bf1c0d47a24672df945331462682d96296d1ab28.1554072478.git.tom.zanussi@linux.intel.com
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Error handling has been moved to the common tracing/error_log, so this
test is no longer valid.
Link: http://lkml.kernel.org/r/876a98b21018814cbf46f0a3605ae0906c51d53c.1554072478.git.tom.zanussi@linux.intel.com
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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The k/uprobe_sytax_errors test case defines a check_error() function
used to run a command and check the position of the caret in the
output.
This would be useful for other ftrace facilities too, so move it to
test.d/functions for use by anyone. In the process, rename it to
ftrace_errlog_check() and parametrize it for general use.
Link: http://lkml.kernel.org/r/9f88080a06f1755811f69081926afe7e5cb53178.1554072478.git.tom.zanussi@linux.intel.com
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Add error_log testcase for error logs on probe events.
This tests most of error cases and checks the error position
is correct.
Link: http://lkml.kernel.org/r/63d695b74e0965988fa54ffa12beeb2c3475250d.1554072478.git.tom.zanussi@linux.intel.com
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
[tom.zanussi@linux.intel.com: changed >& redirection to 2>]
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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As each instance has their own error_log file, it makes more sense that the
instances show the errors of their own instead of all error_logs having the
same data. Make it that the errors show up in the instance error_log file
that the error happens in. If no instance trace_array is available, then
NULL can be passed in which will create the error in the top level instance
(the one at the top of the tracefs directory).
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Have the trace_array that associates the trace instance of the histogram
passed around to functions so that error handling can display the error
message in the proper instance.
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Pass in the trace_array that represents the instance the filter being
changed is in to create_event_filter(). This will allow for error messages
that happen when writing to the filter can be displayed in the proper
instance "error_log" file.
Note, for calls to create_filter() (that was also modified to support
create_event_filter()), that changes filters that do not exist in a instance
(for perf for example), NULL may be passed in, which means that there will
not be any message to log for that filter.
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Use tracing error_log with probe events for logging error more
precisely. This also makes all parse error returns -EINVAL
(except for -ENOMEM), because user can see better error message
in error_log file now.
Link: http://lkml.kernel.org/r/6a4d90e141d138040ea61f4776b991597077451e.1554072478.git.tom.zanussi@linux.intel.com
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Use tracing_log_err() from the new tracing error_log mechanism to send
filter parse errors to tracing/error_log.
With this change, users will be able to see filter errors by looking
at tracing/error_log.
The same errors will also be available in the filter file, as
expected.
Link: http://lkml.kernel.org/r/1d942c419941539a11d78a6810fc5740a99b2974.1554072478.git.tom.zanussi@linux.intel.com
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Replace hist_err() and hist_err_event() with tracing_log_err() from
the new tracing error_log mechanism.
Also add a couple related helper functions and remove most of the old
hist_err()-related code.
With this change, users no longer read the hist files for hist trigger
error information, but instead look at tracing/error_log for the same
information.
Link: http://lkml.kernel.org/r/c98f77a97c9715d18b623eeb5741057b330d5ac0.1554072478.git.tom.zanussi@linux.intel.com
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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In preparation for making use of the new trace error log, save the
subsystem and event name associated with the last hist command - it
will be passed as the location param in the event_log_err() calls.
Link: http://lkml.kernel.org/r/eb0fd1362be8f39facb86c83eecf441b7a5876f8.1554072478.git.tom.zanussi@linux.intel.com
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Introduce a new ftrace file, tracing/error_log, for ftrace commands to
log errors. This is useful for allowing more complex commands such as
hist trigger and kprobe_event commands to point out specifically where
something may have gone wrong without forcing them to resort to more
ad hoc methods such as tacking error messages onto existing output
files.
To log a tracing error, call the event_log_err() function, passing it
a location string describing where it came from e.g. kprobe_events or
system:event, the command that caused the error, an array of static
error strings describing errors and an index within that array which
describes the specific error, along with the position to place the
error caret.
Reading the log displays the last (currently) 8 errors logged in the
following format:
[timestamp] <loc>: error: <static error text>
Command: <command that caused the error>
^
Memory for the error log isn't allocated unless there has been a trace
event error, and the error log can be cleared and have its memory
freed by writing the empty string in truncation mode to it:
# echo > tracing/error_log.
Link: http://lkml.kernel.org/r/0c2c82571fd38c5f3a88ca823627edff250e9416.1554072478.git.tom.zanussi@linux.intel.com
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Suggested-by: Masami Hiramatsu <mhiramat@kernel.org>
Improvements-suggested-by: Steve Rostedt <rostedt@goodmis.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Ftrace provides the feature “instances” that provides the capability to
create multiple Ftrace ring buffers. However, currently these buffers
are created/accessed via userspace only. The kernel APIs providing these
features are not exported, hence cannot be used by other kernel
components.
This patch aims to extend this infrastructure to provide the
flexibility to create/log/remove/ enable-disable existing trace events
to these buffers from within the kernel.
Link: http://lkml.kernel.org/r/1553106531-3281-2-git-send-email-divya.indi@oracle.com
Signed-off-by: Divya Indi <divya.indi@oracle.com>
Reviewed-by: Joe Jin <joe.jin@oracle.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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'cnt' should be used to calculate ring buffer size rather than data->cnt
Link: http://lkml.kernel.org/r/1537704693-184237-1-git-send-email-yuehaibing@huawei.com
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kconfig updates from Masahiro Yamada:
- error out if a user specifies a directory instead of a file from
"Save" menu of GUI interfaces
- do not overwrite .config if there is no change in the configuration
- create parent directories as needed when a user specifies a new file
path from "Save" menu of menuconfig/nconfig
- fix potential buffer overflow
- some trivial cleanups
* tag 'kconfig-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kconfig: make conf_get_autoconfig_name() static
kconfig: use snprintf for formatting pathnames
kconfig: remove useless NULL pointer check in conf_write_dep()
kconfig: make parent directories for the saved .config as needed
kconfig: do not write .config if the content is the same
kconfig: do not accept a directory for configuration output
kconfig: remove trailing whitespaces
kconfig: Make nconf-cfg.sh executable
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This is only used in confdata.c
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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Valid pathnames will never exceed PATH_MAX, but these file names
are unsanitized and can cause buffer overflow if set incorrectly.
Use snprintf to avoid this. This was flagged during a Coverity scan
of the coreboot project, which also uses kconfig for its build system.
Signed-off-by: Jacob Garber <jgarber1@ualberta.ca>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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conf_write_dep() has just one caller:
conf_write_dep("include/config/auto.conf.cmd");
"name" always points to a valid string.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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With menuconfig / nconfig, users can input any file path from the
"Save" menu, but it fails if the parent directory does not exist.
Why not create the parent directory automatically. I think this is
a user-friendly behavior.
I changed the error messages in menuconfig / nconfig.
"Nonexistent directory" is no longer the most likely reason of the
failure. Perhaps, the user specified the existing directory, or
attempted to write to the location without write permission.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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