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author | Linus Torvalds <torvalds@linux-foundation.org> | 2023-05-05 13:11:02 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-05-05 13:11:02 -0700 |
commit | e919a3f7057b5ca918dea98826b39a38eff9bebb (patch) | |
tree | 614e799fb722519f7e0a43890ced165b4d825664 /kernel/trace/ftrace.c | |
parent | b115d85a9584c98f9a7dec209d835462aa1adc09 (diff) | |
parent | 6ce2c04fcbcaa5eb086e5142ab359be306cbc3e1 (diff) | |
download | linux-stable-e919a3f7057b5ca918dea98826b39a38eff9bebb.tar.gz linux-stable-e919a3f7057b5ca918dea98826b39a38eff9bebb.tar.bz2 linux-stable-e919a3f7057b5ca918dea98826b39a38eff9bebb.zip |
Merge tag 'trace-v6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull more tracing updates from Steven Rostedt:
- Make buffer_percent read/write.
The buffer_percent file is how users can state how long to block on
the tracing buffer depending on how much is in the buffer. When it
hits the "buffer_percent" it will wake the task waiting on the
buffer. For some reason it was set to read-only.
This was not noticed because testing was done as root without
SELinux, but with SELinux it will prevent even root to write to it
without having CAP_DAC_OVERRIDE.
- The "touched_functions" was added this merge window, but one of the
reasons for adding it was not implemented.
That was to show what functions were not only touched, but had either
a direct trampoline attached to it, or a kprobe or live kernel
patching that can "hijack" the function to run a different function.
The point is to know if there's functions in the kernel that may not
be behaving as the kernel code shows. This can be used for debugging.
TODO: Add this information to kernel oops too.
* tag 'trace-v6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
ftrace: Add MODIFIED flag to show if IPMODIFY or direct was attached
tracing: Fix permissions for the buffer_percent file
Diffstat (limited to 'kernel/trace/ftrace.c')
-rw-r--r-- | kernel/trace/ftrace.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 76973a70ab9d..764668467155 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -46,7 +46,8 @@ #include "trace_stat.h" /* Flags that do not get reset */ -#define FTRACE_NOCLEAR_FLAGS (FTRACE_FL_DISABLED | FTRACE_FL_TOUCHED) +#define FTRACE_NOCLEAR_FLAGS (FTRACE_FL_DISABLED | FTRACE_FL_TOUCHED | \ + FTRACE_FL_MODIFIED) #define FTRACE_INVALID_FUNCTION "__ftrace_invalid_address__" @@ -2273,6 +2274,10 @@ static int ftrace_check_record(struct dyn_ftrace *rec, bool enable, bool update) rec->flags &= ~FTRACE_FL_TRAMP_EN; } + /* Keep track of anything that modifies the function */ + if (rec->flags & (FTRACE_FL_DIRECT | FTRACE_FL_IPMODIFY)) + rec->flags |= FTRACE_FL_MODIFIED; + if (flag & FTRACE_FL_DIRECT) { /* * If there's only one user (direct_ops helper) @@ -3866,12 +3871,13 @@ static int t_show(struct seq_file *m, void *v) if (iter->flags & (FTRACE_ITER_ENABLED | FTRACE_ITER_TOUCHED)) { struct ftrace_ops *ops; - seq_printf(m, " (%ld)%s%s%s%s", + seq_printf(m, " (%ld)%s%s%s%s%s", ftrace_rec_count(rec), rec->flags & FTRACE_FL_REGS ? " R" : " ", rec->flags & FTRACE_FL_IPMODIFY ? " I" : " ", rec->flags & FTRACE_FL_DIRECT ? " D" : " ", - rec->flags & FTRACE_FL_CALL_OPS ? " O" : " "); + rec->flags & FTRACE_FL_CALL_OPS ? " O" : " ", + rec->flags & FTRACE_FL_MODIFIED ? " M " : " "); if (rec->flags & FTRACE_FL_TRAMP_EN) { ops = ftrace_find_tramp_ops_any(rec); if (ops) { |