linux/kernel/trace/ftrace.c, branch v5.10

ftrace: Fix updating FTRACE_FL_TRAMP

2020-12-01T02:43:07Z

On powerpc, kprobe-direct.tc triggered FTRACE_WARN_ON() in ftrace_get_addr_new() followed by the below message: Bad trampoline accounting at: 000000004222522f (wake_up_process+0xc/0x20) (f0000001) The set of steps leading to this involved: - modprobe ftrace-direct-too - enable_probe - modprobe ftrace-direct - rmmod ftrace-direct <-- trigger The problem turned out to be that we were not updating flags in the ftrace record properly. From the above message about the trampoline accounting being bad, it can be seen that the ftrace record still has FTRACE_FL_TRAMP set though ftrace-direct module is going away. This happens because we are checking if any ftrace_ops has the FTRACE_FL_TRAMP flag set _before_ updating the filter hash. The fix for this is to look for any _other_ ftrace_ops that also needs FTRACE_FL_TRAMP. Link: https://lkml.kernel.org/r/56c113aa9c3e10c19144a36d9684c7882bf09af5.1606412433.git.naveen.n.rao@linux.vnet.ibm.com Cc: stable@vger.kernel.org Fixes: a124692b698b0 ("ftrace: Enable trampoline when rec count returns back to one") Signed-off-by: Naveen N. Rao Signed-off-by: Steven Rostedt (VMware)

Merge tag 'trace-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2020-10-15T22:51:28Z

Pull tracing updates from Steven Rostedt: "Updates for tracing and bootconfig: - Add support for "bool" type in synthetic events - Add per instance tracing for bootconfig - Support perf-style return probe ("SYMBOL%return") in kprobes and uprobes - Allow for kprobes to be enabled earlier in boot up - Added tracepoint helper function to allow testing if tracepoints are enabled in headers - Synthetic events can now have dynamic strings (variable length) - Various fixes and cleanups" * tag 'trace-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (58 commits) tracing: support "bool" type in synthetic trace events selftests/ftrace: Add test case for synthetic event syntax errors tracing: Handle synthetic event array field type checking correctly selftests/ftrace: Change synthetic event name for inter-event-combined test tracing: Add synthetic event error logging tracing: Check that the synthetic event and field names are legal tracing: Move is_good_name() from trace_probe.h to trace.h tracing: Don't show dynamic string internals in synthetic event description tracing: Fix some typos in comments tracing/boot: Add ftrace.instance.*.alloc_snapshot option tracing: Fix race in trace_open and buffer resize call tracing: Check return value of __create_val_fields() before using its result tracing: Fix synthetic print fmt check for use of __get_str() tracing: Remove a pointless assignment ftrace: ftrace_global_list is renamed to ftrace_ops_list ftrace: Format variable declarations of ftrace_allocate_records ftrace: Simplify the calculation of page number for ftrace_page->records ftrace: Simplify the dyn_ftrace->flags macro ftrace: Simplify the hash calculation ftrace: Use fls() to get the bits for dup_hash() ...

ftrace: Format variable declarations of ftrace_allocate_records

2020-10-08T19:29:06Z

I hate when unrelated variables are declared on the same line. Split them. Signed-off-by: Steven Rostedt (VMware)

ftrace: Simplify the calculation of page number for ftrace_page->records

2020-10-08T19:29:06Z

Based on the following two reasones, we could simplify the calculation: - If the number after roundup count is not power of 2, we would definitely have more than 1 empty page with a higher order. - get_count_order() just return current order, so one lower order could meet the requirement. The calculation could be simplified by lower one order level when pages are not power of 2. Link: https://lkml.kernel.org/r/20200831031104.23322-5-richard.weiyang@linux.alibaba.com Signed-off-by: Wei Yang Signed-off-by: Steven Rostedt (VMware)

ftrace: Simplify the hash calculation

2020-10-08T19:29:06Z

No need to add a check to subtract the number of bits if bits is zero after fls(). Just divide the size by two before calling it. This does give the same answer for size of 0 and 1, but that's fine. Signed-off-by: Steven Rostedt (VMware)

ftrace: Use fls() to get the bits for dup_hash()

2020-10-08T19:29:06Z

The effect here is to get the number of bits, lets use fls() to do this job. Link: https://lkml.kernel.org/r/20200831031104.23322-3-richard.weiyang@linux.alibaba.com Signed-off-by: Wei Yang Signed-off-by: Steven Rostedt (VMware)

ftrace: Fix some typos in comment

2020-10-02T18:05:48Z

s/coorditate/coordinate/ s/emty/empty/ s/preeptive/preemptive/ s/succes/success/ s/carefule/careful/ Link: https://lkml.kernel.org/r/20201002143126.2890-1-hqjagain@gmail.com Signed-off-by: Qiujun Huang Signed-off-by: Steven Rostedt (VMware)

ftrace: Move RCU is watching check after recursion check

2020-09-29T17:05:10Z

The first thing that the ftrace function callback helper functions should do is to check for recursion. Peter Zijlstra found that when "rcu_is_watching()" had its notrace removed, it caused perf function tracing to crash. This is because the call of rcu_is_watching() is tested before function recursion is checked and and if it is traced, it will cause an infinite recursion loop. rcu_is_watching() should still stay notrace, but to prevent this should never had crashed in the first place. The recursion prevention must be the first thing done in callback functions. Link: https://lore.kernel.org/r/20200929112541.GM2628@hirez.programming.kicks-ass.net Cc: stable@vger.kernel.org Cc: Paul McKenney Fixes: c68c0fa293417 ("ftrace: Have ftrace_ops_get_func() handle RCU and PER_CPU flags too") Acked-by: Peter Zijlstra (Intel) Reported-by: Peter Zijlstra (Intel) Signed-off-by: Steven Rostedt (VMware)

tracing: Delete repeated words in comments

2020-09-22T01:06:02Z

Drop repeated words in kernel/trace/. {and, the, not} Link: https://lkml.kernel.org/r/20200807033259.13778-1-rdunlap@infradead.org Cc: Ingo Molnar Signed-off-by: Randy Dunlap Signed-off-by: Steven Rostedt (VMware)

ftrace: Let ftrace_enable_sysctl take a kernel pointer buffer

2020-09-18T17:15:56Z

Commit 32927393dc1c ("sysctl: pass kernel pointers to ->proc_handler") changed ctl_table.proc_handler to take a kernel pointer. Adjust the signature of ftrace_enable_sysctl to match ctl_table.proc_handler which fixes the following sparse warning: kernel/trace/ftrace.c:7544:43: warning: incorrect type in argument 3 (different address spaces) kernel/trace/ftrace.c:7544:43: expected void * kernel/trace/ftrace.c:7544:43: got void [noderef] __user *buffer Link: https://lkml.kernel.org/r/20200907093207.13540-1-tklauser@distanz.ch Fixes: 32927393dc1c ("sysctl: pass kernel pointers to ->proc_handler") Cc: Andrew Morton Cc: Ingo Molnar Cc: Christoph Hellwig Cc: Al Viro Signed-off-by: Tobias Klauser Signed-off-by: Steven Rostedt (VMware)