summaryrefslogtreecommitdiffstats
Commit message (Collapse)AuthorAgeFilesLines
* Merge tag 'trace-seq-buf-3.19' of ↵Linus Torvalds2014-12-1012-144/+783
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull nmi-safe seq_buf printk update from Steven Rostedt: "This code is a fork from the trace-3.19 pull as it needed the trace_seq clean ups from that branch. This code solves the issue of performing stack dumps from NMI context. The issue is that printk() is not safe from NMI context as if the NMI were to trigger when a printk() was being performed, the NMI could deadlock from the printk() internal locks. This has been seen in practice. With lots of review from Petr Mladek, this code went through several iterations, and we feel that it is now at a point of quality to be accepted into mainline. Here's what is contained in this patch set: - Creates a "seq_buf" generic buffer utility that allows a descriptor to be passed around where functions can write their own "printk()" formatted strings into it. The generic version was pulled out of the trace_seq() code that was made specifically for tracing. - The seq_buf code was change to model the seq_file code. I have a patch (not included for 3.19) that converts the seq_file.c code over to use seq_buf.c like the trace_seq.c code does. This was done to make sure that seq_buf.c is compatible with seq_file.c. I may try to get that patch in for 3.20. - The seq_buf.c file was moved to lib/ to remove it from being dependent on CONFIG_TRACING. - The printk() was updated to allow for a per_cpu "override" of the internal calls. That is, instead of writing to the console, a call to printk() may do something else. This made it easier to allow the NMI to change what printk() does in order to call dump_stack() without needing to update that code as well. - Finally, the dump_stack from all CPUs via NMI code was converted to use the seq_buf code. The caller to trigger the NMI code would wait till all the NMIs finished, and then it would print the seq_buf data to the console safely from a non NMI context One added bonus is that this code also makes the NMI dump stack work on PREEMPT_RT kernels. As printk() includes sleeping locks on PREEMPT_RT, printk() only writes to console if the console does not use any rt_mutex converted spin locks. Which a lot do" * tag 'trace-seq-buf-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: x86/nmi: Fix use of unallocated cpumask_var_t printk/percpu: Define printk_func when printk is not defined x86/nmi: Perform a safe NMI stack trace on all CPUs printk: Add per_cpu printk func to allow printk to be diverted seq_buf: Move the seq_buf code to lib/ seq-buf: Make seq_buf_bprintf() conditional on CONFIG_BINARY_PRINTF tracing: Add seq_buf_get_buf() and seq_buf_commit() helper functions tracing: Have seq_buf use full buffer seq_buf: Add seq_buf_can_fit() helper function tracing: Add paranoid size check in trace_printk_seq() tracing: Use trace_seq_used() and seq_buf_used() instead of len tracing: Clean up tracing_fill_pipe_page() seq_buf: Create seq_buf_used() to find out how much was written tracing: Add a seq_buf_clear() helper and clear len and readpos in init tracing: Convert seq_buf fields to be like seq_file fields tracing: Convert seq_buf_path() to be like seq_path() tracing: Create seq_buf layer in trace_seq
| * x86/nmi: Fix use of unallocated cpumask_var_tSasha Levin2014-11-251-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit "x86/nmi: Perform a safe NMI stack trace on all CPUs" has introduced a cpumask_var_t variable: +static cpumask_var_t printtrace_mask; But never allocated it before using it, which caused a NULL ptr deref when trying to print the stack trace: [ 1110.296154] BUG: unable to handle kernel NULL pointer dereference at (null) [ 1110.296169] IP: __memcpy (arch/x86/lib/memcpy_64.S:151) [ 1110.296178] PGD 4c34b3067 PUD 4c351b067 PMD 0 [ 1110.296186] Oops: 0002 [#1] PREEMPT SMP KASAN [ 1110.296234] Dumping ftrace buffer: [ 1110.296330] (ftrace buffer empty) [ 1110.296339] Modules linked in: [ 1110.296345] CPU: 1 PID: 10538 Comm: trinity-c99 Not tainted 3.18.0-rc5-next-20141124-sasha-00058-ge2a8c09-dirty #1499 [ 1110.296348] task: ffff880152650000 ti: ffff8804c3560000 task.ti: ffff8804c3560000 [ 1110.296357] RIP: __memcpy (arch/x86/lib/memcpy_64.S:151) [ 1110.296360] RSP: 0000:ffff8804c3563870 EFLAGS: 00010246 [ 1110.296363] RAX: 0000000000000000 RBX: ffffe8fff3c4a809 RCX: 0000000000000000 [ 1110.296366] RDX: 0000000000000008 RSI: ffffffff9e254040 RDI: 0000000000000000 [ 1110.296369] RBP: ffff8804c3563908 R08: 0000000000ffffff R09: 0000000000ffffff [ 1110.296371] R10: 0000000000000000 R11: 0000000000000006 R12: 0000000000000000 [ 1110.296375] R13: 0000000000000000 R14: ffffffff9e254040 R15: ffffe8fff3c4a809 [ 1110.296379] FS: 00007f9e43b0b700(0000) GS:ffff880107e00000(0000) knlGS:0000000000000000 [ 1110.296382] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 1110.296385] CR2: 0000000000000000 CR3: 00000004e4334000 CR4: 00000000000006a0 [ 1110.296400] Stack: [ 1110.296406] ffffffff81b1e46c 0000000000000000 ffff880107e03fb8 000000000000000b [ 1110.296413] ffff880107dfffc0 ffff880107e03fc0 0000000000000008 ffffffff93f2e9c8 [ 1110.296419] 0000000000000000 ffffda0020fc07f7 0000000000000008 ffff8804c3563901 [ 1110.296420] Call Trace: [ 1110.296429] ? memcpy (mm/kasan/kasan.c:275) [ 1110.296437] ? arch_trigger_all_cpu_backtrace (include/linux/bitmap.h:215 include/linux/cpumask.h:506 arch/x86/kernel/apic/hw_nmi.c:76) [ 1110.296444] arch_trigger_all_cpu_backtrace (include/linux/bitmap.h:215 include/linux/cpumask.h:506 arch/x86/kernel/apic/hw_nmi.c:76) [ 1110.296451] ? dump_stack (./arch/x86/include/asm/preempt.h:95 lib/dump_stack.c:55) [ 1110.296458] do_raw_spin_lock (./arch/x86/include/asm/spinlock.h:86 kernel/locking/spinlock_debug.c:130 kernel/locking/spinlock_debug.c:137) [ 1110.296468] _raw_spin_lock (include/linux/spinlock_api_smp.h:143 kernel/locking/spinlock.c:151) [ 1110.296474] ? __page_check_address (include/linux/spinlock.h:309 mm/rmap.c:630) [ 1110.296481] __page_check_address (include/linux/spinlock.h:309 mm/rmap.c:630) [ 1110.296487] ? preempt_count_sub (kernel/sched/core.c:2615) [ 1110.296493] try_to_unmap_one (include/linux/rmap.h:202 mm/rmap.c:1146) [ 1110.296504] ? anon_vma_interval_tree_iter_next (mm/interval_tree.c:72 mm/interval_tree.c:103) [ 1110.296514] rmap_walk (mm/rmap.c:1653 mm/rmap.c:1725) [ 1110.296521] ? page_get_anon_vma (include/linux/rcupdate.h:423 include/linux/rcupdate.h:935 mm/rmap.c:435) [ 1110.296530] try_to_unmap (mm/rmap.c:1545) [ 1110.296536] ? page_get_anon_vma (mm/rmap.c:437) [ 1110.296545] ? try_to_unmap_nonlinear (mm/rmap.c:1138) [ 1110.296551] ? SyS_msync (mm/rmap.c:1501) [ 1110.296558] ? page_remove_rmap (mm/rmap.c:1409) [ 1110.296565] ? page_get_anon_vma (mm/rmap.c:448) [ 1110.296571] ? anon_vma_ctor (mm/rmap.c:1496) [ 1110.296579] migrate_pages (mm/migrate.c:913 mm/migrate.c:956 mm/migrate.c:1136) [ 1110.296586] ? _raw_spin_unlock_irq (./arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:169 kernel/locking/spinlock.c:199) [ 1110.296593] ? buffer_migrate_lock_buffers (mm/migrate.c:1584) [ 1110.296601] ? handle_mm_fault (mm/memory.c:3163 mm/memory.c:3223 mm/memory.c:3336 mm/memory.c:3365) [ 1110.296607] migrate_misplaced_page (mm/migrate.c:1738) [ 1110.296614] handle_mm_fault (mm/memory.c:3170 mm/memory.c:3223 mm/memory.c:3336 mm/memory.c:3365) [ 1110.296623] __do_page_fault (arch/x86/mm/fault.c:1246) [ 1110.296630] ? vtime_account_user (kernel/sched/cputime.c:701) [ 1110.296638] ? get_parent_ip (kernel/sched/core.c:2559) [ 1110.296646] ? context_tracking_user_exit (kernel/context_tracking.c:144) [ 1110.296656] trace_do_page_fault (arch/x86/mm/fault.c:1329 include/linux/jump_label.h:114 include/linux/context_tracking_state.h:27 include/linux/context_tracking.h:45 arch/x86/mm/fault.c:1330) [ 1110.296664] do_async_page_fault (arch/x86/kernel/kvm.c:280) [ 1110.296670] async_page_fault (arch/x86/kernel/entry_64.S:1285) [ 1110.296755] Code: 08 4c 8b 54 16 f0 4c 8b 5c 16 f8 4c 89 07 4c 89 4f 08 4c 89 54 17 f0 4c 89 5c 17 f8 c3 90 83 fa 08 72 1b 4c 8b 06 4c 8b 4c 16 f8 <4c> 89 07 4c 89 4c 17 f8 c3 66 2e 0f 1f 84 00 00 00 00 00 83 fa All code ======== 0: 08 4c 8b 54 or %cl,0x54(%rbx,%rcx,4) 4: 16 (bad) 5: f0 4c 8b 5c 16 f8 lock mov -0x8(%rsi,%rdx,1),%r11 b: 4c 89 07 mov %r8,(%rdi) e: 4c 89 4f 08 mov %r9,0x8(%rdi) 12: 4c 89 54 17 f0 mov %r10,-0x10(%rdi,%rdx,1) 17: 4c 89 5c 17 f8 mov %r11,-0x8(%rdi,%rdx,1) 1c: c3 retq 1d: 90 nop 1e: 83 fa 08 cmp $0x8,%edx 21: 72 1b jb 0x3e 23: 4c 8b 06 mov (%rsi),%r8 26: 4c 8b 4c 16 f8 mov -0x8(%rsi,%rdx,1),%r9 2b:* 4c 89 07 mov %r8,(%rdi) <-- trapping instruction 2e: 4c 89 4c 17 f8 mov %r9,-0x8(%rdi,%rdx,1) 33: c3 retq 34: 66 2e 0f 1f 84 00 00 nopw %cs:0x0(%rax,%rax,1) 3b: 00 00 00 3e: 83 fa 00 cmp $0x0,%edx Code starting with the faulting instruction =========================================== 0: 4c 89 07 mov %r8,(%rdi) 3: 4c 89 4c 17 f8 mov %r9,-0x8(%rdi,%rdx,1) 8: c3 retq 9: 66 2e 0f 1f 84 00 00 nopw %cs:0x0(%rax,%rax,1) 10: 00 00 00 13: 83 fa 00 cmp $0x0,%edx [ 1110.296760] RIP __memcpy (arch/x86/lib/memcpy_64.S:151) [ 1110.296763] RSP <ffff8804c3563870> [ 1110.296765] CR2: 0000000000000000 Link: http://lkml.kernel.org/r/1416931560-10603-1-git-send-email-sasha.levin@oracle.com Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * printk/percpu: Define printk_func when printk is not definedSteven Rostedt (Red Hat)2014-11-213-2/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To avoid include hell, the per_cpu variable printk_func was declared in percpu.h. But it is only defined if printk is defined. As users of printk may also use the printk_func variable, it needs to be defined even if CONFIG_PRINTK is not. Also add a printk.h include in percpu.h just to be safe. Link: http://lkml.kernel.org/r/20141121183215.01ba539c@canb.auug.org.au Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * x86/nmi: Perform a safe NMI stack trace on all CPUsSteven Rostedt (Red Hat)2014-11-191-5/+86
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When trigger_all_cpu_backtrace() is called on x86, it will trigger an NMI on each CPU and call show_regs(). But this can lead to a hard lock up if the NMI comes in on another printk(). In order to avoid this, when the NMI triggers, it switches the printk routine for that CPU to call a NMI safe printk function that records the printk in a per_cpu seq_buf descriptor. After all NMIs have finished recording its data, the seq_bufs are printed in a safe context. Link: http://lkml.kernel.org/p/20140619213952.360076309@goodmis.org Link: http://lkml.kernel.org/r/20141115050605.055232587@goodmis.org Tested-by: Jiri Kosina <jkosina@suse.cz> Acked-by: Jiri Kosina <jkosina@suse.cz> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Petr Mladek <pmladek@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * printk: Add per_cpu printk func to allow printk to be divertedSteven Rostedt (Red Hat)2014-11-193-9/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Being able to divert printk to call another function besides the normal logging is useful for such things like NMI handling. If some functions are to be called from NMI that does printk() it is possible to lock up the box if the nmi handler triggers when another printk is happening. One example of this use is to perform a stack trace on all CPUs via NMI. But if the NMI is to do the printk() it can cause the system to lock up. By allowing the printk to be diverted to another function that can safely record the printk output and then print it when it in a safe context then NMIs will be safe to call these functions like show_regs(). Link: http://lkml.kernel.org/p/20140619213952.209176403@goodmis.org Tested-by: Jiri Kosina <jkosina@suse.cz> Acked-by: Jiri Kosina <jkosina@suse.cz> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Petr Mladek <pmladek@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * seq_buf: Move the seq_buf code to lib/Steven Rostedt (Red Hat)2014-11-193-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The seq_buf functions are rather useful outside of tracing. Instead of having it be dependent on CONFIG_TRACING, move the code into lib/ and allow other users to have access to it even when tracing is not configured. The seq_buf utility is similar to the seq_file utility, but instead of writing sending data back up to userland, it writes it into a buffer defined at seq_buf_init(). This allows us to send a descriptor around that writes printf() formatted strings into it that can be retrieved later. It is currently used by the tracing facility for such things like trace events to convert its binary saved data in the ring buffer into an ASCII human readable context to be displayed in /sys/kernel/debug/trace. It can also be used for doing NMI prints safely from NMI context into the seq_buf and retrieved later and dumped to printk() safely. Doing printk() from an NMI context is dangerous because an NMI can preempt a current printk() and deadlock on it. Link: http://lkml.kernel.org/p/20140619213952.058255809@goodmis.org Tested-by: Jiri Kosina <jkosina@suse.cz> Acked-by: Jiri Kosina <jkosina@suse.cz> Reviewed-by: Petr Mladek <pmladek@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * seq-buf: Make seq_buf_bprintf() conditional on CONFIG_BINARY_PRINTFSteven Rostedt (Red Hat)2014-11-192-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The function bstr_printf() from lib/vsprnintf.c is only available if CONFIG_BINARY_PRINTF is defined. This is due to the only user currently being the tracing infrastructure, which needs to select this config when tracing is configured. Until there is another user of the binary printf formats, this will continue to be the case. Since seq_buf.c is now lives in lib/ and is compiled even without tracing, it must encompass its use of bstr_printf() which is used by seq_buf_printf(). This too is only used by the tracing infrastructure and is still encapsulated by the CONFIG_BINARY_PRINTF. Link: http://lkml.kernel.org/r/20141104160222.969013383@goodmis.org Tested-by: Jiri Kosina <jkosina@suse.cz> Acked-by: Jiri Kosina <jkosina@suse.cz> Reviewed-by: Petr Mladek <pmladek@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Add seq_buf_get_buf() and seq_buf_commit() helper functionsSteven Rostedt (Red Hat)2014-11-192-4/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add two helper functions; seq_buf_get_buf() and seq_buf_commit() that are used by seq_buf_path(). This makes the code similar to the seq_file: seq_path() function, and will help to be able to consolidate the functions between seq_file and trace_seq. Link: http://lkml.kernel.org/r/20141104160222.644881406@goodmis.org Link: http://lkml.kernel.org/r/20141114011412.977571447@goodmis.org Tested-by: Jiri Kosina <jkosina@suse.cz> Acked-by: Jiri Kosina <jkosina@suse.cz> Reviewed-by: Petr Mladek <pmladek@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Have seq_buf use full bufferSteven Rostedt (Red Hat)2014-11-192-6/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently seq_buf is full when all but one byte of the buffer is filled. Change it so that the seq_buf is full when all of the buffer is filled. Some of the functions would fill the buffer completely and report everything was fine. This was inconsistent with the max of size - 1. Changing this to be max of size makes all functions consistent. Link: http://lkml.kernel.org/r/20141104160222.502133196@goodmis.org Link: http://lkml.kernel.org/r/20141114011412.811957882@goodmis.org Tested-by: Jiri Kosina <jkosina@suse.cz> Acked-by: Jiri Kosina <jkosina@suse.cz> Reviewed-by: Petr Mladek <pmladek@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * seq_buf: Add seq_buf_can_fit() helper functionSteven Rostedt (Red Hat)2014-11-191-5/+18
| | | | | | | | | | | | | | | | | | | | | | Add a seq_buf_can_fit() helper function that removes the possible mistakes of comparing the seq_buf length plus added data compared to the size of the buffer. Link: http://lkml.kernel.org/r/20141118164025.GL23958@pathway.suse.cz Reviewed-by: Petr Mladek <pmladek@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Add paranoid size check in trace_printk_seq()Steven Rostedt (Red Hat)2014-11-191-0/+8
| | | | | | | | | | | | | | | | | | | | | | To be really paranoid about writing out of bound data in trace_printk_seq(), add another check of len compared to size. Link: http://lkml.kernel.org/r/20141119144004.GB2332@dhcp128.suse.cz Suggested-by: Petr Mladek <pmladek@suse.cz> Reviewed-by: Petr Mladek <pmladek@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Use trace_seq_used() and seq_buf_used() instead of lenSteven Rostedt (Red Hat)2014-11-196-17/+42
| | | | | | | | | | | | | | | | | | | | | | | | As the seq_buf->len will soon be +1 size when there's an overflow, we must use trace_seq_used() or seq_buf_used() methods to get the real length. This will prevent buffer overflow issues if just the len of the seq_buf descriptor is used to copy memory. Link: http://lkml.kernel.org/r/20141114121911.09ba3d38@gandalf.local.home Reported-by: Petr Mladek <pmladek@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Clean up tracing_fill_pipe_page()Steven Rostedt (Red Hat)2014-11-191-6/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The function tracing_fill_pipe_page() logic is a little confusing with the use of count saving the seq.len and reusing it. Instead of subtracting a number that is calculated from the saved value of the seq.len from seq.len, just save the seq.len at the start and if we need to reset it, just assign it again. When the seq_buf overflow is len == size + 1, the current logic will break. Changing it to use a saved length for resetting back to the original value is more robust and will work when we change the way seq_buf sets the overflow. Link: http://lkml.kernel.org/r/20141118161546.GJ23958@pathway.suse.cz Reviewed-by: Petr Mladek <pmladek@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * seq_buf: Create seq_buf_used() to find out how much was writtenSteven Rostedt (Red Hat)2014-11-192-4/+7
| | | | | | | | | | | | | | | | | | | | | | | | Add a helper function seq_buf_used() that replaces the SEQ_BUF_USED() private macro to let callers have a method to know how much of the seq_buf was written to. Link: http://lkml.kernel.org/r/20141114011412.170377300@goodmis.org Link: http://lkml.kernel.org/r/20141114011413.321654244@goodmis.org Reviewed-by: Petr Mladek <pmladek@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Add a seq_buf_clear() helper and clear len and readpos in initSteven Rostedt (Red Hat)2014-11-191-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | Add a helper function seq_buf_clear() that resets the len and readpos fields of a seq_buf. Currently it is only used in the seq_buf_init() but will be used later when updating the seq_file code. Link: http://lkml.kernel.org/r/20141104160222.352309995@goodmis.org Tested-by: Jiri Kosina <jkosina@suse.cz> Acked-by: Jiri Kosina <jkosina@suse.cz> Reviewed-by: Petr Mladek <pmladek@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Convert seq_buf fields to be like seq_file fieldsSteven Rostedt (Red Hat)2014-11-191-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | In facilitating the conversion of seq_file to use seq_buf, have the seq_buf fields match the types used by seq_file. Link: http://lkml.kernel.org/r/20141104160222.195301024@goodmis.org Tested-by: Jiri Kosina <jkosina@suse.cz> Acked-by: Jiri Kosina <jkosina@suse.cz> Reviewed-by: Petr Mladek <pmladek@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Convert seq_buf_path() to be like seq_path()Steven Rostedt (Red Hat)2014-11-193-16/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rewrite seq_buf_path() like it is done in seq_path() and allow it to accept any escape character instead of just "\n". Making seq_buf_path() like seq_path() will help prevent problems when converting seq_file to use the seq_buf logic. Link: http://lkml.kernel.org/r/20141104160222.048795666@goodmis.org Link: http://lkml.kernel.org/r/20141114011412.338523371@goodmis.org Tested-by: Jiri Kosina <jkosina@suse.cz> Acked-by: Jiri Kosina <jkosina@suse.cz> Reviewed-by: Petr Mladek <pmladek@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Create seq_buf layer in trace_seqSteven Rostedt (Red Hat)2014-11-198-126/+538
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Create a seq_buf layer that trace_seq sits on. The seq_buf will not be limited to page size. This will allow other usages of seq_buf instead of a hard set PAGE_SIZE one that trace_seq has. Link: http://lkml.kernel.org/r/20141104160221.864997179@goodmis.org Link: http://lkml.kernel.org/r/20141114011412.170377300@goodmis.org Tested-by: Jiri Kosina <jkosina@suse.cz> Acked-by: Jiri Kosina <jkosina@suse.cz> Reviewed-by: Petr Mladek <pmladek@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | Merge tag 'ftracetest-3.19' of ↵Linus Torvalds2014-12-1014-13/+484
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull ftrace self-test updates from Steven Rostedt: "Updates for the ftrace self tests: - Added kprobes on ftrace testcase - Sort test cases - Add file to hold helper functions - Use logfile name supported by busybox's mktemp - Clear trace buffer after running kprobe test - Fix show descriptions when run on dash shell - Add --verbose option for showing echo output" * tag 'ftracetest-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ftracetest: Add --verbose option for showing echo output ftracetest: Fix to show descriptions on dash ftracetest: Add basic event tracing test cases ftracetest: Clear trace buffer after running kprobe testcases ftracetest: Use logfile name supported by busybox's mktemp ftracetest: Add a couple of ftrace test cases ftracetest: Add functions file that holds helper functions ftracetest: Sort testcases ftracetest: Add kprobes on ftrace testcase
| * | ftracetest: Add --verbose option for showing echo outputMasami Hiramatsu2014-12-041-10/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add --verbose/-v option for showing echo output in testcases. This is good for checking the progress of testcases which take a longer time to run. To implement this feature, all the testcase failures are captured in ftracetest and send signal to set SIG_RESULT=FAIL. Link: http://lkml.kernel.org/r/20141204194123.7376.22964.stgit@localhost.localdomain Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | ftracetest: Fix to show descriptions on dashMasami Hiramatsu2014-12-041-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ftracetest doesn't show testcase's descriptions when it is executed on dash. This fixes that to show the descriptions on dash correctly by passing it via a variable instead of directly passing the grep command output. Link: http://lkml.kernel.org/r/20141204194116.7376.78940.stgit@localhost.localdomain Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | ftracetest: Add basic event tracing test casesNamhyung Kim2014-11-064-0/+158
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds basic event tracing tests like enable/disable with top-level, subsystem-level and individual event files. # ./ftracetest === Ftrace unit tests === [1] Basic trace file check [PASS] [2] Basic trace clock test [PASS] [3] Basic event tracing check [PASS] [4] Basic test for tracers [PASS] [5] event tracing - enable/disable with top level files [PASS] [6] event tracing - enable/disable with subsystem level files [PASS] [7] event tracing - enable/disable with event level files [PASS] [8] ftrace - function graph filters [PASS] [9] ftrace - function profiler with function tracing [PASS] [10] ftrace - function graph filters with stack tracer [PASS] [11] Kretprobe dynamic event with arguments [PASS] [12] Kprobe dynamic event - busy event check [PASS] [13] Kprobe dynamic event with arguments [PASS] [14] Kprobe dynamic event - adding and removing [PASS] # of passed: 14 # of failed: 0 # of unresolved: 0 # of untested: 0 # of unsupported: 0 # of xfailed: 0 # of undefined(test bug): 0 Link: http://lkml.kernel.org/r/1415239470-28705-3-git-send-email-namhyung@kernel.org Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | ftracetest: Clear trace buffer after running kprobe testcasesNamhyung Kim2014-11-064-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The kprobe testcases create, use and delete dynamic events during the test but didn't clear the trace buffer so it'll leave the result after it finishes. # ./ftracetest ... # cat trace # tracer: nop # # entries-in-buffer/entries-written: 2/2 #P:12 # # _-----=> irqs-off # / _----=> need-resched # | / _---=> hardirq/softirq # || / _--=> preempt-depth # ||| / delay # TASK-PID CPU# |||| TIMESTAMP FUNCTION # | | | |||| | | ftracetest-26474 [009] d..1 79417.143782: Unknown type 1099 ftracetest-26498 [009] d..1 79417.208034: Unknown type 1101 Link: http://lkml.kernel.org/r/1415239470-28705-2-git-send-email-namhyung@kernel.org Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | ftracetest: Use logfile name supported by busybox's mktempNamhyung Kim2014-11-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When I run the ftracetest in a busybox docker container, I saw following error. Make the logfile template to comply with busybox's mktemp. It also keep the logfiles under the logs directory. # /linux/tools/testing/selftests/ftrace/ftracetest === Ftrace unit tests === mktemp: unrecognized option `--tmpdir=/linux/tools/testing/selftests/ftrace/logs/20141106-003624/' BusyBox v1.22.1 (2014-05-22 23:22:11 UTC) multi-call binary. Usage: mktemp [-dt] [-p DIR] [TEMPLATE] Create a temporary file with name based on TEMPLATE and print its name. TEMPLATE must end with XXXXXX (e.g. [/dir/]nameXXXXXX). Without TEMPLATE, -t tmp.XXXXXX is assumed. -d Make directory, not file -q Fail silently on errors -t Prepend base directory name to TEMPLATE -p DIR Use DIR as a base directory (implies -t) -u Do not create anything; print a name Base directory is: -p DIR, else $TMPDIR, else /tmp [1] Basic trace file check/linux/tools/testing/selftests/ftrace/ftracetest: line 244: can't create : nonexistent directory /linux/tools/testing/selftests/ftrace/ftracetest: line 244: can't create : nonexistent directory [FAIL] Link: http://lkml.kernel.org/r/1415239470-28705-1-git-send-email-namhyung@kernel.org Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | ftracetest: Add a couple of ftrace test casesSteven Rostedt (Red Hat)2014-11-063-0/+221
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Added three test cases to get the feel of adding tests to ftracetest. The three cases are: function profiling test, to make sure function profiling still works with function tracing (was a regression) function graph filter test to make sure that function graph filtering works. function graph filter with stack tracing test to make sure that the function graph filter does filter and also continues to filter when another function tracer is running (like the stack tracer) Link: http://lkml.kernel.org/r/20141103212737.696365174@goodmis.org Link: http://lkml.kernel.org/r/20141104153028.602754370@goodmis.org Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | ftracetest: Add functions file that holds helper functionsSteven Rostedt (Red Hat)2014-11-062-0/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Created the file tools/testing/ftrace/test.d/functions that will hold helper functions. Current helper functions include: Add clear_trace() helper to reset the trace file Used as a descriptive name to show that "echo > trace" is clearing the trace file. Add disable/enable_tracing() helper calls Add calls that disable and enable tracing respectively by echoing 0 or 1 into tracing_on. Add helper reset_tracer() function Add a helper function reset_tracer() that will clear the current_tracer (echo nop > current_tracer). Link: http://lkml.kernel.org/r/20141103212737.696365174@goodmis.org Link: http://lkml.kernel.org/r/20141104153028.465517119@goodmis.org Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | ftracetest: Sort testcasesHeiko Carstens2014-11-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make sure the order of the executed testcases is always the same. Link: http://lkml.kernel.org/p/1413802323-5297-3-git-send-email-heiko.carstens@de.ibm.com Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | ftracetest: Add kprobes on ftrace testcaseHeiko Carstens2014-11-031-0/+55
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a kprobes on ftrace testcase. The testcase verifies that - enabling and disabling function tracing works on a function which already contains a dynamic kprobe - adding and removing a dynamic kprobe works on a function which is already enabled for function tracing Link: http://lkml.kernel.org/p/1413802323-5297-2-git-send-email-heiko.carstens@de.ibm.com Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | Merge tag 'trace-3.19' of ↵Linus Torvalds2014-12-1038-1312/+1680
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "There was a lot of clean ups and minor fixes. One of those clean ups was to the trace_seq code. It also removed the return values to the trace_seq_*() functions and use trace_seq_has_overflowed() to see if the buffer filled up or not. This is similar to work being done to the seq_file code as well in another tree. Some of the other goodies include: - Added some "!" (NOT) logic to the tracing filter. - Fixed the frame pointer logic to the x86_64 mcount trampolines - Added the logic for dynamic trampolines on !CONFIG_PREEMPT systems. That is, the ftrace trampoline can be dynamically allocated and be called directly by functions that only have a single hook to them" * tag 'trace-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (55 commits) tracing: Truncated output is better than nothing tracing: Add additional marks to signal very large time deltas Documentation: describe trace_buf_size parameter more accurately tracing: Allow NOT to filter AND and OR clauses tracing: Add NOT to filtering logic ftrace/fgraph/x86: Have prepare_ftrace_return() take ip as first parameter ftrace/x86: Get rid of ftrace_caller_setup ftrace/x86: Have save_mcount_regs macro also save stack frames if needed ftrace/x86: Add macro MCOUNT_REG_SIZE for amount of stack used to save mcount regs ftrace/x86: Simplify save_mcount_regs on getting RIP ftrace/x86: Have save_mcount_regs store RIP in %rdi for first parameter ftrace/x86: Rename MCOUNT_SAVE_FRAME and add more detailed comments ftrace/x86: Move MCOUNT_SAVE_FRAME out of header file ftrace/x86: Have static tracing also use ftrace_caller_setup ftrace/x86: Have static function tracing always test for function graph kprobes: Add IPMODIFY flag to kprobe_ftrace_ops ftrace, kprobes: Support IPMODIFY flag to find IP modify conflict kprobes/ftrace: Recover original IP if pre_handler doesn't change it tracing/trivial: Fix typos and make an int into a bool tracing: Deletion of an unnecessary check before iput() ...
| * | | tracing: Truncated output is better than nothingDan Carpenter2014-12-031-5/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The initial reason for this patch is that I noticed that: if (len > TRACE_BUF_SIZE) is off by one. In this code, if len == TRACE_BUF_SIZE, then it means we have truncated the last character off the output string. If we truncate two or more characters then we exit without printing. After some discussion, we decided that printing truncated data is better than not printing at all so we should just use vscnprintf() and remove the test entirely. Also I have updated memcpy() to copy the NUL char instead of setting the NUL in a separate step. Link: http://lkml.kernel.org/r/20141127155752.GA21914@mwanda Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | tracing: Add additional marks to signal very large time deltasByungchul Park2014-12-034-28/+41
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, function graph tracer prints "!" or "+" just before function execution time to signal a function overhead, depending on the time. And some tracers tracing latency also print "!" or "+" just after time to signal overhead, depending on the interval between events. Even it is usually enough to do that, we sometimes need to signal for bigger execution time than 100 micro seconds. For example, I used function graph tracer to detect if there is any case that exit_mm() takes too much time. I did following steps in /sys/kernel/debug/tracing. It was easier to detect very large excution time with patched kernel than with original kernel. $ echo exit_mm > set_graph_function $ echo function_graph > current_tracer $ echo > trace $ cat trace_pipe > $LOGFILE ... (do something and terminate logging) $ grep "\\$" $LOGFILE 3) $ 22082032 us | } /* kernel_map_pages */ 3) $ 22082040 us | } /* free_pages_prepare */ 3) $ 22082113 us | } /* free_hot_cold_page */ 3) $ 22083455 us | } /* free_hot_cold_page_list */ 3) $ 22083895 us | } /* release_pages */ 3) $ 22177873 us | } /* free_pages_and_swap_cache */ 3) $ 22178929 us | } /* unmap_single_vma */ 3) $ 22198885 us | } /* unmap_vmas */ 3) $ 22206949 us | } /* exit_mmap */ 3) $ 22207659 us | } /* mmput */ 3) $ 22207793 us | } /* exit_mm */ And then, it was easy to find out that a schedule-out occured by sub_preempt_count() within kernel_map_pages(). To detect very large function exection time caused by either problematic function implementation or scheduling issues, this patch can be useful. Link: http://lkml.kernel.org/r/1416789259-24038-1-git-send-email-byungchul.park@lge.com Signed-off-by: Byungchul Park <byungchul.park@lge.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | Documentation: describe trace_buf_size parameter more accuratelyJoonsoo Kim2014-12-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I'm stuck into panic that too litte free memory is left when I boot with trace_buf_size parameter. After digging into the problem, I found that trace_buf_size is the size of trace buffer on each cpu rather than total size of trace buffer. To prevent victim like me, change description of trace_buf_size parameter more accurately. Link: http://lkml.kernel.org/r/1417570760-10620-1-git-send-email-iamjoonsoo.kim@lge.com Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | tracing: Allow NOT to filter AND and OR clausesSteven Rostedt (Red Hat)2014-12-031-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add support to allow not "!" for and (&&) and (||). That is: !(field1 == X && field2 == Y) Where the value of the full clause will be notted. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | tracing: Add NOT to filtering logicSteven Rostedt (Red Hat)2014-12-031-2/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Ted noticed that he could not filter on an event for a bit being cleared. That's because the filtering logic only tests event fields with a limited number of comparisons which, for bit logic, only include "&", which can test if a bit is set, but there's no good way to see if a bit is clear. This adds a way to do: !(field & 2048) Which returns true if the bit is not set, and false otherwise. Note, currently !(field1 == 10 && field2 == 15) is not supported. That is, the 'not' only works for direct comparisons, not for the AND and OR logic. Link: http://lkml.kernel.org/r/20141202021912.GA29096@thunk.org Link: http://lkml.kernel.org/r/20141202120430.71979060@gandalf.local.home Acked-by: Alexei Starovoitov <ast@plumgrid.com> Suggested-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | ftrace/fgraph/x86: Have prepare_ftrace_return() take ip as first parameterSteven Rostedt (Red Hat)2014-12-012-9/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The function graph helper function prepare_ftrace_return() which does the work to hijack the parent pointer has that parent pointer as its first parameter. Instead, if we make it the second parameter and have ip as the first parameter (self_addr), then it can use the %rdi from save_mcount_regs that loads it already. Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | ftrace/x86: Get rid of ftrace_caller_setupSteven Rostedt (Red Hat)2014-12-011-29/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move all the work from ftrace_caller_setup into save_mcount_regs. This simplifies the code and makes it easier to understand. Link: http://lkml.kernel.org/r/CA+55aFxUTUbdxpjVMW8X9c=o8sui7OB_MYPfcbJuDyfUWtNrNg@mail.gmail.com Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | ftrace/x86: Have save_mcount_regs macro also save stack frames if neededSteven Rostedt (Red Hat)2014-12-011-51/+67
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The save_mcount_regs macro saves and restores the required mcount regs that need to be saved before calling C code. It is done for all the function hook utilities (static tracing, dynamic tracing, regs, function graph). When frame pointers are enabled, the ftrace trampolines need to set up frames and pointers such that a back trace (dump stack) can continue passed them. Currently, a separate macro is used (create_frame) to do this, but it's only done for the ftrace_caller and ftrace_reg_caller functions. It is not done for the static tracer or function graph tracing. Instead of having a separate macro doing the recording of the frames, have the save_mcount_regs perform this task. This also has all tracers saving the frame pointers when needed. Link: http://lkml.kernel.org/r/CA+55aFwF+qCGSKdGaEgW4p6N65GZ5_XTV=1NbtWDvxnd5yYLiw@mail.gmail.com Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | ftrace/x86: Add macro MCOUNT_REG_SIZE for amount of stack used to save ↵Steven Rostedt (Red Hat)2014-12-011-12/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | mcount regs The macro save_mcount_regs saves regs onto the stack. But to uncouple the amount of stack used in that macro from the users of the macro, we need to have a define that tells all the users how much stack is used by that macro. This way we can change the amount of stack the macro uses without breaking its users. Also remove some dead code that was left over from commit fdc841b58cf5 "ftrace: x86: Remove check of obsolete variable function_trace_stop". Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | ftrace/x86: Simplify save_mcount_regs on getting RIPSteven Rostedt (Red Hat)2014-12-011-19/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently save_mcount_regs is passed a "skip" parameter to know how much stack updated the pt_regs, as it tries to keep the saved pt_regs in the same location for all users. This is rather stupid, especially since the part stored on the pt_regs has nothing to do with what is suppose to be in that location. Instead of doing that, just pass in an "added" parameter that lets that macro know how much stack was added before it was called so that it can get to the RIP. But the difference is that it will now offset the pt_regs by that "added" count. The caller now needs to take care of the offset of the pt_regs. This will make it easier to simplify the code later. Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | ftrace/x86: Have save_mcount_regs store RIP in %rdi for first parameterSteven Rostedt (Red Hat)2014-12-011-4/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of having save_mcount_regs store the RIP in %rdx as a temp register to place it in the proper location of the pt_regs on the stack. Use the %rdi register as the temp register. This lets us remove the extra store in the ftrace_caller_setup macro. Link: http://lkml.kernel.org/r/CA+55aFwF+qCGSKdGaEgW4p6N65GZ5_XTV=1NbtWDvxnd5yYLiw@mail.gmail.com Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | ftrace/x86: Rename MCOUNT_SAVE_FRAME and add more detailed commentsSteven Rostedt (Red Hat)2014-12-011-8/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The name MCOUNT_SAVE_FRAME is rather confusing as it really isn't a function frame that is saved, but just the required mcount registers that are needed to be saved before C code may be called. The word "frame" confuses it as being a function frame which it is not. Rename MCOUNT_SAVE_FRAME and MCOUNT_RESTORE_FRAME to save_mcount_regs and restore_mcount_regs respectively. Noticed the lower case, which keeps it from screaming at the reviewers. Link: http://lkml.kernel.org/r/CA+55aFwF+qCGSKdGaEgW4p6N65GZ5_XTV=1NbtWDvxnd5yYLiw@mail.gmail.com Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | ftrace/x86: Move MCOUNT_SAVE_FRAME out of header fileSteven Rostedt (Red Hat)2014-12-012-33/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Linus pointed out that MCOUNT_SAVE_FRAME is used in only a single file and that there's no reason that it should be in a header file. Move the macro to the code that uses it. Link: http://lkml.kernel.org/r/CA+55aFwF+qCGSKdGaEgW4p6N65GZ5_XTV=1NbtWDvxnd5yYLiw@mail.gmail.com Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | ftrace/x86: Have static tracing also use ftrace_caller_setupSteven Rostedt (Red Hat)2014-12-011-15/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Linus pointed out that there were locations that did the hard coded update of the parent and rip parameters. One of them was the static tracer which could also use the ftrace_caller_setup to do that work. In fact, because it did not use it, it is prone to bugs, and since the static tracer is hardly ever used (who wants function tracing code always being called?) it doesn't get tested very often. I only run a few "does it still work" tests on it. But I do not run stress tests on that code. Although, since it is never turned off, just having it on should be stressful enough. (especially for the performance folks) There's no reason that the static tracer can't also use ftrace_caller_setup. Have it do so. Link: http://lkml.kernel.org/r/CA+55aFwF+qCGSKdGaEgW4p6N65GZ5_XTV=1NbtWDvxnd5yYLiw@mail.gmail.com Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | ftrace/x86: Have static function tracing always test for function graphSteven Rostedt (Red Hat)2014-11-241-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | New updates to the ftrace generic code had ftrace_stub not always being called when ftrace is off. This causes the static tracer to always save and restore functions. But it also showed that when function tracing is running, the function graph tracer can not. We should always check to see if function graph tracing is running even if the function tracer is running too. The function tracer code is not the only one that uses the hook to function mcount. Cc: Markos Chandras <Markos.Chandras@imgtec.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | kprobes: Add IPMODIFY flag to kprobe_ftrace_opsMasami Hiramatsu2014-11-211-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add FTRACE_OPS_FL_IPMODIFY flag to kprobe_ftrace_ops since kprobes can changes regs->ip. Link: http://lkml.kernel.org/r/20141121102523.11844.21298.stgit@localhost.localdomain Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | ftrace, kprobes: Support IPMODIFY flag to find IP modify conflictMasami Hiramatsu2014-11-213-4/+159
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce FTRACE_OPS_FL_IPMODIFY to avoid conflict among ftrace users who may modify regs->ip to change the execution path. If two or more users modify the regs->ip on the same function entry, one of them will be broken. So they must add IPMODIFY flag and make sure that ftrace_set_filter_ip() succeeds. Note that ftrace doesn't allow ftrace_ops which has IPMODIFY flag to have notrace hash, and the ftrace_ops must have a filter hash (so that the ftrace_ops can hook only specific entries), because it strongly depends on the address and must be allowed for only few selected functions. Link: http://lkml.kernel.org/r/20141121102516.11844.27829.stgit@localhost.localdomain Cc: Jiri Kosina <jkosina@suse.cz> Cc: Seth Jennings <sjenning@redhat.com> Cc: Petr Mladek <pmladek@suse.cz> Cc: Vojtech Pavlik <vojtech@suse.cz> Cc: Miroslav Benes <mbenes@suse.cz> Cc: Ingo Molnar <mingo@kernel.org> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> [ fixed up some of the comments ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | kprobes/ftrace: Recover original IP if pre_handler doesn't change itMasami Hiramatsu2014-11-201-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Recover original IP register if the pre_handler doesn't change it. Since current kprobes doesn't expect that another ftrace handler may change regs->ip, it sets kprobe.addr + MCOUNT_INSN_SIZE to regs->ip and returns to ftrace. This seems wrong behavior since kprobes can recover regs->ip and safely pass it to another handler. This adds code which recovers original regs->ip passed from ftrace right before returning to ftrace, so that another ftrace user can change regs->ip. Link: http://lkml.kernel.org/r/20141009130106.4698.26362.stgit@kbuild-f20.novalocal Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | tracing/trivial: Fix typos and make an int into a boolSteven Rostedt (Red Hat)2014-11-202-4/+4
| | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | Fix up a few typos in comments and convert an int into a bool in update_traceon_count(). Link: http://lkml.kernel.org/r/546DD445.5080108@hitachi.com Suggested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | tracing: Deletion of an unnecessary check before iput()Markus Elfring2014-11-191-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The iput() function tests whether its argument is NULL and then returns immediately. Thus the test around the call is not needed. This issue was detected by using the Coccinelle software. Link: http://lkml.kernel.org/r/5468F875.7080907@users.sourceforge.net Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | tracing: Fix return value of ftrace_raw_output_prep()Steven Rostedt (Red Hat)2014-11-192-5/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the trace_seq of ftrace_raw_output_prep() is full this function returns TRACE_TYPE_PARTIAL_LINE, otherwise it returns zero. The problem is that TRACE_TYPE_PARTIAL_LINE happens to be zero! The thing is, the caller of ftrace_raw_output_prep() expects a success to be zero. Change that to expect it to be TRACE_TYPE_HANDLED. Link: http://lkml.kernel.org/r/20141114112522.GA2988@dhcp128.suse.cz Reminded-by: Petr Mladek <pmladek@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
OpenPOWER on IntegriCloud