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* recordmcount: Remove redundant cleanup() callsMatt Helsley2019-08-312-15/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Redundant cleanup calls were introduced when transitioning from the old error/success handling via setjmp/longjmp -- the longjmp ensured the cleanup() call only happened once but replacing the success_file()/fail_file() calls with cleanup() meant that multiple cleanup() calls can happen as we return from function calls. In do_file(), looking just before and after the "goto out" jumps we can see that multiple cleanups() are being performed. We remove cleanup() calls from the nested functions because it makes the code easier to review -- the resources being cleaned up are generally allocated and initialized in the callers so freeing them there makes more sense. Other redundant cleanup() calls: mmap_file() is only called from do_file() and, if mmap_file() fails, then we goto out and do cleanup() there too. write_file() is only called from do_file() and do_file() calls cleanup() unconditionally after returning from write_file() therefore the cleanup() calls in write_file() are not necessary. find_secsym_ndx(), called from do_func()'s for-loop, when we are cleaning up here it's obvious that we break out of the loop and do another cleanup(). __has_rel_mcount() is called from two parts of do_func() and calls cleanup(). In theory we move them into do_func(), however these in turn prove redundant so another simplification step removes them as well. Link: http://lkml.kernel.org/r/de197e17fc5426623a847ea7cf3a1560a7402a4b.1564596289.git.mhelsley@vmware.com Signed-off-by: Matt Helsley <mhelsley@vmware.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* recordmcount: Kernel style formattingMatt Helsley2019-08-311-22/+25
| | | | | | | | | | | | | | Fix up the whitespace irregularity in the ELF switch blocks. Swapping the initial value of gpfx allows us to simplify all but one of the one-line switch cases even further. Link: http://lkml.kernel.org/r/647f21f43723d3e831cedd3238c893db03eea6f0.1564596289.git.mhelsley@vmware.com Signed-off-by: Matt Helsley <mhelsley@vmware.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* recordmcount: Kernel style function signature formattingMatt Helsley2019-08-312-21/+13
| | | | | | | | | | | The uwrite() and ulseek() functions are formatted inconsistently with the rest of the file and the kernel overall. While we're making other changes here let's fix this. Link: http://lkml.kernel.org/r/4c67698f734be9867a2aba7035fe0ce59e1e4423.1564596289.git.mhelsley@vmware.com Signed-off-by: Matt Helsley <mhelsley@vmware.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* recordmcount: Rewrite error/success handlingMatt Helsley2019-08-312-119/+184
| | | | | | | | | | | | | | | | | | | | | | | | Recordmcount uses setjmp/longjmp to manage control flow as it reads and then writes the ELF file. This unusual control flow is hard to follow and check in addition to being unlike kernel coding style. So we rewrite these paths to use regular return values to indicate error/success. When an error or previously-completed object file is found we return an error code following kernel coding conventions -- negative error values and 0 for success when we're not returning a pointer. We return NULL for those that fail and return non-NULL pointers otherwise. One oddity is already_has_rel_mcount -- there we use pointer comparison rather than string comparison to differentiate between previously-processed object files and returning the name of a text section. Link: http://lkml.kernel.org/r/8ba8633d4afe444931f363c8d924bf9565b89a86.1564596289.git.mhelsley@vmware.com Signed-off-by: Matt Helsley <mhelsley@vmware.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* selftests/ftrace: Add syntax error test for multiprobeMasami Hiramatsu2019-08-312-1/+11
| | | | | | | | | | Add syntax error test cases for multiprobe appending errors. Link: http://lkml.kernel.org/r/156095694541.28024.11918630805148623119.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* selftests/ftrace: Add syntax error test for immediatesMasami Hiramatsu2019-08-311-0/+5
| | | | | | | | | | Add syntax error test cases for immediate value and immediate string. Link: http://lkml.kernel.org/r/156095693553.28024.7730929892585591691.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* selftests/ftrace: Add a testcase for kprobe multiprobe eventMasami Hiramatsu2019-08-311-0/+35
| | | | | | | | | Add a testcase for kprobe event with multi-probe. Link: http://lkml.kernel.org/r/156095692637.28024.17188971794698768977.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* tracing/probe: Add immediate string parameter supportMasami Hiramatsu2019-08-315-15/+51
| | | | | | | | | | | | | | | | | | | | | | Add immediate string parameter (\"string") support to probe events. This allows you to specify an immediate (or dummy) parameter instead of fetching a string from memory. This feature looks odd, but imagine that you put a probe on a code to trace some string data. If the code is compiled into 2 instructions and 1 instruction has a string on memory but other has no string since it is optimized out. In that case, you can not fold those into one event, even if ftrace supported multiple probes on one event. With this feature, you can set a dummy string like foo=\"(optimized)":string instead of something like foo=+0(+0(%bp)):string. Link: http://lkml.kernel.org/r/156095691687.28024.13372712423865047991.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* tracing/probe: Add immediate parameter supportMasami Hiramatsu2019-08-315-1/+22
| | | | | | | | | | | | | | | | | | | | | Add immediate value parameter (\1234) support to probe events. This allows you to specify an immediate (or dummy) parameter instead of fetching from memory or register. This feature looks odd, but imagine when you put a probe on a code to trace some data. If the code is compiled into 2 instructions and 1 instruction has a value but other has nothing since it is optimized out. In that case, you can not fold those into one event, even if ftrace supported multiple probes on one event. With this feature, you can set a dummy value like foo=\deadbeef instead of something like foo=%di. Link: http://lkml.kernel.org/r/156095690733.28024.13258186548822649469.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* tracing/uprobe: Add per-probe delete from eventMasami Hiramatsu2019-08-311-1/+30
| | | | | | | | | | | Add per-probe delete method from one event passing the head of definition. In other words, the events which match the head N parameters are deleted. Link: http://lkml.kernel.org/r/156095689811.28024.221706761151739433.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* tracing/kprobe: Add per-probe delete from eventMasami Hiramatsu2019-08-313-1/+44
| | | | | | | | | | | | | | | | | | | Allow user to delete a probe from event. This is done by head match. For example, if we have 2 probes on an event $ cat kprobe_events p:kprobes/testprobe _do_fork r1=%ax r2=%dx p:kprobes/testprobe idle_fork r1=%ax r2=%cx Then you can remove one of them by passing the head of definition which identify the probe. $ echo "-:kprobes/testprobe idle_fork" >> kprobe_events Link: http://lkml.kernel.org/r/156095688848.28024.15798690082378432435.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* tracing/uprobe: Add multi-probe per uprobe event supportMasami Hiramatsu2019-08-312-19/+43
| | | | | | | | | | | Allow user to define several probes on one uprobe event. Note that this only support appending method. So deleting event will delete all probes on the event. Link: http://lkml.kernel.org/r/156095687876.28024.13840331032234992863.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* tracing/kprobe: Add multi-probe per event supportMasami Hiramatsu2019-08-314-18/+111
| | | | | | | | | | | | | | | | | | | | | | | | Add multi-probe per one event support to kprobe events. User can define several different probes on one trace event if those events have same "event signature", e.g. # echo p:testevent _do_fork > kprobe_events # echo p:testevent fork_idle >> kprobe_events # kprobe_events p:kprobes/testevent _do_fork p:kprobes/testevent fork_idle The event signature is defined by kprobe type (retprobe or not), the number of args, argument names, and argument types. Note that this only support appending method. Delete event operation will delete all probes on the event. Link: http://lkml.kernel.org/r/156095686913.28024.9357292202316540742.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* tracing/dynevent: Pass extra arguments to match operationMasami Hiramatsu2019-08-315-10/+13
| | | | | | | | | | | Pass extra arguments to match operation for checking exact match. If the event doesn't support exact match, it will be ignored. Link: http://lkml.kernel.org/r/156095685930.28024.10405547027475590975.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* tracing/dynevent: Delete all matched eventsMasami Hiramatsu2019-08-311-3/+5
| | | | | | | | | | | | | | | | | | | | | When user gives an event name to delete, delete all matched events instead of the first one. This means if there are several events which have same name but different group (subsystem) name, those are removed if user passed only the event name, e.g. # cat kprobe_events p:group1/testevent _do_fork p:group2/testevent fork_idle # echo -:testevent >> kprobe_events # cat kprobe_events # Link: http://lkml.kernel.org/r/156095684958.28024.16597826267117453638.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* tracing/probe: Split trace_event related data from trace_probeMasami Hiramatsu2019-08-314-113/+311
| | | | | | | | | | | Split the trace_event related data from trace_probe data structure and introduce trace_probe_event data structure for its folder. This trace_probe_event data structure can have multiple trace_probe. Link: http://lkml.kernel.org/r/156095683995.28024.7552150340561557873.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* recordmcount: Remove unused fd from uwrite() and ulseek()Matt Helsley2019-08-312-21/+21
| | | | | | | | | | | | | | | | | uwrite() works within the pseudo-mapping and extends it as necessary without needing the file descriptor (fd) parameter passed to it. Similarly, ulseek() doesn't need its fd parameter. These parameters were only added because the functions bear a conceptual resemblance to write() and lseek(). Worse, they obscure the fact that at the time uwrite() and ulseek() are called fd_map is not a valid file descriptor. Remove the unused file descriptor parameters that make it look like fd_map is still valid. Link: http://lkml.kernel.org/r/2a136e820ee208469d375265c7b8eb28570749a0.1563992889.git.mhelsley@vmware.com Signed-off-by: Matt Helsley <mhelsley@vmware.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* recordmcount: Remove uread()Matt Helsley2019-08-311-13/+5
| | | | | | | | | | | | | | | | | | uread() is only used to initialize the ELF file's pseudo private-memory mapping while uwrite() and ulseek() work within the pseudo-mapping and extend it as necessary. Thus it is not a complementary function to uwrite() and ulseek(). It also makes no sense to do cleanups inside uread() when its only caller, mmap_file(), is doing the relevant allocations and associated initializations. Therefore it's clearer to use a plain read() call to initialize the data in mmap_file() and remove uread(). Link: http://lkml.kernel.org/r/31a87c22b19150cec1c8dc800c8b0873a2741703.1563992889.git.mhelsley@vmware.com Signed-off-by: Matt Helsley <mhelsley@vmware.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* recordmcount: Remove redundant strcmpMatt Helsley2019-08-311-2/+1
| | | | | | | | | | The strcmp is unnecessary since .text is already accepted as a prefix in the strncmp(). Link: http://lkml.kernel.org/r/358e590b49adbe4185e161a8b364e323f3d52857.1563992889.git.mhelsley@vmware.com Signed-off-by: Matt Helsley <mhelsley@vmware.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* kprobes: Allow kprobes coexist with livepatchMasami Hiramatsu2019-08-311-16/+40
| | | | | | | | | | | | | | | | Allow kprobes which do not modify regs->ip, coexist with livepatch by dropping FTRACE_OPS_FL_IPMODIFY from ftrace_ops. User who wants to modify regs->ip (e.g. function fault injection) must set a dummy post_handler to its kprobes when registering. However, if such regs->ip modifying kprobes is set on a function, that function can not be livepatched. Link: http://lkml.kernel.org/r/156403587671.30117.5233558741694155985.stgit@devnote2 Acked-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* tracing: Correct kdoc formatsJakub Kicinski2019-08-311-12/+14
| | | | | | | | | | | | | | | | | | | | | | Fix the following kdoc warnings: kernel/trace/trace.c:1579: warning: Function parameter or member 'tr' not described in 'update_max_tr_single' kernel/trace/trace.c:1579: warning: Function parameter or member 'tsk' not described in 'update_max_tr_single' kernel/trace/trace.c:1579: warning: Function parameter or member 'cpu' not described in 'update_max_tr_single' kernel/trace/trace.c:1776: warning: Function parameter or member 'type' not described in 'register_tracer' kernel/trace/trace.c:2239: warning: Function parameter or member 'task' not described in 'tracing_record_taskinfo' kernel/trace/trace.c:2239: warning: Function parameter or member 'flags' not described in 'tracing_record_taskinfo' kernel/trace/trace.c:2269: warning: Function parameter or member 'prev' not described in 'tracing_record_taskinfo_sched_switch' kernel/trace/trace.c:2269: warning: Function parameter or member 'next' not described in 'tracing_record_taskinfo_sched_switch' kernel/trace/trace.c:2269: warning: Function parameter or member 'flags' not described in 'tracing_record_taskinfo_sched_switch' kernel/trace/trace.c:3078: warning: Function parameter or member 'ip' not described in 'trace_vbprintk' kernel/trace/trace.c:3078: warning: Function parameter or member 'fmt' not described in 'trace_vbprintk' kernel/trace/trace.c:3078: warning: Function parameter or member 'args' not described in 'trace_vbprintk' Link: http://lkml.kernel.org/r/20190828052549.2472-2-jakub.kicinski@netronome.com Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* ftrace/x86: Remove mcount() declarationJisheng Zhang2019-08-311-1/+0
| | | | | | | | | | | Commit 562e14f72292 ("ftrace/x86: Remove mcount support") removed the support for using mcount, so we could remove the mcount() declaration to clean up. Link: http://lkml.kernel.org/r/20190826170150.10f101ba@xhacker.debian Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* tracing/probe: Fix null pointer dereferenceXinpeng Liu2019-08-311-1/+2
| | | | | | | | | | | | | | BUG: KASAN: null-ptr-deref in trace_probe_cleanup+0x8d/0xd0 Read of size 8 at addr 0000000000000000 by task syz-executor.0/9746 trace_probe_cleanup+0x8d/0xd0 free_trace_kprobe.part.14+0x15/0x50 alloc_trace_kprobe+0x23e/0x250 Link: http://lkml.kernel.org/r/1565220563-980-1-git-send-email-danielliu861@gmail.com Fixes: e3dc9f898ef9c ("tracing/probe: Add trace_event_call accesses APIs") Signed-off-by: Xinpeng Liu <danielliu861@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* tracing: Make exported ftrace_set_clr_event non-staticDenis Efremov2019-08-312-1/+2
| | | | | | | | | | | | | | The function ftrace_set_clr_event is declared static and marked EXPORT_SYMBOL_GPL(), which is at best an odd combination. Because the function was decided to be a part of API, this commit removes the static attribute and adds the declaration to the header. Link: http://lkml.kernel.org/r/20190704172110.27041-1-efremov@linux.com Fixes: f45d1225adb04 ("tracing: Kernel access to Ftrace instances") Reviewed-by: Joe Jin <joe.jin@oracle.com> Signed-off-by: Denis Efremov <efremov@linux.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* ftrace: Check for successful allocation of hashNaveen N. Rao2019-08-301-0/+5
| | | | | | | | | | | | | | In register_ftrace_function_probe(), we are not checking the return value of alloc_and_copy_ftrace_hash(). The subsequent call to ftrace_match_records() may end up dereferencing the same. Add a check to ensure this doesn't happen. Link: http://lkml.kernel.org/r/26e92574f25ad23e7cafa3cf5f7a819de1832cbe.1562249521.git.naveen.n.rao@linux.vnet.ibm.com Cc: stable@vger.kernel.org Fixes: 1ec3a81a0cf42 ("ftrace: Have each function probe use its own ftrace_ops") Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* ftrace: Check for empty hash and comment the race with registering probesSteven Rostedt (VMware)2019-08-301-1/+9
| | | | | | | | | | The race between adding a function probe and reading the probes that exist is very subtle. It needs a comment. Also, the issue can also happen if the probe has has the EMPTY_HASH as its func_hash. Cc: stable@vger.kernel.org Fixes: 7b60f3d876156 ("ftrace: Dynamically create the probe ftrace_ops for the trace_array") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* ftrace: Fix NULL pointer dereference in t_probe_next()Naveen N. Rao2019-08-301-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | LTP testsuite on powerpc results in the below crash: Unable to handle kernel paging request for data at address 0x00000000 Faulting instruction address: 0xc00000000029d800 Oops: Kernel access of bad area, sig: 11 [#1] LE SMP NR_CPUS=2048 NUMA PowerNV ... CPU: 68 PID: 96584 Comm: cat Kdump: loaded Tainted: G W NIP: c00000000029d800 LR: c00000000029dac4 CTR: c0000000001e6ad0 REGS: c0002017fae8ba10 TRAP: 0300 Tainted: G W MSR: 9000000000009033 <SF,HV,EE,ME,IR,DR,RI,LE> CR: 28022422 XER: 20040000 CFAR: c00000000029d90c DAR: 0000000000000000 DSISR: 40000000 IRQMASK: 0 ... NIP [c00000000029d800] t_probe_next+0x60/0x180 LR [c00000000029dac4] t_mod_start+0x1a4/0x1f0 Call Trace: [c0002017fae8bc90] [c000000000cdbc40] _cond_resched+0x10/0xb0 (unreliable) [c0002017fae8bce0] [c0000000002a15b0] t_start+0xf0/0x1c0 [c0002017fae8bd30] [c0000000004ec2b4] seq_read+0x184/0x640 [c0002017fae8bdd0] [c0000000004a57bc] sys_read+0x10c/0x300 [c0002017fae8be30] [c00000000000b388] system_call+0x5c/0x70 The test (ftrace_set_ftrace_filter.sh) is part of ftrace stress tests and the crash happens when the test does 'cat $TRACING_PATH/set_ftrace_filter'. The address points to the second line below, in t_probe_next(), where filter_hash is dereferenced: hash = iter->probe->ops.func_hash->filter_hash; size = 1 << hash->size_bits; This happens due to a race with register_ftrace_function_probe(). A new ftrace_func_probe is created and added into the func_probes list in trace_array under ftrace_lock. However, before initializing the filter, we drop ftrace_lock, and re-acquire it after acquiring regex_lock. If another process is trying to read set_ftrace_filter, it will be able to acquire ftrace_lock during this window and it will end up seeing a NULL filter_hash. Fix this by just checking for a NULL filter_hash in t_probe_next(). If the filter_hash is NULL, then this probe is just being added and we can simply return from here. Link: http://lkml.kernel.org/r/05e021f757625cbbb006fad41380323dbe4e3b43.1562249521.git.naveen.n.rao@linux.vnet.ibm.com Cc: stable@vger.kernel.org Fixes: 7b60f3d876156 ("ftrace: Dynamically create the probe ftrace_ops for the trace_array") Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* Linux 5.3-rc6v5.3-rc6Linus Torvalds2019-08-251-1/+1
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* Merge tag 'auxdisplay-for-linus-v5.3-rc7' of git://github.com/ojeda/linuxLinus Torvalds2019-08-251-2/+2
|\ | | | | | | | | | | | | | | Pull auxdisplay cleanup from Miguel Ojeda: "Make ht16k33_fb_fix and ht16k33_fb_var constant (Nishka Dasgupta)" * tag 'auxdisplay-for-linus-v5.3-rc7' of git://github.com/ojeda/linux: auxdisplay: ht16k33: Make ht16k33_fb_fix and ht16k33_fb_var constant
| * auxdisplay: ht16k33: Make ht16k33_fb_fix and ht16k33_fb_var constantNishka Dasgupta2019-08-201-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | The static structures ht16k33_fb_fix and ht16k33_fb_var, of types fb_fix_screeninfo and fb_var_screeninfo respectively, are not used except to be copied into other variables. Hence make both of them constant to prevent unintended modification. Issue found with Coccinelle. Acked-by: Robin van der Gracht <robin@protonic.nl> Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com> Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
* | Merge tag 'for-linus-5.3-rc6' of ↵Linus Torvalds2019-08-253-12/+20
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml Pull UML fix from Richard Weinberger: "Fix time travel mode" * tag 'for-linus-5.3-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml: um: fix time travel mode
| * | um: fix time travel modeJohannes Berg2019-08-233-12/+20
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | Unfortunately, my build fix for when time travel mode isn't enabled broke time travel mode, because I forgot that we need to use the timer time after the timer has been marked disabled, and thus need to leave the time stored instead of zeroing it. Fix that by splitting the inline into two, so we can call only the _mode() one in the relevant code path. Fixes: b482e48d29f1 ("um: fix build without CONFIG_UML_TIME_TRAVEL_SUPPORT") Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at>
* | Merge tag 'for-linus-5.3-rc6' of ↵Linus Torvalds2019-08-254-8/+5
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rw/ubifs Pull UBIFS and JFFS2 fixes from Richard Weinberger: "UBIFS: - Don't block too long in writeback_inodes_sb() - Fix for a possible overrun of the log head - Fix double unlock in orphan_delete() JFFS2: - Remove C++ style from UAPI header and unbreak picky toolchains" * tag 'for-linus-5.3-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/ubifs: ubifs: Limit the number of pages in shrink_liability ubifs: Correctly initialize c->min_log_bytes ubifs: Fix double unlock around orphan_delete() jffs2: Remove C++ style comments from uapi header
| * | ubifs: Limit the number of pages in shrink_liabilityLiu Song2019-08-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the number of dirty pages to be written back is large, then writeback_inodes_sb will block waiting for a long time, causing hung task detection alarm. Therefore, we should limit the maximum number of pages written back this time, which let the budget be completed faster. The remaining dirty pages tend to rely on the writeback mechanism to complete the synchronization. Fixes: b6e51316daed ("writeback: separate starting of sync vs opportunistic writeback") Signed-off-by: Liu Song <liu.song11@zte.com.cn> Signed-off-by: Richard Weinberger <richard@nod.at>
| * | ubifs: Correctly initialize c->min_log_bytesRichard Weinberger2019-08-221-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently on a freshly mounted UBIFS, c->min_log_bytes is 0. This can lead to a log overrun and make commits fail. Recent kernels will report the following assert: UBIFS assert failed: c->lhead_lnum != c->ltail_lnum, in fs/ubifs/log.c:412 c->min_log_bytes can have two states, 0 and c->leb_size. It controls how much bytes of the log area are reserved for non-bud nodes such as commit nodes. After a commit it has to be set to c->leb_size such that we have always enough space for a commit. While a commit runs it can be 0 to make the remaining bytes of the log available to writers. Having it set to 0 right after mount is wrong since no space for commits is reserved. Fixes: 1e51764a3c2ac ("UBIFS: add new flash file system") Reported-and-tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Richard Weinberger <richard@nod.at>
| * | ubifs: Fix double unlock around orphan_delete()Richard Weinberger2019-08-221-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | We unlock after orphan_delete(), so no need to unlock in the function too. Reported-by: Han Xu <han.xu@nxp.com> Fixes: 8009ce956c3d ("ubifs: Don't leak orphans on memory during commit") Signed-off-by: Richard Weinberger <richard@nod.at>
| * | jffs2: Remove C++ style comments from uapi headerMasahiro Yamada2019-08-221-5/+0
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Linux kernel tolerates C++ style comments these days. Actually, the SPDX License tags for .c files start with //. On the other hand, uapi headers are written in more strict C, where the C++ comment style is forbidden. I simply dropped these lines instead of fixing the comment style. This code has been always commented out since it was added around Linux 2.4.9 (i.e. commented out for more than 17 years). 'Maybe later...' will never happen. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Richard Weinberger <richard@nod.at> Signed-off-by: Richard Weinberger <richard@nod.at>
* | Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds2019-08-259-33/+227
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: "A few fixes for x86: - Fix a boot regression caused by the recent bootparam sanitizing change, which escaped the attention of all people who reviewed that code. - Address a boot problem on machines with broken E820 tables caused by an underflow which ended up placing the trampoline start at physical address 0. - Handle machines which do not advertise a legacy timer of any form, but need calibration of the local APIC timer gracefully by making the calibration routine independent from the tick interrupt. Marked for stable as well as there seems to be quite some new laptops rolled out which expose this. - Clear the RDRAND CPUID bit on AMD family 15h and 16h CPUs which are affected by broken firmware which does not initialize RDRAND correctly after resume. Add a command line parameter to override this for machine which either do not use suspend/resume or have a fixed BIOS. Unfortunately there is no way to detect this on boot, so the only safe decision is to turn it off by default. - Prevent RFLAGS from being clobbers in CALL_NOSPEC on 32bit which caused fast KVM instruction emulation to break. - Explain the Intel CPU model naming convention so that the repeating discussions come to an end" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/retpoline: Don't clobber RFLAGS during CALL_NOSPEC on i386 x86/boot: Fix boot regression caused by bootparam sanitizing x86/CPU/AMD: Clear RDRAND CPUID bit on AMD family 15h/16h x86/boot/compressed/64: Fix boot on machines with broken E820 table x86/apic: Handle missing global clockevent gracefully x86/cpu: Explain Intel model naming convention
| * | x86/retpoline: Don't clobber RFLAGS during CALL_NOSPEC on i386Sean Christopherson2019-08-231-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use 'lea' instead of 'add' when adjusting %rsp in CALL_NOSPEC so as to avoid clobbering flags. KVM's emulator makes indirect calls into a jump table of sorts, where the destination of the CALL_NOSPEC is a small blob of code that performs fast emulation by executing the target instruction with fixed operands. adcb_al_dl: 0x000339f8 <+0>: adc %dl,%al 0x000339fa <+2>: ret A major motiviation for doing fast emulation is to leverage the CPU to handle consumption and manipulation of arithmetic flags, i.e. RFLAGS is both an input and output to the target of CALL_NOSPEC. Clobbering flags results in all sorts of incorrect emulation, e.g. Jcc instructions often take the wrong path. Sans the nops... asm("push %[flags]; popf; " CALL_NOSPEC " ; pushf; pop %[flags]\n" 0x0003595a <+58>: mov 0xc0(%ebx),%eax 0x00035960 <+64>: mov 0x60(%ebx),%edx 0x00035963 <+67>: mov 0x90(%ebx),%ecx 0x00035969 <+73>: push %edi 0x0003596a <+74>: popf 0x0003596b <+75>: call *%esi 0x000359a0 <+128>: pushf 0x000359a1 <+129>: pop %edi 0x000359a2 <+130>: mov %eax,0xc0(%ebx) 0x000359b1 <+145>: mov %edx,0x60(%ebx) ctxt->eflags = (ctxt->eflags & ~EFLAGS_MASK) | (flags & EFLAGS_MASK); 0x000359a8 <+136>: mov -0x10(%ebp),%eax 0x000359ab <+139>: and $0x8d5,%edi 0x000359b4 <+148>: and $0xfffff72a,%eax 0x000359b9 <+153>: or %eax,%edi 0x000359bd <+157>: mov %edi,0x4(%ebx) For the most part this has gone unnoticed as emulation of guest code that can trigger fast emulation is effectively limited to MMIO when running on modern hardware, and MMIO is rarely, if ever, accessed by instructions that affect or consume flags. Breakage is almost instantaneous when running with unrestricted guest disabled, in which case KVM must emulate all instructions when the guest has invalid state, e.g. when the guest is in Big Real Mode during early BIOS. Fixes: 776b043848fd2 ("x86/retpoline: Add initial retpoline support") Fixes: 1a29b5b7f347a ("KVM: x86: Make indirect calls in emulator speculation safe") Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20190822211122.27579-1-sean.j.christopherson@intel.com
| * | x86/boot: Fix boot regression caused by bootparam sanitizingJohn Hubbard2019-08-211-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit a90118c445cc ("x86/boot: Save fields explicitly, zero out everything else") had two errors: * It preserved boot_params.acpi_rsdp_addr, and * It failed to preserve boot_params.hdr Therefore, zero out acpi_rsdp_addr, and preserve hdr. Fixes: a90118c445cc ("x86/boot: Save fields explicitly, zero out everything else") Reported-by: Neil MacLeod <neil@nmacleod.com> Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Hubbard <jhubbard@nvidia.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Neil MacLeod <neil@nmacleod.com> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20190821192513.20126-1-jhubbard@nvidia.com
| * | x86/CPU/AMD: Clear RDRAND CPUID bit on AMD family 15h/16hTom Lendacky2019-08-194-13/+147
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There have been reports of RDRAND issues after resuming from suspend on some AMD family 15h and family 16h systems. This issue stems from a BIOS not performing the proper steps during resume to ensure RDRAND continues to function properly. RDRAND support is indicated by CPUID Fn00000001_ECX[30]. This bit can be reset by clearing MSR C001_1004[62]. Any software that checks for RDRAND support using CPUID, including the kernel, will believe that RDRAND is not supported. Update the CPU initialization to clear the RDRAND CPUID bit for any family 15h and 16h processor that supports RDRAND. If it is known that the family 15h or family 16h system does not have an RDRAND resume issue or that the system will not be placed in suspend, the "rdrand=force" kernel parameter can be used to stop the clearing of the RDRAND CPUID bit. Additionally, update the suspend and resume path to save and restore the MSR C001_1004 value to ensure that the RDRAND CPUID setting remains in place after resuming from suspend. Note, that clearing the RDRAND CPUID bit does not prevent a processor that normally supports the RDRAND instruction from executing it. So any code that determined the support based on family and model won't #UD. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andrew Cooper <andrew.cooper3@citrix.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Chen Yu <yu.c.chen@intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: "linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org> Cc: "linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org> Cc: Nathan Chancellor <natechancellor@gmail.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: <stable@vger.kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "x86@kernel.org" <x86@kernel.org> Link: https://lkml.kernel.org/r/7543af91666f491547bd86cebb1e17c66824ab9f.1566229943.git.thomas.lendacky@amd.com
| * | x86/boot/compressed/64: Fix boot on machines with broken E820 tableKirill A. Shutemov2019-08-191-3/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BIOS on Samsung 500C Chromebook reports very rudimentary E820 table that consists of 2 entries: BIOS-e820: [mem 0x0000000000000000-0x0000000000000fff] usable BIOS-e820: [mem 0x00000000fffff000-0x00000000ffffffff] reserved It breaks logic in find_trampoline_placement(): bios_start lands on the end of the first 4k page and trampoline start gets placed below 0. Detect underflow and don't touch bios_start for such cases. It makes kernel ignore E820 table on machines that doesn't have two usable pages below BIOS_START_MAX. Fixes: 1b3a62643660 ("x86/boot/compressed/64: Validate trampoline placement against E820") Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86-ml <x86@kernel.org> Link: https://bugzilla.kernel.org/show_bug.cgi?id=203463 Link: https://lkml.kernel.org/r/20190813131654.24378-1-kirill.shutemov@linux.intel.com
| * | x86/apic: Handle missing global clockevent gracefullyThomas Gleixner2019-08-191-15/+53
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some newer machines do not advertise legacy timers. The kernel can handle that situation if the TSC and the CPU frequency are enumerated by CPUID or MSRs and the CPU supports TSC deadline timer. If the CPU does not support TSC deadline timer the local APIC timer frequency has to be known as well. Some Ryzens machines do not advertize legacy timers, but there is no reliable way to determine the bus frequency which feeds the local APIC timer when the machine allows overclocking of that frequency. As there is no legacy timer the local APIC timer calibration crashes due to a NULL pointer dereference when accessing the not installed global clock event device. Switch the calibration loop to a non interrupt based one, which polls either TSC (if frequency is known) or jiffies. The latter requires a global clockevent. As the machines which do not have a global clockevent installed have a known TSC frequency this is a non issue. For older machines where TSC frequency is not known, there is no known case where the legacy timers do not exist as that would have been reported long ago. Reported-by: Daniel Drake <drake@endlessm.com> Reported-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Daniel Drake <drake@endlessm.com> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1908091443030.21433@nanos.tec.linutronix.de Link: http://bugzilla.opensuse.org/show_bug.cgi?id=1142926#c12
| * | x86/cpu: Explain Intel model naming conventionTony Luck2019-08-171-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Dave Hansen spelled out the rules in an e-mail: https://lkml.kernel.org/r/91eefbe4-e32b-d762-be4d-672ff915db47@intel.com Copy those right into the <asm/intel-family.h> file to make it easy for people to find them. Suggested-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190815224704.GA10025@agluck-desk2.amr.corp.intel.com
* | | Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds2019-08-253-9/+23
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timekeeping fix from Thomas Gleixner: "A single fix for a regression caused by the generic VDSO implementation where a math overflow causes CLOCK_BOOTTIME to become a random number generator" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: timekeeping/vsyscall: Prevent math overflow in BOOTTIME update
| * | | timekeeping/vsyscall: Prevent math overflow in BOOTTIME updateThomas Gleixner2019-08-233-9/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The VDSO update for CLOCK_BOOTTIME has a overflow issue as it shifts the nanoseconds based boot time offset left by the clocksource shift. That overflows once the boot time offset becomes large enough. As a consequence CLOCK_BOOTTIME in the VDSO becomes a random number causing applications to misbehave. Fix it by storing a timespec64 representation of the offset when boot time is adjusted and add that to the MONOTONIC base time value in the vdso data page. Using the timespec64 representation avoids a 64bit division in the update code. Fixes: 44f57d788e7d ("timekeeping: Provide a generic update_vsyscall() implementation") Reported-by: Chris Clayton <chris2553@googlemail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Chris Clayton <chris2553@googlemail.com> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1908221257580.1983@nanos.tec.linutronix.de
* | | | Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds2019-08-251-1/+4
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fix from Thomas Gleixner: "Handle the worker management in situations where a task is scheduled out on a PI lock contention correctly and schedule a new worker if possible" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/core: Schedule new worker even if PI-blocked
| * | | | sched/core: Schedule new worker even if PI-blockedSebastian Andrzej Siewior2019-08-191-1/+4
| | |_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a task is PI-blocked (blocking on sleeping spinlock) then we don't want to schedule a new kworker if we schedule out due to lock contention because !RT does not do that as well. A spinning spinlock disables preemption and a worker does not schedule out on lock contention (but spin). On RT the RW-semaphore implementation uses an rtmutex so tsk_is_pi_blocked() will return true if a task blocks on it. In this case we will now start a new worker which may deadlock if one worker is waiting on progress from another worker. Since a RW-semaphore starts a new worker on !RT, we should do the same on RT. XFS is able to trigger this deadlock. Allow to schedule new worker if the current worker is PI-blocked. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20190816160626.12742-1-bigeasy@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds2019-08-252-5/+5
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Thomas Gleixner: "Two small fixes for kprobes and perf: - Prevent a deadlock in kprobe_optimizer() causes by reverse lock ordering - Fix a comment typo" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: kprobes: Fix potential deadlock in kprobe_optimizer() perf/x86: Fix typo in comment
| * | | | kprobes: Fix potential deadlock in kprobe_optimizer()Andrea Righi2019-08-191-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | lockdep reports the following deadlock scenario: WARNING: possible circular locking dependency detected kworker/1:1/48 is trying to acquire lock: 000000008d7a62b2 (text_mutex){+.+.}, at: kprobe_optimizer+0x163/0x290 but task is already holding lock: 00000000850b5e2d (module_mutex){+.+.}, at: kprobe_optimizer+0x31/0x290 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (module_mutex){+.+.}: __mutex_lock+0xac/0x9f0 mutex_lock_nested+0x1b/0x20 set_all_modules_text_rw+0x22/0x90 ftrace_arch_code_modify_prepare+0x1c/0x20 ftrace_run_update_code+0xe/0x30 ftrace_startup_enable+0x2e/0x50 ftrace_startup+0xa7/0x100 register_ftrace_function+0x27/0x70 arm_kprobe+0xb3/0x130 enable_kprobe+0x83/0xa0 enable_trace_kprobe.part.0+0x2e/0x80 kprobe_register+0x6f/0xc0 perf_trace_event_init+0x16b/0x270 perf_kprobe_init+0xa7/0xe0 perf_kprobe_event_init+0x3e/0x70 perf_try_init_event+0x4a/0x140 perf_event_alloc+0x93a/0xde0 __do_sys_perf_event_open+0x19f/0xf30 __x64_sys_perf_event_open+0x20/0x30 do_syscall_64+0x65/0x1d0 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 (text_mutex){+.+.}: __lock_acquire+0xfcb/0x1b60 lock_acquire+0xca/0x1d0 __mutex_lock+0xac/0x9f0 mutex_lock_nested+0x1b/0x20 kprobe_optimizer+0x163/0x290 process_one_work+0x22b/0x560 worker_thread+0x50/0x3c0 kthread+0x112/0x150 ret_from_fork+0x3a/0x50 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(module_mutex); lock(text_mutex); lock(module_mutex); lock(text_mutex); *** DEADLOCK *** As a reproducer I've been using bcc's funccount.py (https://github.com/iovisor/bcc/blob/master/tools/funccount.py), for example: # ./funccount.py '*interrupt*' That immediately triggers the lockdep splat. Fix by acquiring text_mutex before module_mutex in kprobe_optimizer(). Signed-off-by: Andrea Righi <andrea.righi@canonical.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: David S. Miller <davem@davemloft.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: d5b844a2cf50 ("ftrace/x86: Remove possible deadlock between register_kprobe() and ftrace_run_update_code()") Link: http://lkml.kernel.org/r/20190812184302.GA7010@xps-13 Signed-off-by: Ingo Molnar <mingo@kernel.org>
generated by cgit v1.2.3 (git 2.25.1) at 2024-08-22 05:10:35 +0000