- 31 Aug, 2019 23 commits
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Matt Helsley authored
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.comSigned-off-by: Matt Helsley <mhelsley@vmware.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Matt Helsley authored
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.comSigned-off-by: Matt Helsley <mhelsley@vmware.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Matt Helsley authored
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.comSigned-off-by: Matt Helsley <mhelsley@vmware.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Masami Hiramatsu authored
Add syntax error test cases for multiprobe appending errors. Link: http://lkml.kernel.org/r/156095694541.28024.11918630805148623119.stgit@devnote2Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Masami Hiramatsu authored
Add syntax error test cases for immediate value and immediate string. Link: http://lkml.kernel.org/r/156095693553.28024.7730929892585591691.stgit@devnote2Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Masami Hiramatsu authored
Add a testcase for kprobe event with multi-probe. Link: http://lkml.kernel.org/r/156095692637.28024.17188971794698768977.stgit@devnote2Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Masami Hiramatsu authored
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@devnote2Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Masami Hiramatsu authored
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@devnote2Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Masami Hiramatsu authored
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@devnote2Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Masami Hiramatsu authored
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@devnote2Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Masami Hiramatsu authored
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@devnote2Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Masami Hiramatsu authored
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@devnote2Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Masami Hiramatsu authored
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@devnote2Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Masami Hiramatsu authored
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@devnote2Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Masami Hiramatsu authored
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@devnote2Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Matt Helsley authored
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.comSigned-off-by: Matt Helsley <mhelsley@vmware.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Matt Helsley authored
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.comSigned-off-by: Matt Helsley <mhelsley@vmware.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Matt Helsley authored
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.comSigned-off-by: Matt Helsley <mhelsley@vmware.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Masami Hiramatsu authored
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@devnote2Acked-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Jakub Kicinski authored
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.comSigned-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Jisheng Zhang authored
Commit 562e14f7 ("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.debianSigned-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Xinpeng Liu authored
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: e3dc9f89 ("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>
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Denis Efremov authored
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: f45d1225 ("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>
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- 30 Aug, 2019 3 commits
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Naveen N. Rao authored
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: 1ec3a81a ("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>
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Steven Rostedt (VMware) authored
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: 7b60f3d8 ("ftrace: Dynamically create the probe ftrace_ops for the trace_array") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Naveen N. Rao authored
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: 7b60f3d8 ("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>
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- 25 Aug, 2019 14 commits
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Linus Torvalds authored
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git://github.com/ojeda/linuxLinus Torvalds authored
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
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git://git.kernel.org/pub/scm/linux/kernel/git/rw/umlLinus Torvalds authored
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
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git://git.kernel.org/pub/scm/linux/kernel/git/rw/ubifsLinus Torvalds authored
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
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
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
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
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
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
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
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
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
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull irq fix from Thomas Gleixner: "A single fix for a imbalanced kobject operation in the irq decriptor code which was unearthed by the new warnings in the kobject code" * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: genirq: Properly pair kobject_del() with kobject_add()
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Linus Torvalds authored
Mergr misc fixes from Andrew Morton: "11 fixes" Mostly VM fixes, one psi polling fix, and one parisc build fix. * emailed patches from Andrew Morton <akpm@linux-foundation.org>: mm/kasan: fix false positive invalid-free reports with CONFIG_KASAN_SW_TAGS=y mm/zsmalloc.c: fix race condition in zs_destroy_pool mm/zsmalloc.c: migration can leave pages in ZS_EMPTY indefinitely mm, page_owner: handle THP splits correctly userfaultfd_release: always remove uffd flags and clear vm_userfaultfd_ctx psi: get poll_work to run when calling poll syscall next time mm: memcontrol: flush percpu vmevents before releasing memcg mm: memcontrol: flush percpu vmstats before releasing memcg parisc: fix compilation errrors mm, page_alloc: move_freepages should not examine struct page of reserved memory mm/z3fold.c: fix race between migration and destruction
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git://git.infradead.org/users/hch/dma-mappingLinus Torvalds authored
Pull dma-mapping fixes from Christoph Hellwig: "Two fixes for regressions in this merge window: - select the Kconfig symbols for the noncoherent dma arch helpers on arm if swiotlb is selected, not just for LPAE to not break then Xen build, that uses swiotlb indirectly through swiotlb-xen - fix the page allocator fallback in dma_alloc_contiguous if the CMA allocation fails" * tag 'dma-mapping-5.3-5' of git://git.infradead.org/users/hch/dma-mapping: dma-direct: fix zone selection after an unaddressable CMA allocation arm: select the dma-noncoherent symbols for all swiotlb builds
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Andrey Ryabinin authored
The code like this: ptr = kmalloc(size, GFP_KERNEL); page = virt_to_page(ptr); offset = offset_in_page(ptr); kfree(page_address(page) + offset); may produce false-positive invalid-free reports on the kernel with CONFIG_KASAN_SW_TAGS=y. In the example above we lose the original tag assigned to 'ptr', so kfree() gets the pointer with 0xFF tag. In kfree() we check that 0xFF tag is different from the tag in shadow hence print false report. Instead of just comparing tags, do the following: 1) Check that shadow doesn't contain KASAN_TAG_INVALID. Otherwise it's double-free and it doesn't matter what tag the pointer have. 2) If pointer tag is different from 0xFF, make sure that tag in the shadow is the same as in the pointer. Link: http://lkml.kernel.org/r/20190819172540.19581-1-aryabinin@virtuozzo.com Fixes: 7f94ffbc ("kasan: add hooks implementation for tag-based mode") Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Reported-by: Walter Wu <walter-zh.wu@mediatek.com> Reported-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Andrey Konovalov <andreyknvl@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Henry Burns authored
In zs_destroy_pool() we call flush_work(&pool->free_work). However, we have no guarantee that migration isn't happening in the background at that time. Since migration can't directly free pages, it relies on free_work being scheduled to free the pages. But there's nothing preventing an in-progress migrate from queuing the work *after* zs_unregister_migration() has called flush_work(). Which would mean pages still pointing at the inode when we free it. Since we know at destroy time all objects should be free, no new migrations can come in (since zs_page_isolate() fails for fully-free zspages). This means it is sufficient to track a "# isolated zspages" count by class, and have the destroy logic ensure all such pages have drained before proceeding. Keeping that state under the class spinlock keeps the logic straightforward. In this case a memory leak could lead to an eventual crash if compaction hits the leaked page. This crash would only occur if people are changing their zswap backend at runtime (which eventually starts destruction). Link: http://lkml.kernel.org/r/20190809181751.219326-2-henryburns@google.com Fixes: 48b4800a ("zsmalloc: page migration support") Signed-off-by: Henry Burns <henryburns@google.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Henry Burns <henrywolfeburns@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Jonathan Adams <jwadams@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Henry Burns authored
In zs_page_migrate() we call putback_zspage() after we have finished migrating all pages in this zspage. However, the return value is ignored. If a zs_free() races in between zs_page_isolate() and zs_page_migrate(), freeing the last object in the zspage, putback_zspage() will leave the page in ZS_EMPTY for potentially an unbounded amount of time. To fix this, we need to do the same thing as zs_page_putback() does: schedule free_work to occur. To avoid duplicated code, move the sequence to a new putback_zspage_deferred() function which both zs_page_migrate() and zs_page_putback() call. Link: http://lkml.kernel.org/r/20190809181751.219326-1-henryburns@google.com Fixes: 48b4800a ("zsmalloc: page migration support") Signed-off-by: Henry Burns <henryburns@google.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Henry Burns <henrywolfeburns@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Jonathan Adams <jwadams@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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