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2021-10-26test_kprobes: Move it from kernel/ to lib/Tiezhu Yang2-372/+0
Since config KPROBES_SANITY_TEST is in lib/Kconfig.debug, it is better to let test_kprobes.c in lib/, just like other similar tests found in lib/. Link: https://lkml.kernel.org/r/1635213091-24387-4-git-send-email-yangtiezhu@loongson.cn Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-26kprobes: Add a test case for stacktrace from kretprobe handlerMasami Hiramatsu1-0/+162
Add a test case for stacktrace from kretprobe handler and nested kretprobe handlers. This test checks both of stack trace inside kretprobe handler and stack trace from pt_regs. Those stack trace must include actual function return address instead of kretprobe trampoline. The nested kretprobe stacktrace test checks whether the unwinder can correctly unwind the call frame on the stack which has been modified by the kretprobe. Since the stacktrace on kretprobe is correctly fixed only on x86, this introduces a meta kconfig ARCH_CORRECT_STACKTRACE_ON_KRETPROBE which tells user that the stacktrace on kretprobe is correct or not. The test results will be shown like below; TAP version 14 1..1 # Subtest: kprobes_test 1..6 ok 1 - test_kprobe ok 2 - test_kprobes ok 3 - test_kretprobe ok 4 - test_kretprobes ok 5 - test_stacktrace_on_kretprobe ok 6 - test_stacktrace_on_nested_kretprobe # kprobes_test: pass:6 fail:0 skip:0 total:6 # Totals: pass:6 fail:0 skip:0 total:6 ok 1 - kprobes_test Link: https://lkml.kernel.org/r/163516211244.604541.18350507860972214415.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-26tracing/hwlat: Make some internal symbols staticWang ShaoBo1-2/+2
The sparse tool complains as follows: kernel/trace/trace_hwlat.c:82:27: warning: symbol 'hwlat_single_cpu_data' was not declared. Should it be static? kernel/trace/trace_hwlat.c:83:1: warning: symbol '__pcpu_scope_hwlat_per_cpu_data' was not declared. Should it be static? This symbol is not used outside of trace_hwlat.c, so this commit marks it static. Link: https://lkml.kernel.org/r/20211021035225.1050685-1-bobo.shaobowang@huawei.com Signed-off-by: Wang ShaoBo <bobo.shaobowang@huawei.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-26tracing: Fix missing trace_boot_init_histograms kstrdup NULL checksMathieu Desnoyers1-0/+4
trace_boot_init_histograms misses NULL pointer checks for kstrdup failure. Link: https://lkml.kernel.org/r/20211015195550.22742-1-mathieu.desnoyers@efficios.com Fixes: 64dc7f6958ef5 ("tracing/boot: Show correct histogram error command") Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-25trace/timerlat: Add migrate-disabled field to the timerlat headerDaniel Bristot de Oliveira1-5/+6
Since "54357f0c9149 tracing: Add migrate-disabled counter to tracing output," the migrate disabled field is also printed in the !PREEMPR_RT kernel config. While this information was added to the vast majority of tracers, osnoise and timerlat were not updated (because they are new tracers). Fix timerlat header by adding the information about migrate disabled. Link: https://lkml.kernel.org/r/bc0c234ab49946cdd63effa6584e1d5e8662cb44.1634308385.git.bristot@kernel.org Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: x86@kernel.org Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Fixes: 54357f0c9149 ("tracing: Add migrate-disabled counter to tracing output.") Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-25trace/osnoise: Add migrate-disabled field to the osnoise headerDaniel Bristot de Oliveira1-7/+7
Since "54357f0c9149 tracing: Add migrate-disabled counter to tracing output," the migrate disabled field is also printed in the !PREEMPR_RT kernel config. While this information was added to the vast majority of tracers, osnoise and timerlat were not updated (because they are new tracers). Fix osnoise header by adding the information about migrate disabled. Link: https://lkml.kernel.org/r/9cb3d54e29e0588dbba12e81486bd8a09adcd8ca.1634308385.git.bristot@kernel.org Cc: Daniel Bristot de Oliveira <bristot@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: x86@kernel.org Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Fixes: 54357f0c9149 ("tracing: Add migrate-disabled counter to tracing output.") Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-25perf/core: allow ftrace for functions in kernel/event/core.cSong Liu1-5/+0
It is useful to trace functions in kernel/event/core.c. Allow ftrace for them by removing $(CC_FLAGS_FTRACE) from Makefile. Link: https://lkml.kernel.org/r/20211006210732.2826289-1-songliubraving@fb.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrii Nakryiko <andrii@kernel.org> Cc: KP Singh <kpsingh@kernel.org> Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-25ftrace: Make ftrace_profile_pages_init staticchongjiapeng1-1/+1
This symbol is not used outside of ftrace.c, so marks it static. Fixes the following sparse warning: kernel/trace/ftrace.c:579:5: warning: symbol 'ftrace_profile_pages_init' was not declared. Should it be static? Link: https://lkml.kernel.org/r/1634640534-18280-1-git-send-email-jiapeng.chong@linux.alibaba.com Reported-by: Abaci Robot <abaci@linux.alibaba.com> Fixes: cafb168a1c92 ("tracing: make the function profiler per cpu") Signed-off-by: chongjiapeng <jiapeng.chong@linux.alibaba.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-21kprobes: convert tests to kunitSven Schnelle2-166/+59
This converts the kprobes testcases to use the kunit framework. It adds a dependency on CONFIG_KUNIT, and the output will change to TAP: TAP version 14 1..1 # Subtest: kprobes_test 1..4 random: crng init done ok 1 - test_kprobe ok 2 - test_kprobes ok 3 - test_kretprobe ok 4 - test_kretprobes ok 1 - kprobes_test Note that the kprobes testcases are no longer run immediately after kprobes initialization, but as a late initcall when kunit is initialized. kprobes itself is initialized with an early initcall, so the order is still correct. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-21tracing: use %ps format string to print symbolsArnd Bergmann1-10/+5
clang started warning about excessive stack usage in hist_trigger_print_key() kernel/trace/trace_events_hist.c:4723:13: error: stack frame size (1336) exceeds limit (1024) in function 'hist_trigger_print_key' [-Werror,-Wframe-larger-than] The problem is that there are two 512-byte arrays on the stack if hist_trigger_stacktrace_print() gets inlined. I don't think this has changed in the past five years, but something probably changed the inlining decisions made by the compiler, so the problem is now made more obvious. Rather than printing the symbol names into separate buffers, it seems we can simply use the special %ps format string modifier to print the pointers symbolically and get rid of both buffers. Marking hist_trigger_stacktrace_print() would be a simpler way of avoiding the warning, but that would not address the excessive stack usage. Link: https://lkml.kernel.org/r/20211019153337.294790-1-arnd@kernel.org Fixes: 69a0200c2e25 ("tracing: Add hist trigger support for stacktraces as keys") Link: https://lore.kernel.org/all/20211015095704.49a99859@gandalf.local.home/ Reviewed-by: Tom Zanussi <zanussi@kernel.org> Tested-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-21ftrace/direct: Do not disable when switching direct callersSteven Rostedt (VMware)1-14/+20
Currently to switch a set of "multi" direct trampolines from one trampoline to another, a full shutdown of the current set needs to be done, followed by an update to what trampoline the direct callers would call, and then re-enabling the callers. This leaves a time when the functions will not be calling anything, and events may be missed. Instead, use a trick to allow all the functions with direct trampolines attached will always call either the new or old trampoline while the switch is happening. To do this, first attach a "dummy" callback via ftrace to all the functions that the current direct trampoline is attached to. This will cause the functions to call the "list func" instead of the direct trampoline. The list function will call the direct trampoline "helper" that will set the function it should call as it returns back to the ftrace trampoline. At this moment, the direct caller descriptor can safely update the direct call trampoline. The list function will pick either the new or old function (depending on the memory coherency model of the architecture). Now removing the dummy function from each of the locations of the direct trampoline caller, will put back the direct call, but now to the new trampoline. A better visual is: [ Changing direct call from my_direct_1 to my_direct_2 ] <traced_func>: call my_direct_1 |||||||||||||||||||| vvvvvvvvvvvvvvvvvvvv <traced_func>: call ftrace_caller <ftrace_caller>: [..] call ftrace_ops_list_func ftrace_ops_list_func() { ops->func() -> direct_helper -> set rax to my_direct_1 or my_direct_2 } call rax (to either my_direct_1 or my_direct_2 |||||||||||||||||||| vvvvvvvvvvvvvvvvvvvv <traced_func>: call my_direct_2 Link: https://lore.kernel.org/all/20211014162819.5c85618b@gandalf.local.home/ Acked-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-21ftrace: Add multi direct modify interfaceJiri Olsa1-0/+62
Adding interface to modify registered direct function for ftrace_ops. Adding following function: modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) The function changes the currently registered direct function for all attached functions. Link: https://lkml.kernel.org/r/20211008091336.33616-8-jolsa@kernel.org Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-21ftrace: Add multi direct register/unregister interfaceJiri Olsa1-0/+142
Adding interface to register multiple direct functions within single call. Adding following functions: register_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) unregister_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) The register_ftrace_direct_multi registers direct function (addr) with all functions in ops filter. The ops filter can be updated before with ftrace_set_filter_ip calls. All requested functions must not have direct function currently registered, otherwise register_ftrace_direct_multi will fail. The unregister_ftrace_direct_multi unregisters ops related direct functions. Link: https://lkml.kernel.org/r/20211008091336.33616-7-jolsa@kernel.org Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-21ftrace: Add ftrace_add_rec_direct functionJiri Olsa1-27/+37
Factor out the code that adds (ip, addr) tuple to direct_functions hash in new ftrace_add_rec_direct function. It will be used in following patches. Link: https://lkml.kernel.org/r/20211008091336.33616-6-jolsa@kernel.org Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-21tracing: Fix selftest config check for function graph start up testSteven Rostedt (VMware)1-1/+5
There's a new test in trace_selftest_startup_function_graph() that requires the use of ftrace args being supported as well does some tricks with dynamic tracing. Although this code checks HAVE_DYNAMIC_FTRACE_WITH_ARGS it fails to check DYNAMIC_FTRACE, and the kernel fails to build due to that dependency. Also only define the prototype of trace_direct_tramp() if it is used. Link: https://lkml.kernel.org/r/20211021134357.7f48e173@gandalf.local.home Acked-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-20tracing: Add trampoline/graph selftestJiri Olsa1-1/+53
Adding selftest for checking that direct trampoline can co-exist together with graph tracer on same function. This is supported for CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS config option, which is defined only for x86_64 for now. Link: https://lkml.kernel.org/r/20211008091336.33616-5-jolsa@kernel.org Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-20x86/ftrace: Make function graph use ftrace directlySteven Rostedt (VMware)1-2/+4
We don't need special hook for graph tracer entry point, but instead we can use graph_ops::func function to install the return_hooker. This moves the graph tracing setup _before_ the direct trampoline prepares the stack, so the return_hooker will be called when the direct trampoline is finished. This simplifies the code, because we don't need to take into account the direct trampoline setup when preparing the graph tracer hooker and we can allow function graph tracer on entries registered with direct trampoline. Link: https://lkml.kernel.org/r/20211008091336.33616-4-jolsa@kernel.org [fixed compile error reported by kernel test robot <lkp@intel.com>] Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-19tracing/perf: Add interrupt_context_level() helperSteven Rostedt (VMware)2-12/+2
Now that there are three different instances of doing the addition trick to the preempt_count() and NMI_MASK, HARDIRQ_MASK and SOFTIRQ_OFFSET macros, it deserves a helper function defined in the preempt.h header. Add the interrupt_context_level() helper and replace the three instances that do that logic with it. Link: https://lore.kernel.org/all/20211015142541.4badd8a9@gandalf.local.home/ Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-19tracing: Reuse logic from perf's get_recursion_context()Steven Rostedt (VMware)1-6/+6
Instead of having branches that adds noise to the branch prediction, use the addition logic to set the bit for the level of interrupt context that the state is currently in. This copies the logic from perf's get_recursion_context() function. Link: https://lore.kernel.org/all/20211015161702.GF174703@worktop.programming.kicks-ass.net/ Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-19tracing/cfi: Fix cmp_entries_* functions signature mismatchKalesh Singh1-17/+23
If CONFIG_CFI_CLANG=y, attempting to read an event histogram will cause the kernel to panic due to failed CFI check. 1. echo 'hist:keys=common_pid' >> events/sched/sched_switch/trigger 2. cat events/sched/sched_switch/hist 3. kernel panics on attempting to read hist This happens because the sort() function expects a generic int (*)(const void *, const void *) pointer for the compare function. To prevent this CFI failure, change tracing map cmp_entries_* function signatures to match this. Also, fix the build error reported by the kernel test robot [1]. [1] https://lore.kernel.org/r/202110141140.zzi4dRh4-lkp@intel.com/ Link: https://lkml.kernel.org/r/20211014045217.3265162-1-kaleshsingh@google.com Signed-off-by: Kalesh Singh <kaleshsingh@google.com> Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-19tracing: Use linker magic instead of recasting ftrace_ops_list_func()Steven Rostedt (VMware)1-13/+10
In an effort to enable -Wcast-function-type in the top-level Makefile to support Control Flow Integrity builds, all function casts need to be removed. This means that ftrace_ops_list_func() can no longer be defined as ftrace_ops_no_ops(). The reason for ftrace_ops_no_ops() is to use that when an architecture calls ftrace_ops_list_func() with only two parameters (called from assembly). And to make sure there's no C side-effects, those archs call ftrace_ops_no_ops() which only has two parameters, as ftrace_ops_list_func() has four parameters. Instead of a typecast, use vmlinux.lds.h to define ftrace_ops_list_func() to arch_ftrace_ops_list_func() that will define the proper set of parameters. Link: https://lore.kernel.org/r/20200614070154.6039-1-oscar.carter@gmx.com Link: https://lkml.kernel.org/r/20200617165616.52241bde@oasis.local.home Link: https://lore.kernel.org/all/20211005053922.GA702049@embeddedor/ Requested-by: Oscar Carter <oscar.carter@gmx.com> Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-13tracing: in_irq() cleanupChangbin Du2-2/+2
Replace the obsolete and ambiguos macro in_irq() with new macro in_hardirq(). Link: https://lkml.kernel.org/r/20210930000342.6016-1-changbin.du@gmail.com Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Changbin Du <changbin.du@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-10ftrace: Add unit test for removing trace functionCarles Pey1-0/+34
A self test is provided for the trace function removal functionality. Link: https://lkml.kernel.org/r/20210918153043.318016-2-carles.pey@gmail.com Signed-off-by: Carles Pey <carles.pey@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-08ftrace: Cleanup ftrace_dyn_arch_init()Weizhao Ouyang1-0/+5
Most of ARCHs use empty ftrace_dyn_arch_init(), introduce a weak common ftrace_dyn_arch_init() to cleanup them. Link: https://lkml.kernel.org/r/20210909090216.1955240-1-o451686892@gmail.com Acked-by: Heiko Carstens <hca@linux.ibm.com> (s390) Acked-by: Helge Deller <deller@gmx.de> (parisc) Signed-off-by: Weizhao Ouyang <o451686892@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-08tracing: Disable "other" permission bits in the tracefs filesSteven Rostedt (VMware)15-96/+103
When building the files in the tracefs file system, do not by default set any permissions for OTH (other). This will make it easier for admins who want to define a group for accessing tracefs and not having to first disable all the permission bits for "other" in the file system. As tracing can leak sensitive information, it should never by default allowing all users access. An admin can still set the permission bits for others to have access, which may be useful for creating a honeypot and seeing who takes advantage of it and roots the machine. Link: https://lkml.kernel.org/r/20210818153038.864149276@goodmis.org Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-07tracing: Initialize upper and lower vars in pid_list_refill_irq()Steven Rostedt (VMware)1-2/+2
The upper and lower variables are set as link lists to add into the sparse array. If they are NULL, after the needed allocations are done, then there is nothing to add. But they need to be initialized to NULL for this to work. Link: https://lore.kernel.org/all/221bc7ba-a475-1cb9-1bbe-730bb9c2d448@canonical.com/ Fixes: 8d6e90983ade ("tracing: Create a sparse bitmask for pid filtering") Reported-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-05tracing: Create a sparse bitmask for pid filteringSteven Rostedt (VMware)2-35/+445
When the trace_pid_list was created, the default pid max was 32768. Creating a bitmask that can hold one bit for all 32768 took up 4096 (one page). Having a one page bitmask was not much of a problem, and that was used for mapping pids. But today, systems are bigger and can run more tasks, and now the default pid_max is usually set to 4194304. Which means to handle that many pids requires 524288 bytes. Worse yet, the pid_max can be set to 2^30 (1073741824 or 1G) which would take 134217728 (128M) of memory to store this array. Since the pid_list array is very sparsely populated, it is a huge waste of memory to store all possible bits for each pid when most will not be set. Instead, use a page table scheme to store the array, and allow this to handle up to 30 bit pids. The pid_mask will start out with 256 entries for the first 8 MSB bits. This will cost 1K for 32 bit architectures and 2K for 64 bit. Each of these will have a 256 array to store the next 8 bits of the pid (another 1 or 2K). These will hold an 2K byte bitmask (which will cover the LSB 14 bits or 16384 pids). When the trace_pid_list is allocated, it will have the 1/2K upper bits allocated, and then it will allocate a cache for the next upper chunks and the lower chunks (default 6 of each). Then when a bit is "set", these chunks will be pulled from the free list and added to the array. If the free list gets down to a lever (default 2), it will trigger an irqwork that will refill the cache back up. On clearing a bit, if the clear causes the bitmask to be zero, that chunk will then be placed back into the free cache for later use, keeping the need to allocate more down to a minimum. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-05tracing: Place trace_pid_list logic into abstract functionsSteven Rostedt (VMware)7-61/+217
Instead of having the logic that does trace_pid_list open coded, wrap it in abstract functions. This will allow a rewrite of the logic that implements the trace_pid_list without affecting the users. Note, this causes a change in behavior. Every time a pid is written into the set_*_pid file, it creates a new list and uses RCU to update it. If pid_max is lowered, but there was a pid currently in the list that was higher than pid_max, those pids will now be removed on updating the list. The old behavior kept that from happening. The rewrite of the pid_list logic will no longer depend on pid_max, and will return the old behavior. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-30x86/kprobes: Fixup return address in generic trampoline handlerMasami Hiramatsu1-0/+11
In x86, the fake return address on the stack saved by __kretprobe_trampoline() will be replaced with the real return address after returning from trampoline_handler(). Before fixing the return address, the real return address can be found in the 'current->kretprobe_instances'. However, since there is a window between updating the 'current->kretprobe_instances' and fixing the address on the stack, if an interrupt happens at that timing and the interrupt handler does stacktrace, it may fail to unwind because it can not get the correct return address from 'current->kretprobe_instances'. This will eliminate that window by fixing the return address right before updating 'current->kretprobe_instances'. Link: https://lkml.kernel.org/r/163163057094.489837.9044470370440745866.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Tested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-30tracing: Show kretprobe unknown indicator only for kretprobe_trampolineMasami Hiramatsu1-13/+4
ftrace shows "[unknown/kretprobe'd]" indicator all addresses in the kretprobe_trampoline, but the modified address by kretprobe should be only kretprobe_trampoline+0. Link: https://lkml.kernel.org/r/163163056044.489837.794883849706638013.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Tested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-30kprobes: Enable stacktrace from pt_regs in kretprobe handlerMasami Hiramatsu1-0/+7
Since the ORC unwinder from pt_regs requires setting up regs->ip correctly, set the correct return address to the regs->ip before calling user kretprobe handler. This allows the kretrprobe handler to trace stack from the kretprobe's pt_regs by stack_trace_save_regs() (eBPF will do this), instead of stack tracing from the handler context by stack_trace_save() (ftrace will do this). Link: https://lkml.kernel.org/r/163163053237.489837.4272653874525136832.stgit@devnote2 Suggested-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Tested-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-30kprobes: Add kretprobe_find_ret_addr() for searching return addressMasami Hiramatsu1-26/+83
Introduce kretprobe_find_ret_addr() and is_kretprobe_trampoline(). These APIs will be used by the ORC stack unwinder and ftrace, so that they can check whether the given address points kretprobe trampoline code and query the correct return address in that case. Link: https://lkml.kernel.org/r/163163046461.489837.1044778356430293962.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Tested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-30kprobes: treewide: Make it harder to refer kretprobe_trampoline directlyMasami Hiramatsu1-1/+1
Since now there is kretprobe_trampoline_addr() for referring the address of kretprobe trampoline code, we don't need to access kretprobe_trampoline directly. Make it harder to refer by renaming it to __kretprobe_trampoline(). Link: https://lkml.kernel.org/r/163163045446.489837.14510577516938803097.stgit@devnote2 Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-30kprobes: treewide: Remove trampoline_address from kretprobe_trampoline_handler()Masami Hiramatsu1-2/+1
The __kretprobe_trampoline_handler() callback, called from low level arch kprobes methods, has the 'trampoline_address' parameter, which is entirely superfluous as it basically just replicates: dereference_kernel_function_descriptor(kretprobe_trampoline) In fact we had bugs in arch code where it wasn't replicated correctly. So remove this superfluous parameter and use kretprobe_trampoline_addr() instead. Link: https://lkml.kernel.org/r/163163044546.489837.13505751885476015002.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Tested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-30kprobes: treewide: Replace arch_deref_entry_point() with ↵Masami Hiramatsu1-6/+1
dereference_symbol_descriptor() ~15 years ago kprobes grew the 'arch_deref_entry_point()' __weak function: 3d7e33825d87: ("jprobes: make jprobes a little safer for users") But this is just open-coded dereference_symbol_descriptor() in essence, and its obscure nature was causing bugs. Just use the real thing and remove arch_deref_entry_point(). Link: https://lkml.kernel.org/r/163163043630.489837.7924988885652708696.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Tested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-30kprobes: Use bool type for functions which returns boolean valueMasami Hiramatsu2-14/+14
Use the 'bool' type instead of 'int' for the functions which returns a boolean value, because this makes clear that those functions don't return any error code. Link: https://lkml.kernel.org/r/163163041649.489837.17311187321419747536.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-30kprobes: treewide: Use 'kprobe_opcode_t *' for the code address in ↵Masami Hiramatsu1-5/+5
get_optimized_kprobe() Since get_optimized_kprobe() is only used inside kprobes, it doesn't need to use 'unsigned long' type for 'addr' parameter. Make it use 'kprobe_opcode_t *' for the 'addr' parameter and subsequent call of arch_within_optimized_kprobe() also should use 'kprobe_opcode_t *'. Note that MAX_OPTIMIZED_LENGTH and RELATIVEJUMP_SIZE are defined by byte-size, but the size of 'kprobe_opcode_t' depends on the architecture. Therefore, we must be careful when calculating addresses using those macros. Link: https://lkml.kernel.org/r/163163040680.489837.12133032364499833736.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-30kprobes: Add assertions for required lockMasami Hiramatsu1-7/+12
Add assertions for required locks instead of comment it so that the lockdep can inspect locks automatically. Link: https://lkml.kernel.org/r/163163039572.489837.18011973177537476885.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-30kprobes: Fix coding style issuesMasami Hiramatsu1-114/+122
Fix coding style issues reported by checkpatch.pl and update comments to quote variable names and add "()" to function name. One TODO comment in __disarm_kprobe() is removed because it has been done by following commit. Link: https://lkml.kernel.org/r/163163037468.489837.4282347782492003960.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-30kprobes: treewide: Cleanup the error messages for kprobesMasami Hiramatsu1-20/+16
This clean up the error/notification messages in kprobes related code. Basically this defines 'pr_fmt()' macros for each files and update the messages which describes - what happened, - what is the kernel going to do or not do, - is the kernel fine, - what can the user do about it. Also, if the message is not needed (e.g. the function returns unique error code, or other error message is already shown.) remove it, and replace the message with WARN_*() macros if suitable. Link: https://lkml.kernel.org/r/163163036568.489837.14085396178727185469.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-30kprobes: Make arch_check_ftrace_location staticPunit Agrawal1-2/+2
arch_check_ftrace_location() was introduced as a weak function in commit f7f242ff004499 ("kprobes: introduce weak arch_check_ftrace_location() helper function") to allow architectures to handle kprobes call site on their own. Recently, the only architecture (csky) to implement arch_check_ftrace_location() was migrated to using the common version. As a result, further cleanup the code to drop the weak attribute and rename the function to remove the architecture specific implementation. Link: https://lkml.kernel.org/r/163163035673.489837.2367816318195254104.stgit@devnote2 Signed-off-by: Punit Agrawal <punitagrawal@gmail.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-30kprobe: Simplify prepare_kprobe() by dropping redundant versionPunit Agrawal1-14/+9
The function prepare_kprobe() is called during kprobe registration and is responsible for ensuring any architecture related preparation for the kprobe is done before returning. One of two versions of prepare_kprobe() is chosen depending on the availability of KPROBE_ON_FTRACE in the kernel configuration. Simplify the code by dropping the version when KPROBE_ON_FTRACE is not selected - instead relying on kprobe_ftrace() to return false when KPROBE_ON_FTRACE is not set. No functional change. Link: https://lkml.kernel.org/r/163163033696.489837.9264661820279300788.stgit@devnote2 Signed-off-by: Punit Agrawal <punitagrawal@gmail.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-30kprobes: Use helper to parse boolean input from userspacePunit Agrawal1-22/+6
The "enabled" file provides a debugfs interface to arm / disarm kprobes in the kernel. In order to parse the buffer containing the values written from userspace, the callback manually parses the user input to convert it to a boolean value. As taking a string value from userspace and converting it to boolean is a common operation, a helper kstrtobool_from_user() is already available in the kernel. Update the callback to use the common helper to parse the write buffer from userspace. Link: https://lkml.kernel.org/r/163163032637.489837.10678039554832855327.stgit@devnote2 Signed-off-by: Punit Agrawal <punitagrawal@gmail.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-30kprobes: Do not use local variable when creating debugfs filePunit Agrawal1-2/+1
debugfs_create_file() takes a pointer argument that can be used during file operation callbacks (accessible via i_private in the inode structure). An obvious requirement is for the pointer to refer to valid memory when used. When creating the debugfs file to dynamically enable / disable kprobes, a pointer to local variable is passed to debugfs_create_file(); which will go out of scope when the init function returns. The reason this hasn't triggered random memory corruption is because the pointer is not accessed during the debugfs file callbacks. Since the enabled state is managed by the kprobes_all_disabled global variable, the local variable is not needed. Fix the incorrect (and unnecessary) usage of local variable during debugfs_file_create() by passing NULL instead. Link: https://lkml.kernel.org/r/163163031686.489837.4476867635937014973.stgit@devnote2 Fixes: bf8f6e5b3e51 ("Kprobes: The ON/OFF knob thru debugfs") Signed-off-by: Punit Agrawal <punitagrawal@gmail.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-26Merge tag 'timers-urgent-2021-09-26' of ↵Linus Torvalds1-1/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fix from Thomas Gleixner: "A single fix for the recently introduced regression in posix CPU timers which failed to stop the timer when requested. That caused unexpected signals to be sent to the process/thread causing malfunction" * tag 'timers-urgent-2021-09-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: posix-cpu-timers: Prevent spuriously armed 0-value itimer
2021-09-26Merge tag 'irq-urgent-2021-09-26' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq fixes from Thomas Gleixner: "A set of fixes for interrupt chip drivers: - Work around a bad GIC integration on a Renesas platform which can't handle byte-sized MMIO access - Plug a potential memory leak in the GICv4 driver - Fix a regression in the Armada 370-XP IPI code which was caused by issuing EOI instack of ACK. - A couple of small fixes here and there" * tag 'irq-urgent-2021-09-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: irqchip/gic: Work around broken Renesas integration irqchip/renesas-rza1: Use semicolons instead of commas irqchip/gic-v3-its: Fix potential VPE leak on error irqchip/goldfish-pic: Select GENERIC_IRQ_CHIP to fix build irqchip/mbigen: Repair non-kernel-doc notation irqdomain: Change the type of 'size' in __irq_domain_add() to be consistent irqchip/armada-370-xp: Fix ack/eoi breakage Documentation: Fix irq-domain.rst build warning
2021-09-25Merge tag 'block-5.15-2021-09-25' of git://git.kernel.dk/linux-blockLinus Torvalds1-0/+8
Pull block fixes from Jens Axboe: - NVMe pull request via Christoph: - keep ctrl->namespaces ordered (Christoph Hellwig) - fix incorrect h2cdata pdu offset accounting in nvme-tcp (Sagi Grimberg) - handled updated hw_queues in nvme-fc more carefully (Daniel Wagner, James Smart) - md lock order fix (Christoph) - fallocate locking fix (Ming) - blktrace UAF fix (Zhihao) - rq-qos bio tracking fix (Ming) * tag 'block-5.15-2021-09-25' of git://git.kernel.dk/linux-block: block: hold ->invalidate_lock in blkdev_fallocate blktrace: Fix uaf in blk_trace access after removing by sysfs block: don't call rq_qos_ops->done_bio if the bio isn't tracked md: fix a lock order reversal in md_alloc nvme: keep ctrl->namespaces ordered nvme-tcp: fix incorrect h2cdata pdu offset accounting nvme-fc: remove freeze/unfreeze around update_nr_hw_queues nvme-fc: avoid race between time out and tear down nvme-fc: update hardware queues before using them
2021-09-24blktrace: Fix uaf in blk_trace access after removing by sysfsZhihao Cheng1-0/+8
There is an use-after-free problem triggered by following process: P1(sda) P2(sdb) echo 0 > /sys/block/sdb/trace/enable blk_trace_remove_queue synchronize_rcu blk_trace_free relay_close rcu_read_lock __blk_add_trace trace_note_tsk (Iterate running_trace_list) relay_close_buf relay_destroy_buf kfree(buf) trace_note(sdb's bt) relay_reserve buf->offset <- nullptr deference (use-after-free) !!! rcu_read_unlock [ 502.714379] BUG: kernel NULL pointer dereference, address: 0000000000000010 [ 502.715260] #PF: supervisor read access in kernel mode [ 502.715903] #PF: error_code(0x0000) - not-present page [ 502.716546] PGD 103984067 P4D 103984067 PUD 17592b067 PMD 0 [ 502.717252] Oops: 0000 [#1] SMP [ 502.720308] RIP: 0010:trace_note.isra.0+0x86/0x360 [ 502.732872] Call Trace: [ 502.733193] __blk_add_trace.cold+0x137/0x1a3 [ 502.733734] blk_add_trace_rq+0x7b/0xd0 [ 502.734207] blk_add_trace_rq_issue+0x54/0xa0 [ 502.734755] blk_mq_start_request+0xde/0x1b0 [ 502.735287] scsi_queue_rq+0x528/0x1140 ... [ 502.742704] sg_new_write.isra.0+0x16e/0x3e0 [ 502.747501] sg_ioctl+0x466/0x1100 Reproduce method: ioctl(/dev/sda, BLKTRACESETUP, blk_user_trace_setup[buf_size=127]) ioctl(/dev/sda, BLKTRACESTART) ioctl(/dev/sdb, BLKTRACESETUP, blk_user_trace_setup[buf_size=127]) ioctl(/dev/sdb, BLKTRACESTART) echo 0 > /sys/block/sdb/trace/enable & // Add delay(mdelay/msleep) before kernel enters blk_trace_free() ioctl$SG_IO(/dev/sda, SG_IO, ...) // Enters trace_note_tsk() after blk_trace_free() returned // Use mdelay in rcu region rather than msleep(which may schedule out) Remove blk_trace from running_list before calling blk_trace_free() by sysfs if blk_trace is at Blktrace_running state. Fixes: c71a896154119f ("blktrace: add ftrace plugin") Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com> Link: https://lore.kernel.org/r/20210923134921.109194-1-chengzhihao1@huawei.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-09-24Merge tag 'irqchip-fixes-5.15-1' of ↵Thomas Gleixner1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/urgent Pull irqchip fixes from Marc Zyngier: - Work around a bad GIC integration on a Renesas platform, where the interconnect cannot deal with byte-sized MMIO accesses - Cleanup another Renesas driver abusing the comma operator - Fix a potential GICv4 memory leak on an error path - Make the type of 'size' consistent with the rest of the code in __irq_domain_add() - Fix a regression in the Armada 370-XP IPI path - Fix the build for the obviously unloved goldfish-pic - Some documentation fixes Link: https://lore.kernel.org/r/20210924090933.2766857-1-maz@kernel.org
2021-09-23posix-cpu-timers: Prevent spuriously armed 0-value itimerFrederic Weisbecker1-1/+2
Resetting/stopping an itimer eventually leads to it being reprogrammed with an actual "0" value. As a result the itimer expires on the next tick, triggering an unexpected signal. To fix this, make sure that struct signal_struct::it[CPUCLOCK_PROF/VIRT]::expires is set to 0 when setitimer() passes a 0 it_value, indicating that the timer must stop. Fixes: 406dd42bd1ba ("posix-cpu-timers: Force next expiration recalc after itimer reset") Reported-by: Victor Stinner <vstinner@redhat.com> Reported-by: Chris Hixon <linux-kernel-bugs@hixontech.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210913145332.232023-1-frederic@kernel.org