user/sven/linux.git/kernel/trace/trace_kprobe.c, branch v5.4.101

tracing/kprobe: Fix to support kretprobe events on unloaded modules

2021-02-13T12:52:54Z

commit 97c753e62e6c31a404183898d950d8c08d752dbd upstream. Fix kprobe_on_func_entry() returns error code instead of false so that register_kretprobe() can return an appropriate error code. append_trace_kprobe() expects the kprobe registration returns -ENOENT when the target symbol is not found, and it checks whether the target module is unloaded or not. If the target module doesn't exist, it defers to probe the target symbol until the module is loaded. However, since register_kretprobe() returns -EINVAL instead of -ENOENT in that case, it always fail on putting the kretprobe event on unloaded modules. e.g. Kprobe event: /sys/kernel/debug/tracing # echo p xfs:xfs_end_io >> kprobe_events [ 16.515574] trace_kprobe: This probe might be able to register after target module is loaded. Continue. Kretprobe event: (p -> r) /sys/kernel/debug/tracing # echo r xfs:xfs_end_io >> kprobe_events sh: write error: Invalid argument /sys/kernel/debug/tracing # cat error_log [ 41.122514] trace_kprobe: error: Failed to register probe event Command: r xfs:xfs_end_io ^ To fix this bug, change kprobe_on_func_entry() to detect symbol lookup failure and return -ENOENT in that case. Otherwise it returns -EINVAL or 0 (succeeded, given address is on the entry). Link: https://lkml.kernel.org/r/161176187132.1067016.8118042342894378981.stgit@devnote2 Cc: stable@vger.kernel.org Fixes: 59158ec4aef7 ("tracing/kprobes: Check the probe on unloaded module correctly") Reported-by: Jianlin Lv Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman

tracing/kprobes: Do the notrace functions check without kprobes on ftrace

2021-01-19T17:26:12Z

commit 7bb83f6fc4ee84e95d0ac0d14452c2619fb3fe70 upstream. Enable the notrace function check on the architecture which doesn't support kprobes on ftrace but support dynamic ftrace. This notrace function check is not only for the kprobes on ftrace but also sw-breakpoint based kprobes. Thus there is no reason to limit this check for the arch which supports kprobes on ftrace. This also changes the dependency of Kconfig. Because kprobe event uses the function tracer's address list for identifying notrace function, if the CONFIG_DYNAMIC_FTRACE=n, it can not check whether the target function is notrace or not. Link: https://lkml.kernel.org/r/20210105065730.2634785-1-naveen.n.rao@linux.vnet.ibm.com Link: https://lkml.kernel.org/r/161007957862.114704.4512260007555399463.stgit@devnote2 Cc: stable@vger.kernel.org Fixes: 45408c4f92506 ("tracing: kprobes: Prohibit probing on notrace function") Acked-by: Naveen N. Rao Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman

tracing/probe: Fix bpf_task_fd_query() for kprobes and uprobes

2020-06-24T15:50:43Z

[ Upstream commit 22d5bd6867364b41576a712755271a7d6161abd6 ] Commit 60d53e2c3b75 ("tracing/probe: Split trace_event related data from trace_probe") removed the trace_[ku]probe structure from the trace_event_call->data pointer. As bpf_get_[ku]probe_info() were forgotten in that change, fix them now. These functions are currently only used by the bpf_task_fd_query() syscall handler to collect information about a perf event. Fixes: 60d53e2c3b75 ("tracing/probe: Split trace_event related data from trace_probe") Signed-off-by: Jean-Philippe Brucker Signed-off-by: Alexei Starovoitov Acked-by: Yonghong Song Acked-by: Masami Hiramatsu Link: https://lore.kernel.org/bpf/20200608124531.819838-1-jean-philippe@linaro.org Signed-off-by: Sasha Levin

tracing/kprobes: Fix a double initialization typo

2020-05-14T05:58:18Z

[ Upstream commit dcbd21c9fca5e954fd4e3d91884907eb6d47187e ] Fix a typo that resulted in an unnecessary double initialization to addr. Link: http://lkml.kernel.org/r/158779374968.6082.2337484008464939919.stgit@devnote2 Cc: Tom Zanussi Cc: Ingo Molnar Cc: stable@vger.kernel.org Fixes: c7411a1a126f ("tracing/kprobe: Check whether the non-suffixed symbol is notrace") Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Sasha Levin

ftrace/kprobe: Show the maxactive number on kprobe_events

2020-04-17T08:50:21Z

commit 6a13a0d7b4d1171ef9b80ad69abc37e1daa941b3 upstream. Show maxactive parameter on kprobe_events. This allows user to save the current configuration and restore it without losing maxactive parameter. Link: http://lkml.kernel.org/r/4762764a-6df7-bc93-ed60-e336146dce1f@gmail.com Link: http://lkml.kernel.org/r/158503528846.22706.5549974121212526020.stgit@devnote2 Cc: stable@vger.kernel.org Fixes: 696ced4fb1d76 ("tracing/kprobes: expose maxactive for kretprobe in kprobe_events") Reported-by: Taeung Song Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman

tracing/uprobe: Fix to make trace_uprobe_filter alignment safe

2020-02-05T21:22:53Z

[ Upstream commit b61387cb732cf283d318b2165c44913525fe545f ] Commit 99c9a923e97a ("tracing/uprobe: Fix double perf_event linking on multiprobe uprobe") moved trace_uprobe_filter on trace_probe_event. However, since it introduced a flexible data structure with char array and type casting, the alignment of trace_uprobe_filter can be broken. This changes the type of the array to trace_uprobe_filter data strucure to fix it. Link: http://lore.kernel.org/r/20200120124022.GA14897@hirez.programming.kicks-ass.net Link: http://lkml.kernel.org/r/157966340499.5107.10978352478952144902.stgit@devnote2 Fixes: 99c9a923e97a ("tracing/uprobe: Fix double perf_event linking on multiprobe uprobe") Suggested-by: Peter Zijlstra Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Sasha Levin

tracing/uprobe: Fix double perf_event linking on multiprobe uprobe

2020-01-29T15:45:25Z

commit 99c9a923e97a583a38050baa92c9377d73946330 upstream. Fix double perf_event linking to trace_uprobe_filter on multiple uprobe event by moving trace_uprobe_filter under trace_probe_event. In uprobe perf event, trace_uprobe_filter data structure is managing target mm filters (in perf_event) related to each uprobe event. Since commit 60d53e2c3b75 ("tracing/probe: Split trace_event related data from trace_probe") left the trace_uprobe_filter data structure in trace_uprobe, if a trace_probe_event has multiple trace_uprobe (multi-probe event), a perf_event is added to different trace_uprobe_filter on each trace_uprobe. This leads a linked list corruption. To fix this issue, move trace_uprobe_filter to trace_probe_event and link it once on each event instead of each probe. Link: http://lkml.kernel.org/r/157862073931.1800.3800576241181489174.stgit@devnote2 Cc: Jiri Olsa Cc: Peter Zijlstra Cc: Ingo Molnar Cc: "Naveen N . Rao" Cc: Anil S Keshavamurthy Cc: "David S . Miller" Cc: Namhyung Kim Cc: =?utf-8?q?Toke_H=C3=B8iland-J?= =?utf-8?b?w7hyZ2Vuc2Vu?= Cc: Jean-Tsung Hsiao Cc: Jesper Dangaard Brouer Cc: stable@vger.kernel.org Fixes: 60d53e2c3b75 ("tracing/probe: Split trace_event related data from trace_probe") Link: https://lkml.kernel.org/r/20200108171611.GA8472@kernel.org Reported-by: Arnaldo Carvalho de Melo Tested-by: Arnaldo Carvalho de Melo Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman

tracing/kprobe: Check whether the non-suffixed symbol is notrace

2019-12-31T15:45:29Z

[ Upstream commit c7411a1a126f649be71526a36d4afac9e5aefa13 ] Check whether the non-suffixed symbol is notrace, since suffixed symbols are generated by the compilers for optimization. Based on these suffixed symbols, notrace check might not work because some of them are just a partial code of the original function. (e.g. cold-cache (unlikely) code is separated from original function as FUNCTION.cold.XX) For example, without this fix, # echo p device_add.cold.67 > /sys/kernel/debug/tracing/kprobe_events sh: write error: Invalid argument # cat /sys/kernel/debug/tracing/error_log [ 135.491035] trace_kprobe: error: Failed to register probe event Command: p device_add.cold.67 ^ # dmesg | tail -n 1 [ 135.488599] trace_kprobe: Could not probe notrace function device_add.cold.67 With this, # echo p device_add.cold.66 > /sys/kernel/debug/tracing/kprobe_events # cat /sys/kernel/debug/kprobes/list ffffffff81599de9 k device_add.cold.66+0x0 [DISABLED] Actually, kprobe blacklist already did similar thing, see within_kprobe_blacklist(). Link: http://lkml.kernel.org/r/157233790394.6706.18243942030937189679.stgit@devnote2 Fixes: 45408c4f9250 ("tracing: kprobes: Prohibit probing on notrace function") Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Sasha Levin

tracing: Add locked_down checks to the open calls of files created for tracefs

2019-10-13T00:48:06Z

Added various checks on open tracefs calls to see if tracefs is in lockdown mode, and if so, to return -EPERM. Note, the event format files (which are basically standard on all machines) as well as the enabled_functions file (which shows what is currently being traced) are not lockde down. Perhaps they should be, but it seems counter intuitive to lockdown information to help you know if the system has been modified. Link: http://lkml.kernel.org/r/CAHk-=wj7fGPKUspr579Cii-w_y60PtRaiDgKuxVtBAMK0VNNkA@mail.gmail.com Suggested-by: Linus Torvalds Signed-off-by: Steven Rostedt (VMware)

Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

2019-09-28T15:14:15Z

Pull kernel lockdown mode from James Morris: "This is the latest iteration of the kernel lockdown patchset, from Matthew Garrett, David Howells and others. From the original description: This patchset introduces an optional kernel lockdown feature, intended to strengthen the boundary between UID 0 and the kernel. When enabled, various pieces of kernel functionality are restricted. Applications that rely on low-level access to either hardware or the kernel may cease working as a result - therefore this should not be enabled without appropriate evaluation beforehand. The majority of mainstream distributions have been carrying variants of this patchset for many years now, so there's value in providing a doesn't meet every distribution requirement, but gets us much closer to not requiring external patches. There are two major changes since this was last proposed for mainline: - Separating lockdown from EFI secure boot. Background discussion is covered here: https://lwn.net/Articles/751061/ - Implementation as an LSM, with a default stackable lockdown LSM module. This allows the lockdown feature to be policy-driven, rather than encoding an implicit policy within the mechanism. The new locked_down LSM hook is provided to allow LSMs to make a policy decision around whether kernel functionality that would allow tampering with or examining the runtime state of the kernel should be permitted. The included lockdown LSM provides an implementation with a simple policy intended for general purpose use. This policy provides a coarse level of granularity, controllable via the kernel command line: lockdown={integrity|confidentiality} Enable the kernel lockdown feature. If set to integrity, kernel features that allow userland to modify the running kernel are disabled. If set to confidentiality, kernel features that allow userland to extract confidential information from the kernel are also disabled. This may also be controlled via /sys/kernel/security/lockdown and overriden by kernel configuration. New or existing LSMs may implement finer-grained controls of the lockdown features. Refer to the lockdown_reason documentation in include/linux/security.h for details. The lockdown feature has had signficant design feedback and review across many subsystems. This code has been in linux-next for some weeks, with a few fixes applied along the way. Stephen Rothwell noted that commit 9d1f8be5cf42 ("bpf: Restrict bpf when kernel lockdown is in confidentiality mode") is missing a Signed-off-by from its author. Matthew responded that he is providing this under category (c) of the DCO" * 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (31 commits) kexec: Fix file verification on S390 security: constify some arrays in lockdown LSM lockdown: Print current->comm in restriction messages efi: Restrict efivar_ssdt_load when the kernel is locked down tracefs: Restrict tracefs when the kernel is locked down debugfs: Restrict debugfs when the kernel is locked down kexec: Allow kexec_file() with appropriate IMA policy when locked down lockdown: Lock down perf when in confidentiality mode bpf: Restrict bpf when kernel lockdown is in confidentiality mode lockdown: Lock down tracing and perf kprobes when in confidentiality mode lockdown: Lock down /proc/kcore x86/mmiotrace: Lock down the testmmiotrace module lockdown: Lock down module params that specify hardware parameters (eg. ioport) lockdown: Lock down TIOCSSERIAL lockdown: Prohibit PCMCIA CIS storage when the kernel is locked down acpi: Disable ACPI table override if the kernel is locked down acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down ACPI: Limit access to custom_method when the kernel is locked down x86/msr: Restrict MSR access when the kernel is locked down x86: Lock down IO port access when the kernel is locked down ...