summaryrefslogtreecommitdiffstats
path: root/samples/hw_breakpoint
Commit message (Collapse)AuthorAgeFilesLines
* samples/hw_breakpoint: mark sample_hbp as staticChen Jiahao2023-07-261-1/+1
| | | | | | | | | | | | | | There is a sparse warning shown as below: samples/hw_breakpoint/data_breakpoint.c:24:19: warning: symbol 'sample_hbp' was not declared. Should it be static? Since 'sample_hbp' is only called within data_breakpoint.c, mark it as static to fix the warning. Fixes: 44ee63587dce ("percpu: Add __percpu sparse annotations to hw_breakpoint") Signed-off-by: Chen Jiahao <chenjiahao16@huawei.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
* samples/hw_breakpoint: fix building without module unloadingArnd Bergmann2023-07-251-0/+2
| | | | | | | | | | | | | | | | | | | | __symbol_put() is really meant as an internal helper and is not available when module unloading is disabled, unlike the previously used symbol_put(): samples/hw_breakpoint/data_breakpoint.c: In function 'hw_break_module_exit': samples/hw_breakpoint/data_breakpoint.c:73:9: error: implicit declaration of function '__symbol_put'; did you mean '__symbol_get'? [-Werror=implicit-function-declaration] The hw_break_module_exit() function is not actually used when module unloading is disabled, but it still causes the build failure for an undefined identifier. Enclose this one call in an appropriate #ifdef to clarify what the requirement is. Leaving out the entire exit function would also work but feels less clar in this case. Fixes: 910e230d5f1bb ("samples/hw_breakpoint: Fix kernel BUG 'invalid opcode: 0000'") Fixes: d8a84d33a4954 ("samples/hw_breakpoint: drop use of kallsyms_lookup_name()") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
* samples/hw_breakpoint: Fix kernel BUG 'invalid opcode: 0000'Rong Tao2023-07-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Macro symbol_put() is defined as __symbol_put(__stringify(x)) ksym_name = "jiffies" symbol_put(ksym_name) will be resolved as __symbol_put("ksym_name") which is clearly wrong. So symbol_put must be replaced with __symbol_put. When we uninstall hw_breakpoint.ko (rmmod), a kernel bug occurs with the following error: [11381.854152] kernel BUG at kernel/module/main.c:779! [11381.854159] invalid opcode: 0000 [#2] PREEMPT SMP PTI [11381.854163] CPU: 8 PID: 59623 Comm: rmmod Tainted: G D OE 6.2.9-200.fc37.x86_64 #1 [11381.854167] Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./B360M-HDV, BIOS P3.20 10/23/2018 [11381.854169] RIP: 0010:__symbol_put+0xa2/0xb0 [11381.854175] Code: 00 e8 92 d2 f7 ff 65 8b 05 c3 2f e6 78 85 c0 74 1b 48 8b 44 24 30 65 48 2b 04 25 28 00 00 00 75 12 48 83 c4 38 c3 cc cc cc cc <0f> 0b 0f 1f 44 00 00 eb de e8 c0 df d8 00 90 90 90 90 90 90 90 90 [11381.854178] RSP: 0018:ffffad8ec6ae7dd0 EFLAGS: 00010246 [11381.854181] RAX: 0000000000000000 RBX: ffffffffc1fd1240 RCX: 000000000000000c [11381.854184] RDX: 000000000000006b RSI: ffffffffc02bf7c7 RDI: ffffffffc1fd001c [11381.854186] RBP: 000055a38b76e7c8 R08: ffffffff871ccfe0 R09: 0000000000000000 [11381.854188] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [11381.854190] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [11381.854192] FS: 00007fbf7c62c740(0000) GS:ffff8c5badc00000(0000) knlGS:0000000000000000 [11381.854195] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [11381.854197] CR2: 000055a38b7793f8 CR3: 0000000363e1e001 CR4: 00000000003726e0 [11381.854200] DR0: ffffffffb3407980 DR1: 0000000000000000 DR2: 0000000000000000 [11381.854202] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [11381.854204] Call Trace: [11381.854207] <TASK> [11381.854212] s_module_exit+0xc/0xff0 [symbol_getput] [11381.854219] __do_sys_delete_module.constprop.0+0x198/0x2f0 [11381.854225] do_syscall_64+0x58/0x80 [11381.854231] ? exit_to_user_mode_prepare+0x180/0x1f0 [11381.854237] ? syscall_exit_to_user_mode+0x17/0x40 [11381.854241] ? do_syscall_64+0x67/0x80 [11381.854245] ? syscall_exit_to_user_mode+0x17/0x40 [11381.854248] ? do_syscall_64+0x67/0x80 [11381.854252] ? exc_page_fault+0x70/0x170 [11381.854256] entry_SYSCALL_64_after_hwframe+0x72/0xdc Signed-off-by: Rong Tao <rongtao@cestc.cn> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
* samples/hw_breakpoint: drop use of kallsyms_lookup_name()Will Deacon2020-04-071-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | The 'data_breakpoint' test code is the only modular user of kallsyms_lookup_name(), which was exported as part of fixing the test in f60d24d2ad04 ("hw-breakpoints: Fix broken hw-breakpoint sample module"). In preparation for un-exporting this symbol, switch the test over to using __symbol_get(), which can be used to place breakpoints on exported symbols. Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by: Quentin Perret <qperret@google.com> Cc: K.Prasad <prasad@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Miroslav Benes <mbenes@suse.cz> Cc: Petr Mladek <pmladek@suse.com> Cc: Joe Lawrence <joe.lawrence@redhat.com> Link: http://lkml.kernel.org/r/20200221114404.14641-3-will@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* samples/hw_breakpoint: drop HW_BREAKPOINT_R when reporting writesWill Deacon2020-04-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "Unexport kallsyms_lookup_name() and kallsyms_on_each_symbol()". Despite having just a single modular in-tree user that I could spot, kallsyms_lookup_name() is exported to modules and provides a mechanism for out-of-tree modules to access and invoke arbitrary, non-exported kernel symbols when kallsyms is enabled. This patch series fixes up that one user and unexports the symbol along with kallsyms_on_each_symbol(), since that could also be abused in a similar manner. I would like to avoid out-of-tree modules being easily able to call functions that are not exported. kallsyms_lookup_name() makes this trivial to the point that there is very little incentive to rework these modules to either use upstream interfaces correctly or propose functionality which may be otherwise missing upstream. Both of these latter solutions would be pre-requisites to upstreaming these modules, and the current state of things actively discourages that approach. The background here is that we are aiming for Android devices to be able to use a generic binary kernel image closely following upstream, with any vendor extensions coming in as kernel modules. In this case, we (Google) end up maintaining the binary module ABI within the scope of a single LTS kernel. Monitoring and managing the ABI surface is not feasible if it effectively includes all data and functions via kallsyms_lookup_name(). Of course, we could just carry this patch in the Android kernel tree, but we're aiming to carry as little as possible (ideally nothing) and I think it's a sensible change in its own right. I'm surprised you object to it, in all honesty. Now, you could turn around and say "that's not upstream's problem", but it still seems highly undesirable to me to have an upstream bypass for exported symbols that isn't even used by upstream modules. It's ripe for abuse and encourages people to work outside of the upstream tree. The usual rule is that we don't export symbols without a user in the tree and that seems especially relevant in this case. Joe Lawrence said: : FWIW, kallsyms was historically used by the out-of-tree kpatch support : module to resolve external symbols as well as call set_memory_r{w,o}() : API. All of that support code has been merged upstream, so modern kpatch : modules* no longer leverage kallsyms by default. : : That said, there are still some users who still use the deprecated support : module with newer kernels, but that is not officially supported by the : project. This patch (of 3): Given the name of a kernel symbol, the 'data_breakpoint' test claims to "report any write operations on the kernel symbol". However, it creates the breakpoint using both HW_BREAKPOINT_W and HW_BREAKPOINT_R, which menas it also fires for read access. Drop HW_BREAKPOINT_R from the breakpoint attributes. Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by: Quentin Perret <qperret@google.com> Cc: K.Prasad <prasad@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Miroslav Benes <mbenes@suse.cz> Cc: Petr Mladek <pmladek@suse.com> Cc: Joe Lawrence <joe.lawrence@redhat.com> Link: http://lkml.kernel.org/r/20200221114404.14641-2-will@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156Thomas Gleixner2019-05-301-14/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1334 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* treewide: Add SPDX license identifier - Makefile/KconfigThomas Gleixner2019-05-211-0/+1
| | | | | | | | | | | | | | Add SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any form These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* perf: Add context field to perf_eventAvi Kivity2011-07-011-1/+1
| | | | | | | | | | | | | | | | | The perf_event overflow handler does not receive any caller-derived argument, so many callers need to resort to looking up the perf_event in their local data structure. This is ugly and doesn't scale if a single callback services many perf_events. Fix by adding a context parameter to perf_event_create_kernel_counter() (and derived hardware breakpoints APIs) and storing it in the perf_event. The field can be accessed from the callback as event->overflow_handler_context. All callers are updated. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1309362157-6596-2-git-send-email-avi@redhat.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf: Remove the nmi parameter from the swevent and overflow interfacePeter Zijlstra2011-07-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The nmi parameter indicated if we could do wakeups from the current context, if not, we would set some state and self-IPI and let the resulting interrupt do the wakeup. For the various event classes: - hardware: nmi=0; PMI is in fact an NMI or we run irq_work_run from the PMI-tail (ARM etc.) - tracepoint: nmi=0; since tracepoint could be from NMI context. - software: nmi=[0,1]; some, like the schedule thing cannot perform wakeups, and hence need 0. As one can see, there is very little nmi=1 usage, and the down-side of not using it is that on some platforms some software events can have a jiffy delay in wakeup (when arch_irq_work_raise isn't implemented). The up-side however is that we can remove the nmi parameter and save a bunch of conditionals in fast paths. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Michael Cree <mcree@orcon.net.nz> Cc: Will Deacon <will.deacon@arm.com> Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com> Cc: Anton Blanchard <anton@samba.org> Cc: Eric B Munson <emunson@mgebm.net> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: David S. Miller <davem@davemloft.net> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Don Zickus <dzickus@redhat.com> Link: http://lkml.kernel.org/n/tip-agjev8eu666tvknpb3iaj0fg@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Fix common misspellingsLucas De Marchi2011-03-311-1/+1
| | | | | | Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
* percpu: Add __percpu sparse annotations to hw_breakpointTejun Heo2010-02-271-3/+3
| | | | | | | | | | | | | | | | | | | | Add __percpu sparse annotations to hw_breakpoint. These annotations are to make sparse consider percpu variables to be in a different address space and warn if accessed without going through percpu accessors. This patch doesn't affect normal builds. In kernel/hw_breakpoint.c, per_cpu(nr_task_bp_pinned, cpu)'s will trigger spurious noderef related warnings from sparse. Changing it to &per_cpu(nr_task_bp_pinned[0], cpu) will work around the problem but deemed to ugly by the maintainer. Leave it alone until better solution can be found. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: K.Prasad <prasad@linux.vnet.ibm.com> LKML-Reference: <4B7B4B7A.9050902@kernel.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
* hw-breakpoints: Use overflow handler instead of the event callbackFrederic Weisbecker2009-12-061-2/+5
| | | | | | | | | | | | | | | | struct perf_event::event callback was called when a breakpoint triggers. But this is a rather opaque callback, pretty tied-only to the breakpoint API and not really integrated into perf as it triggers even when we don't overflow. We prefer to use overflow_handler() as it fits into the perf events rules, being called only when we overflow. Reported-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: "K. Prasad" <prasad@linux.vnet.ibm.com>
* hw-breakpoints: Use struct perf_event_attr to define kernel breakpointsFrederic Weisbecker2009-11-271-5/+5
| | | | | | | | | | | | | | | | | Kernel breakpoints are created using functions in which we pass breakpoint parameters as individual variables: address, length and type. Although it fits well for x86, this just does not scale across architectures that may support this api later as these may have more or different needs. Pass in a perf_event_attr structure instead because it is meant to evolve as much as possible into a generic hardware breakpoint parameter structure. Reported-by: K.Prasad <prasad@linux.vnet.ibm.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <1259294154-5197-2-git-send-regression-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* hw-breakpoints: Simplify error handling in breakpoint creation requestsFrederic Weisbecker2009-11-261-3/+0
| | | | | | | | | | | | | | | | This simplifies the error handling when we create a breakpoint. We don't need to check the NULL return value corner case anymore since we have improved perf_event_create_kernel_counter() to always return an error code in the failure case. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Prasad <prasad@linux.vnet.ibm.com> LKML-Reference: <1259210142-5714-3-git-send-regression-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* hw-breakpoint: Attribute authorship of hw-breakpoint related filesK.Prasad2009-11-231-0/+2
| | | | | | | | | | | | Attribute authorship to developers of hw-breakpoint related files. Signed-off-by: K.Prasad <prasad@linux.vnet.ibm.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <20091123154713.GA5593@in.ibm.com> [ v2: moved it to latest -tip ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
* hw-breakpoints: Fix broken hw-breakpoint sample moduleFrederic Weisbecker2009-11-101-19/+24
| | | | | | | | | The hw-breakpoint sample module has been broken during the hw-breakpoint internals refactoring. Propagate the changes to it. Reported-by: "K. Prasad" <prasad@linux.vnet.ibm.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
* hw-breakpoints: sample HW breakpoint over kernel data addressK.Prasad2009-06-022-0/+84
This patch introduces a sample kernel module to demonstrate the use of Hardware Breakpoint feature. It places a breakpoint over the kernel variable 'pid_max' to monitor all write operations and emits a function-backtrace when done. Signed-off-by: K.Prasad <prasad@linux.vnet.ibm.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-23 23:43:19 +0000