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2024-05-02docs, kprobes: Add riscv as supported architectureIvan Orlov
Support of kprobes and kretprobes for riscv was introduced 3 years ago by the following change: commit c22b0bcb1dd0 ("riscv: Add kprobes supported") Add riscv to the list of supported architectures. Signed-off-by: Ivan Orlov <ivan.orlov@codethink.co.uk> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/r/20240429155735.68781-1-ivan.orlov@codethink.co.uk
2024-01-11docs, kprobes: Add loongarch as supported architectureTiezhu Yang
After the following three changes at the beginning of the year: commit 6d4cc40fb5f5 ("LoongArch: Add kprobes support") commit 3f5536860086 ("LoongArch: Add kretprobes support") commit 09e679c28a4d ("LoongArch: Add kprobes on ftrace support") it is appropriate to add loongarch as supported architecture in kprobes documentation. Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Acked-by: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/r/20231219062330.22813-3-yangtiezhu@loongson.cn
2024-01-11docs, kprobes: Update email address of Masami HiramatsuTiezhu Yang
According to the latest authorship and Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Masami Hiramatsu is working at Google, so the current email @redhat.com is out of date, it is better to use the email @kernel.org. Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Acked-by: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/r/20231219062330.22813-2-yangtiezhu@loongson.cn
2023-09-11Documentation: Drop or replace remaining mentions of IA64Ard Biesheuvel
Drop or update mentions of IA64, as appropriate. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-12-15kprobes: kretprobe events missing on 2-core KVM guestwuqiang
Default value of maxactive is set as num_possible_cpus() for nonpreemptable systems. For a 2-core system, only 2 kretprobe instances would be allocated in default, then these 2 instances for execve kretprobe are very likely to be used up with a pipelined command. Here's the testcase: a shell script was added to crontab, and the content of the script is: #!/bin/sh do_something_magic `tr -dc a-z < /dev/urandom | head -c 10` cron will trigger a series of program executions (4 times every hour). Then events loss would be noticed normally after 3-4 hours of testings. The issue is caused by a burst of series of execve requests. The best number of kretprobe instances could be different case by case, and should be user's duty to determine, but num_possible_cpus() as the default value is inadequate especially for systems with small number of cpus. This patch enables the logic for preemption as default, thus increases the minimum of maxactive to 10 for nonpreemptable systems. Link: https://lore.kernel.org/all/20221110081502.492289-1-wuqiang.matt@bytedance.com/ Signed-off-by: wuqiang <wuqiang.matt@bytedance.com> Reviewed-by: Solar Designer <solar@openwall.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2022-09-29docs, kprobes: Fix the wrong location of KprobesTiezhu Yang
After commit 22471e1313f2 ("kconfig: use a menu in arch/Kconfig to reduce clutter"), the location of Kprobes is under "General architecture-dependent options" rather than "General setup". Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> Fixes: 22471e1313f2 ("kconfig: use a menu in arch/Kconfig to reduce clutter") Link: https://lore.kernel.org/r/1663322106-12178-1-git-send-email-yangtiezhu@loongson.cn Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-10-26docs, kprobes: Remove invalid URL and add new referenceTiezhu Yang
The following reference is invalid, remove it. https://www.ibm.com/developerworks/library/l-kprobes/index.html Add the following new reference "An introduction to KProbes": https://lwn.net/Articles/132196/ Link: https://lkml.kernel.org/r/1635213091-24387-3-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>
2021-06-01kprobes: Remove kprobe::fault_handlerPeter Zijlstra
The reason for kprobe::fault_handler(), as given by their comment: * We come here because instructions in the pre/post * handler caused the page_fault, this could happen * if handler tries to access user space by * copy_from_user(), get_user() etc. Let the * user-specified handler try to fix it first. Is just plain bad. Those other handlers are ran from non-preemptible context and had better use _nofault() functions. Also, there is no upstream usage of this. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Link: https://lore.kernel.org/r/20210525073213.561116662@infradead.org
2020-07-23docs: Move kprobes.rst from staging/ to trace/Naveen N. Rao
Kprobes contitutes a dynamic tracing technology and as such can be moved alongside documentation of other tracing technologies. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Link: https://lore.kernel.org/r/8a09c01c64b2e003d5486c4f0c89740618f1bae4.1595331824.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>