linux-dev/arch/csky/kernel/probes, branch master

csky/kprobe: reclaim insn_slot on kprobe unregistration

2022-07-23T01:36:14Z

On kprobe registration kernel allocate one insn_slot for new kprobe, but it forget to reclaim the insn_slot on unregistration, leading to a potential leakage. Reported-by: Chen Guokai Reviewed-by: Masami Hiramatsu (Google) Signed-off-by: Liao Chang Signed-off-by: Guo Ren

csky: patch_text: Fixup last cpu should be master

2022-04-07T07:35:57Z

These patch_text implementations are using stop_machine_cpuslocked infrastructure with atomic cpu_count. The original idea: When the master CPU patch_text, the others should wait for it. But current implementation is using the first CPU as master, which couldn't guarantee the remaining CPUs are waiting. This patch changes the last CPU as the master to solve the potential risk. Fixes: 33e53ae1ce41 ("csky: Add kprobes supported") Signed-off-by: Guo Ren Signed-off-by: Guo Ren Reviewed-by: Masami Hiramatsu Cc:

csky: fix typos in comments

2022-04-06T14:37:58Z

Various spelling mistakes in comments. Detected with the help of Coccinelle. Signed-off-by: Julia Lawall Signed-off-by: Guo Ren

ftrace: disable preemption when recursion locked

2021-10-27T15:21:49Z

As the documentation explained, ftrace_test_recursion_trylock() and ftrace_test_recursion_unlock() were supposed to disable and enable preemption properly, however currently this work is done outside of the function, which could be missing by mistake. And since the internal using of trace_test_and_set_recursion() and trace_clear_recursion() also require preemption disabled, we can just merge the logical. This patch will make sure the preemption has been disabled when trace_test_and_set_recursion() return bit >= 0, and trace_clear_recursion() will enable the preemption if previously enabled. Link: https://lkml.kernel.org/r/13bde807-779c-aa4c-0672-20515ae365ea@linux.alibaba.com CC: Petr Mladek Cc: Guo Ren Cc: Ingo Molnar Cc: "James E.J. Bottomley" Cc: Helge Deller Cc: Michael Ellerman Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Albert Ou Cc: Thomas Gleixner Cc: Borislav Petkov Cc: "H. Peter Anvin" Cc: Josh Poimboeuf Cc: Jiri Kosina Cc: Joe Lawrence Cc: Masami Hiramatsu Cc: Nicholas Piggin Cc: Jisheng Zhang CC: Steven Rostedt CC: Miroslav Benes Reported-by: Abaci Suggested-by: Peter Zijlstra Signed-off-by: Michael Wang [ Removed extra line in comment - SDR ] Signed-off-by: Steven Rostedt (VMware)

kprobes: treewide: Make it harder to refer kretprobe_trampoline directly

2021-10-01T01:24:06Z

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 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

kprobes: treewide: Remove trampoline_address from kretprobe_trampoline_handler()

2021-10-01T01:24:06Z

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 Tested-by: Andrii Nakryiko Signed-off-by: Steven Rostedt (VMware)

kprobes: treewide: Cleanup the error messages for kprobes

2021-10-01T01:24:05Z

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 Signed-off-by: Steven Rostedt (VMware)

csky: ftrace: Drop duplicate implementation of arch_check_ftrace_location()

2021-10-01T01:24:05Z

The csky specific arch_check_ftrace_location() shadows a weak implementation of the function in core code that offers the same functionality but with additional error checking. Drop the architecture specific function as a step towards further cleanup in core code. Link: https://lkml.kernel.org/r/163163034617.489837.7789033031868135258.stgit@devnote2 Signed-off-by: Punit Agrawal Acked-by: Guo Ren Acked-by: Masami Hiramatsu Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

arch/csky/kernel/probes/kprobes.c: fix bugon.cocci warnings

2021-09-03T16:58:09Z

Use BUG_ON instead of a if condition followed by BUG. Generated by: scripts/coccinelle/misc/bugon.cocci Link: https://lkml.kernel.org/r/alpine.DEB.2.22.394.2107061049150.7197@hadrien Fixes: 7d37cb2c912d ("lib: fix kconfig dependency on ARCH_WANT_FRAME_POINTERS") Signed-off-by: kernel test robot Signed-off-by: Julia Lawall Reported-by: kernel test robot Cc: Julian Braha Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kprobes: Do not increment probe miss count in the fault handler

2021-06-03T13:47:26Z

Kprobes has a counter 'nmissed', that is used to count the number of times a probe handler was not called. This generally happens when we hit a kprobe while handling another kprobe. However, if one of the probe handlers causes a fault, we are currently incrementing 'nmissed'. The comment in fault handler indicates that this can be used to account faults taken by the probe handlers. But, this has never been the intention as is evident from the comment above 'nmissed' in 'struct kprobe': /*count the number of times this probe was temporarily disarmed */ unsigned long nmissed; Signed-off-by: Naveen N. Rao Signed-off-by: Peter Zijlstra (Intel) Acked-by: Masami Hiramatsu Link: https://lkml.kernel.org/r/20210601120150.672652-1-naveen.n.rao@linux.vnet.ibm.com