kernel.git/arch/sh/kernel/kprobes.c, branch linux-6.0.y

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: 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

kprobes: Remove kprobe::fault_handler

2021-06-01T14:00:08Z

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) Reviewed-by: Christoph Hellwig Acked-by: Masami Hiramatsu Link: https://lore.kernel.org/r/20210525073213.561116662@infradead.org

sh: kprobes: Use generic kretprobe trampoline handler

2020-09-08T09:52:34Z

Use the generic kretprobe trampoline handler. Don't use framepointer verification. Signed-off-by: Masami Hiramatsu Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/159870613547.1229682.15519965962108261812.stgit@devnote2

arch/sh: Check for kprobe trap number before trying to handle a kprobe trap

2019-06-26T10:11:13Z

The DIE_TRAP notifier chain is run both for kprobe traps and for BUG/WARN traps. The kprobe code assumes to be only called for BREAKPOINT_INSTRUCTION, and concludes to have hit a concurrently removed kprobe if it finds anything else at the faulting locations. This includes TRAPA_BUG_OPCODE used for BUG and WARN. The consequence is that kprobe_handler returns 1. This makes kprobe_exceptions_notify return NOTIFY_STOP, and prevents handling the BUG statement. This also prevents moving $pc away from the trap instruction, so the system locks up in an endless loop Signed-off-by: Michael Karcher Signed-off-by: Yoshinori Sato

sh: kernel: convert to SPDX identifiers

2018-12-28T20:11:45Z

Update license to use SPDX-License-Identifier instead of verbose license text. Link: http://lkml.kernel.org/r/8736rccswn.wl-kuninori.morimoto.gx@renesas.com Signed-off-by: Kuninori Morimoto Reviewed-by: Simon Horman Cc: Rich Felker Cc: Yoshinori Sato Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

bpf/error-inject/kprobes: Clear current_kprobe and enable preempt in kprobe

2018-06-21T10:33:19Z

Clear current_kprobe and enable preemption in kprobe even if pre_handler returns !0. This simplifies function override using kprobes. Jprobe used to require to keep the preemption disabled and keep current_kprobe until it returned to original function entry. For this reason kprobe_int3_handler() and similar arch dependent kprobe handers checks pre_handler result and exit without enabling preemption if the result is !0. After removing the jprobe, Kprobes does not need to keep preempt disabled even if user handler returns !0 anymore. But since the function override handler in error-inject and bpf is also returns !0 if it overrides a function, to balancing the preempt count, it enables preemption and reset current kprobe by itself. That is a bad design that is very buggy. This fixes such unbalanced preempt-count and current_kprobes setting in kprobes, bpf and error-inject. Note: for powerpc and x86, this removes all preempt_disable from kprobe_ftrace_handler because ftrace callbacks are called under preempt disabled. Signed-off-by: Masami Hiramatsu Acked-by: Thomas Gleixner Acked-by: Naveen N. Rao Cc: Alexei Starovoitov Cc: Ananth N Mavinakayanahalli Cc: Andrew Morton Cc: Benjamin Herrenschmidt Cc: Catalin Marinas Cc: David S. Miller Cc: Fenghua Yu Cc: Heiko Carstens Cc: James Hogan Cc: Josef Bacik Cc: Linus Torvalds Cc: Martin Schwidefsky Cc: Michael Ellerman Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Ralf Baechle Cc: Rich Felker Cc: Russell King Cc: Steven Rostedt Cc: Tony Luck Cc: Vineet Gupta Cc: Will Deacon Cc: Yoshinori Sato Cc: linux-arch@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-ia64@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: linux-s390@vger.kernel.org Cc: linux-sh@vger.kernel.org Cc: linux-snps-arc@lists.infradead.org Cc: linuxppc-dev@lists.ozlabs.org Cc: sparclinux@vger.kernel.org Link: https://lore.kernel.org/lkml/152942494574.15209.12323837825873032258.stgit@devbox Signed-off-by: Ingo Molnar

sh/kprobes: Don't call the ->break_handler() in SH kprobes code

2018-06-21T10:33:18Z

Don't call the ->break_handler() from the SH kprobes code, because it was only used by jprobes which got removed. Signed-off-by: Masami Hiramatsu Acked-by: Thomas Gleixner Cc: Ananth N Mavinakayanahalli Cc: Andrew Morton Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Rich Felker Cc: Steven Rostedt Cc: Yoshinori Sato Cc: linux-arch@vger.kernel.org Cc: linux-sh@vger.kernel.org Link: https://lore.kernel.org/lkml/152942488763.15209.7791710414058030809.stgit@devbox Signed-off-by: Ingo Molnar

sh/kprobes: Remove jprobe implementation

2018-06-21T10:33:11Z

Remove arch dependent setjump/longjump functions and unused fields in kprobe_ctlblk for jprobes from arch/sh. Signed-off-by: Masami Hiramatsu Acked-by: Thomas Gleixner Cc: Ananth N Mavinakayanahalli Cc: Andrew Morton Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Rich Felker Cc: Steven Rostedt Cc: Yoshinori Sato Cc: linux-arch@vger.kernel.org Cc: linux-sh@vger.kernel.org Link: https://lore.kernel.org/lkml/152942456877.15209.5482537226935729621.stgit@devbox Signed-off-by: Ingo Molnar