Home
last modified time | relevance | path

Searched hist:bf094cffea2a6503ce84062f9f0243bef77c58f9 (Results 1 – 1 of 1) sorted by relevance

/linux/include/linux/
H A Dkprobes.hdiff bf094cffea2a6503ce84062f9f0243bef77c58f9 Tue Sep 14 16:42:51 CEST 2021 Masami Hiramatsu <mhiramat@kernel.org> x86/kprobes: Fixup return address in generic trampoline handler

In x86, the fake return address on the stack saved by
__kretprobe_trampoline() will be replaced with the real return
address after returning from trampoline_handler(). Before fixing
the return address, the real return address can be found in the
'current->kretprobe_instances'.

However, since there is a window between updating the
'current->kretprobe_instances' and fixing the address on the stack,
if an interrupt happens at that timing and the interrupt handler
does stacktrace, it may fail to unwind because it can not get
the correct return address from 'current->kretprobe_instances'.

This will eliminate that window by fixing the return address
right before updating 'current->kretprobe_instances'.

Link: https://lkml.kernel.org/r/163163057094.489837.9044470370440745866.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>