30b8fdbbe3
Jiri Olsa says:
====================
Martynas reported bpf_get_func_ip returning +4 address when
CONFIG_X86_KERNEL_IBT option is enabled and I found there are
some failing bpf tests when this option is enabled.
The CONFIG_X86_KERNEL_IBT option adds endbr instruction at the
function entry, so the idea is to 'fix' entry ip for kprobe_multi
and trampoline probes, because they are placed on the function
entry.
v5 changes:
- updated uapi/linux/bpf.h headers with comment for
bpf_get_func_ip returning 0 [Andrii]
- added acks
v4 changes:
- used get_kernel_nofault to read previous instruction [Peter]
- used movabs instruction in trampoline comment [Peter]
- renamed fentry_ip argument in kprobe_multi_link_handler [Peter]
v3 changes:
- using 'unused' bpf function to get IBT config option
into selftest skeleton
- rebased to current bpf-next/master
- added ack/review from Masami
v2 changes:
- change kprobes get_func_ip to return zero for kprobes
attached within the function body [Andrii]
- detect IBT config and properly test kprobe with offset
[Andrii]
v1 changes:
- read previous instruction in kprobe_multi link handler
and adjust entry_ip for CONFIG_X86_KERNEL_IBT option
- split first patch into 2 separate changes
- update changelogs
====================
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.