x86/ibt,ftrace: Search for __fentry__ location
[ Upstream commit aebfd12521d9c7d0b502cf6d06314cfbcdccfe3b ]
Currently a lot of ftrace code assumes __fentry__ is at sym+0. However
with Intel IBT enabled the first instruction of a function will most
likely be ENDBR.
Change ftrace_location() to not only return the __fentry__ location
when called for the __fentry__ location, but also when called for the
sym+0 location.
Then audit/update all callsites of this function to consistently use
these new semantics.
BUG=b/368548903
TEST=presubmit
RELEASE_NOTE=Fixes CVE-2024-38588 in the Linux kernel
cos-patch: security-high
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Change-Id: I7a71e751c414da305e51cf1d5a39906e0e2a3bfb
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220308154318.227581603@infradead.org
Stable-dep-of: e60b613df8b6 ("ftrace: Fix possible use-after-free issue in ftrace_location()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kevin Berry <kpberry@google.com>
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/81800
Reviewed-by: Arnav Kansal <rnv@google.com>
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
Reviewed-by: Oleksandr Tymoshenko <ovt@google.com>
4 files changed
