On 03/14/2017 05:09 PM, Alexander Potapenko wrote: > On Tue, Mar 14, 2017 at 12:03 AM, tip-bot for Andrey Ryabinin > <[email protected]> wrote: >> Commit-ID: be3606ff739d1c1be36389f8737c577ad87e1f57 >> Gitweb: >> http://git.kernel.org/tip/be3606ff739d1c1be36389f8737c577ad87e1f57 >> Author: Andrey Ryabinin <[email protected]> >> AuthorDate: Mon, 13 Mar 2017 19:33:37 +0300 >> Committer: Thomas Gleixner <[email protected]> >> CommitDate: Tue, 14 Mar 2017 00:00:55 +0100 >> >> x86/kasan: Fix boot with KASAN=y and PROFILE_ANNOTATED_BRANCHES=y >> >> The kernel doesn't boot with both PROFILE_ANNOTATED_BRANCHES=y and KASAN=y >> options selected. With branch profiling enabled we end up calling >> ftrace_likely_update() before kasan_early_init(). ftrace_likely_update() is >> built with KASAN instrumentation, so calling it before kasan has been >> initialized leads to crash. >> >> Use DISABLE_BRANCH_PROFILING define to make sure that we don't call >> ftrace_likely_update() from early code before kasan_early_init(). > Won't it suffice to disable instrumentation of ftrace_likely_update() and > alike?
Not just ftrace_likely_update(), but also all functions that ftrace_likely_update() might call. That would suffice, but it would be unreasonable way to fix this, given that we can just ftrace_likely_update() call. Plus we don't have any sane way to disable instrumentation per-function.
