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linux-next/arch/x86/kernel/kprobes
Peter Zijlstra d8a7386897 x86/optprobe: Fix OPTPROBE vs UACCESS
While looking at an objtool UACCESS warning, it suddenly occurred to me
that it is entirely possible to have an OPTPROBE right in the middle of
an UACCESS region.

In this case we must of course clear FLAGS.AC while running the KPROBE.
Luckily the trampoline already saves/restores [ER]FLAGS, so all we need
to do is inject a CLAC. Unfortunately we cannot use ALTERNATIVE() in the
trampoline text, so we have to frob that manually.

Fixes: ca0bbc70f147 ("sched/x86_64: Don't save flags on context switch")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lkml.kernel.org/r/20200305092130.GU2596@hirez.programming.kicks-ass.net
2020-03-20 13:06:22 +01:00
..
common.h x86/stackframe/32: Provide consistent pt_regs 2019-06-25 10:23:47 +02:00
core.c Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-01-28 09:44:15 -08:00
ftrace.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156 2019-05-30 11:26:35 -07:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
opt.c x86/optprobe: Fix OPTPROBE vs UACCESS 2020-03-20 13:06:22 +01:00