xavi/android_kernel_m2note/arch/arm64/kernel/entry.S, branch o-8.1Unnamed repository; edit this file 'description' to name the repository.
https://gitea.privatedns.org/xavi/android_kernel_m2note/atom?h=o-8.12018-01-15T21:49:56+00:00BACKPORT: arm64: Add CNTVCT_EL0 trap handler2018-01-15T21:49:56+00:00Marc Zyngiermarc.zyngier@arm.com2017-02-01T11:48:58+00:00urn:sha1:2d6dba834d9d3fc3654d0cd647dc033ba6821721
Since people seem to make a point in breaking the userspace visible
counter, we have no choice but to trap the access. Add the required
handler.
Bug: 68266545
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit 6126ce0588eb5a0752d5c8b5796a7fca324fd887)
Change-Id: I0705f47c85a78040df38df18f51a4a22500b904d
arm64: avoid returning from bad_mode2017-04-11T08:57:49+00:00Mark Rutlandmark.rutland@arm.com2017-01-23T18:28:50+00:00urn:sha1:2de5b1ee69fe5e6477e753d59845d05b2c3e1034
commit 7d9e8f71b989230bc613d121ca38507d34ada849 upstream.
Generally, taking an unexpected exception should be a fatal event, and
bad_mode is intended to cater for this. However, it should be possible
to contain unexpected synchronous exceptions from EL0 without bringing
the kernel down, by sending a SIGILL to the task.
We tried to apply this approach in commit 9955ac47f4ba1c95 ("arm64:
don't kill the kernel on a bad esr from el0"), by sending a signal for
any bad_mode call resulting from an EL0 exception.
However, this also applies to other unexpected exceptions, such as
SError and FIQ. The entry paths for these exceptions branch to bad_mode
without configuring the link register, and have no kernel_exit. Thus, if
we take one of these exceptions from EL0, bad_mode will eventually
return to the original user link register value.
This patch fixes this by introducing a new bad_el0_sync handler to cater
for the recoverable case, and restoring bad_mode to its original state,
whereby it calls panic() and never returns. The recoverable case
branches to bad_el0_sync with a bl, and returns to userspace via the
usual ret_to_user mechanism.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Fixes: 9955ac47f4ba1c95 ("arm64: don't kill the kernel on a bad esr from el0")
Reported-by: Mark Salter <msalter@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
first commit2016-08-15T02:19:42+00:00Meizu OpenSourcepatchwork@meizu.com2016-08-15T02:19:42+00:00urn:sha1:d2e1446d81725c351dc73a03b397ce043fb18452