linux-stable.git/arch/arm64/kernel/entry.S, branch linux-3.10.y

arm64: avoid returning from bad_mode

2017-02-06T22:32:54+00:00

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 
Fixes: 9955ac47f4ba1c95 ("arm64: don't kill the kernel on a bad esr from el0")
Reported-by: Mark Salter 
Cc: Will Deacon 
Cc: stable@vger.kernel.org
Signed-off-by: Catalin Marinas 
Signed-off-by: Willy Tarreau

arm64: Bug fix in stack alignment exception

2014-07-09T18:14:01+00:00

commit 3906c2b53cd23c2ae03e6ce41432c8e7f0a3cbbb upstream.

The value of ESR has been stored into x1, and should be directly pass to
do_sp_pc_abort function, "MOV x1, x25" is an extra operation and do_sp_pc_abort
will get the wrong value of ESR.

Signed-off-by: ChiaHao 
Signed-off-by: Catalin Marinas 
Cc: 
Signed-off-by: Greg Kroah-Hartman

arm64: Change kernel stack size to 16K

2014-01-09T20:24:26+00:00

commit 845ad05ec31e0f3872a321e10dbeaf872022632c upstream.

Written by Catalin Marinas, tested by APM on storm platform. This is needed
because of the failures encountered when running SpecWeb benchmark test.

Signed-off-by: Feng Kan 
Acked-by: Kumar Sankaran 
Signed-off-by: Catalin Marinas 
Cc: Mark Brown 
Signed-off-by: Greg Kroah-Hartman

arm64: treat unhandled compat el0 traps as undef

2013-05-31T15:04:44+00:00

Currently, if a compat process reads or writes from/to a disabled
cp15/cp14 register, the trap is not handled by the el0_sync_compat
handler, and the kernel will head to bad_mode, where it will die(), and
oops(). For 64 bit processes, disabled system register accesses are
currently treated as unhandled instructions.

This patch modifies entry.S to treat these unhandled traps as undefined
instructions, sending a SIGILL to userspace. This gives processes a
chance to handle this and stop using inaccessible registers, and
prevents further issues in the kernel as a result of the die().

Reported-by: Johannes Jensen 
Signed-off-by: Mark Rutland 
Signed-off-by: Catalin Marinas

arm64: add explicit symbols to ESR_EL1 decoding

2013-04-17T14:58:25+00:00

The ESR_EL1 decoding process is a bit cryptic, and KVM has also
a need for the same constants.

Add a new esr.h file containing the appropriate exception classes
constants, and change entry.S to use it. Fix a small bug in the
EL1 breakpoint check while we're at it.

Signed-off-by: Marc Zyngier 
Signed-off-by: Will Deacon 
Signed-off-by: Catalin Marinas

arm64: switch to generic sigaltstack

2013-02-14T14:17:29+00:00

Signed-off-by: Al Viro

arm64: move vector entry macro to assembler.h

2012-12-05T11:26:47+00:00

This macro is also useful to other bits defining vectors (hypervisor
stub, KVM...).

Move it to a common location.

Signed-off-by: Marc Zyngier 
Signed-off-by: Catalin Marinas

arm64: get rid of fork/vfork/clone wrappers

2012-10-22T22:14:17+00:00

[fixes from Catalin Marinas folded]

Acked-by: Catalin Marinas 
Tested-by: Catalin Marinas 
Signed-off-by: Al Viro

arm64: Use generic sys_execve() implementation

2012-10-17T13:41:51+00:00

This patch converts the arm64 port to use the generic sys_execve()
implementation removing the arm64-specific (compat_)sys_execve_wrapper()
functions.

Signed-off-by: Catalin Marinas

arm64: Use generic kernel_execve() implementation

2012-10-17T13:35:04+00:00

This patch enables CONFIG_GENERIC_KERNEL_EXECVE on arm64 and removes the
arm64-specific implementation of kernel_execve().

Signed-off-by: Catalin Marinas