linux-stable.git/arch/arm64/kernel/stacktrace.c, branch linux-4.3.y Linux kernel stable tree Revert "ARM64: unwind: Fix PC calculation" 2015-10-28T17:07:07+00:00 Will Deacon will.deacon@arm.com 2015-10-28T16:56:13+00:00 9702970c7bd3e2d6fecb642a190269131d4ac16c This reverts commit e306dfd06fcb44d21c80acb8e5a88d55f3d1cf63. With this patch applied, we were the only architecture making this sort of adjustment to the PC calculation in the unwinder. This causes problems for ftrace, where the PC values are matched against the contents of the stack frames in the callchain and fail to match any records after the address adjustment. Whilst there has been some effort to change ftrace to workaround this, those patches are not yet ready for mainline and, since we're the odd architecture in this regard, let's just step in line with other architectures (like arch/arm/) for now. Cc: <stable@vger.kernel.org> Signed-off-by: Will Deacon <will.deacon@arm.com> 
This reverts commit e306dfd06fcb44d21c80acb8e5a88d55f3d1cf63.

With this patch applied, we were the only architecture making this sort
of adjustment to the PC calculation in the unwinder. This causes
problems for ftrace, where the PC values are matched against the
contents of the stack frames in the callchain and fail to match any
records after the address adjustment.

Whilst there has been some effort to change ftrace to workaround this,
those patches are not yet ready for mainline and, since we're the odd
architecture in this regard, let's just step in line with other
architectures (like arch/arm/) for now.

Cc: <stable@vger.kernel.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
arm64: LLVMLinux: Use current_stack_pointer in save_stack_trace_tsk 2014-09-08T13:39:19+00:00 Behan Webster behanw@converseincode.com 2014-08-27T04:29:30+00:00 bb28cec4ea2f5151c08e061c6de825a8c853bbd6 Use the global current_stack_pointer to get the value of the stack pointer. This change supports being able to compile the kernel with both gcc and clang. Signed-off-by: Behan Webster <behanw@converseincode.com> Signed-off-by: Mark Charlebois <charlebm@gmail.com> Reviewed-by: Jan-Simon Möller <dl9pf@gmx.de> Reviewed-by: Olof Johansson <olof@lixom.net> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> 
Use the global current_stack_pointer to get the value of the stack pointer.
This change supports being able to compile the kernel with both gcc and clang.

Signed-off-by: Behan Webster <behanw@converseincode.com>
Signed-off-by: Mark Charlebois <charlebm@gmail.com>
Reviewed-by: Jan-Simon Möller <dl9pf@gmx.de>
Reviewed-by: Olof Johansson <olof@lixom.net>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
arm64: Add 'notrace' attribute to unwind_frame() for ftrace 2014-05-29T08:04:31+00:00 AKASHI Takahiro takahiro.akashi@linaro.org 2014-04-30T09:54:31+00:00 26e2ae39995469b9289aa1ec0144e256d56eb044 walk_stackframe() calls unwind_frame(), and if walk_stackframe() is "notrace", unwind_frame() should be also "notrace". Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com> 
walk_stackframe() calls unwind_frame(), and if walk_stackframe() is
"notrace", unwind_frame() should be also "notrace".

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
ARM64: unwind: Fix PC calculation 2014-02-17T09:16:33+00:00 Olof Johansson olof@lixom.net 2014-02-14T19:35:15+00:00 e306dfd06fcb44d21c80acb8e5a88d55f3d1cf63 The frame PC value in the unwind code used to just take the saved LR value and use that. That's incorrect as a stack trace, since it shows the return path stack, not the call path stack. In particular, it shows faulty information in case the bl is done as the very last instruction of one label, since the return point will be in the next label. That can easily be seen with tail calls to panic(), which is marked __noreturn and thus doesn't have anything useful after it. Easiest here is to just correct the unwind code and do a -4, to get the actual call site for the backtrace instead of the return site. Signed-off-by: Olof Johansson <olof@lixom.net> Cc: stable@vger.kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> 
The frame PC value in the unwind code used to just take the saved LR
value and use that.  That's incorrect as a stack trace, since it shows
the return path stack, not the call path stack.

In particular, it shows faulty information in case the bl is done as
the very last instruction of one label, since the return point will be
in the next label. That can easily be seen with tail calls to panic(),
which is marked __noreturn and thus doesn't have anything useful after it.

Easiest here is to just correct the unwind code and do a -4, to get the
actual call site for the backtrace instead of the return site.

Signed-off-by: Olof Johansson <olof@lixom.net>
Cc: stable@vger.kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
ARM64: fix framepointer check in unwind_frame 2013-12-19T17:43:10+00:00 Konstantin Khlebnikov k.khlebnikov@samsung.com 2013-12-05T13:30:16+00:00 26920dd2da79a3207803da9453c0e6c82ac968ca We need at least 24 bytes above frame pointer. Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> 
We need at least 24 bytes above frame pointer.

Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
arm64: Exception handling 2012-09-17T09:24:46+00:00 Catalin Marinas catalin.marinas@arm.com 2012-03-05T11:49:27+00:00 60ffc30d5652810dd34ea2eec41504222f5d5791 The patch contains the exception entry code (kernel/entry.S), pt_regs structure and related accessors, undefined instruction trapping and stack tracing. AArch64 Linux kernel (including kernel threads) runs in EL1 mode using the SP1 stack. The vectors don't have a fixed address, only alignment (2^11) requirements. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de> 
The patch contains the exception entry code (kernel/entry.S), pt_regs
structure and related accessors, undefined instruction trapping and
stack tracing.

AArch64 Linux kernel (including kernel threads) runs in EL1 mode using
the SP1 stack. The vectors don't have a fixed address, only alignment
(2^11) requirements.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Olof Johansson <olof@lixom.net>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>