linux-stable.git/arch/arm/kernel, branch v2.6.38 Linux kernel stable tree ARM: 6768/1: hw_breakpoint: ensure debug logic is powered up on v7 cores 2011-02-26T13:35:51+00:00 Will Deacon will.deacon@arm.com 2011-02-25T19:20:42+00:00 c09bae709182046ab104757115dfbd74a1ba1a15 ARMv7 allows the debug core logic to be powered down and provides the DBGPRSR register so that software can power-up and check the status of the logic. This patch ensures that the debug logic is powered up on ARMv7 cores before we attempt to access the extended debug registers. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
ARMv7 allows the debug core logic to be powered down and provides the
DBGPRSR register so that software can power-up and check the status of
the logic.

This patch ensures that the debug logic is powered up on ARMv7 cores
before we attempt to access the extended debug registers.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 6767/1: ptrace: fix register indexing in GETHBPREGS request 2011-02-26T13:35:50+00:00 Will Deacon will.deacon@arm.com 2011-02-25T19:19:32+00:00 ba55d3db9bb59a52fe45dbc5d62776adbb289e54 The GETHBPREGS ptrace request incorrectly maps its index argument onto the thread's saved debug state when the index != 0. This has not yet been seen from userspace because GDB (the only user of this request) only reads from register 0. This patch fixes the indexing. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
The GETHBPREGS ptrace request incorrectly maps its index argument onto
the thread's saved debug state when the index != 0. This has not yet
been seen from userspace because GDB (the only user of this request)
only reads from register 0.

This patch fixes the indexing.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 6745/1: kprobes insn decoding fix 2011-02-21T19:29:29+00:00 Nicolas Pitre nicolas.pitre@linaro.org 2011-02-21T03:37:20+00:00 5a5af730536fbf15fc354980cba2a0400afa6b76 Marcin Slusarz says: > In arch/arm/kernel/kprobes-decode.c there's a function > arm_kprobe_decode_insn which does: > > } else if ((insn & 0x0e000000) == 0x0c400000) { > ... > > This is always false, so code below is dead. > I found this bug by coccinelle (http://coccinelle.lip6.fr/). Reported-by: Marcin Slusarz <marcin.slusarz@gmail.com> Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
Marcin Slusarz says:

> In arch/arm/kernel/kprobes-decode.c there's a function
> arm_kprobe_decode_insn which does:
>
> } else if ((insn & 0x0e000000) == 0x0c400000) {
> ...
>
> This is always false, so code below is dead.
> I found this bug by coccinelle (http://coccinelle.lip6.fr/).

Reported-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: Keep exit text/data around for SMP_ON_UP 2011-02-21T19:29:27+00:00 Russell King rmk+kernel@arm.linux.org.uk 2011-02-21T10:13:36+00:00 a9ad21fed09cb95d34af9474be0831525b30c4c6 When SMP_ON_UP is used and the spinlocks are inlined, we end up with inline spinlocks in the exit code, with references from the SMP alternatives section to the exit sections. This causes link time errors. Avoid this by placing the exit sections in the init-discarded region. Cc: <stable@kernel.org> Tested-by: Dave Martin <dave.martin@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
When SMP_ON_UP is used and the spinlocks are inlined, we end up with
inline spinlocks in the exit code, with references from the SMP
alternatives section to the exit sections.  This causes link time
errors.  Avoid this by placing the exit sections in the init-discarded
region.

Cc: <stable@kernel.org>
Tested-by: Dave Martin <dave.martin@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: Ensure predictable endian state on signal handler entry 2011-02-21T19:29:26+00:00 Russell King rmk+kernel@arm.linux.org.uk 2011-02-20T12:22:52+00:00 53399053eb505cf541b2405bd9d9bca5ecfb96fb Ensure a predictable endian state when entering signal handlers. This avoids programs which use SETEND to momentarily switch their endian state from having their signal handlers entered with an unpredictable endian state. Cc: <stable@kernel.org> Acked-by: Dave Martin <dave.martin@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
Ensure a predictable endian state when entering signal handlers.  This
avoids programs which use SETEND to momentarily switch their endian
state from having their signal handlers entered with an unpredictable
endian state.

Cc: <stable@kernel.org>
Acked-by: Dave Martin <dave.martin@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 6740/1: Place correctly notes section in the linker script 2011-02-21T19:29:25+00:00 Pawel Moll pawel.moll@arm.com 2011-02-16T17:54:01+00:00 dc810efb0ca5702c9d96782b99282d4b4383e877 Commit 18991197b4b588255ccabf472ebc84db7b66a19c added --build-id linker option when toolchain supports it. ARM one does, but for some reason places the section at 0 when linker script doesn't mention it explicitly. The 1e621a8e3752367d4aae78a8ab00a18fb2793f34 worked around the problem removing this section from binary image with explicit objcopy options, but it still exists in vmlinux, confusing tools like debuggers and perf. This problem was discussed here: http://lists.infradead.org/pipermail/linux-arm-kernel/2010-May/015994.html http://lists.infradead.org/pipermail/linux-arm-kernel/2010-May/015994.html but the proposed changes to the linker script were substantial. This patch simply places NOTES (36 bytes long, at least when compiled with CodeSourcery toolchain) between data and bss, which seem to be the right place (and suggested by the sample linker script in include/asm-generic/vmlinux.lds.h). It is enough to place it correctly in vmlinux (so debuggers are happy): Section Headers: [11] .data PROGBITS c07ce000 7ce000 020fc0 00 WA 0 0 32 [12] .notes NOTE c07eefc0 7eefc0 000024 00 AX 0 0 4 [13] .bss NOBITS c07ef000 7eefe4 01e628 00 WA 0 0 32 Program Headers: LOAD 0x008000 0xc0008000 0xc0008000 0x7e6fe4 0x805628 RWE 0x8000 NOTE 0x7eefc0 0xc07eefc0 0xc07eefc0 0x00024 0x00024 R E 0x4 Section to Segment mapping: Segment Sections... 00 <...> .data .notes .bss 01 .notes and to get it exposed as /sys/kernel/notes used by perf tools. Signed-off-by: Pawel Moll <pawel.moll@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
Commit 18991197b4b588255ccabf472ebc84db7b66a19c added --build-id
linker option when toolchain supports it. ARM one does, but for some
reason places the section at 0 when linker script doesn't mention it
explicitly.

The 1e621a8e3752367d4aae78a8ab00a18fb2793f34 worked around the problem
removing this section from binary image with explicit objcopy options,
but it still exists in vmlinux, confusing tools like debuggers and perf.

This problem was discussed here:
http://lists.infradead.org/pipermail/linux-arm-kernel/2010-May/015994.html
http://lists.infradead.org/pipermail/linux-arm-kernel/2010-May/015994.html
but the proposed changes to the linker script were substantial.

This patch simply places NOTES (36 bytes long, at least when compiled
with CodeSourcery toolchain) between data and bss, which seem to be
the right place (and suggested by the sample linker script in
include/asm-generic/vmlinux.lds.h).

It is enough to place it correctly in vmlinux (so debuggers are happy):

Section Headers:
  [11] .data             PROGBITS        c07ce000 7ce000 020fc0 00  WA  0   0 32
  [12] .notes            NOTE            c07eefc0 7eefc0 000024 00  AX  0   0  4
  [13] .bss              NOBITS          c07ef000 7eefe4 01e628 00  WA  0   0 32
Program Headers:
  LOAD           0x008000 0xc0008000 0xc0008000 0x7e6fe4 0x805628 RWE 0x8000
  NOTE           0x7eefc0 0xc07eefc0 0xc07eefc0 0x00024 0x00024 R E 0x4
Section to Segment mapping:
  Segment Sections...
   00     <...> .data .notes .bss
   01     .notes

and to get it exposed as /sys/kernel/notes used by perf tools.

Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 6676/1: Correct the cpu_architecture() function for ARMv7 2011-02-19T11:24:28+00:00 Catalin Marinas catalin.marinas@arm.com 2011-02-15T17:06:57+00:00 315cfe7835c9a3fe27f15519bdeee8bf0a293e33 If ID_MMFR0[3:0] >= 3, the architecture version is ARMv7. The code was currently only testing for ID_MMFR0[3:0] == 3. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
If ID_MMFR0[3:0] >= 3, the architecture version is ARMv7. The code was
currently only testing for ID_MMFR0[3:0] == 3.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 6742/1: pmu: avoid setting IRQ affinity on UP systems 2011-02-19T11:24:05+00:00 Will Deacon will.deacon@arm.com 2011-02-18T15:21:06+00:00 71efb063f4a145ae420be054f5a91dcf7c19b375 Now that we can execute a CONFIG_SMP kernel on a uniprocessor system, extra care has to be taken in the PMU IRQ affinity setting code to ensure that we don't always fail to initialise. This patch changes the CPU PMU initialisation code so that when we only have a single IRQ, whose affinity can not be changed at the controller, we report success (0) rather than -EINVAL. Reported-by: Avik Sil <avik.sil@linaro.org> Acked-by: Jamie Iles <jamie@jamieiles.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
Now that we can execute a CONFIG_SMP kernel on a uniprocessor system,
extra care has to be taken in the PMU IRQ affinity setting code to
ensure that we don't always fail to initialise.

This patch changes the CPU PMU initialisation code so that when we
only have a single IRQ, whose affinity can not be changed at the
controller, we report success (0) rather than -EINVAL.

Reported-by: Avik Sil <avik.sil@linaro.org>
Acked-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 6657/1: hw_breakpoint: fix ptrace breakpoint advertising on unsupported arch 2011-02-11T22:54:48+00:00 Will Deacon will.deacon@arm.com 2011-02-11T15:01:42+00:00 66e1cfe6d52c69d317e9df76ebc8538a34af0d51 The ptrace debug information register was advertising breakpoint and watchpoint resources for unsupported debug architectures. This meant that setting breakpoints on these architectures would appear to succeed, although they would never fire in reality. This patch fixes the breakpoint slot probing so that it returns 0 when running on an unsupported debug architecture. Reported-by: Ulrich Weigand <ulrich.weigand@de.ibm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
The ptrace debug information register was advertising breakpoint and
watchpoint resources for unsupported debug architectures. This meant
that setting breakpoints on these architectures would appear to succeed,
although they would never fire in reality.

This patch fixes the breakpoint slot probing so that it returns 0 when
running on an unsupported debug architecture.

Reported-by: Ulrich Weigand <ulrich.weigand@de.ibm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 6656/1: hw_breakpoint: avoid UNPREDICTABLE behaviour when reading DBGDSCR 2011-02-11T22:54:47+00:00 Will Deacon will.deacon@arm.com 2011-02-11T14:55:12+00:00 ed19b739c5c76ad241d30f6c6a5ee96fb284f4cf Reading baseline CP14 registers, other than DBGDIDR, when the OS Lock is set leads to UNPREDICTABLE behaviour. This patch ensures that we clear the OS lock before accessing anything other than the DBGDIDR, thereby avoiding this behaviour. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
Reading baseline CP14 registers, other than DBGDIDR, when the OS Lock
is set leads to UNPREDICTABLE behaviour.

This patch ensures that we clear the OS lock before accessing anything
other than the DBGDIDR, thereby avoiding this behaviour.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>