linux-stable.git/arch/arm/kernel/traps.c, branch linux-3.4.y Linux kernel stable tree ARM: fix "bad mode in ... handler" message for undefined instructions 2014-01-15T23:27:11+00:00 Russell King rmk+kernel@arm.linux.org.uk 2014-01-03T15:01:39+00:00 10252aa2278e1d53c420bacdf9ee239784712541 commit 29c350bf28da333e41e30497b649fe335712a2ab upstream. The array was missing the final entry for the undefined instruction exception handler; this commit adds it. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 29c350bf28da333e41e30497b649fe335712a2ab upstream.

The array was missing the final entry for the undefined instruction
exception handler; this commit adds it.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARM: 7526/1: traps: send SIGILL if get_user fails on undef handling path 2012-10-02T17:29:52+00:00 Will Deacon will.deacon@arm.com 2012-09-07T17:21:44+00:00 eff605bb6c699aae80b199010f0beb26563fc399 commit 2b2040af0b64cd93e5d4df2494c4486cf604090d upstream. get_user may fail to load from the provided __user address due to an unhandled fault generated by the access. In the case of the undefined instruction trap, this results in failure to load the faulting instruction, in which case we should send SIGILL to the task rather than continue with potentially uninitialised data. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 2b2040af0b64cd93e5d4df2494c4486cf604090d upstream.

get_user may fail to load from the provided __user address due to an
unhandled fault generated by the access.

In the case of the undefined instruction trap, this results in failure
to load the faulting instruction, in which case we should send SIGILL to
the task rather than continue with potentially uninitialised data.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARM: Fix undefined instruction exception handling 2012-08-15T15:10:07+00:00 Russell King rmk+kernel@arm.linux.org.uk 2012-07-30T18:42:10+00:00 81155539833d8c492261a8fdd91e3e6579c274dd commit 15ac49b65024f55c4371a53214879a9c77c4fbf9 upstream. While trying to get a v3.5 kernel booted on the cubox, I noticed that VFP does not work correctly with VFP bounce handling. This is because of the confusion over 16-bit vs 32-bit instructions, and where PC is supposed to point to. The rule is that FP handlers are entered with regs->ARM_pc pointing at the _next_ instruction to be executed. However, if the exception is not handled, regs->ARM_pc points at the faulting instruction. This is easy for ARM mode, because we know that the next instruction and previous instructions are separated by four bytes. This is not true of Thumb2 though. Since all FP instructions are 32-bit in Thumb2, it makes things easy. We just need to select the appropriate adjustment. Do this by moving the adjustment out of do_undefinstr() into the assembly code, as only the assembly code knows whether it's dealing with a 32-bit or 16-bit instruction. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 15ac49b65024f55c4371a53214879a9c77c4fbf9 upstream.

While trying to get a v3.5 kernel booted on the cubox, I noticed that
VFP does not work correctly with VFP bounce handling.  This is because
of the confusion over 16-bit vs 32-bit instructions, and where PC is
supposed to point to.

The rule is that FP handlers are entered with regs->ARM_pc pointing at
the _next_ instruction to be executed.  However, if the exception is
not handled, regs->ARM_pc points at the faulting instruction.

This is easy for ARM mode, because we know that the next instruction and
previous instructions are separated by four bytes.  This is not true of
Thumb2 though.

Since all FP instructions are 32-bit in Thumb2, it makes things easy.
We just need to select the appropriate adjustment.  Do this by moving
the adjustment out of do_undefinstr() into the assembly code, as only
the assembly code knows whether it's dealing with a 32-bit or 16-bit
instruction.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARM: 7409/1: Do not call flush_cache_user_range with mmap_sem held 2012-06-01T07:18:28+00:00 Dima Zavin dima@android.com 2012-04-30T09:26:14+00:00 8209f1cb6873c4e43fba6e768d244b77f1c9d4b3 commit 435a7ef52db7d86e67a009b36cac1457f8972391 upstream. We can't be holding the mmap_sem while calling flush_cache_user_range because the flush can fault. If we fault on a user address, the page fault handler will try to take mmap_sem again. Since both places acquire the read lock, most of the time it succeeds. However, if another thread tries to acquire the write lock on the mmap_sem (e.g. mmap) in between the call to flush_cache_user_range and the fault, the down_read in do_page_fault will deadlock. [will: removed drop of vma parameter as already queued by rmk (7365/1)] Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Dima Zavin <dima@android.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 435a7ef52db7d86e67a009b36cac1457f8972391 upstream.

We can't be holding the mmap_sem while calling flush_cache_user_range
because the flush can fault. If we fault on a user address, the
page fault handler will try to take mmap_sem again. Since both places
acquire the read lock, most of the time it succeeds. However, if another
thread tries to acquire the write lock on the mmap_sem (e.g. mmap) in
between the call to flush_cache_user_range and the fault, the down_read
in do_page_fault will deadlock.

[will: removed drop of vma parameter as already queued by rmk (7365/1)]

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Dima Zavin <dima@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARM: 7365/1: drop unused parameter from flush_cache_user_range 2012-06-01T07:18:28+00:00 Dima Zavin dima@android.com 2012-03-29T19:44:06+00:00 6019ae78aa65afe273da8c0dfeed8e89fb5edf8f commit 4542b6a0fa6b48d9ae6b41c1efeb618b7a221b2a upstream. vma isn't used and flush_cache_user_range isn't a standard macro that is used on several archs with the same prototype. In fact only unicore32 has a macro with the same name (with an identical implementation and no in-tree users). This is a part of a patch proposed by Dima Zavin (with Message-id: 1272439931-12795-1-git-send-email-dima@android.com) that didn't get accepted. Cc: Dima Zavin <dima@android.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 4542b6a0fa6b48d9ae6b41c1efeb618b7a221b2a upstream.

vma isn't used and flush_cache_user_range isn't a standard macro that
is used on several archs with the same prototype. In fact only unicore32
has a macro with the same name (with an identical implementation and no
in-tree users).

This is a part of a patch proposed by Dima Zavin (with Message-id:
1272439931-12795-1-git-send-email-dima@android.com) that didn't get
accepted.

Cc: Dima Zavin <dima@android.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-arm 2012-03-29T23:53:48+00:00 Linus Torvalds torvalds@linux-foundation.org 2012-03-29T23:53:48+00:00 12679a2d7e3bfbdc7586e3e86d1ca90c46659363 Pull more ARM updates from Russell King. This got a fair number of conflicts with the <asm/system.h> split, but also with some other sparse-irq and header file include cleanups. They all looked pretty trivial, though. * 'for-linus' of git://git.linaro.org/people/rmk/linux-arm: (59 commits) ARM: fix Kconfig warning for HAVE_BPF_JIT ARM: 7361/1: provide XIP_VIRT_ADDR for no-MMU builds ARM: 7349/1: integrator: convert to sparse irqs ARM: 7259/3: net: JIT compiler for packet filters ARM: 7334/1: add jump label support ARM: 7333/2: jump label: detect %c support for ARM ARM: 7338/1: add support for early console output via semihosting ARM: use set_current_blocked() and block_sigmask() ARM: exec: remove redundant set_fs(USER_DS) ARM: 7332/1: extract out code patch function from kprobes ARM: 7331/1: extract out insn generation code from ftrace ARM: 7330/1: ftrace: use canonical Thumb-2 wide instruction format ARM: 7351/1: ftrace: remove useless memory checks ARM: 7316/1: kexec: EOI active and mask all interrupts in kexec crash path ARM: Versatile Express: add NO_IOPORT ARM: get rid of asm/irq.h in asm/prom.h ARM: 7319/1: Print debug info for SIGBUS in user faults ARM: 7318/1: gic: refactor irq_start assignment ARM: 7317/1: irq: avoid NULL check in for_each_irq_desc loop ARM: 7315/1: perf: add support for the Cortex-A7 PMU ... 
Pull more ARM updates from Russell King.

This got a fair number of conflicts with the <asm/system.h> split, but
also with some other sparse-irq and header file include cleanups.  They
all looked pretty trivial, though.

* 'for-linus' of git://git.linaro.org/people/rmk/linux-arm: (59 commits)
  ARM: fix Kconfig warning for HAVE_BPF_JIT
  ARM: 7361/1: provide XIP_VIRT_ADDR for no-MMU builds
  ARM: 7349/1: integrator: convert to sparse irqs
  ARM: 7259/3: net: JIT compiler for packet filters
  ARM: 7334/1: add jump label support
  ARM: 7333/2: jump label: detect %c support for ARM
  ARM: 7338/1: add support for early console output via semihosting
  ARM: use set_current_blocked() and block_sigmask()
  ARM: exec: remove redundant set_fs(USER_DS)
  ARM: 7332/1: extract out code patch function from kprobes
  ARM: 7331/1: extract out insn generation code from ftrace
  ARM: 7330/1: ftrace: use canonical Thumb-2 wide instruction format
  ARM: 7351/1: ftrace: remove useless memory checks
  ARM: 7316/1: kexec: EOI active and mask all interrupts in kexec crash path
  ARM: Versatile Express: add NO_IOPORT
  ARM: get rid of asm/irq.h in asm/prom.h
  ARM: 7319/1: Print debug info for SIGBUS in user faults
  ARM: 7318/1: gic: refactor irq_start assignment
  ARM: 7317/1: irq: avoid NULL check in for_each_irq_desc loop
  ARM: 7315/1: perf: add support for the Cortex-A7 PMU
  ...
Disintegrate asm/system.h for ARM 2012-03-28T17:30:01+00:00 David Howells dhowells@redhat.com 2012-03-28T17:30:01+00:00 9f97da78bf018206fb623cd351d454af2f105fe0 Disintegrate asm/system.h for ARM. Signed-off-by: David Howells <dhowells@redhat.com> cc: Russell King <linux@arm.linux.org.uk> cc: linux-arm-kernel@lists.infradead.org 
Disintegrate asm/system.h for ARM.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Russell King <linux@arm.linux.org.uk>
cc: linux-arm-kernel@lists.infradead.org
ARM: Add compiled ISA to oops dumps 2012-03-24T09:38:52+00:00 Russell King rmk+kernel@arm.linux.org.uk 2012-02-04T12:12:11+00:00 8211ca658728d03ba331de0276950289e52a1b0f Add the compiled ISA to oops dumps, along side the preempt/smp configuration. This allows us to see immediately whether the kernel was compiled for Thumb-2 or not. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
Add the compiled ISA to oops dumps, along side the preempt/smp
configuration.  This allows us to see immediately whether the kernel
was compiled for Thumb-2 or not.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 7322/1: Print BUG instead of undefined instruction on BUG_ON() 2012-02-09T16:25:37+00:00 Stephen Boyd sboyd@codeaurora.org 2012-02-07T18:42:33+00:00 bdf800c4fceb6d8dbe65471d214eb44a61f5bfc9 The ARM kernel uses undefined instructions to implement BUG/BUG_ON(). This leads to problems where people don't read one line above the Oops message and see the "kernel BUG at ..." message and so they wrongly assume the kernel has hit an undefined instruction. Instead of printing: Internal error: Oops - undefined instruction: 0 [#1] PREEMPT SMP print Internal error: Oops - BUG: 0 [#1] PREEMPT SMP This should prevent people from thinking the BUG_ON was an undefined instruction when it was actually intentional. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Acked-by: Simon Glass <sjg@chromium.org> Tested-by: Simon Glass <sjg@chromium.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
The ARM kernel uses undefined instructions to implement
BUG/BUG_ON(). This leads to problems where people don't read one
line above the Oops message and see the "kernel BUG at ..."
message and so they wrongly assume the kernel has hit an
undefined instruction.

Instead of printing:

 Internal error: Oops - undefined instruction: 0 [#1] PREEMPT SMP

print

 Internal error: Oops - BUG: 0 [#1] PREEMPT SMP

This should prevent people from thinking the BUG_ON was an
undefined instruction when it was actually intentional.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: earlier initialization of vectors page 2012-01-23T10:24:11+00:00 Russell King rmk+kernel@arm.linux.org.uk 2012-01-18T15:32:49+00:00 94e5a85b3be0ce109d26aa6812b2a02c518a0e4b Initialize the contents of the vectors page immediately after we allocate the page, but before we map it. This avoids any possible aliases with other mappings which may need to be flushed after the page has been mapped irrespective of the cache type. We follow this later with a flush_cache_all() after all static memory mappings have been initialized, which ensures that this is safe from any cache effects. Tested-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
Initialize the contents of the vectors page immediately after we
allocate the page, but before we map it.  This avoids any possible
aliases with other mappings which may need to be flushed after the
page has been mapped irrespective of the cache type.

We follow this later with a flush_cache_all() after all static memory
mappings have been initialized, which ensures that this is safe from
any cache effects.

Tested-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>