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  1. 26 7月, 2013 4 次提交
    • W
      ARM: 7791/1: a.out: remove partial a.out support · acfdd4b1
      由 Will Deacon 提交于 
      a.out support on ARM requires that argc, argv and envp are passed in
r0-r2 respectively, which requires hacking load_aout_binary to
prevent argc being clobbered by the return code. Whilst mainline kernels
do set the registers up in start_thread, the aout loader has never
carried the hack in mainline.

Initialising the registers in this way actually goes against the libc
expectations for ELF binaries, where argc, argv and envp are passed on
the stack, with r0 being used to hold a pointer to an exit function for
cleaning up after the dynamic linker if required. If the pointer is
NULL, then it is ignored. When execing an ELF binary, Linux currently
zeroes r0, then sets it to argc and then finally clobbers it with the
return value of the execve syscall, so we actually end up with:

	r0 = 0
	stack[0] = argc
	r1 = stack[1] = argv
	r2 = stack[2] = envp

libc treats r1 and r2 as undefined. The clobbering of r0 by sys_execve
works for user-spawned threads, but when executing an ELF binary from a
kernel thread (via call_usermodehelper), the execve is performed on the
ret_from_fork path, which restores r0 from the saved pt_regs, resulting
in argc being presented to the C library. This has horrible consequences
when the application exits, since we have an exit function registered
using argc, resulting in a jump to hyperspace.

This patch solves the problem by removing the partial a.out support from
arch/arm/ altogether.

Cc: <stable@vger.kernel.org>
Cc: Ashish Sangwan <ashishsangwan2@gmail.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      acfdd4b1
    • C
      ARM: 7790/1: Fix deferred mm switch on VIVT processors · bdae73cd
      由 Catalin Marinas 提交于 
      As of commit b9d4d42a (ARM: Remove __ARCH_WANT_INTERRUPTS_ON_CTXSW on
pre-ARMv6 CPUs), the mm switching on VIVT processors is done in the
finish_arch_post_lock_switch() function to avoid whole cache flushing
with interrupts disabled. The need for deferred mm switch is stored as a
thread flag (TIF_SWITCH_MM). However, with preemption enabled, we can
have another thread switch before finish_arch_post_lock_switch(). If the
new thread has the same mm as the previous 'next' thread, the scheduler
will not call switch_mm() and the TIF_SWITCH_MM flag won't be set for
the new thread.

This patch moves the switch pending flag to the mm_context_t structure
since this is specific to the mm rather than thread.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Reported-by: NMarc Kleine-Budde <mkl@pengutronix.de>
Tested-by: NMarc Kleine-Budde <mkl@pengutronix.de>
Cc: <stable@vger.kernel.org> # 3.5+
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      bdae73cd
    • F
      ARM: 7789/1: Do not run dummy_flush_tlb_a15_erratum() on non-Cortex-A15 · 1f49856b
      由 Fabio Estevam 提交于 
      Commit 93dc6887 (ARM: 7684/1: errata: Workaround for Cortex-A15 erratum 798181 (TLBI/DSB operations)) causes the following undefined instruction error on a mx53 (Cortex-A8):

Internal error: Oops - undefined instruction: 0 [#1] SMP ARM
CPU: 0 PID: 275 Comm: modprobe Not tainted 3.11.0-rc2-next-20130722-00009-g9b0f371 #881
task: df46cc00 ti: df48e000 task.ti: df48e000
PC is at check_and_switch_context+0x17c/0x4d0
LR is at check_and_switch_context+0xdc/0x4d0

This problem happens because check_and_switch_context() calls dummy_flush_tlb_a15_erratum() without checking if we are really running on a Cortex-A15 or not.

To avoid this issue, only call dummy_flush_tlb_a15_erratum() inside
check_and_switch_context() if erratum_a15_798181() returns true, which means that we are really running on a Cortex-A15.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Reviewed-by: NRoger Quadros <rogerq@ti.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      1f49856b
    • M
      ARM: 7787/1: virt: ensure visibility of __boot_cpu_mode · 8fbac214
      由 Mark Rutland 提交于 
      Secondary CPUs write to __boot_cpu_mode with caches disabled, and thus a
cached value of __boot_cpu_mode may be incoherent with that in memory.
This could lead to a failure to detect mismatched boot modes.

This patch adds flushing to ensure that writes by secondaries to
__boot_cpu_mode are made visible before we test against it.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Acked-by: NDave Martin <Dave.Martin@arm.com>
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Cc: Christoffer Dall <cdall@cs.columbia.edu>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      8fbac214
  3. 22 7月, 2013 5 次提交
    • T
      ARM: 7788/1: elf: fix lpae hwcap feature reporting in proc/cpuinfo · ab8d46c0
      由 Tetsuyuki Kobayashi 提交于 
      Commit a469abd0 ("ARM: elf: add new hwcap for identifying atomic
ldrd/strd instructions") added a new hwcap to identify LPAE on CPUs
which support it. Whilst the hwcap data is correct, the string reported
in /proc/cpuinfo actually matches on HWCAP_VFPD32, which was missing
an entry in the string table.

This patch fixes this problem by adding a "vfpd32" string at the correct
offset, preventing us from falsely advertising LPAE on CPUs which do not
support it.

[will: added commit message]
Acked-by: NWill Deacon <will.deacon@arm.com>
Tested-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NTetsuyuki Kobayashi <koba@kmckk.co.jp>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      ab8d46c0
    • M
      ARM: 7786/1: hyp: fix macro parameterisation · b60d5db6
      由 Mark Rutland 提交于 
      Currently, compare_cpu_mode_with_primary uses a mixture of macro
arguments and hardcoded registers, and does so incorrectly, as it
stores (__boot_cpu_mode_offset | BOOT_CPU_MODE_MISMATCH) to
(__boot_cpu_mode + &__boot_cpu_mode_offset), which could corrupt an
arbitrary portion of memory.

This patch fixes up compare_cpu_mode_with_primary to use the macro
arguments, correctly updating __boot_cpu_mode.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Acked-by: NDave Martin <Dave.Martin@arm.com>
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Cc: Christoffer Dall <cdall@cs.columbia.edu>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      b60d5db6
    • R
      ARM: 7785/1: mm: restrict early_alloc to section-aligned memory · c65b7e98
      由 Russell King 提交于 
      When map_lowmem() runs, and processes a memory bank whose start or end
is not section-aligned, memory must be allocated to store the 2nd-level
page tables. Those allocations are made by calling memblock_alloc().

At this point, the only memory that is free *and* mapped is memory which
has already been mapped by map_lowmem() itself. For this reason, we must
calculate the first point at which map_lowmem() will need to allocate
memory, and set the memblock allocation limit to a lower address, so that
memblock_alloc() is guaranteed to return memory that is already mapped.

This patch enhances sanity_check_meminfo() to calculate that memory
address, and pass it to memblock_set_current_limit(), rather than just
assuming the limit is arm_lowmem_limit.

The algorithm applied is:

* Default memblock_limit to arm_lowmem_limit in the absence of any other
  limit; arm_lowmem_limit is the highest memory that is mapped by
  map_lowmem().

* While walking the list of memblocks, if the start of a block is not
  aligned, 2nd-level page tables will need to be allocated to map the
  first few pages of the block. Hence, the memblock_limit must be before
  the start of the block.

* Similarly, if the end of any block is not aligned, 2nd-level page
  tables will need to be allocated to map the last few pages of the
  block. Hence, the memblock_limit must point at the end of the block,
  rounded down to section-alignment.

* The memory blocks are assumed to be sorted in address order, so the
  first unaligned block start or end is used to set the limit.

With this algorithm, the start or end of almost any bank can be non-
section-aligned. The only exception is that the start of bank 0 must
be section-aligned, since otherwise memory would need to be allocated
when mapping the start of bank 0, which occurs before any free memory
is mapped.

[swarren, wrote commit description, rewrote calculation of memblock_limit]
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      c65b7e98
    • W
      ARM: 7784/1: mm: ensure SMP alternates assemble to exactly 4 bytes with Thumb-2 · bf3f0f33
      由 Will Deacon 提交于 
      Commit ae8a8b95 ("ARM: 7691/1: mm: kill unused TLB_CAN_READ_FROM_L1_CACHE
and use ALT_SMP instead") added early function returns for page table
cache flushing operations on ARMv7 SMP CPUs.

Unfortunately, when targetting Thumb-2, these `mov pc, lr' sequences
assemble to 2 bytes which can lead to corruption of the instruction
stream after code patching.

This patch fixes the alternates to use wide (32-bit) instructions for
Thumb-2, therefore ensuring that the patching code works correctly.

Cc: <stable@vger.kernel.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      bf3f0f33
    • R
      ARM: document DEBUG_UNCOMPRESS Kconfig option · b6992fa9
      由 Russell King 提交于 
      This non-user visible option lacked any kind of documentation.  This
is quite common for non-user visible options; certian people can't
understand the point of documenting such options with help text.

However, here we have a case in point: developers don't understand the
option either, as they were thinking that when the option is not set,
the decompressor should produce no output what so ever.  This is
incorrect, as the purpose of this option is to control whether a
multiplatform kernel uses the kernel debugging macros to produce
output or not.

So let's document this via help rather than commentry to prevent others
falling into this misunderstanding.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      b6992fa9
  5. 19 7月, 2013 18 次提交
  7. 18 7月, 2013 6 次提交
  9. 17 7月, 2013 3 次提交
  11. 16 7月, 2013 3 次提交
  13. 15 7月, 2013 1 次提交
    • P
      x86: delete __cpuinit usage from all x86 files · 148f9bb8
      由 Paul Gortmaker 提交于 
      The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications.  For example, the fix in
commit 5e427ec2 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.

After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out.  Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.

Note that some harmless section mismatch warnings may result, since
notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c)
are flagged as __cpuinit  -- so if we remove the __cpuinit from
arch specific callers, we will also get section mismatch warnings.
As an intermediate step, we intend to turn the linux/init.h cpuinit
content into no-ops as early as possible, since that will get rid
of these warnings.  In any case, they are temporary and harmless.

This removes all the arch/x86 uses of the __cpuinit macros from
all C files.  x86 only had the one __CPUINIT used in assembly files,
and it wasn't paired off with a .previous or a __FINIT, so we can
delete it directly w/o any corresponding additional change there.

[1] https://lkml.org/lkml/2013/5/20/589

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Acked-by: NIngo Molnar <mingo@kernel.org>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NH. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
      148f9bb8