1. 26 3月, 2013 2 次提交
  2. 14 3月, 2013 3 次提交
  3. 08 3月, 2013 1 次提交
    • I
      ARM: 7668/1: fix memset-related crashes caused by recent GCC (4.7.2) optimizations · 455bd4c4
      Ivan Djelic 提交于
      Recent GCC versions (e.g. GCC-4.7.2) perform optimizations based on
      assumptions about the implementation of memset and similar functions.
      The current ARM optimized memset code does not return the value of
      its first argument, as is usually expected from standard implementations.
      
      For instance in the following function:
      
      void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter)
      {
      	memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter));
      	waiter->magic = waiter;
      	INIT_LIST_HEAD(&waiter->list);
      }
      
      compiled as:
      
      800554d0 <debug_mutex_lock_common>:
      800554d0:       e92d4008        push    {r3, lr}
      800554d4:       e1a00001        mov     r0, r1
      800554d8:       e3a02010        mov     r2, #16 ; 0x10
      800554dc:       e3a01011        mov     r1, #17 ; 0x11
      800554e0:       eb04426e        bl      80165ea0 <memset>
      800554e4:       e1a03000        mov     r3, r0
      800554e8:       e583000c        str     r0, [r3, #12]
      800554ec:       e5830000        str     r0, [r3]
      800554f0:       e5830004        str     r0, [r3, #4]
      800554f4:       e8bd8008        pop     {r3, pc}
      
      GCC assumes memset returns the value of pointer 'waiter' in register r0; causing
      register/memory corruptions.
      
      This patch fixes the return value of the assembly version of memset.
      It adds a 'mov' instruction and merges an additional load+store into
      existing load/store instructions.
      For ease of review, here is a breakdown of the patch into 4 simple steps:
      
      Step 1
      ======
      Perform the following substitutions:
      ip -> r8, then
      r0 -> ip,
      and insert 'mov ip, r0' as the first statement of the function.
      At this point, we have a memset() implementation returning the proper result,
      but corrupting r8 on some paths (the ones that were using ip).
      
      Step 2
      ======
      Make sure r8 is saved and restored when (! CALGN(1)+0) == 1:
      
      save r8:
      -       str     lr, [sp, #-4]!
      +       stmfd   sp!, {r8, lr}
      
      and restore r8 on both exit paths:
      -       ldmeqfd sp!, {pc}               @ Now <64 bytes to go.
      +       ldmeqfd sp!, {r8, pc}           @ Now <64 bytes to go.
      (...)
              tst     r2, #16
              stmneia ip!, {r1, r3, r8, lr}
      -       ldr     lr, [sp], #4
      +       ldmfd   sp!, {r8, lr}
      
      Step 3
      ======
      Make sure r8 is saved and restored when (! CALGN(1)+0) == 0:
      
      save r8:
      -       stmfd   sp!, {r4-r7, lr}
      +       stmfd   sp!, {r4-r8, lr}
      
      and restore r8 on both exit paths:
              bgt     3b
      -       ldmeqfd sp!, {r4-r7, pc}
      +       ldmeqfd sp!, {r4-r8, pc}
      (...)
              tst     r2, #16
              stmneia ip!, {r4-r7}
      -       ldmfd   sp!, {r4-r7, lr}
      +       ldmfd   sp!, {r4-r8, lr}
      
      Step 4
      ======
      Rewrite register list "r4-r7, r8" as "r4-r8".
      Signed-off-by: NIvan Djelic <ivan.djelic@parrot.com>
      Reviewed-by: NNicolas Pitre <nico@linaro.org>
      Signed-off-by: NDirk Behme <dirk.behme@gmail.com>
      Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      455bd4c4
  4. 07 3月, 2013 2 次提交
    • S
      ARM: 7667/1: perf: Fix section mismatch on armpmu_init() · 44d6b1fc
      Stephen Boyd 提交于
      WARNING: vmlinux.o(.text+0xfb80): Section mismatch in reference
      from the function armpmu_register() to the function
      .init.text:armpmu_init()
      The function armpmu_register() references
      the function __init armpmu_init().
      This is often because armpmu_register lacks a __init
      annotation or the annotation of armpmu_init is wrong.
      
      Just drop the __init marking on armpmu_init() because
      armpmu_register() no longer has an __init marking.
      Acked-by: NWill Deacon <will.deacon@arm.com>
      Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
      Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      44d6b1fc
    • J
      ARM: 7666/1: decompressor: add -mno-single-pic-base for building the decompressor · b8083f86
      Jonathan Austin 提交于
      Before jumping to (position independent) C-code from the decompressor's
      assembler world we set-up the C environment. This setup currently does not
      set r9, which for arm-none-uclinux-uclibceabi toolchains is by default
      expected to be the PIC offset base register (IE should point to the
      beginning of the GOT).
      
      Currently, therefore, in order to build working kernels that use the
      decompressor it is necessary to use an arm-linux-gnueabi toolchain, or
      similar. uClinux toolchains cause a prefetch abort to occur at the beginning
      of the decompress_kernel function.
      
      This patch allows uClinux toolchains to build bootable zImages by forcing
      the -mno-single-pic-base option, which ensures that the location of the GOT
      is re-derived each time it is required, and r9 becomes free for use as a
      general purpose register.
      
      This has a small (4% in instruction terms) advantage over the alternative of
      setting r9 to point to the GOT before calling into the C-world.
      Signed-off-by: NJonathan Austin <jonathan.austin@arm.com>
      Acked-by: NNicolas Pitre <nico@linaro.org>
      Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      b8083f86
  5. 04 3月, 2013 12 次提交
  6. 02 3月, 2013 1 次提交
    • R
      ARM: Fix broken commit 0cc41e4a corrupting kernel messages · ded3ef0f
      Russell King 提交于
      Commit 0cc41e4a (arch: remove direct definitions of KERN_<LEVEL>
      uses) is broken - not enough thought was put into changing:
      
      	.asciz	"string"
      
      to
      
      	.asciz	"string1" "string2"
      
      The problem is that each string gets _separately_ NUL terminated, so
      the result is a string containing:
      
      	"string1\0string2\0"
      
      rather than:
      
      	"string1string2\0"
      
      With our new printk levels, this ends up as - eg, KERN_DEBUG "string":
      
      	0x01 0x00 0x07 0x00 "string" 0x00
      
      which produces lots of \x01 in the kernel log.
      Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      ded3ef0f
  7. 01 3月, 2013 19 次提交