lkml.org 
[lkml]   [2009]   [Aug]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    SubjectRe: [patch] Fix vdso32 relocation for paddr
    From
    On Thu, Aug 27, 2009 at 6:31 AM, Jan
    Kratochvil<jan.kratochvil@redhat.com> wrote:
    > Hi,
    >
    > `readelf -Wl file-dumped-from-/proc/self/maps-[vdso]' for x86_64 process prints:
    > Program Headers:
    >  Type           Offset   VirtAddr           PhysAddr           FileSiz  MemSiz   Flg Align
    >  LOAD           0x000000 0xffffffffff700000 0xffffffffff700000 0x000890 0x000890 R E 0x1000
    >  DYNAMIC        0x000410 0xffffffffff700410 0xffffffffff700410 0x0000f0 0x0000f0 R   0x8
    >  NOTE           0x0002d0 0xffffffffff7002d0 0xffffffffff7002d0 0x00003c 0x00003c R   0x4
    >  GNU_EH_FRAME   0x00030c 0xffffffffff70030c 0xffffffffff70030c 0x000034 0x000034 R   0x4
    >
    > while such dump for i386 process prints:
    > Program Headers:
    >  Type           Offset   VirtAddr   PhysAddr   FileSiz MemSiz  Flg Align
    >  LOAD           0x000000 0xffffe000 0x00000000 0x00434 0x00434 R E 0x1000
    >  DYNAMIC        0x000350 0xffffe350 0x00000350 0x00078 0x00078 R   0x4
    >  NOTE           0x0001c4 0xffffe1c4 0x000001c4 0x00060 0x00060 R   0x4
    >  GNU_EH_FRAME   0x000224 0xffffe224 0x00000224 0x00024 0x00024 R   0x4
    >
    > The mapped location can be arbirary (according to the rules of PIC - Position
    > Independent Code) but currently the i386 vdso (vdso32) looks as an overlayed
    > code as it has LMA != VMA (rule contained in GDB function section_is_overlay,
    > as suggested by Daniel Jacobowitz).
    >
    > Fixed vdso32 prints:
    > Program Headers:
    >  Type           Offset   VirtAddr   PhysAddr   FileSiz MemSiz  Flg Align
    >  LOAD           0x000000 0xffffe000 0xffffe000 0x00434 0x00434 R E 0x1000
    >  DYNAMIC        0x000350 0xffffe350 0xffffe350 0x00078 0x00078 R   0x4
    >  NOTE           0x0001c4 0xffffe1c4 0xffffe1c4 0x00060 0x00060 R   0x4
    >  GNU_EH_FRAME   0x000224 0xffffe224 0xffffe224 0x00024 0x00024 R   0x4
    >
    > It required now a workaround in GDB patch so at least to fix it in Linux kernel:
    >        http://sourceware.org/ml/gdb-patches/2009-08/msg00437.html
    >
    >

    Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com>

    This patch looks fine for me. But I think we should hear from Roland.
    Roland?


    > Thanks,
    > Jan
    >
    >
    > Signed-off-by: Jan Kratochvil <jan.kratochvil@redhat.com>
    >
    > --- linux-2.6.30.x86_64/arch/x86/vdso/vdso32-setup.c-orig       2009-08-26 22:23:08.000000000 +0200
    > +++ linux-2.6.30.x86_64/arch/x86/vdso/vdso32-setup.c    2009-08-26 22:38:10.000000000 +0200
    > @@ -172,6 +172,7 @@ static __init void relocate_vdso(Elf32_E
    >        phdr = (void *)ehdr + ehdr->e_phoff;
    >        for (i = 0; i < ehdr->e_phnum; i++) {
    >                phdr[i].p_vaddr += VDSO_ADDR_ADJUST;
    > +               phdr[i].p_paddr += VDSO_ADDR_ADJUST;
    >
    >                /* relocate dynamic stuff */
    >                if (phdr[i].p_type == PT_DYNAMIC)
    > --
    > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    > the body of a message to majordomo@vger.kernel.org
    > More majordomo info at  http://vger.kernel.org/majordomo-info.html
    > Please read the FAQ at  http://www.tux.org/lkml/
    >
    --
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2009-08-28 11:17    [W:0.024 / U:180.100 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site