lkml.org 
[lkml]   [2007]   [Jan]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 1/11] Fix CONFIG_COMPAT_VDSO
    Date

    I wouldn't mind if CONFIG_COMPAT_VDSO went away entirely.
    But if it's there, it should work properly. Currently
    it's quite haphazard: both real vma and fixmap are
    mapped, both are put in the two different AT_* slots,
    sysenter returns to the vma address rather than the
    fixmap address, and core dumps yet are another story.

    This patch makes CONFIG_COMPAT_VDSO disable the real vma
    and use the fixmap area consistently. This makes it
    actually compatible with what the old vdso implementation did.

    Signed-off-by: Roland McGrath <roland@redhat.com>
    ---
    arch/i386/kernel/entry.S | 4 ++++
    arch/i386/kernel/sysenter.c | 2 ++
    include/asm-i386/elf.h | 7 +++----
    include/asm-i386/fixmap.h | 2 ++
    include/asm-i386/page.h | 2 ++
    5 files changed, 13 insertions(+), 4 deletions(-)

    diff --git a/arch/i386/kernel/entry.S b/arch/i386/kernel/entry.S
    index 06461b8..5e47683 100644
    --- a/arch/i386/kernel/entry.S
    +++ b/arch/i386/kernel/entry.S
    @@ -302,12 +302,16 @@ sysenter_past_esp:
    pushl $(__USER_CS)
    CFI_ADJUST_CFA_OFFSET 4
    /*CFI_REL_OFFSET cs, 0*/
    +#ifndef CONFIG_COMPAT_VDSO
    /*
    * Push current_thread_info()->sysenter_return to the stack.
    * A tiny bit of offset fixup is necessary - 4*4 means the 4 words
    * pushed above; +8 corresponds to copy_thread's esp0 setting.
    */
    pushl (TI_sysenter_return-THREAD_SIZE+8+4*4)(%esp)
    +#else
    + pushl $SYSENTER_RETURN
    +#endif
    CFI_ADJUST_CFA_OFFSET 4
    CFI_REL_OFFSET eip, 0

    diff --git a/arch/i386/kernel/sysenter.c b/arch/i386/kernel/sysenter.c
    index 7de9117..454d12d 100644
    --- a/arch/i386/kernel/sysenter.c
    +++ b/arch/i386/kernel/sysenter.c
    @@ -100,6 +100,7 @@ int __init sysenter_setup(void)
    return 0;
    }

    +#ifndef CONFIG_COMPAT_VDSO
    static struct page *syscall_nopage(struct vm_area_struct *vma,
    unsigned long adr, int *type)
    {
    @@ -187,3 +188,4 @@ int in_gate_area_no_task(unsigned long a
    {
    return 0;
    }
    +#endif
    diff --git a/include/asm-i386/elf.h b/include/asm-i386/elf.h
    index 45d21a0..0515d61 100644
    --- a/include/asm-i386/elf.h
    +++ b/include/asm-i386/elf.h
    @@ -143,11 +143,8 @@ extern int dump_task_extended_fpu (struc
    # define VDSO_PRELINK 0
    #endif

    -#define VDSO_COMPAT_SYM(x) \
    - (VDSO_COMPAT_BASE + (unsigned long)(x) - VDSO_PRELINK)
    -
    #define VDSO_SYM(x) \
    - (VDSO_BASE + (unsigned long)(x) - VDSO_PRELINK)
    + (VDSO_COMPAT_BASE + (unsigned long)(x) - VDSO_PRELINK)

    #define VDSO_HIGH_EHDR ((const struct elfhdr *) VDSO_HIGH_BASE)
    #define VDSO_EHDR ((const struct elfhdr *) VDSO_COMPAT_BASE)
    @@ -156,10 +153,12 @@ extern void __kernel_vsyscall;

    #define VDSO_ENTRY VDSO_SYM(&__kernel_vsyscall)

    +#ifndef CONFIG_COMPAT_VDSO
    #define ARCH_HAS_SETUP_ADDITIONAL_PAGES
    struct linux_binprm;
    extern int arch_setup_additional_pages(struct linux_binprm *bprm,
    int executable_stack);
    +#endif

    extern unsigned int vdso_enabled;

    diff --git a/include/asm-i386/fixmap.h b/include/asm-i386/fixmap.h
    index 02428cb..3e9f610 100644
    --- a/include/asm-i386/fixmap.h
    +++ b/include/asm-i386/fixmap.h
    @@ -23,6 +23,8 @@
    extern unsigned long __FIXADDR_TOP;
    #else
    #define __FIXADDR_TOP 0xfffff000
    +#define FIXADDR_USER_START __fix_to_virt(FIX_VDSO)
    +#define FIXADDR_USER_END __fix_to_virt(FIX_VDSO - 1)
    #endif

    #ifndef __ASSEMBLY__
    diff --git a/include/asm-i386/page.h b/include/asm-i386/page.h
    index fd3f64a..7b19f45 100644
    --- a/include/asm-i386/page.h
    +++ b/include/asm-i386/page.h
    @@ -143,7 +143,9 @@ extern int page_is_ram(unsigned long pag
    #include <asm-generic/memory_model.h>
    #include <asm-generic/page.h>

    +#ifndef CONFIG_COMPAT_VDSO
    #define __HAVE_ARCH_GATE_AREA 1
    +#endif
    #endif /* __KERNEL__ */

    #endif /* _I386_PAGE_H */
    -
    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: 2007-01-14 06:55    [W:0.023 / U:2.144 seconds]
    ©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site