lkml.org 
[lkml]   [2009]   [Nov]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 07/16] X86: use ACCESS_ONCE for rlimits
    Date
    Make sure compiler won't do weird things with limits. E.g. fetching
    them twice may return 2 different values after writable limits are
    implemented.

    Signed-off-by: Jiri Slaby <jslaby@novell.com>
    Cc: James Morris <jmorris@namei.org>
    Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
    Cc: Andrew Morton <akpm@linux-foundation.org>
    Cc: Ingo Molnar <mingo@elte.hu>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: "H. Peter Anvin" <hpa@zytor.com>
    Cc: x86@kernel.org
    ---
    arch/x86/ia32/ia32_aout.c | 2 +-
    arch/x86/mm/mmap.c | 6 ++++--
    2 files changed, 5 insertions(+), 3 deletions(-)

    diff --git a/arch/x86/ia32/ia32_aout.c b/arch/x86/ia32/ia32_aout.c
    index 2a4d073..239071b 100644
    --- a/arch/x86/ia32/ia32_aout.c
    +++ b/arch/x86/ia32/ia32_aout.c
    @@ -297,7 +297,7 @@ static int load_aout_binary(struct linux_binprm *bprm, struct pt_regs *regs)
    * size limits imposed on them by creating programs with large
    * arrays in the data or bss.
    */
    - rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur;
    + rlim = ACCESS_ONCE(current->signal->rlim[RLIMIT_DATA].rlim_cur);
    if (rlim >= RLIM_INFINITY)
    rlim = ~0;
    if (ex.a_data + ex.a_bss > rlim)
    diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c
    index c8191de..5578c84 100644
    --- a/arch/x86/mm/mmap.c
    +++ b/arch/x86/mm/mmap.c
    @@ -71,7 +71,8 @@ static int mmap_is_legacy(void)
    if (current->personality & ADDR_COMPAT_LAYOUT)
    return 1;

    - if (current->signal->rlim[RLIMIT_STACK].rlim_cur == RLIM_INFINITY)
    + if (ACCESS_ONCE(current->signal->rlim[RLIMIT_STACK].rlim_cur)
    + == RLIM_INFINITY)
    return 1;

    return sysctl_legacy_va_layout;
    @@ -96,7 +97,8 @@ static unsigned long mmap_rnd(void)

    static unsigned long mmap_base(void)
    {
    - unsigned long gap = current->signal->rlim[RLIMIT_STACK].rlim_cur;
    + unsigned long gap =
    + ACCESS_ONCE(current->signal->rlim[RLIMIT_STACK].rlim_cur);

    if (gap < MIN_GAP)
    gap = MIN_GAP;
    --
    1.6.4.2


    \
     
     \ /
      Last update: 2009-11-18 15:55    [W:2.515 / U:0.072 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site