Messages in this thread Patch in this message | | | From | Jiri Slaby <> | Subject | [PATCH 07/16] X86: use ACCESS_ONCE for rlimits | Date | Wed, 18 Nov 2009 15:51:53 +0100 |
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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
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