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authorMartin Schwidefsky <schwidefsky@de.ibm.com>2013-12-17 13:41:31 +0100
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2013-12-18 17:36:38 +0100
commit9efe4f2992025c3a4027c60bf36ae9d710ca3781 (patch)
tree599ce2a4d390994a52df0edc122495b0db1359c8 /arch/s390/kernel/process.c
parent61aa4884b70cdf3b2d373e18ebbbada43789eade (diff)
downloadlinux-9efe4f2992025c3a4027c60bf36ae9d710ca3781.tar.bz2
s390/mm: optimize randomize_et_dyn for !PF_RANDOMIZE
Skip the call to brk_rnd() if the PF_RANDOMIZE flag is not set for the process. This avoids the costly get_random_int() call. Modify arch_randomize_brk() as well to make it look like randomize_et_dyn(). Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/kernel/process.c')
-rw-r--r--arch/s390/kernel/process.c14
1 files changed, 6 insertions, 8 deletions
diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
index 7ed0d4e2a435..dd145321d215 100644
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -261,20 +261,18 @@ static inline unsigned long brk_rnd(void)
unsigned long arch_randomize_brk(struct mm_struct *mm)
{
- unsigned long ret = PAGE_ALIGN(mm->brk + brk_rnd());
+ unsigned long ret;
- if (ret < mm->brk)
- return mm->brk;
- return ret;
+ ret = PAGE_ALIGN(mm->brk + brk_rnd());
+ return (ret > mm->brk) ? ret : mm->brk;
}
unsigned long randomize_et_dyn(unsigned long base)
{
- unsigned long ret = PAGE_ALIGN(base + brk_rnd());
+ unsigned long ret;
if (!(current->flags & PF_RANDOMIZE))
return base;
- if (ret < base)
- return base;
- return ret;
+ ret = PAGE_ALIGN(base + brk_rnd());
+ return (ret > base) ? ret : base;
}