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authorDave Airlie <airlied@redhat.com>2015-04-20 11:32:26 +1000
committerDave Airlie <airlied@redhat.com>2015-04-20 13:05:20 +1000
commit2c33ce009ca2389dbf0535d0672214d09738e35e (patch)
tree6186a6458c3c160385d794a23eaf07c786a9e61b /arch/x86/mm/mmap.c
parentcec32a47010647e8b0603726ebb75b990a4057a4 (diff)
parent09d51602cf84a1264946711dd4ea0dddbac599a1 (diff)
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Merge Linus master into drm-next
The merge is clean, but the arm build fails afterwards, due to API changes in the regulator tree. I've included the patch into the merge to fix the build. Signed-off-by: Dave Airlie <airlied@redhat.com>
Diffstat (limited to 'arch/x86/mm/mmap.c')
-rw-r--r--arch/x86/mm/mmap.c38
1 files changed, 21 insertions, 17 deletions
diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c
index df4552bd239e..9d518d693b4b 100644
--- a/arch/x86/mm/mmap.c
+++ b/arch/x86/mm/mmap.c
@@ -65,24 +65,23 @@ static int mmap_is_legacy(void)
return sysctl_legacy_va_layout;
}
-static unsigned long mmap_rnd(void)
+unsigned long arch_mmap_rnd(void)
{
- unsigned long rnd = 0;
+ unsigned long rnd;
/*
- * 8 bits of randomness in 32bit mmaps, 20 address space bits
- * 28 bits of randomness in 64bit mmaps, 40 address space bits
- */
- if (current->flags & PF_RANDOMIZE) {
- if (mmap_is_ia32())
- rnd = get_random_int() % (1<<8);
- else
- rnd = get_random_int() % (1<<28);
- }
+ * 8 bits of randomness in 32bit mmaps, 20 address space bits
+ * 28 bits of randomness in 64bit mmaps, 40 address space bits
+ */
+ if (mmap_is_ia32())
+ rnd = (unsigned long)get_random_int() % (1<<8);
+ else
+ rnd = (unsigned long)get_random_int() % (1<<28);
+
return rnd << PAGE_SHIFT;
}
-static unsigned long mmap_base(void)
+static unsigned long mmap_base(unsigned long rnd)
{
unsigned long gap = rlimit(RLIMIT_STACK);
@@ -91,19 +90,19 @@ static unsigned long mmap_base(void)
else if (gap > MAX_GAP)
gap = MAX_GAP;
- return PAGE_ALIGN(TASK_SIZE - gap - mmap_rnd());
+ return PAGE_ALIGN(TASK_SIZE - gap - rnd);
}
/*
* Bottom-up (legacy) layout on X86_32 did not support randomization, X86_64
* does, but not when emulating X86_32
*/
-static unsigned long mmap_legacy_base(void)
+static unsigned long mmap_legacy_base(unsigned long rnd)
{
if (mmap_is_ia32())
return TASK_UNMAPPED_BASE;
else
- return TASK_UNMAPPED_BASE + mmap_rnd();
+ return TASK_UNMAPPED_BASE + rnd;
}
/*
@@ -112,13 +111,18 @@ static unsigned long mmap_legacy_base(void)
*/
void arch_pick_mmap_layout(struct mm_struct *mm)
{
- mm->mmap_legacy_base = mmap_legacy_base();
- mm->mmap_base = mmap_base();
+ unsigned long random_factor = 0UL;
+
+ if (current->flags & PF_RANDOMIZE)
+ random_factor = arch_mmap_rnd();
+
+ mm->mmap_legacy_base = mmap_legacy_base(random_factor);
if (mmap_is_legacy()) {
mm->mmap_base = mm->mmap_legacy_base;
mm->get_unmapped_area = arch_get_unmapped_area;
} else {
+ mm->mmap_base = mmap_base(random_factor);
mm->get_unmapped_area = arch_get_unmapped_area_topdown;
}
}