powerpc: Align vDSO base address
The ABI specifies a 64K alignment, we need to map the vDSO accordingly
Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c
index 94e2df3..137dc22 100644
--- a/arch/powerpc/kernel/vdso.c
+++ b/arch/powerpc/kernel/vdso.c
@@ -50,6 +50,9 @@
/* Max supported size for symbol names */
#define MAX_SYMNAME 64
+/* The alignment of the vDSO */
+#define VDSO_ALIGNMENT (1 << 16)
+
extern char vdso32_start, vdso32_end;
static void *vdso32_kbase = &vdso32_start;
static unsigned int vdso32_pages;
@@ -231,15 +234,21 @@
* pick a base address for the vDSO in process space. We try to put it
* at vdso_base which is the "natural" base for it, but we might fail
* and end up putting it elsewhere.
+ * Add enough to the size so that the result can be aligned.
*/
down_write(&mm->mmap_sem);
vdso_base = get_unmapped_area(NULL, vdso_base,
- vdso_pages << PAGE_SHIFT, 0, 0);
+ (vdso_pages << PAGE_SHIFT) +
+ ((VDSO_ALIGNMENT - 1) & PAGE_MASK),
+ 0, 0);
if (IS_ERR_VALUE(vdso_base)) {
rc = vdso_base;
goto fail_mmapsem;
}
+ /* Add required alignment. */
+ vdso_base = ALIGN(vdso_base, VDSO_ALIGNMENT);
+
/*
* Put vDSO base into mm struct. We need to do this before calling
* install_special_mapping or the perf counter mmap tracking code