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powerpc: Align vDSO base address

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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>
This commit is contained in:
Andreas Schwab 2009-10-04 02:35:41 +00:00 committed by Benjamin Herrenschmidt
parent 7de80284d6
commit 348aa30300
1 changed files with 10 additions and 1 deletions
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11
arch/powerpc/kernel/vdso.c
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@ -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 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
* 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