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authorChris Metcalf <cmetcalf@tilera.com>2013-08-07 15:33:32 -0400
committerChris Metcalf <cmetcalf@tilera.com>2013-08-13 16:26:21 -0400
commit4a556f4f56da3110b27e265b79f0e7582115445c (patch)
treef5af0b865c867160855e4722b49d7e850dddf944 /arch/tile/mm
parent0c1d1917c547c8e787fb58e20e2de577453c980c (diff)
downloadblackbird-op-linux-4a556f4f56da3110b27e265b79f0e7582115445c.tar.gz
blackbird-op-linux-4a556f4f56da3110b27e265b79f0e7582115445c.zip
tile: implement gettimeofday() via vDSO
This change creates the framework for vDSO calls, makes the existing rt_sigreturn() mechanism use it, and adds a fast gettimeofday(). Now that we need to expose the vDSO address to userspace, we add AT_SYSINFO_EHDR to the set of aux entries provided to userspace. (You can disable any extra vDSO support by booting with vdso=0, but the rt_sigreturn vDSO page will still be provided.) Note that glibc has supported the tile vDSO since release 2.17. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Diffstat (limited to 'arch/tile/mm')
-rw-r--r--arch/tile/mm/elf.c37
1 files changed, 2 insertions, 35 deletions
diff --git a/arch/tile/mm/elf.c b/arch/tile/mm/elf.c
index 1691b81b2b0c..23f044e8a7ab 100644
--- a/arch/tile/mm/elf.c
+++ b/arch/tile/mm/elf.c
@@ -21,6 +21,7 @@
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/sections.h>
+#include <asm/vdso.h>
#include <arch/sim.h>
/* Notify a running simulator, if any, that an exec just occurred. */
@@ -102,37 +103,10 @@ static void sim_notify_interp(unsigned long load_addr)
}
-/* Kernel address of page used to map read-only kernel data into userspace. */
-static void *vdso_page;
-
-/* One-entry array used for install_special_mapping. */
-static struct page *vdso_pages[1];
-
-static int __init vdso_setup(void)
-{
- vdso_page = (void *)get_zeroed_page(GFP_ATOMIC);
- memcpy(vdso_page, __rt_sigreturn, __rt_sigreturn_end - __rt_sigreturn);
- vdso_pages[0] = virt_to_page(vdso_page);
- return 0;
-}
-device_initcall(vdso_setup);
-
-const char *arch_vma_name(struct vm_area_struct *vma)
-{
- if (vma->vm_private_data == vdso_pages)
- return "[vdso]";
-#ifndef __tilegx__
- if (vma->vm_start == MEM_USER_INTRPT)
- return "[intrpt]";
-#endif
- return NULL;
-}
-
int arch_setup_additional_pages(struct linux_binprm *bprm,
int executable_stack)
{
struct mm_struct *mm = current->mm;
- unsigned long vdso_base;
int retval = 0;
down_write(&mm->mmap_sem);
@@ -145,14 +119,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm,
if (!notify_exec(mm))
sim_notify_exec(bprm->filename);
- /*
- * MAYWRITE to allow gdb to COW and set breakpoints
- */
- vdso_base = VDSO_BASE;
- retval = install_special_mapping(mm, vdso_base, PAGE_SIZE,
- VM_READ|VM_EXEC|
- VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
- vdso_pages);
+ retval = setup_vdso_pages();
#ifndef __tilegx__
/*
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