diff options
| author | Chris Metcalf <cmetcalf@tilera.com> | 2013-08-07 15:33:32 -0400 |
|---|---|---|
| committer | Chris Metcalf <cmetcalf@tilera.com> | 2013-08-13 16:26:21 -0400 |
| commit | 4a556f4f56da3110b27e265b79f0e7582115445c (patch) | |
| tree | f5af0b865c867160855e4722b49d7e850dddf944 /arch/tile/mm | |
| parent | 0c1d1917c547c8e787fb58e20e2de577453c980c (diff) | |
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.c | 37 |
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__ /* |