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| author | Chris Metcalf <cmetcalf@tilera.com> | 2013-08-07 21:33:32 +0200 |
|---|---|---|
| committer | Chris Metcalf <cmetcalf@tilera.com> | 2013-08-13 22:26:21 +0200 |
| commit | 4a556f4f56da3110b27e265b79f0e7582115445c (patch) | |
| tree | f5af0b865c867160855e4722b49d7e850dddf944 /arch/tile/kernel/stack.c | |
| parent | tile: support simulator notification for ET_DYN objects (diff) | |
| download | linux-4a556f4f56da3110b27e265b79f0e7582115445c.tar.xz 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/kernel/stack.c')
| -rw-r--r-- | arch/tile/kernel/stack.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/tile/kernel/stack.c b/arch/tile/kernel/stack.c index 176ffe48eee9..a9db923bb9eb 100644 --- a/arch/tile/kernel/stack.c +++ b/arch/tile/kernel/stack.c @@ -29,6 +29,7 @@ #include <asm/switch_to.h> #include <asm/sigframe.h> #include <asm/stack.h> +#include <asm/vdso.h> #include <arch/abi.h> #include <arch/interrupts.h> @@ -119,7 +120,7 @@ static struct pt_regs *valid_fault_handler(struct KBacktraceIterator* kbt) /* Is the pc pointing to a sigreturn trampoline? */ static int is_sigreturn(unsigned long pc) { - return (pc == VDSO_BASE); + return current->mm && (pc == VDSO_SYM(&__vdso_rt_sigreturn)); } /* Return a pt_regs pointer for a valid signal handler frame */ @@ -128,7 +129,7 @@ static struct pt_regs *valid_sigframe(struct KBacktraceIterator* kbt, { BacktraceIterator *b = &kbt->it; - if (b->pc == VDSO_BASE && b->sp < PAGE_OFFSET && + if (is_sigreturn(b->pc) && b->sp < PAGE_OFFSET && b->sp % sizeof(long) == 0) { int retval; pagefault_disable(); |