From 4a556f4f56da3110b27e265b79f0e7582115445c Mon Sep 17 00:00:00 2001 From: Chris Metcalf Date: Wed, 7 Aug 2013 15:33:32 -0400 Subject: 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 --- arch/tile/kernel/stack.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'arch/tile/kernel/stack.c') 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 #include #include +#include #include #include @@ -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(); -- cgit v1.2.3