From d22e4cc9397ed41534c9422d0b0ffef8c77bfa53 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Sat, 7 Aug 2010 21:24:05 -0700 Subject: x86: Add support for frame pointer less mcount --- sysdeps/i386/i386-mcount.S | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) (limited to 'sysdeps/i386') diff --git a/sysdeps/i386/i386-mcount.S b/sysdeps/i386/i386-mcount.S index 8b11adb2e3..43bc0194dd 100644 --- a/sysdeps/i386/i386-mcount.S +++ b/sysdeps/i386/i386-mcount.S @@ -53,3 +53,28 @@ C_LABEL(_mcount) #undef mcount weak_alias (_mcount, mcount) + + /* Same as above, but doesn't require a frame pointer */ + ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME(__fentry__) + ASM_TYPE_DIRECTIVE(C_SYMBOL_NAME(__fentry__), @function) + .align ALIGNARG(4) +C_LABEL(__fentry__) + /* Save the caller-clobbered registers. */ + pushl %eax + pushl %ecx + pushl %edx + + movl 12(%esp), %edx + movl 16(%esp), %eax + + /* No need to access the PLT or GOT, __mcount_internal is an + internal function and we can make a relative call. */ + call C_SYMBOL_NAME(__mcount_internal) + + /* Pop the saved registers. Please note that `__fentry__' has no + return value. */ + popl %edx + popl %ecx + popl %eax + ret + ASM_SIZE_DIRECTIVE(C_SYMBOL_NAME(__fentry__)) -- cgit v1.2.3