diff options
| author | David S. Miller <davem@davemloft.net> | 2010-04-06 19:59:46 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-04-12 22:37:15 -0700 |
| commit | a71d1d6bb1b26e566e5c06c37857f4cdc1664780 (patch) | |
| tree | 5b982f3bd77f47ef6ebbd2a9529a4efcb1df106e /arch/sparc/lib | |
| parent | daecbf58a509bc27c112647e825df763c3e3b0f4 (diff) | |
| download | lwn-a71d1d6bb1b26e566e5c06c37857f4cdc1664780.tar.gz lwn-a71d1d6bb1b26e566e5c06c37857f4cdc1664780.zip | |
sparc64: Give a stack frame to the ftrace call sites.
It's the only way we'll be able to implement the function
graph tracer properly.
A positive is that we no longer have to worry about the
linker over-optimizing the tail call, since we don't
use a tail call any more.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/sparc/lib')
| -rw-r--r-- | arch/sparc/lib/mcount.S | 31 |
1 files changed, 16 insertions, 15 deletions
diff --git a/arch/sparc/lib/mcount.S b/arch/sparc/lib/mcount.S index 73ed0f3aaa0c..153c80e62cf1 100644 --- a/arch/sparc/lib/mcount.S +++ b/arch/sparc/lib/mcount.S @@ -33,9 +33,13 @@ mcount: or %g2, %lo(ftrace_stub), %g2 cmp %g1, %g2 be,pn %icc, 1f - mov %i7, %o1 - jmpl %g1, %g0 - mov %o7, %o0 + mov %i7, %g2 + save %sp, -128, %sp + mov %g2, %o1 + jmpl %g1, %o7 + mov %i7, %o0 + ret + restore /* not reached */ 1: #endif @@ -57,21 +61,18 @@ ftrace_stub: .type ftrace_caller,#function ftrace_caller: sethi %hi(function_trace_stop), %g1 - mov %i7, %o1 - lduw [%g1 + %lo(function_trace_stop)], %g2 - brnz,pn %g2, ftrace_stub - mov %o7, %o0 + mov %i7, %g2 + lduw [%g1 + %lo(function_trace_stop)], %g3 + brnz,pn %g3, ftrace_stub + nop + save %sp, -128, %sp + mov %g2, %o1 .globl ftrace_call ftrace_call: - /* If the final kernel link ever turns on relaxation, we'll need - * to do something about this tail call. Otherwise the linker - * will rewrite the call into a branch and nop out the move - * instruction. - */ call ftrace_stub - mov %o0, %o7 - retl - nop + mov %i7, %o0 + ret + restore .size ftrace_call,.-ftrace_call .size ftrace_caller,.-ftrace_caller #endif |