diff options
| author | Tony Lu <zlu@ezchip.com> | 2015-03-27 14:46:38 -0400 |
|---|---|---|
| committer | Chris Metcalf <cmetcalf@ezchip.com> | 2015-04-17 14:01:38 -0400 |
| commit | 437d3e124d25daaa671bfecfd4015ecd2503a955 (patch) | |
| tree | ddc6e9491b9a14a09c6476d0543e9f4896dfd77d /arch/tile/kernel | |
| parent | a84f24230c137a4e0ab14185e9175798ca1b0376 (diff) | |
| download | lwn-437d3e124d25daaa671bfecfd4015ecd2503a955.tar.gz lwn-437d3e124d25daaa671bfecfd4015ecd2503a955.zip | |
tile: ftrace: fix function_graph tracer issues
- Add support for ARCH_SUPPORTS_FTRACE_OPS
- Replace the instruction in ftrace_call with the bundle {move r10, lr;
jal ftrace_stub}, so that the lr contains the right value after returning
from ftrace_stub. An alternative fix might be to leave the instruction
in ftrace_call alone when it is being updated with ftrace_stub.
Signed-off-by: Tony Lu <zlu@ezchip.com>
Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
Diffstat (limited to 'arch/tile/kernel')
| -rw-r--r-- | arch/tile/kernel/ftrace.c | 6 | ||||
| -rw-r--r-- | arch/tile/kernel/mcount_64.S | 7 |
2 files changed, 11 insertions, 2 deletions
diff --git a/arch/tile/kernel/ftrace.c b/arch/tile/kernel/ftrace.c index 8d52d83cc516..0c0996175b1e 100644 --- a/arch/tile/kernel/ftrace.c +++ b/arch/tile/kernel/ftrace.c @@ -74,7 +74,11 @@ static unsigned long ftrace_gen_branch(unsigned long pc, unsigned long addr, create_JumpOff_X1(pcrel_by_instr); } - if (addr == FTRACE_ADDR) { + /* + * Also put { move r10, lr; jal ftrace_stub } in a bundle, which + * is used to replace the instruction in address ftrace_call. + */ + if (addr == FTRACE_ADDR || addr == (unsigned long)ftrace_stub) { /* opcode: or r10, lr, zero */ opcode_x0 = create_Dest_X0(10) | diff --git a/arch/tile/kernel/mcount_64.S b/arch/tile/kernel/mcount_64.S index 3c2b8d5e1d1a..6c6702451962 100644 --- a/arch/tile/kernel/mcount_64.S +++ b/arch/tile/kernel/mcount_64.S @@ -81,7 +81,12 @@ STD_ENTRY(ftrace_caller) /* arg1: self return address */ /* arg2: parent's return address */ - { move r0, lr; move r1, r10 } + /* arg3: ftrace_ops */ + /* arg4: regs (but make it NULL) */ + { move r0, lr; moveli r2, hw2_last(function_trace_op) } + { move r1, r10; shl16insli r2, r2, hw1(function_trace_op) } + { movei r3, 0; shl16insli r2, r2, hw0(function_trace_op) } + ld r2,r2 .global ftrace_call ftrace_call: |