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| author | Bernd Schmidt <bernds_cb1@t-online.de> | 2008-04-23 07:17:34 +0800 |
|---|---|---|
| committer | Bryan Wu <cooloney@kernel.org> | 2008-04-23 07:17:34 +0800 |
| commit | 2a0c4fdb6602ea066380aaf71ff7bb2f61ffeee8 (patch) | |
| tree | b77ed1db44e1d0948ac2ab8414066e365da21ddd /arch/blackfin/mach-common/entry.S | |
| parent | dbfe44f02b6855efb5a596e942ec2fd96d592f60 (diff) | |
| download | linux-2a0c4fdb6602ea066380aaf71ff7bb2f61ffeee8.tar.bz2 | |
[Blackfin] arch: fix bug - when using trace buffer with CONFIG_MPU enabled.
There were a couple of problems with the way the trace buffer state
is saved/restored in assembly. The DEBUG_HWTRACE_SAVE/RESTORE macros
save a value to the stack, which is not immediately obvious; the CPLB
exception code needed changes to load the correct value of the stack
pointer. The other problem is that the SAVE/RESTORE macros weren't
pushing and popping the value downwards on the stack, but rather moving
it _upwards_, which is of course completely broken.
We also need to make sure there's a matching DEBUG_HWTRACE_RESTORE in
the error case of the CPLB handler.
Signed-off-by: Bernd Schmidt <bernds_cb1@t-online.de>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Diffstat (limited to 'arch/blackfin/mach-common/entry.S')
| -rw-r--r-- | arch/blackfin/mach-common/entry.S | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/arch/blackfin/mach-common/entry.S b/arch/blackfin/mach-common/entry.S index cee54cebbc65..a504c65d9990 100644 --- a/arch/blackfin/mach-common/entry.S +++ b/arch/blackfin/mach-common/entry.S @@ -121,10 +121,14 @@ ENTRY(_ex_icplb_miss) (R7:6,P5:4) = [sp++]; ASTAT = [sp++]; SAVE_ALL_SYS - DEBUG_HWTRACE_SAVE(p5, r7) #ifdef CONFIG_MPU + /* We must load R1 here, _before_ DEBUG_HWTRACE_SAVE, since that + * will change the stack pointer. */ R0 = SEQSTAT; R1 = SP; +#endif + DEBUG_HWTRACE_SAVE(p5, r7) +#ifdef CONFIG_MPU sp += -12; call _cplb_hdr; sp += 12; @@ -191,6 +195,7 @@ ENTRY(_bfin_return_from_exception) ENDPROC(_bfin_return_from_exception) ENTRY(_handle_bad_cplb) + DEBUG_HWTRACE_RESTORE(p5, r7) /* To get here, we just tried and failed to change a CPLB * so, handle things in trap_c (C code), by lowering to * IRQ5, just like we normally do. Since this is not a |