diff options
| author | John David Anglin <dave.anglin@bell.net> | 2012-12-28 23:18:01 (GMT) |
|---|---|---|
| committer | Helge Deller <deller@gmx.de> | 2013-01-07 22:06:27 (GMT) |
| commit | 34360f080cb5848990576e1465d2d01a3c261762 (patch) | |
| tree | 42103381d3b28801443b609a1f0bc9bf0001eaf7 | |
| parent | cac1f12b9f7409510a5abcf3eaecc2c56b75242a (diff) | |
| download | linux-34360f080cb5848990576e1465d2d01a3c261762.tar.xz | |
parisc: improve ptrace support for gdb single-step
Various GCC tests use gdb to simulate a multithreaded application. Many of
these tests have been failing on parisc linux.
GCC does this by using gdb to single-step the application, then gdb is used to
call other test specific code. Where this fails is when the application is
stepped into the delay slot of a taken branch. This sets the PSW B bit. When
the test specific code is executed, this usually clears the PSW B bit.
Currently, gdb is not allowed to set the B bit. So, the code falls through what
should be a taken branch.
The attached patch adds the PSW B bit to the set of bits that gdb is allowed to
set. In order to set the B bit, the trace system call must return using an
interrupt restore. The patch also modifies this code to use the saved IAOQ
values when they are saved by a ptrace syscall or interruption.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
| -rw-r--r-- | arch/parisc/kernel/entry.S | 18 | ||||
| -rw-r--r-- | arch/parisc/kernel/ptrace.c | 2 |
2 files changed, 14 insertions, 6 deletions
diff --git a/arch/parisc/kernel/entry.S b/arch/parisc/kernel/entry.S index bfb4424..eb7850b 100644 --- a/arch/parisc/kernel/entry.S +++ b/arch/parisc/kernel/entry.S @@ -1865,7 +1865,7 @@ syscall_restore: /* Are we being ptraced? */ ldw TASK_FLAGS(%r1),%r19 - ldi (_TIF_SINGLESTEP|_TIF_BLOCKSTEP),%r2 + ldi _TIF_SYSCALL_TRACE_MASK,%r2 and,COND(=) %r19,%r2,%r0 b,n syscall_restore_rfi @@ -1978,15 +1978,23 @@ syscall_restore_rfi: /* sr2 should be set to zero for userspace syscalls */ STREG %r0,TASK_PT_SR2(%r1) -pt_regs_ok: LDREG TASK_PT_GR31(%r1),%r2 - depi 3,31,2,%r2 /* ensure return to user mode. */ - STREG %r2,TASK_PT_IAOQ0(%r1) + depi 3,31,2,%r2 /* ensure return to user mode. */ + STREG %r2,TASK_PT_IAOQ0(%r1) ldo 4(%r2),%r2 STREG %r2,TASK_PT_IAOQ1(%r1) + b intr_restore copy %r25,%r16 + +pt_regs_ok: + LDREG TASK_PT_IAOQ0(%r1),%r2 + depi 3,31,2,%r2 /* ensure return to user mode. */ + STREG %r2,TASK_PT_IAOQ0(%r1) + LDREG TASK_PT_IAOQ1(%r1),%r2 + depi 3,31,2,%r2 + STREG %r2,TASK_PT_IAOQ1(%r1) b intr_restore - nop + copy %r25,%r16 .import schedule,code syscall_do_resched: diff --git a/arch/parisc/kernel/ptrace.c b/arch/parisc/kernel/ptrace.c index 857c2f5..534abd4 100644 --- a/arch/parisc/kernel/ptrace.c +++ b/arch/parisc/kernel/ptrace.c @@ -26,7 +26,7 @@ #include <asm/asm-offsets.h> /* PSW bits we allow the debugger to modify */ -#define USER_PSW_BITS (PSW_N | PSW_V | PSW_CB) +#define USER_PSW_BITS (PSW_N | PSW_B | PSW_V | PSW_CB) /* * Called by kernel/ptrace.c when detaching.. |