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| author |   John David Anglin <dave.anglin@bell.net> | 2012-12-28 23:18:01 +0000 |
|---|---|---|
| committer |   Helge Deller <deller@gmx.de> | 2013-01-07 23:06:27 +0100 |
| commit | 34360f080cb5848990576e1465d2d01a3c261762 (patch) | |
| tree | 42103381d3b28801443b609a1f0bc9bf0001eaf7 /arch/parisc/kernel/entry.S | |
| parent | parisc: don't claim cpu irqs more than once (diff) | |
| download | linux-dev-34360f080cb5848990576e1465d2d01a3c261762.tar.xz linux-dev-34360f080cb5848990576e1465d2d01a3c261762.zip | |
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>
Diffstat (limited to 'arch/parisc/kernel/entry.S')
| -rw-r--r-- | arch/parisc/kernel/entry.S | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/arch/parisc/kernel/entry.S b/arch/parisc/kernel/entry.S index bfb44247d7a7..eb7850b46c25 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: |