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authorJohn David Anglin <dave.anglin@bell.net>2012-12-28 23:18:01 +0000
committerHelge Deller <deller@gmx.de>2013-01-07 23:06:27 +0100
commit34360f080cb5848990576e1465d2d01a3c261762 (patch)
tree42103381d3b28801443b609a1f0bc9bf0001eaf7 /arch/parisc
parentcac1f12b9f7409510a5abcf3eaecc2c56b75242a (diff)
downloadtalos-obmc-linux-34360f080cb5848990576e1465d2d01a3c261762.tar.gz
talos-obmc-linux-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')
-rw-r--r--arch/parisc/kernel/entry.S18
-rw-r--r--arch/parisc/kernel/ptrace.c2
2 files changed, 14 insertions, 6 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:
diff --git a/arch/parisc/kernel/ptrace.c b/arch/parisc/kernel/ptrace.c
index 857c2f545470..534abd4936e1 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..
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