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authorMartin Schwidefsky <schwidefsky@de.ibm.com>2008-11-27 11:05:55 +0100
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2008-11-27 11:06:56 +0100
commit59da21398e680e8100625d689c8bebee6a139e93 (patch)
tree7d93f87d2942dac06367af8b3a269e9f6d557b29 /arch/s390/include/asm/syscall.h
parented313489badef16d700f5a3be50e8fd8f8294bc8 (diff)
downloadlinux-sh-59da21398e680e8100625d689c8bebee6a139e93.tar.gz
[S390] fix system call parameter functions.
syscall_get_nr() currently returns a valid result only if the call chain of the traced process includes do_syscall_trace_enter(). But collect_syscall() can be called for any sleeping task, the result of syscall_get_nr() in general is completely bogus. To make syscall_get_nr() work for any sleeping task the traps field in pt_regs is replace with svcnr - the system call number the process is executing. If svcnr == 0 the process is not on a system call path. The syscall_get_arguments and syscall_set_arguments use regs->gprs[2] for the first system call parameter. This is incorrect since gprs[2] may have been overwritten with the system call number if the call chain includes do_syscall_trace_enter. Use regs->orig_gprs2 instead. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/include/asm/syscall.h')
-rw-r--r--arch/s390/include/asm/syscall.h28
1 files changed, 16 insertions, 12 deletions
diff --git a/arch/s390/include/asm/syscall.h b/arch/s390/include/asm/syscall.h
index 6e623971fbb9..2429b87eb28d 100644
--- a/arch/s390/include/asm/syscall.h
+++ b/arch/s390/include/asm/syscall.h
@@ -17,9 +17,7 @@
static inline long syscall_get_nr(struct task_struct *task,
struct pt_regs *regs)
{
- if (regs->trap != __LC_SVC_OLD_PSW)
- return -1;
- return regs->gprs[2];
+ return regs->svcnr ? regs->svcnr : -1;
}
static inline void syscall_rollback(struct task_struct *task,
@@ -52,18 +50,20 @@ static inline void syscall_get_arguments(struct task_struct *task,
unsigned int i, unsigned int n,
unsigned long *args)
{
+ unsigned long mask = -1UL;
+
BUG_ON(i + n > 6);
#ifdef CONFIG_COMPAT
- if (test_tsk_thread_flag(task, TIF_31BIT)) {
- if (i + n == 6)
- args[--n] = (u32) regs->args[0];
- while (n-- > 0)
- args[n] = (u32) regs->gprs[2 + i + n];
- }
+ if (test_tsk_thread_flag(task, TIF_31BIT))
+ mask = 0xffffffff;
#endif
if (i + n == 6)
- args[--n] = regs->args[0];
- memcpy(args, &regs->gprs[2 + i], n * sizeof(args[0]));
+ args[--n] = regs->args[0] & mask;
+ while (n-- > 0)
+ if (i + n > 0)
+ args[n] = regs->gprs[2 + i + n] & mask;
+ if (i == 0)
+ args[0] = regs->orig_gpr2 & mask;
}
static inline void syscall_set_arguments(struct task_struct *task,
@@ -74,7 +74,11 @@ static inline void syscall_set_arguments(struct task_struct *task,
BUG_ON(i + n > 6);
if (i + n == 6)
regs->args[0] = args[--n];
- memcpy(&regs->gprs[2 + i], args, n * sizeof(args[0]));
+ while (n-- > 0)
+ if (i + n > 0)
+ regs->gprs[2 + i + n] = args[n];
+ if (i == 0)
+ regs->orig_gpr2 = args[0];
}
#endif /* _ASM_SYSCALL_H */