From 59da21398e680e8100625d689c8bebee6a139e93 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Thu, 27 Nov 2008 11:05:55 +0100 Subject: [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 --- arch/s390/include/asm/syscall.h | 28 ++++++++++++++++------------ 1 file changed, 16 insertions(+), 12 deletions(-) (limited to 'arch/s390/include/asm/syscall.h') diff --git a/arch/s390/include/asm/syscall.h b/arch/s390/include/asm/syscall.h index 6e62397..2429b87 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, ®s->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(®s->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 */ -- cgit v1.1