BMC/Intel-BMC/linux.git/arch/s390/include/asm/syscall.h, branch dev

s390/syscalls: simplify syscall_get_arch()

2015-03-30T11:26:07+00:00

Given that sizeof(long) is now always 8, we can simplify syscall_get_arch() a bit. Just another piece I didn't find when removing 31 bit support. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

s390/seccomp: fix error return for filtered system calls

2014-07-28T08:02:31+00:00

The syscall_set_return_value function of s390 negates the error argument before storing the value to the return register gpr2. This is incorrect, the seccomp code already passes the negative error value. Store the unmodified error value to gpr2. Signed-off-by: Jan Willeke Signed-off-by: Martin Schwidefsky

s390: split TIF bits into CIF, PIF and TIF bits

2014-05-20T06:58:47+00:00

The oi and ni instructions used in entry[64].S to set and clear bits in the thread-flags are not guaranteed to be atomic in regard to other CPUs. Split the TIF bits into CPU, pt_regs and thread-info specific bits. Updates on the TIF bits are done with atomic instructions, updates on CPU and pt_regs bits are done with non-atomic instructions. Signed-off-by: Martin Schwidefsky

audit: use uapi/linux/audit.h for AUDIT_ARCH declarations

2014-03-20T14:11:59+00:00

The syscall.h headers were including linux/audit.h but really only needed the uapi/linux/audit.h to get the requisite defines. Switch to the uapi headers. Signed-off-by: Eric Paris Cc: linux-arm-kernel@lists.infradead.org Cc: linux-mips@linux-mips.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org

syscall_get_arch: remove useless function arguments

2014-03-20T14:11:59+00:00

Every caller of syscall_get_arch() uses current for the task and no implementors of the function need args. So just get rid of both of those things. Admittedly, since these are inline functions we aren't wasting stack space, but it just makes the prototypes better. Signed-off-by: Eric Paris Cc: linux-arm-kernel@lists.infradead.org Cc: linux-mips@linux-mips.org Cc: linux390@de.ibm.com Cc: x86@kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-s390@vger.kernel.org Cc: linux-arch@vger.kernel.org

s390: system call path micro optimization

2013-04-26T07:07:05+00:00

Add a pointer to the system call table to the thread_info structure. The TIF_31BIT bit is set or cleared by SET_PERSONALITY exactly once for the lifetime of a process. With the pointer to the correct system call table in thread_info the system call code in entry64.S path can drop the check for TIF_31BIT which saves a couple of instructions. Signed-off-by: Martin Schwidefsky

s390/seccomp: add support for system call filtering using BPF

2012-08-08T14:32:56+00:00

Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

[S390] cleanup trap handling

2011-12-27T10:27:12+00:00

Move the program interruption code and the translation exception identifier to the pt_regs structure as 'int_code' and 'int_parm_long' and make the first level interrupt handler in entry[64].S store the two values. That makes it possible to drop 'prot_addr' and 'trap_no' from the thread_struct and to reduce the number of arguments to a lot of functions. Finally un-inline do_trap. Overall this saves 5812 bytes in the .text section of the 64 bit kernel. Signed-off-by: Martin Schwidefsky

[S390] add TIF_SYSCALL thread flag

2011-10-30T14:16:43+00:00

Add an explicit TIF_SYSCALL bit that indicates if a task is inside a system call. The svc_code in the pt_regs structure is now only valid if TIF_SYSCALL is set. With this definition TIF_RESTART_SVC can be replaced with TIF_SYSCALL. Overall do_signal is a bit more readable and it saves a few lines of code. Signed-off-by: Martin Schwidefsky

[S390] signal race with restarting system calls

2011-10-30T14:16:43+00:00

For a ERESTARTNOHAND/ERESTARTSYS/ERESTARTNOINTR restarting system call do_signal will prepare the restart of the system call with a rewind of the PSW before calling get_signal_to_deliver (where the debugger might take control). For A ERESTART_RESTARTBLOCK restarting system call do_signal will set -EINTR as return code. There are two issues with this approach: 1) strace never sees ERESTARTNOHAND, ERESTARTSYS, ERESTARTNOINTR or ERESTART_RESTARTBLOCK as the rewinding already took place or the return code has been changed to -EINTR 2) if get_signal_to_deliver does not return with a signal to deliver the restart via the repeat of the svc instruction is left in place. This opens a race if another signal is made pending before the system call instruction can be reexecuted. The original system call will be restarted even if the second signal would have ended the system call with -EINTR. These two issues can be solved by dropping the early rewind of the system call before get_signal_to_deliver has been called and by using the TIF_RESTART_SVC magic to do the restart if no signal has to be delivered. The only situation where the system call restart via the repeat of the svc instruction is appropriate is when a SA_RESTART signal is delivered to user space. Unfortunately this breaks inferior calls by the debugger again. The system call number and the length of the system call instruction is lost over the inferior call and user space will see ERESTARTNOHAND/ ERESTARTSYS/ERESTARTNOINTR/ERESTART_RESTARTBLOCK. To correct this a new ptrace interface is added to save/restore the system call number and system call instruction length. Signed-off-by: Martin Schwidefsky