- 03 Feb, 2013 3 commits
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Al Viro authored
Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk>
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Al Viro authored
Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk>
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Al Viro authored
Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk>
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- 23 Nov, 2012 1 commit
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Martin Schwidefsky authored
The current single step code is racy in regard to concurrent delivery of signals. If a signal is delivered after a PER program check occurred but before the TIF_PER_TRAP bit has been checked in entry[64].S the code clears TIF_PER_TRAP and then calls do_signal. This is wrong, if the instruction completed (or has been suppressed) a SIGTRAP should be delivered to the debugger in any case. Only if the instruction has been nullified the SIGTRAP may not be send. The new logic always sets TIF_PER_TRAP if the program check indicates PER tracing but removes it again for all program checks that are nullifying. The effect is that for each change in the PSW address we now get a single SIGTRAP. Reported-by:
Andreas Arnez <arnez@linux.vnet.ibm.com> Signed-off-by:
Martin Schwidefsky <schwidefsky@de.ibm.com>
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- 12 Nov, 2012 1 commit
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Martin Schwidefsky authored
If user space is running in primary mode it can switch to secondary or access register mode, this is used e.g. in the clock_gettime code of the vdso. If a signal is delivered to the user space process while it has been running in access register mode the signal handler is executed in access register mode as well which will result in a crash most of the time. Set the address space control bits in the PSW to the default for the execution of the signal handler and make sure that the previous address space control is restored on signal return. Take care that user space can not switch to the kernel address space by modifying the registers in the signal frame. Cc: stable@vger.kernel.org Signed-off-by:
Martin Schwidefsky <schwidefsky@de.ibm.com>
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- 20 Jul, 2012 1 commit
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Heiko Carstens authored
Remove the file name from the comment at top of many files. In most cases the file name was wrong anyway, so it's rather pointless. Also unify the IBM copyright statement. We did have a lot of sightly different statements and wanted to change them one after another whenever a file gets touched. However that never happened. Instead people start to take the old/"wrong" statements to use as a template for new files. So unify all of them in one go. Signed-off-by:
Heiko Carstens <heiko.carstens@de.ibm.com>
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- 01 Jun, 2012 5 commits
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Al Viro authored
Does block_sigmask() + tracehook_signal_handler(); called when sigframe has been successfully built. All architectures converted to it; block_sigmask() itself is gone now (merged into this one). I'm still not too happy with the signature, but that's a separate story (IMO we need a structure that would contain signal number + siginfo + k_sigaction, so that get_signal_to_deliver() would fill one, signal_delivered(), handle_signal() and probably setup...frame() - take one). Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk>
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Al Viro authored
Only 3 out of 63 do not. Renamed the current variant to __set_current_blocked(), added set_current_blocked() that will exclude unblockable signals, switched open-coded instances to it. Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk>
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Al Viro authored
Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk>
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Al Viro authored
replace boilerplate "should we use ->saved_sigmask or ->blocked?" with calls of obvious inlined helper... Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk>
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Al Viro authored
first fruits of ..._restore_sigmask() helpers: now we can take boilerplate "signal didn't have a handler, clear RESTORE_SIGMASK and restore the blocked mask from ->saved_mask" into a common helper. Open-coded instances switched... Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk>
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- 24 May, 2012 1 commit
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Al Viro authored
Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk>
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- 22 May, 2012 1 commit
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Al Viro authored
guts of saved_sigmask-based sigsuspend/rt_sigsuspend. Takes kernel sigset_t *. Open-coded instances replaced with calling it. Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk>
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- 16 May, 2012 1 commit
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Martin Schwidefsky authored
The code in entry[64].S calls do_signal only on return to user space. user_mode(regs) is true for every calls to do_signal, it is unnecessary to recheck user_mode at the start of do_signal and the legacy signal stack switching path in get_sigframe is never reached. Signed-off-by:
Martin Schwidefsky <schwidefsky@de.ibm.com>
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- 28 Mar, 2012 1 commit
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David Howells authored
Disintegrate asm/system.h for S390. Signed-off-by:
David Howells <dhowells@redhat.com> cc: linux-s390@vger.kernel.org
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- 11 Mar, 2012 1 commit
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Matt Fleming authored
Use the new helper function introduced in commit 5e6292c0 ("signal: add block_sigmask() for adding sigmask to current->blocked") which centralises the code for updating current->blocked after successfully delivering a signal and reduces the amount of duplicate code across architectures. In the past some architectures got this code wrong, so using this helper function should stop that from happening again. Cc: Oleg Nesterov <oleg@redhat.com> Acked-by:
Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: linux-s390@vger.kernel.org Signed-off-by:
Matt Fleming <matt.fleming@intel.com> Signed-off-by:
Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by:
Martin Schwidefsky <schwidefsky@de.ibm.com>
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- 27 Feb, 2012 1 commit
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Heiko Carstens authored
The new is_compat_task() define for the !COMPAT case in include/linux/compat.h conflicts with a similar define in arch/s390/include/asm/compat.h. This is the minimal patch which fixes the build issues. Signed-off-by:
Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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- 27 Dec, 2011 1 commit
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Martin Schwidefsky authored
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 <schwidefsky@de.ibm.com>
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- 01 Dec, 2011 1 commit
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Martin Schwidefsky authored
The TIF_SYSCALL bit needs to be cleared if the debugger changes the state of the ptraced process in regard to the presence of a system call. Otherwise the system call will be restarted although the debugger set up an inferior call. Signed-off-by:
Martin Schwidefsky <schwidefsky@de.ibm.com>
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- 30 Oct, 2011 5 commits
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Martin Schwidefsky authored
The user space program can change its addressing mode between the 24-bit, 31-bit and the 64-bit mode if the kernel is 64 bit. Currently the kernel always forces the standard amode on signal delivery and signal return and on ptrace: 64-bit for a 64-bit process, 31-bit for a compat process and 31-bit kernels. Change the signal and ptrace code to allow the full range of addressing modes. Signal handlers are run in the standard addressing mode for the process. One caveat is that even an 31-bit compat process can switch to the 64-bit mode. The next signal will switch back into the 31-bit mode and there is no room in the 31-bit compat signal frame to store the information that the program came from the 64-bit mode. Signed-off-by:
Martin Schwidefsky <schwidefsky@de.ibm.com>
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Martin Schwidefsky authored
Split out addressing mode bits from PSW_BASE_BITS, rename PSW_BASE_BITS to PSW_MASK_BASE, get rid of psw_user32_bits, remove unused function enabled_wait(), introduce PSW_MASK_USER, and drop PSW_MASK_MERGE macros. Change psw_kernel_bits / psw_user_bits to contain only the bits that are always set in the respective mode. Signed-off-by:
Martin Schwidefsky <schwidefsky@de.ibm.com>
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Martin Schwidefsky authored
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 <schwidefsky@de.ibm.com>
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Martin Schwidefsky authored
An instruction with an address right below the adress limit for the current addressing mode will wrap. The instruction restart logic in the protection fault handler and the signal code need to follow the wrapping rules to find the correct instruction address. Signed-off-by:
Martin Schwidefsky <schwidefsky@de.ibm.com>
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Martin Schwidefsky authored
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 <schwidefsky@de.ibm.com>
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- 03 Aug, 2011 2 commits
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Heiko Carstens authored
We should call set_restore_sigmask() instead of directly setting TIF_RESTORE_SIGMASK. This change should have been done three years earlier... see 4e4c22 "signals: add set_restore_sigmask". Signed-off-by:
Heiko Carstens <heiko.carstens@de.ibm.com>
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Heiko Carstens authored
Convert to use set_current_blocked() like x86. Signed-off-by:
Heiko Carstens <heiko.carstens@de.ibm.com>
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- 05 Jan, 2011 1 commit
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Martin Schwidefsky authored
Overhaul program event recording and the code dealing with the ptrace user space interface. Signed-off-by:
Martin Schwidefsky <schwidefsky@de.ibm.com>
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- 17 May, 2010 1 commit
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Martin Schwidefsky authored
Copy the last breaking event address from the lowcore to a new field in the thread_struct on each system entry. Add a new ptrace request PTRACE_GET_LAST_BREAK and a new utrace regset REGSET_LAST_BREAK to query the last breaking event. This is useful for debugging wild branches in user space code. Signed-off-by:
Martin Schwidefsky <schwidefsky@de.ibm.com>
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- 27 Jan, 2010 1 commit
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Martin Schwidefsky authored
Use set_current_state instead of a direct assignment to set the task state of the current process. Signed-off-by:
Martin Schwidefsky <schwidefsky@de.ibm.com>
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- 13 Jan, 2010 1 commit
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Martin Schwidefsky authored
The code in do_signal sets the TIF_SINGLE_STEP bit and calls tracehook_signal_handler after the signal frame has been set up. This causes two SIGTRAP signals to be delivered to the tracer. Stop setting the TIF_SINGLE_STEP bit in do_signal to get the correct number of SIGTRAPs. Signed-off-by:
Martin Schwidefsky <schwidefsky@de.ibm.com>
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- 02 Sep, 2009 1 commit
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David Howells authored
Add a keyctl to install a process's session keyring onto its parent. This replaces the parent's session keyring. Because the COW credential code does not permit one process to change another process's credentials directly, the change is deferred until userspace next starts executing again. Normally this will be after a wait*() syscall. To support this, three new security hooks have been provided: cred_alloc_blank() to allocate unset security creds, cred_transfer() to fill in the blank security creds and key_session_to_parent() - which asks the LSM if the process may replace its parent's session keyring. The replacement may only happen if the process has the same ownership details as its parent, and the process has LINK permission on the session keyring, and the session keyring is owned by the process, and the LSM permits it. Note that this requires alteration to each architecture's notify_resume path. This has been done for all arches barring blackfin, m68k* and xtensa, all of which need assembly alteration to support TIF_NOTIFY_RESUME. This allows the replacement to be performed at the point the parent process resumes userspace execution. This allows the userspace AFS pioctl emulation to fully emulate newpag() and the VIOCSETTOK and VIOCSETTOK2 pioctls, all of which require the ability to alter the parent process's PAG membership. However, since kAFS doesn't use PAGs per se, but rather dumps the keys into the session keyring, the session keyring of the parent must be replaced if, for example, VIOCSETTOK is passed the newpag flag. This can be tested with the following program: #include <stdio.h> #include <stdlib.h> #include <keyutils.h> #define KEYCTL_SESSION_TO_PARENT 18 #define OSERROR(X, S) do { if ((long)(X) == -1) { perror(S); exit(1); } } while(0) int main(int argc, char **argv) { key_serial_t keyring, key; long ret; keyring = keyctl_join_session_keyring(argv[1]); OSERROR(keyring, "keyctl_join_session_keyring"); key = add_key("user", "a", "b", 1, keyring); OSERROR(key, "add_key"); ret = keyctl(KEYCTL_SESSION_TO_PARENT); OSERROR(ret, "KEYCTL_SESSION_TO_PARENT"); return 0; } Compiled and linked with -lkeyutils, you should see something like: [dhowells@andromeda ~]$ keyctl show Session Keyring -3 --alswrv 4043 4043 keyring: _ses 355907932 --alswrv 4043 -1 \_ keyring: _uid.4043 [dhowells@andromeda ~]$ /tmp/newpag [dhowells@andromeda ~]$ keyctl show Session Keyring -3 --alswrv 4043 4043 keyring: _ses 1055658746 --alswrv 4043 4043 \_ user: a [dhowells@andromeda ~]$ /tmp/newpag hello [dhowells@andromeda ~]$ keyctl show Session Keyring -3 --alswrv 4043 4043 keyring: hello 340417692 --alswrv 4043 4043 \_ user: a Where the test program creates a new session keyring, sticks a user key named 'a' into it and then installs it on its parent. Signed-off-by:
David Howells <dhowells@redhat.com> Signed-off-by:
James Morris <jmorris@namei.org>
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- 12 Jun, 2009 1 commit
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Heiko Carstens authored
Implement is_compat_task and use it all over the place. Signed-off-by:
Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by:
Martin Schwidefsky <schwidefsky@de.ibm.com>
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- 14 Jan, 2009 1 commit
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Heiko Carstens authored
Signed-off-by:
Heiko Carstens <heiko.carstens@de.ibm.com>
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- 27 Nov, 2008 1 commit
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Martin Schwidefsky authored
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>
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- 10 Oct, 2008 1 commit
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Martin Schwidefsky authored
* System call parameter and result access functions * Add tracehook calls * Split syscall_trace into two functions do_syscall_trace_enter and do_syscall_trace_exit Signed-off-by:
Martin Schwidefsky <schwidefsky@de.ibm.com>
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- 17 Apr, 2008 2 commits
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Heiko Carstens authored
Most noteable part of this commit is the new local header file entry.h which contains all the function declarations of functions that get only called from asm code or are arch internal. That way we can avoid extern declarations in C files. This is more or less the same that was done for sparc64. Signed-off-by:
Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by:
Heiko Carstens <heiko.carstens@de.ibm.com>
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Heiko Carstens authored
This is just a port of 83bd0102 "x86: protect against sigaltstack wraparound". Signed-off-by:
Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by:
Heiko Carstens <heiko.carstens@de.ibm.com>
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- 26 Jan, 2008 1 commit
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Roland McGrath authored
Signed-off-by:
Roland McGrath <roland@redhat.com> Signed-off-by:
Martin Schwidefsky <schwidefsky@de.ibm.com>
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- 08 May, 2007 1 commit
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Randy Dunlap authored
Remove includes of <linux/smp_lock.h> where it is not used/needed. Suggested by Al Viro. Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc, sparc64, and arm (all 59 defconfigs). Signed-off-by:
Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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- 27 Apr, 2007 1 commit
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Martin Schwidefsky authored
Remove system call glue for sys_clone, sys_fork, sys_vfork, sys_execve, sys_sigreturn, sys_rt_sigreturn and sys_sigaltstack. Call do_execve from kernel_execve directly, move pt_regs to the right place and branch to sysc_return to start the user space program. This removes the last in-kernel system call. Signed-off-by:
Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by:
Heiko Carstens <heiko.carstens@de.ibm.com>
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