28 Feb, 2013
1 commit
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access_ok() always returns 'true' on s390. Therefore all calls
are quite pointless and can be removed.Signed-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky
04 Feb, 2013
3 commits
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Signed-off-by: Al Viro
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Signed-off-by: Al Viro
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Signed-off-by: Al Viro
23 Nov, 2012
1 commit
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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
Signed-off-by: Martin Schwidefsky
12 Nov, 2012
1 commit
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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
20 Jul, 2012
1 commit
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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
02 Jun, 2012
5 commits
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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
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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
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Signed-off-by: Al Viro
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replace boilerplate "should we use ->saved_sigmask or ->blocked?"
with calls of obvious inlined helper...Signed-off-by: Al Viro
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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
24 May, 2012
1 commit
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Signed-off-by: Al Viro
22 May, 2012
1 commit
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guts of saved_sigmask-based sigsuspend/rt_sigsuspend. Takes
kernel sigset_t *.Open-coded instances replaced with calling it.
Signed-off-by: Al Viro
16 May, 2012
1 commit
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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
29 Mar, 2012
1 commit
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Disintegrate asm/system.h for S390.
Signed-off-by: David Howells
cc: linux-s390@vger.kernel.org
11 Mar, 2012
1 commit
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Use the new helper function introduced in commit 5e6292c0f28f
("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
Acked-by: Martin Schwidefsky
Cc: linux-s390@vger.kernel.org
Signed-off-by: Matt Fleming
Signed-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky
27 Feb, 2012
1 commit
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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
Signed-off-by: Linus Torvalds
27 Dec, 2011
1 commit
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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
01 Dec, 2011
1 commit
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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
30 Oct, 2011
5 commits
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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
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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
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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
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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
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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
03 Aug, 2011
2 commits
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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
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Convert to use set_current_blocked() like x86.
Signed-off-by: Heiko Carstens
05 Jan, 2011
1 commit
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Overhaul program event recording and the code dealing with the ptrace
user space interface.Signed-off-by: Martin Schwidefsky
17 May, 2010
1 commit
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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
27 Jan, 2010
1 commit
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Use set_current_state instead of a direct assignment to set the
task state of the current process.Signed-off-by: Martin Schwidefsky
14 Jan, 2010
1 commit
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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
02 Sep, 2009
1 commit
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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
#include
#include#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: aWhere 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
Signed-off-by: James Morris
12 Jun, 2009
1 commit
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Implement is_compat_task and use it all over the place.
Signed-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky
14 Jan, 2009
1 commit
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Signed-off-by: Heiko Carstens
27 Nov, 2008
1 commit
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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
11 Oct, 2008
1 commit
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* System call parameter and result access functions
* Add tracehook calls
* Split syscall_trace into two functions do_syscall_trace_enter and
do_syscall_trace_exitSigned-off-by: Martin Schwidefsky
17 Apr, 2008
2 commits
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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
Signed-off-by: Heiko Carstens -
This is just a port of 83bd01024b1fdfc41d9b758e5669e80fca72df66
"x86: protect against sigaltstack wraparound".Signed-off-by: Martin Schwidefsky
Signed-off-by: Heiko Carstens
26 Jan, 2008
1 commit
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Signed-off-by: Roland McGrath
Signed-off-by: Martin Schwidefsky
09 May, 2007
1 commit
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Remove includes of 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
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
