linux-toradex.git/arch/alpha/kernel/signal.c, branch v3.4.67

alpha: use set_current_blocked() and block_sigmask()

2012-04-05T22:25:51+00:00

As described in e6fa16ab9c1e ("signal: sigprocmask() should do
retarget_shared_pending()") the modification of current->blocked is
incorrect as we need to check for shared signals we're about to block.

Also, 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: Richard Henderson 
Cc: Ivan Kokshaysky 
Cc: Matt Turner 
Cc: Al Viro 
Acked-by: Oleg Nesterov 
Signed-off-by: Matt Fleming 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Fix up more fallout form alpha signal cleanups

2010-09-30T15:37:38+00:00

Commit c52c2ddc1dfa ("alpha: switch osf_sigprocmask() to use of
sigprocmask()") had several problems.  The more obvious compile issues
got fixed in commit 0f44fbd297e1 ("alpha: fix compile problem in
arch/alpha/kernel/signal.c"), but it also caused a regression.

Since _BLOCKABLE is already the set of signals that can be blocked, the
code should do "newmask & _BLOCKABLE" rather than inverting _BLOCKABLE
before masking.

Reported-by: Michael Cree 
Patch-by: Al Viro 
Patch-by: Ivan Kokshaysky 
Signed-off-by: Linus Torvalds

alpha: fix compile problem in arch/alpha/kernel/signal.c

2010-09-28T20:26:57+00:00

Tssk.  Apparently Al hadn't checked commit c52c2ddc1dfa ("alpha: switch
osf_sigprocmask() to use of sigprocmask()") at all. It doesn't compile.

Fixed as per suggestions from Michael Cree.

Reported-by: Michael Cree 
Cc: Al Viro 
Signed-off-by: Linus Torvalds

alpha: __get_user/__put_user results need to be checked...

2010-09-27T19:19:53+00:00

Signed-off-by: Al Viro 
Signed-off-by: Linus Torvalds

alpha: switch osf_sigprocmask() to use of sigprocmask()

2010-09-27T19:19:53+00:00

get rid of a useless wrapper, while we are at it

Signed-off-by: Al Viro 
Signed-off-by: Linus Torvalds

alpha: unb0rk sigsuspend() and rt_sigsuspend()

2010-09-19T03:08:28+00:00

Old code used to set regs->r0 and regs->r19 to force the right
return value.  Leaving that after switch to ERESTARTNOHAND
was a Bad Idea(tm), since now that screws the restart - if we
hit the case when get_signal_to_deliver() returns 0, we will
step back to syscall insn, with v0 set to EINTR and a3 to 1.
The latter won't matter, since EINTR is 4, aka __NR_write.

Testcase:

	#include 
	#define _GNU_SOURCE
	#include 
	#include 

	main()
	{
		sigset_t mask;
		sigemptyset(&mask);
		sigaddset(&mask, SIGCONT);
		sigprocmask(SIG_SETMASK, &mask, NULL);
		kill(0, SIGCONT);
		syscall(__NR_sigsuspend, 1, "b0rken\n", 7);
	}

results on alpha in immediate message to stdout...

Fix is obvious; moreover, since we don't need regs anymore, we can
switch to normal prototypes for these guys and lose the wrappers.
Even better, rt_sigsuspend() is identical to generic version in
kernel/signal.c now.

Tested-by: Michael Cree 
Signed-off-by: Al Viro 
Signed-off-by: Matt Turner

alpha: belated ERESTART_RESTARTBLOCK race fix

2010-09-19T03:08:27+00:00

same thing as had been done on other targets back in 2003 -
move setting ->restart_block.fn into {rt_,}sigreturn().

Tested-by: Michael Cree 
Signed-off-by: Al Viro 
Signed-off-by: Matt Turner

KEYS: Add missing linux/tracehook.h #inclusions

2009-09-09T08:30:02+00:00

Add #inclusions of linux/tracehook.h to those arch files that had the tracehook
call for TIF_NOTIFY_RESUME added when support for that flag was added to that
arch.

Signed-off-by: David Howells 
Signed-off-by: James Morris

KEYS: Add a keyctl to install a process's session keyring on its parent [try #6]

2009-09-02T11:29:22+00:00

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: 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 
Signed-off-by: James Morris

KEYS: Extend TIF_NOTIFY_RESUME to (almost) all architectures [try #6]

2009-09-02T11:29:19+00:00

Implement TIF_NOTIFY_RESUME for most of those architectures in which isn't yet
available, and, whilst we're at it, have it call the appropriate tracehook.

After this patch, blackfin, m68k* and xtensa still lack support and need
alteration of assembly code to make it work.

Resume notification can then be used (by a later patch) to install a new
session keyring on the parent of a process.

Signed-off-by: David Howells 
Acked-by: Russell King 

cc: linux-arch@vger.kernel.org
Signed-off-by: James Morris