It has been reported that the way Linux handles NODEFER for signals is
not consistent with the way other Unix boxes handle it. I've written a
program to test the behavior of how this flag affects signals and had
several reports from people who ran this on various Unix boxes,
confirming that Linux seems to be unique on the way this is handled.
The way NODEFER affects signals on other Unix boxes is as follows:
1) If NODEFER is set, other signals in sa_mask are still blocked.
2) If NODEFER is set and the signal is in sa_mask, then the signal is
still blocked. (Note: this is the behavior of all tested but Linux _and_
NetBSD 2.0 *).
The way NODEFER affects signals on Linux:
1) If NODEFER is set, other signals are _not_ blocked regardless of
sa_mask (Even NetBSD doesn't do this).
2) If NODEFER is set and the signal is in sa_mask, then the signal being
handled is not blocked.
The patch converts signal handling in all current Linux architectures to
the way most Unix boxes work.
Unix boxes that were tested: DU4, AIX 5.2, Irix 6.5, NetBSD 2.0, SFU
3.5 on WinXP, AIX 5.3, Mac OSX, and of course Linux 2.6.13-rcX.
* NetBSD was the only other Unix to behave like Linux on point #2. The
main concern was brought up by point #1 which even NetBSD isn't like
Linux. So with this patch, we leave NetBSD as the lonely one that
behaves differently here with #2.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
a bunch of functions switched from volatile to __attribute__((noreturn)) and
from const to __attribute_pure__
Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In yenta_socket, we default to using the resource setting of the CardBus
bridge. However, this is a PCI-bus-centric view of resources and thus needs
to be converted to generic resources first. Therefore, add a call to
pcibios_bus_to_resource() call in between. This function is a mere wrapper on
x86 and friends, however on some others it already exists, is added in this
patch (alpha, arm, ppc, ppc64) or still needs to be provided (parisc -- where
is its pcibios_resource_to_bus() ?).
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Since ARMv6 CPUs will not flush the TLB on context switches, it is
possible that we may end up with some global TLB entries remaining
present, eventually upsetting userspace. Explicitly flush the
entire TLB on secondary CPUs as they startup, after we have switched
to the init_mm page tables.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
machine_restart, machine_halt and machine_power_off are machine
specific hooks deep into the reboot logic, that modules
have no business messing with. Usually code should be calling
kernel_restart, kernel_halt, kernel_power_off, or
emergency_restart. So don't export machine_restart,
machine_halt, and machine_power_off so we can catch buggy users.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Preserve the interrupt status across a call to register_undef_hook.
This allows it to be called while interrupts are disabled.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Todd Poynor
Fix module versioning for 3 ARM symbols that do not have CRCs added,
avoid "disagrees about version of symbol struct_module" errors at module
load time. From David Singleton.
Signed-off-by: Todd Poynor <tpoynor@mvista.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Make the magic address values in head.S more obvious as to where
they came from. Wrap all debug code in CONFIG_DEBUG_LL.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
If we receive an unrecognised abort during boot, don't try to
send a signal to pid0, but instead report the current state.
This leads to less confusing debug reports.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Nicolas Pitre
Those are big, slow and generally not recommended for kernel code.
They are even not present on i386. So it should be concluded that
one could as well get away with do_div() alone.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Catalin Marinas
The compiler allocates r14 for the stk variable in the __asm__ directive.
This is a shadowed register and gets changed when the mode is changed,
causing random values in the SP register. The patch adds a clobber for
the r14 register.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This call allows the dynamic tick support to reprogram the timer
immediately before the CPU idles.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Another swsusp fixup.
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds support for Dynamic Tick Timer for ARM. Dynamic Tick is
also known as VST (Variable Scheduling Timeouts).
Dynamic Tick has been in use in the OMAP tree since last October. The
patch is not intrusive, and does not do anything unless CONFIG_NO_IDLE_HZ
is defined. This patch has the following fixed based on comments from
RMK:
- Time is updated before calling interrupt handlers.
- Added new interrupt flag SA_TIMER to avoid duplicate timer interrupts
- Moved struct dyn_tick_timer to time.h until we at some point probably
have an arch independent dyn-tick.h
- Cleaned up testing for DYN_TICK_ENABLED in irq.c
I've cleaned up this patch to fix some remaining issues:
- Call the timer tick handler with irqs disabled, as it would be from
a normal interrupt
- if we have a dyn_tick, we better implement all methods.
- generic timer_dyn_reprogram() call, to be called before sleeping
- added command line option - "dyntick=" to allow boot-time control
of this feature
-- rmk
Signed-off-by: Tony Lindgren
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Move the signal return code into the vector page instead of placing
it on the user mode stack, which will allow us to avoid flushing
the instruction cache on signals, as well as eventually allowing
non-exec stack.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
We need to re-initialise the stack pointers for undefined, IRQ
and abort mode handlers whenever we resume.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Create a temporary page table to startup secondary processors. This
page table must have a 1:1 virtual/physical mapping for the kernel
in addition to the standard mappings to ensure that the secondary
CPU can enable its MMU safely.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Nicolas Pitre
Not that there might be many of them on the planet, but at least RMK
apparently has one.
Signed-off-by: Nicolas Pitre
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The current vector entry system does not allow for SMP. In
order to work around this, we need to eliminate our reliance
on the fixed save areas, which breaks the way we enable
alignment traps. This patch changes the way we handle the
save areas such that we can have one per CPU.
Signed-off-by: Russell King <rmk@arm.linux.org.uk>
The current vector entry system does not allow for SMP. In
order to work around this, we need to eliminate our reliance
on the fixed save areas, which breaks the way we enable
alignment traps. This patch makes the alignment trap enable
code independent of the way we handle the save areas.
Signed-off-by: Russell King <rmk@arm.linux.org.uk>
By changing r9 -> r8 and r8 to 'tsk' (r9) we are able to remove
one instruction from the preempt path.
Signed-off-by: Russell King <rmk@arm.linux.org.uk>
Patch from Nicolas Pitre
This better express things, and should cover RMK's weird SMP toys.
Signed-off-by: Nicolas Pitre
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Various places in the ARM kernel implicitly assumed that kernel
stacks are always 8K due to hard coded constants. Replace these
constants with definitions.
Correct the allowable range of kernel stack pointer values within
the allocation. Arrange for the entire kernel stack to be zeroed,
not just the upper 4K if CONFIG_DEBUG_STACK_USAGE is set.
Signed-off-by: Russell King <rmk@arm.linux.org.uk>
Convert most of the current code that uses _NSIG directly to instead use
valid_signal(). This avoids gcc -W warnings and off-by-one errors.
Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Patch from Nicolas Pitre
This patch entirely reworks the kernel assistance for NPTL on ARM.
In particular this provides an efficient way to retrieve the TLS
value and perform atomic operations without any instruction emulation
nor special system call. This even allows for pre ARMv6 binaries to
be forward compatible with SMP systems without any penalty.
The problematic and performance critical operations are performed
through segment of kernel provided user code reachable from user space
at a fixed address in kernel memory. Those fixed entry points are
within the vector page so we basically get it for free as no extra
memory page is required and nothing else may be mapped at that
location anyway.
This is different from (but doesn't preclude) a full blown VDSO
implementation, however a VDSO would prevent some assembly tricks with
constants that allows for efficient branching to those code segments.
And since those code segments only use a few cycles before returning to
user code, the overhead of a VDSO far call would add a significant
overhead to such minimalistic operations.
The ARM_NR_set_tls syscall also changed number. This is done for two
reasons:
1) this patch changes the way the TLS value was previously meant to be
retrieved, therefore we ensure whatever library using the old way
gets fixed (they only exist in private tree at the moment since the
NPTL work is still progressing).
2) the previous number was allocated in a range causing an undefined
instruction trap on kernels not supporting that syscall and it was
determined that allocating it in a range returning -ENOSYS would be
much nicer for libraries trying to determine if the feature is
present or not.
Signed-off-by: Nicolas Pitre
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
SVC_MODE reflects the MODE_SVC definition in asm/ptrace.h. Use
the asm/ptrace.h definition instead, and remove SVC_MODE.
Signed-off-by: Russell King <rmk@arm.linux.org.uk>
Steven Rostedt
Al Viro
Robert Love
Russell King
Dominik Brodowski
Eric W. Biederman
Todd Poynor
Nicolas Pitre
Catalin Marinas
Andrew Morton
Linus Torvalds
Yani Ioannou
Nicolas Pitre
Jesper Juhl
Stephen Rothwell