Commit Graph

20 Commits

Author SHA1 Message Date
Nicolas Pitre
3f2829a315 [ARM] 3105/4: ARM EABI: new syscall entry convention
Patch from Nicolas Pitre

For a while we wanted to change the way syscalls were called on ARM.
Instead of encoding the syscall number in the swi instruction which
requires reading back the instruction from memory to extract that number
and polluting the data cache, it was decided that simply storing the
syscall number into r7 would be more efficient. Since this represents
an ABI change then making that change at the same time as EABI support
is the right thing to do.

It is now expected that EABI user space binaries put the syscall number
into r7 and use "swi 0" to call the kernel. Syscall register argument
are also expected to have "EABI arrangement" i.e. 64-bit arguments
should be put in a pair of registers from an even register number.

Example with long ftruncate64(unsigned int fd, loff_t length):

	legacy ABI:
	- put fd into r0
	- put length into r1-r2
	- use "swi #(0x900000 + 194)" to call the kernel

	new ARM EABI:
	- put fd into r0
	- put length into r2-r3 (skipping over r1)
	- put 194 into r7
	- use "swi 0" to call the kernel

Note that it is important to use 0 for the swi argument as backward
compatibility with legacy ABI user space relies on this.
The syscall macros in asm-arm/unistd.h were also updated to support
both ABIs and implement the right call method automatically.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-01-14 16:31:29 +00:00
Al Viro
32d39a9355 [PATCH] arm: task_stack_page()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-12 09:08:56 -08:00
Al Viro
5520582392 [PATCH] arm: end_of_stack()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-12 09:08:56 -08:00
Russell King
78ff18a412 [ARM] Cleanup ARM includes
arch/arm/kernel/entry-armv.S has contained a comment suggesting
that asm/hardware.h and asm/arch/irqs.h should be moved into the
asm/arch/entry-macro.S include.  So move the includes to these
two files as required.

Add missing includes (asm/hardware.h, asm/io.h) to asm/arch/system.h
includes which use those facilities, and remove asm/io.h from
kernel/process.c.

Remove other unnecessary includes from arch/arm/kernel, arch/arm/mm
and arch/arm/mach-footbridge.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-01-03 17:39:34 +00:00
Russell King
d362979aa2 [ARM] Re-organise die()
Provide __die() which can be called from various contexts to provide
an oops report.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-10-30 19:01:43 +00:00
Hugh Dickins
69b0475456 [PATCH] mm: arm ready for split ptlock
Prepare arm for the split page_table_lock: three issues.

Signal handling's preserve and restore of iwmmxt context currently involves
reading and writing that context to and from user space, while holding
page_table_lock to secure the user page(s) against kswapd.  If we split the
lock, then the structure might span two pages, secured by to read into and
write from a kernel stack buffer, copying that out and in without locking (the
structure is 160 bytes in size, and here we're near the top of the kernel
stack).  Or would the overhead be noticeable?

arm_syscall's cmpxchg emulation use pte_offset_map_lock, instead of
pte_offset_map and mm-wide page_table_lock; and strictly, it should now also
take mmap_sem before descending to pmd, to guard against another thread
munmapping, and the page table pulled out beneath this thread.

Updated two comments in fault-armv.c.  adjust_pte is interesting, since its
modification of a pte in one part of the mm depends on the lock held when
calling update_mmu_cache for a pte in some other part of that mm.  This can't
be done with a split page_table_lock (and we've already taken the lowest lock
in the hierarchy here): so we'll have to disable split on arm, unless
CONFIG_CPU_CACHE_VIPT to ensures adjust_pte never used.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-29 21:40:42 -07:00
Nicolas Pitre
a999cb04b4 [ARM] 3035/1: RISCOS compat code fix
Patch from Nicolas Pitre

From: Daniel Jacobowitz <dan@debian.org>

> I also fixed a bug that confused me greatly while trying to debug: one
> SIGILL has long been a SIGSEGV because of some broken RISCOS
> compatibility code.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-10-28 16:35:46 +01:00
Nicolas Pitre
74f8849496 [ARM] 2951/1: fix wrong comment
Patch from Nicolas Pitre

The cmpxchg emulation syscall needs write access.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-10-04 23:17:52 +01:00
Catalin Marinas
6a1ced59b3 [ARM] 2932/1: Avoid the "noreturn" warning in arch/arm/kernel/traps.c
Patch from Catalin Marinas

This patch prevents the "noreturn function does return" warning in the
__bug() function in arch/arm/kernel/traps.c

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-09-21 22:14:05 +01:00
Al Viro
33215652e4 [PATCH] qualifiers in return types - easy cases
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>
2005-08-23 18:43:45 -07:00
Russell King
109d89ca0e [PATCH] ARM: Allow register_undef_hook to be called with IRQs off
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>
2005-07-16 16:43:33 +01:00
Russell King
cfb0810eab [PATCH] ARM: Don't try to send a signal to pid0
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>
2005-06-30 11:06:49 +01:00
Russell King
e00d349e77 [PATCH] ARM: Move signal return code into vector page
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>
2005-06-22 20:26:05 +01:00
Nicolas Pitre
dcef1f6346 [PATCH] ARM: 2664/2: add support for atomic ops on pre-ARMv6 SMP systems
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>
2005-06-08 19:00:47 +01:00
Nicolas Pitre
4b0e07a556 [PATCH] ARM: 2663/1: straightify TLS register emulation a bit more
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>
2005-05-05 23:24:45 +01:00
Russell King
4f7a18124c [PATCH] ARM: Fix kernel stack offset calculations
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>
2005-05-05 13:11:00 +01:00
Nicolas Pitre
2d2669b629 [PATCH] ARM: 2651/3: kernel helpers for NPTL support
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>
2005-04-29 22:08:33 +01:00
Russell King
7933523dc7 [PATCH] ARM: remove some entry initialisation asm code
Convert the trivial vector entry initialisation code to C code.

Signed-off-by: Russell King <rmk@arm.linux.org.uk>
2005-04-26 15:17:42 +01:00
Russell King
652a12ef98 [PATCH] ARM: showregs
Fix show_regs() to provide a backtrace.  Provide a new __show_regs()
function which implements the common subset of show_regs() and die().
Add prototypes to asm-arm/system.h

Signed-off-by: Russell King <rmk@arm.linux.org.uk>
2005-04-17 15:50:36 +01:00
Linus Torvalds
1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00