Make PROT_WRITE imply PROT_READ for a number of architectures which don't
support write only in hardware.
While looking at this, I noticed that some architectures which do not
support write only mappings already take the exact same approach. For
example, in arch/alpha/mm/fault.c:
"
if (cause < 0) {
if (!(vma->vm_flags & VM_EXEC))
goto bad_area;
} else if (!cause) {
/* Allow reads even for write-only mappings */
if (!(vma->vm_flags & (VM_READ | VM_WRITE)))
goto bad_area;
} else {
if (!(vma->vm_flags & VM_WRITE))
goto bad_area;
}
"
Thus, this patch brings other architectures which do not support write only
mappings in-line and consistent with the rest. I've verified the patch on
ia64, x86_64 and x86.
Additional discussion:
Several architectures, including x86, can not support write-only mappings.
The pte for x86 reserves a single bit for protection and its two states are
read only or read/write. Thus, write only is not supported in h/w.
Currently, if i 'mmap' a page write-only, the first read attempt on that page
creates a page fault and will SEGV. That check is enforced in
arch/blah/mm/fault.c. However, if i first write that page it will fault in
and the pte will be set to read/write. Thus, any subsequent reads to the page
will succeed. It is this inconsistency in behavior that this patch is
attempting to address. Furthermore, if the page is swapped out, and then
brought back the first read will also cause a SEGV. Thus, any arbitrary read
on a page can potentially result in a SEGV.
According to the SuSv3 spec, "if the application requests only PROT_WRITE, the
implementation may also allow read access." Also as mentioned, some
archtectures, such as alpha, shown above already take the approach that i am
suggesting.
The counter-argument to this raised by Arjan, is that the kernel is enforcing
the write only mapping the best it can given the h/w limitations. This is
true, however Alan Cox, and myself would argue that the inconsitency in
behavior, that is applications can sometimes work/sometimes fails is highly
undesireable. If you read through the thread, i think people, came to an
agreement on the last patch i posted, as nobody has objected to it...
Signed-off-by: Jason Baron <jbaron@redhat.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Andi Kleen <ak@muc.de>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp>
Cc: Ian Molton <spyro@f2s.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Since sys_sysctl is deprecated start allow it to be compiled out. This
should catch any remaining user space code that cares, and paves the way
for further sysctl cleanups.
[akpm@osdl.org: If sys_sysctl() is not compiled-in, emit a warning]
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This eliminates the i_blksize field from struct inode. Filesystems that want
to provide a per-inode st_blksize can do so by providing their own getattr
routine instead of using the generic_fillattr() function.
Note that some filesystems were providing pretty much random (and incorrect)
values for i_blksize.
[bunk@stusta.de: cleanup]
[akpm@osdl.org: generic_fillattr() fix]
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The following patches reduce the size of the VFS inode structure by 28 bytes
on a UP x86. (It would be more on an x86_64 system). This is a 10% reduction
in the inode size on a UP kernel that is configured in a production mode
(i.e., with no spinlock or other debugging functions enabled; if you want to
save memory taken up by in-core inodes, the first thing you should do is
disable the debugging options; they are responsible for a huge amount of bloat
in the VFS inode structure).
This patch:
The filesystem or device-specific pointer in the inode is inside a union,
which is pretty pointless given that all 30+ users of this field have been
using the void pointer. Get rid of the union and rename it to i_private, with
a comment to explain who is allowed to use the void pointer. This is just a
cleanup, but it allows us to reuse the union 'u' for something something where
the union will actually be used.
[judith@osdl.org: powerpc build fix]
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Judith Lebzelter <judith@osdl.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
0x08 is the HT capability, while PCI_CAP_ID_HT_IRQCONF would be
the subtype 0x80 that mpic_scan_ht_pic() uses.
Rename PCI_CAP_ID_HT_IRQCONF into PCI_CAP_ID_HT.
And by the way, use it in the ipath driver instead of defining its
own HT_CAPABILITY_ID.
Signed-off-by: Brice Goglin <brice@myri.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The name of the pagedir_nosave variable does not make sense any more, so it
seems reasonable to change it to something more meaningful.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
On detection of an EEH error, some Power4 systems seem to occasionally
want to be reset twice before they report themselves as fully recovered.
This patch re-arranges the code to attempt additional resets if the first
one doesn't take.
Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch causes fsl_soc.h to import the definition of phys_addr_t
itself, rather than relying on its includer to do so.
Signed-off-by: Scott Wood <scott@freescale.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Noticed that the U3_*CFA macros have some typos:
#define U3_HT_CFA0(devfn, off) \
((((unsigned long)devfn) << 8) | offset)
(refers to offset rather than off)
#define U3_AGP_CFA0(devfn, off) \
((1 << (unsigned long)PCI_SLOT(dev_fn)) \
| (((unsigned long)PCI_FUNC(dev_fn)) << 8) \
(refers to dev_fn rather than devfn)
Things happen to work, but there doesn't seem to be any reason these
shouldn't be functions. Overall behavior should be unchanged.
Signed-off-by: Nathan Lynch <ntl@pobox.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
When there is a PCI-X mode 2 capable device behind the HT<->PCI-X
bridge, the pci core decides that the device has the extended 4K
config space, even though the bus is not operating in mode 2. This is
because the u3_ht pci ops silently accept offsets greater than 255 but
use only the 8 least significant bits, which means reading at offset
0x100 gets the data at offset 0x0, and causes confusion for lspci.
Reject accesses to configuration space offsets greater than 255.
Signed-off-by: Nathan Lynch <ntl@pobox.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch fixes the assignment of pending registers to IRQ numbers for
the IPIC; the code previously assigned all IRQs to the high pending word
regardless of which word the interrupt belonged to.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch changes the io operations so that they are out of line if
CONFIG_PPC_ISERIES is set and includes a firmware feature check in
that case.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Update to the PowerPC PCI error recovery code.
Add code to enable MMIO if a device driver reports that it is capable
of recovering on its own. One anticipated use of this having a device
driver enable MMIO so that it can take a register dump, which might
then be followed by the device driver requesting a full reset.
Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Add wrapper around the rtas call to enable MMIO or DMA on a frozen pci
slot.
Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Clean up subroutine documentation; mostly formatting changes, with
some new content.
Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This corrects a pci_dev get/put imbalance that can occur only in
highly unlikely situations (kmalloc failures, pci devices with
overlapping resource addresses). No actual failures seen, this was
spotted during code review.
Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Jakub noticed the cputable.c entry for Xilinx Virtex-4 FX was missing
a .platform value, so the AT_PLATFORM value wouldn't be set correctly.
This adds it.
Signed-off-by: Peter Bergner <bergner@vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This abstracts the operations used in the bootwrapper, and defines
the operations needed for the bootwrapper to run on an OF platform.
The operations have been divided up into platform ops (platform_ops),
firmware ops (fw_ops), device tree ops (dt_ops), and console ops
(console_ops).
The proper operations will be hooked up at runtime to provide the
functionality that you need.
Signed-off-by: Mark A. Greer <mgreer@mvista.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
There are various places where we want to extract an unsigned long
value from a device-tree property that can be 1 or 2 cells in length.
This replaces some open-coded calculations, and one place where we
assumed without checking that properties were the length we wanted,
with a little of_read_ulong() helper.
Signed-off-by: Paul Mackerras <paulus@samba.org>
This produces essentially the same code and will make the iSeries i/o
consolidation easier.
The count parameter is changed to long since that will produce the same
(better) code on 32 and 64 bit builds.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
This fixes a compile error that only surfaces on CONFIG_SMP=n builds;
<asm/hvcall.h> seems to get pulled in through another header file for
SMP builds. This problem was introduced by the hvcall stats patch.
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
It seems that the occasional data corruption observed with the tg3
driver wasn't due to missing barriers after all, but rather seems to
be due to the DART (= IOMMU) in the U4 northbridge reading stale
IOMMU table entries from memory due to a race. This fixes it by
making the CPU read the entry back from memory before using it.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This changes the writeX family of functions to have a sync instruction
before the MMIO store rather than after, because the generally expected
behaviour is that the device receiving the MMIO store can be guaranteed
to see the effects of any preceding writes to normal memory.
To preserve ordering between writeX and readX, and to preserve ordering
between preceding stores and the readX, the readX family of functions
have had an sync added before the load.
Although writeX followed by spin_unlock is not officially guaranteed
to keep the writeX inside the spin-locked region unless an mmiowb()
is used, there are currently drivers that depend on the previous
behaviour on powerpc, which was that the mmiowb wasn't actually required.
Therefore we have a per-cpu flag that is set by writeX, cleared by
__raw_spin_lock and mmiowb, and tested by __raw_spin_unlock. If it is
set, __raw_spin_unlock does a sync and clears it.
This changes both 32-bit and 64-bit readX/writeX. 32-bit already has a
sync in __raw_spin_unlock (since lwsync doesn't exist on 32-bit), and thus
doesn't need the per-cpu flag.
Tested on G5 (PPC970) and POWER5.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Export copy_4K_page() for use by modules via copy_page() (such as
CacheFiles).
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
xmon does not print a backtrace per default. This is bad on systems with
USB keyboard, the most needed info about the crash is lost.
print a backtrace during the very first xmon entry.
Booting with xmon=nobt disables the autobacktrace functionality.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Add instrumentation for hypervisor calls on pseries. Call statistics
include number of calls, wall time and cpu cycles (if available) and
are made available via debugfs. Instrumentation code is behind the
HCALL_STATS config option and has no impact if not enabled.
Signed-off-by: Mike Kravetz <kravetz@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Base patch for PA6T and PA6T-1682M. This introduces the
arch/powerpc/platform/pasemi directory, together with basic
implementations for various setup.
Much of this was based on other platform code, i.e. Maple, etc.
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Reduce default cacheline size on 64-bit powerpc from 128 bytes to 64.
This is the architected minimum. In most cases we'll still end up using
cache line information from the device tree, but defaults are used during
early boot and doing a few dcbst/icbi's too many there won't do any harm.
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
In an attempt to make it easier for a power5 optimized app to run on a
power4 or a 970 or random earlier machine, this provides emulation of
the popcntb instruction.
Signed-off-by: Will Schmidt <will_schmidt@vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
As part of the new irq code pseries_kexec_cpu_down() was split into a
xics and mpic version. The vpa unregister logic is now only done in the
xics routine, and although that's ok in practice (we don't have SPLPAR
machines with mpic), I'd rather have the two concepts stay separate.
So move the vpa unregister into pseries_kexec_cpu_down(), which gets called
by both the xics and mpic routines. This also gives us an obvious place to
put any new kexec-down logic needed in future.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Call chip->eoi(irq) to clear any pending interrupt in case of kdump
shutdown sequence. chip->end(irq) does not serve this purpose.
Signed-off-by: Mohan Kumar M <mohan@in.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Take default arch/*/kernel/audit.c to lib/, have those with special
needs (== biarch) define AUDIT_ARCH in their Kconfig.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
New sparse caught that typo which could have caused erratic hardware
behaviour on some machines if the platform functions are used by the
firmware to change bits in some FCR registers.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The port to genirq & the new powerpc interrupt model in 2.6.18 introduced a
bug in the legacy PowerMac PIC code (used on older machines) because of a
typo potentially causing hangs due to interrupt storms. This fixes it,
along with a performance issue causing us to do spurrious retriggers after
masking an interrupt.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
