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This is some preliminary work to improve TLB management on SW loaded
TLB powerpc platforms. This introduce support for non-atomic PTE
operations in pgtable-ppc32.h and removes write back to the PTE from
the TLB miss handlers. In addition, the DSI interrupt code no longer
tries to fixup write permission, this is left to generic code, and
_PAGE_HWWRITE is gone.
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
Signed-off-by: Josh Boyer <[email protected]>
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This makes the setjmp/longjmp code used by xmon, generically available
to other code. It also removes the requirement for debugger hooks to
be only called on 0x300 (data storage) exception.
Signed-off-by: Michael Neuling <[email protected]>
Signed-off-by: Paul Mackerras <[email protected]>
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Signed-off-by: Joe Perches <[email protected]>
Signed-off-by: Paul Mackerras <[email protected]>
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On 4xx CPUs, the current implementation of flush_tlb_page() uses
a low level _tlbie() assembly function that only works for the
current PID. Thus, invalidations caused by, for example, a COW
fault triggered by get_user_pages() from a different context will
not work properly, causing among other things, gdb breakpoints
to fail.
This patch adds a "pid" argument to _tlbie() on 4xx processors,
and uses it to flush entries in the right context. FSL BookE
also gets the argument but it seems they don't need it (their
tlbivax form ignores the PID when invalidating according to the
document I have).
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
Acked-by: Kumar Gala <[email protected]>
Signed-off-by: Josh Boyer <[email protected]>
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is_init() is an ambiguous name for the pid==1 check. Split it into
is_global_init() and is_container_init().
A cgroup init has it's tsk->pid == 1.
A global init also has it's tsk->pid == 1 and it's active pid namespace
is the init_pid_ns. But rather than check the active pid namespace,
compare the task structure with 'init_pid_ns.child_reaper', which is
initialized during boot to the /sbin/init process and never changes.
Changelog:
2.6.22-rc4-mm2-pidns1:
- Use 'init_pid_ns.child_reaper' to determine if a given task is the
global init (/sbin/init) process. This would improve performance
and remove dependence on the task_pid().
2.6.21-mm2-pidns2:
- [Sukadev Bhattiprolu] Changed is_container_init() calls in {powerpc,
ppc,avr32}/traps.c for the _exception() call to is_global_init().
This way, we kill only the cgroup if the cgroup's init has a
bug rather than force a kernel panic.
[[email protected]: fix comment]
[[email protected]: Use is_global_init() in arch/m32r/mm/fault.c]
[[email protected]: kernel/pid.c: remove unused exports]
[[email protected]: Fix capability.c to work with threaded init]
Signed-off-by: Serge E. Hallyn <[email protected]>
Signed-off-by: Sukadev Bhattiprolu <[email protected]>
Acked-by: Pavel Emelianov <[email protected]>
Cc: Eric W. Biederman <[email protected]>
Cc: Cedric Le Goater <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Herbert Poetzel <[email protected]>
Cc: Kirill Korotaev <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Classic 32-bit PowerPC CPUs, and the early 64-bit PowerPC CPUs, don't
provide a way to prevent execution from readable pages, that is, the
MMU doesn't distinguish between data reads and instruction reads,
although a different exception is taken for faults in data accesses
and instruction accesses.
Commit 9ba4ace39fdfe22268daca9f28c5df384ae462cf, in the course of
fixing another bug, added a check that meant that a page fault due
to an instruction access would fail if the vma did not have the
VM_EXEC flag set. This gives an inconsistent enforcement on these
CPUs of the no-execute status of the vma (since reading from the page
is sufficient to allow subsequent execution from it), and causes old
versions of ppc32 glibc (2.2 and earlier) to fail, since they rely
on executing the word before the GOT but don't have it marked
executable.
This fixes the problem by allowing execution from readable (or writable)
areas on CPUs which do not provide separate control over data and
instruction reads.
Signed-off-by: Paul Mackerras <[email protected]>
Acked-by: Jon Loeliger <[email protected]>
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This patch completes Linus's wish that the fault return codes be made into
bit flags, which I agree makes everything nicer. This requires requires
all handle_mm_fault callers to be modified (possibly the modifications
should go further and do things like fault accounting in handle_mm_fault --
however that would be for another patch).
[[email protected]: fix alpha build]
[[email protected]: fix s390 build]
[[email protected]: fix sparc build]
[[email protected]: fix sparc64 build]
[[email protected]: fix ia64 build]
Signed-off-by: Nick Piggin <[email protected]>
Cc: Richard Henderson <[email protected]>
Cc: Ivan Kokshaysky <[email protected]>
Cc: Russell King <[email protected]>
Cc: Ian Molton <[email protected]>
Cc: Bryan Wu <[email protected]>
Cc: Mikael Starvik <[email protected]>
Cc: David Howells <[email protected]>
Cc: Yoshinori Sato <[email protected]>
Cc: "Luck, Tony" <[email protected]>
Cc: Hirokazu Takata <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Cc: Roman Zippel <[email protected]>
Cc: Greg Ungerer <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Paul Mundt <[email protected]>
Cc: Kazumoto Kojima <[email protected]>
Cc: Richard Curnow <[email protected]>
Cc: William Lee Irwin III <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Jeff Dike <[email protected]>
Cc: Paolo 'Blaisorblade' Giarrusso <[email protected]>
Cc: Miles Bader <[email protected]>
Cc: Chris Zankel <[email protected]>
Acked-by: Kyle McMartin <[email protected]>
Acked-by: Haavard Skinnemoen <[email protected]>
Acked-by: Ralf Baechle <[email protected]>
Acked-by: Andi Kleen <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
[ Still apparently needs some ARM and PPC loving - Linus ]
Signed-off-by: Linus Torvalds <[email protected]>
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The "is_exec" branch of the protection check in do_page_fault()
didn't do anything on 32-bit PowerPC. So if a userland program
jumps to a page with Linux protection flags "---p", all the tests
happily fall through, and handle_mm_fault() is called, which in
turn calls handle_pte_fault(), which calls update_mmu_cache(),
which goes flush the dcache to a page with no access rights.
Boom.
This fixes it.
Signed-off-by: Segher Boessenkool <[email protected]>
Cc: Johannes Berg <[email protected]>
Signed-off-by: Paul Mackerras <[email protected]>
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We have had complaints where a threaded application is left in a bad state
after one of it's threads is killed when we hit a VM: out_of_memory
condition.
Killing just one of the process threads can leave the application in a
bad state, whereas killing the entire process group would allow for
the application to restart, or be otherwise handled, and makes it very
obvious that something has gone wrong.
This change allows the entire process group to be taken down, rather than
just the one thread.
lightly tested on powerpc
Signed-off-by: Will <[email protected]>
Signed-off-by: Paul Mackerras <[email protected]>
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git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc
* 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc: (77 commits)
[POWERPC] Abolish powerpc_flash_init()
[POWERPC] Early serial debug support for PPC44x
[POWERPC] Support for the Ebony 440GP reference board in arch/powerpc
[POWERPC] Add device tree for Ebony
[POWERPC] Add powerpc/platforms/44x, disable platforms/4xx for now
[POWERPC] MPIC U3/U4 MSI backend
[POWERPC] MPIC MSI allocator
[POWERPC] Enable MSI mappings for MPIC
[POWERPC] Tell Phyp we support MSI
[POWERPC] RTAS MSI implementation
[POWERPC] PowerPC MSI infrastructure
[POWERPC] Rip out the existing powerpc msi stubs
[POWERPC] Remove use of 4level-fixup.h for ppc32
[POWERPC] Add powerpc PCI-E reset API implementation
[POWERPC] Holly bootwrapper
[POWERPC] Holly DTS
[POWERPC] Holly defconfig
[POWERPC] Add support for 750CL Holly board
[POWERPC] Generalize tsi108 PCI setup
[POWERPC] Generalize tsi108 PHY types
...
Fixed conflict in include/asm-powerpc/kdebug.h manually
Signed-off-by: Linus Torvalds <[email protected]>
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This patch moves the die notifier handling to common code. Previous
various architectures had exactly the same code for it. Note that the new
code is compiled unconditionally, this should be understood as an appel to
the other architecture maintainer to implement support for it aswell (aka
sprinkling a notify_die or two in the proper place)
arm had a notifiy_die that did something totally different, I renamed it to
arm_notify_die as part of the patch and made it static to the file it's
declared and used at. avr32 used to pass slightly less information through
this interface and I brought it into line with the other architectures.
[[email protected]: build fix]
[[email protected]: fix vmalloc_sync_all bustage]
[[email protected]: fix vmalloc_sync_all in nommu]
Signed-off-by: Christoph Hellwig <[email protected]>
Cc: <[email protected]>
Cc: Russell King <[email protected]>
Signed-off-by: Bryan Wu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Call the kprobes pagefault handler directly instead of going through
the complex notifier chain.
Signed-off-by: Christoph Hellwig <[email protected]>
Signed-off-by: Paul Mackerras <[email protected]>
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bad_page_fault() prints a message telling the user what type of bad
fault we took. The first line of this message is currently implemented
as two separate printks. This has the unfortunate effect that if
several cpus simultaneously take a bad fault, the first and second parts
of the printk get jumbled up, which looks dodge and is hard to read.
So do a single one-line printk for each fault type.
Signed-off-by: Michael Ellerman <[email protected]>
Signed-off-by: Paul Mackerras <[email protected]>
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This is an updated version of Eric Biederman's is_init() patch.
(http://lkml.org/lkml/2006/2/6/280). It applies cleanly to 2.6.18-rc3 and
replaces a few more instances of ->pid == 1 with is_init().
Further, is_init() checks pid and thus removes dependency on Eric's other
patches for now.
Eric's original description:
There are a lot of places in the kernel where we test for init
because we give it special properties. Most significantly init
must not die. This results in code all over the kernel test
->pid == 1.
Introduce is_init to capture this case.
With multiple pid spaces for all of the cases affected we are
looking for only the first process on the system, not some other
process that has pid == 1.
Signed-off-by: Eric W. Biederman <[email protected]>
Signed-off-by: Sukadev Bhattiprolu <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Serge Hallyn <[email protected]>
Cc: Cedric Le Goater <[email protected]>
Cc: <[email protected]>
Acked-by: Paul Mackerras <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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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 <[email protected]>
Cc: Russell King <[email protected]>
Cc: "Luck, Tony" <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Roman Zippel <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Acked-by: Andi Kleen <[email protected]>
Acked-by: Alan Cox <[email protected]>
Cc: Arjan van de Ven <[email protected]>
Acked-by: Paul Mundt <[email protected]>
Cc: Kazumoto Kojima <[email protected]>
Cc: Ian Molton <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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Signed-off-by: Jörn Engel <[email protected]>
Signed-off-by: Adrian Bunk <[email protected]>
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Overloading of page fault notification with the notify_die() has performance
issues(since the only interested components for page fault is kprobes and/or
kdb) and hence this patch introduces the new notifier call chain exclusively
for page fault notifications their by avoiding notifying unnecessary
components in the do_page_fault() code path.
Signed-off-by: Anil S Keshavamurthy <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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This comment exceeded my bad spelling threshold :)
Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Paul Mackerras <[email protected]>
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Fix 44x and BookE page fault handler to correctly lock PTE before
trying to pte_update() it, otherwise this PTE might be swapped out
after pte_present() check but before pte_uptdate() call, resulting in
corrupted PTE. This can happen with enabled preemption and low memory
condition.
Signed-off-by: Eugene Surovegin <[email protected]>
Signed-off-by: Paul Mackerras <[email protected]>
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This patch removes all self references and fixes references to files
in the now defunct arch/ppc64 tree. I think this accomplises
everything wanted, though there might be a few references I missed.
Signed-off-by: Jon Mason <[email protected]>
Signed-off-by: Paul Mackerras <[email protected]>
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When taking a DABR exception we were reporting the PC. It makes more
sense to report the address that caused the exception, and the gdb guys
would like it that way.
Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: Paul Mackerras <[email protected]>
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Add nicer printing of faulting address on unresolvable kernel faults.
Makes life a little easier for those who don't know how to decode our
register contents at oops time.
Signed-off-by: Olof Johansson <[email protected]>
Signed-off-by: Paul Mackerras <[email protected]>
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do_dabr() is not relevant on 40x or Book-E processors so dont build it
Signed-off-by: Kumar K. Gala <[email protected]>
Signed-off-by: Paul Mackerras <[email protected]>
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This creates the directory structure under arch/powerpc and a bunch
of Kconfig files. It does a first-cut merge of arch/powerpc/mm,
arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough
to build a 32-bit powermac kernel with ARCH=powerpc.
For now we are getting some unmerged files from arch/ppc/kernel and
arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes
to files in those directories and files outside arch/powerpc.
The boot directory is still not merged. That's going to be interesting.
Signed-off-by: Paul Mackerras <[email protected]>
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