kernel.git/arch/sh/mm, branch linux-2.6.19.y

sh: Zero-out coherent buffer in consistent_alloc().

2006-10-10T09:33:10Z

Be sure to zero out the buffer, this was causing occasional problems under heavier PCI tests. Signed-off-by: Paul Mundt

sh: build fixes for defconfigs.

2006-10-03T04:14:04Z

Get all of the defconfigs building again. Signed-off-by: Paul Mundt

[PATCH] pidspace: is_init()

2006-09-29T16:18:12Z

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 Signed-off-by: Sukadev Bhattiprolu Cc: Dave Hansen Cc: Serge Hallyn Cc: Cedric Le Goater Cc: Acked-by: Paul Mackerras Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] make PROT_WRITE imply PROT_READ

2006-09-29T16:18:05Z

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 Cc: Russell King Cc: "Luck, Tony" Cc: Hugh Dickins Cc: Roman Zippel Cc: Geert Uytterhoeven Cc: Paul Mackerras Cc: Benjamin Herrenschmidt Acked-by: Andi Kleen Acked-by: Alan Cox Cc: Arjan van de Ven Acked-by: Paul Mundt Cc: Kazumoto Kojima Cc: Ian Molton Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

sh: Fix occasional flush_cache_4096() stack corruption.

2006-09-27T09:37:30Z

IRQs disabling in flush_cache_4096 for cache purge. Under certain workloads we would get an IRQ in the middle of a purge operation, and the cachelines would remain in an inconsistent state, leading to occasional stack corruption. Signed-off-by: Takeo Takahashi Signed-off-by: Paul Mundt

sh: Initial vsyscall page support.

2006-09-27T09:33:49Z

This implements initial support for the vsyscall page on SH. At the moment we leave it configurable due to having nommu to support from the same code base. We hook it up for the signal trampoline return at present, with more to be added later, once uClibc catches up. Signed-off-by: Paul Mundt

sh: Selective flush_cache_mm() flushing.

2006-09-27T09:30:07Z

flush_cache_mm() wraps in to flush_cache_all(), which is rather excessive given that the number of PTEs within the specified context are generally quite low. Optimize for walking the mm's VMA list and selectively flushing the VMA ranges from the dcache. Invalidate the icache only if a VMA sets VM_EXEC. Signed-off-by: Paul Mundt

sh: Enable /proc/kcore support.

2006-09-27T09:20:58Z

This was previously unimplemented.. Signed-off-by: Paul Mundt

sh: Add support for cacheline poking through debugfs.

2006-09-27T08:51:01Z

A simple debugging aid for easier visibility of the respective cachelines. Signed-off-by: Paul Mundt

sh: Add support for SH7706/SH7710/SH7343 CPUs.

2006-09-27T08:38:11Z

This adds support for the aforementioned CPU subtypes, and cleans up some build issues encountered as a result. Signed-off-by: Paul Mundt