- 27 Sep, 2006 40 commits
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Vivek Goyal authored
Resetting the devices during driver initialization can be a costly operation in terms of time (especially scsi devices). This option can be used by drivers to know that user forcibly wants the devices to be reset during initialization. This option can be useful while kernel is booting in unreliable environment. For ex. during kdump boot where devices are in unknown random state and BIOS execution has been skipped. Signed-off-by:
Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by:
Andrew Morton <akpm@osdl.org> Signed-off-by:
Linus Torvalds <torvalds@osdl.org>
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Ian Kent authored
For a long time now I have had a problem with not being able to return a lookup failure on an existsing directory. In autofs this corresponds to a mount failure on a autofs managed mount entry that is browsable (and so the mount point directory exists). While this problem has been present for a long time I've avoided resolving it because it was not very visible. But now that autofs v5 has "mount and expire on demand" of nested multiple mounts, such as is found when mounting an export list from a server, solving the problem cannot be avoided any longer. I've tried very hard to find a way to do this entirely within the autofs4 module but have not been able to find a satisfactory way to achieve it. So, I need to propose a change to the VFS. Signed-off-by:
Ian Kent <raven@themaw.net> Signed-off-by:
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Jeff Dike authored
Fix an instance of ptr=alloc(sizeof(ptr)). Grepping showed no more instances of this pattern. Also fixed the formatting in the area. Signed-off-by:
Jeff Dike <jdike@addtoit.com> Signed-off-by:
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Jeff Dike authored
um_timer shouldn't add local_offset to the host time since get_time already did it. This threw off sleep when a settimeofday or equivalent had happened. Signed-off-by:
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Jeff Dike authored
Some modules need strnlen_user_skas. Signed-off-by:
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Jeff Dike authored
Move some foo_kern.c files to foo.c now that the old foo.c files are out of the way. Also cleaned up some whitespace and an emacs formatting comment. Signed-off-by:
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Jeff Dike authored
fork on UML has always somewhat subtle. The underlying cause has been the need to initialize a stack for the new process. The only portable way to initialize a new stack is to set it as the alternate signal stack and take a signal. The signal handler does whatever initialization is needed and jumps back to the original stack, where the fork processing is finished. The basic context switching mechanism is a jmp_buf for each process. You switch to a new process by longjmping to its jmp_buf. Now that UML has its own implementation of setjmp and longjmp, and I can poke around inside a jmp_buf without fear that libc will change the structure, a much simpler mechanism is possible. The jmpbuf can simply be initialized by hand. This eliminates - the need to set up and remove the alternate signal stack sending and handling a signal the signal blocking needed around the stack switching, since there is no stack switching setting up the jmp_buf needed to jump back to the original stack after the new one is set up In addition, since jmp_buf is now defined by UML, and not by libc, it can be embedded in the thread struct. This makes it unnecessary to have it exist on the stack, where it used to be. It also simplifies interfaces, since the switch jmp_buf used to be a void * inside the thread struct, and functions which took it as an argument needed to define a jmp_buf variable and assign it from the void *. Signed-off-by:
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Jeff Dike authored
Mark a symbol and file as being tt-mode only. This shrinks the binary slightly when tt mode support is compiled out and makes it easier to identity stuff when tt mode is removed. Signed-off-by:
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Jeff Dike authored
Make checkstack work for UML. We need to pass the underlying architecture name, rather than "um" to checkstack.pl. Signed-off-by:
Matt Mackall <mpm@selenic.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by:
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Jeff Dike authored
BB noticed that we had the wrong bus error handler. Signed-off-by:
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Jeff Dike authored
Make __bb_init_func weak in order to avoid a link failure with some libcs and/or gccs. Signed-off-by:
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Jeff Dike authored
The UML/x86_64 headers were missing ptrace support for some segment registers. The underlying problem was that the x86_64 kernel uses user_regs_struct rather than the ptrace register definitions in ptrace. This patch switches UML/x86_64 to using user_regs_struct for its definitions of the host's registers. Signed-off-by:
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Jeff Dike authored
ZONE_DMA might become dependent on CONFIG_ZONE_DMA, which UML doesn't define (we're still arguing about this) So, let's change ZONE_DMA to ZONE_NORMAL. This is prompted by optional-zone_dma-in-the-vm.patch, but should be harmless on its own. Signed-off-by:
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Jeff Dike authored
Make lots of structures const in order to make it obvious that they need no locking. Signed-off-by:
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Paolo 'Blaisorblade' Giarrusso authored
This spinlock can be taken on interrupt too, so spin_lock_irq[save] must be used. However, Documentation/networking/netdevices.txt explains we are called with rtnl_lock() held - so we don't need to care about other concurrent opens. Verified also in LDD3 and by direct checking. Also verified that the network layer (through a state machine) guarantees us that nobody will close the interface while it's being used. Please correct me if I'm wrong. Also, we must check we don't sleep with irqs disabled!!! But anyway, this is not news - we already can't sleep while holding a spinlock. Who says this is guaranted really by the present code? Signed-off-by:
Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Jeff Dike <jdike@addtoit.com> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by:
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Paolo 'Blaisorblade' Giarrusso authored
We have never used this flag and recently one user experienced a complaining warning about this (there was a symbol in the positive half of the address space IIRC). So fix it. Signed-off-by:
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Hirokazu Takata authored
Signed-off-by:
Hirokazu Takata <takata@linux-m32r.org> Cc: Matthew Wilcox <matthew@wil.cx> Signed-off-by:
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Hirokazu Takata authored
Fix to remove annoying gcc-4.1 warnings "value computed not used" for m32r; Modify set_mb to cast to void for SMP. Signed-off-by:
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David Howells authored
Move the fallback arch_vma_name() to a sensible place (kernel/signal.c). Currently it's in fs/proc/task_mmu.c, a file that is dependent on both CONFIG_PROC_FS and CONFIG_MMU being enabled, but it's used from kernel/signal.c from where it is called unconditionally. [akpm@osdl.org: build fix] Signed-off-by:
David Howells <dhowells@redhat.com> Signed-off-by:
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David Howells authored
Make futexes work under NOMMU conditions. This can be tested by running this in one shell: #define SYSERROR(X, Y) \ do { if ((long)(X) == -1L) { perror(Y); exit(1); }} while(0) int main() { int shmid, tmp, *f, n; shmid = shmget(23, 4, IPC_CREAT|0666); SYSERROR(shmid, "shmget"); f = shmat(shmid, NULL, 0); SYSERROR(f, "shmat"); n = *f; printf("WAIT: %p{%x}\n", f, n); tmp = futex(f, FUTEX_WAIT, n, NULL, NULL, 0); SYSERROR(tmp, "futex"); printf("WAITED: %d\n", tmp); tmp = shmdt(f); SYSERROR(tmp, "shmdt"); exit(0); } And then this in the other shell: #define SYSERROR(X, Y) \ do { if ((long)(X) == -1L) { perror(Y); exit(1); }} while(0) int main() { int shmid, tmp, *f; shmid = shmget(23, 4, IPC_CREAT|0666); SYSERROR(shmid, "shmget"); f = shmat(shmid, NULL, 0); SYSERROR(f, "shmat"); (*f)++; printf("WAKE: %p{%x}\n", f, *f); tmp = futex(f, FUTEX_WAKE, 1, NULL, NULL, 0); SYSERROR(tmp, "futex"); printf("WOKE: %d\n", tmp); tmp = shmdt(f); SYSERROR(tmp, "shmdt"); exit(0); } The first program will set up a SYSV IPC SHM segment and wait on a futex in it for the number at the start to change. The program will increment that number and wake the first program up. This leads to output of the form: SHELL 1 SHELL 2 ======================= ======================= # /dowait WAIT: 0xc32ac000{0} # /dowake WAKE: 0xc32ac000{1} WAITED: 0 WOKE: 1 Signed-off-by: -
David Howells authored
Add documentation about using shared memory in NOMMU mode. Signed-off-by:
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David Howells authored
Make mremap() partially work for NOMMU kernels. It may resize a VMA provided that it doesn't exceed the size of the slab object in which the storage is allocated that the VMA refers to. Shareable VMAs may not be resized. Moving VMAs (as permitted by MREMAP_MAYMOVE) is not currently supported. This patch also makes use of the fact that the VMA list is now ordered to cut it short when possible. Signed-off-by:
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David Howells authored
Order the per-mm_struct VMA list by address so that searching it can be cut short when the appropriate address has been exceeded. Signed-off-by:
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David Howells authored
Implement /proc/pid/maps for NOMMU by reading the vm_area_list attached to current->mm->context.vmlist. Signed-off-by:
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David Howells authored
Permit ptrace to modify a section that's non-shared but is marked unwritable, such as is obtained by mapping the text segment of an ELF-FDPIC executable binary with into a binary that's being ptraced[*]. [*] Under NOMMU conditions ptrace causes read-only MAP_PRIVATE mmaps to become totally private copies because if a private mapping was actually shared then the debugging setting breakpoints in it would potentially crash other processes. This is done by using the VM_MAYWRITE flag rather than the VM_WRITE flag when deciding whether to permit a write. Without this patch a debugger can't set breakpoints in the mapped text sections of executables that are mapped read-only private, even if the mmap() syscall has taken a private copy because PT_PTRACED is set. In addition, VM_MAYREAD is used instead of VM_READ for similar reasons. Signed-off-by: -
David Howells authored
Check the VMA protections in get_user_pages() against what's being asked. This checks to see that we don't accidentally write on a non-writable VMA or permit an I/O mapping VMA to be accessed (which may lack page structs). Signed-off-by:
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Sonic Zhang authored
In NOMMU arch, if run "cat /proc/self/mem", data from physical address 0 are read. This behavior is different from MMU arch. In IA32, message "cat: /proc/self/mem: Input/output error" is reported. This issue is rootcaused by not validate the start address in NOMMU function get_user_pages(). Following patch solves this issue. Signed-off-by:
Sonic Zhang <sonic.adi@gmail.com> Cc: David Howells <dhowells@redhat.com> Signed-off-by:
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David Howells authored
Use find_vma() in the NOMMU version of access_process_vm() rather than reimplementing it. Signed-off-by:
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David Howells authored
Set the backing device info capabilities for /dev/mem and /dev/kmem to permit direct sharing under no-MMU conditions and full mapping capabilities under MMU conditions. Make the BDI used by these available to all directly mappable character devices. Also comment the capabilities for /dev/zero. [akpm@osdl.org: ifdef reductions] Signed-off-by:
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David Howells authored
Check that access_process_vm() is accessing a valid mapping in the target process. This limits ptrace() accesses and accesses through /proc/<pid>/maps to only those regions actually mapped by a program. Signed-off-by:
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Haavard Skinnemoen authored
Signed-off-by:
Haavard Skinnemoen <hskinnemoen@atmel.com> Signed-off-by:
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Rolf Eike Beer authored
The function is exported but not used from anywhere else. It's also marked as "not for driver use" so noone out there should really care. Signed-off-by:
Rolf Eike Beer <eike-kernel@sf-tec.de> Signed-off-by:
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Rolf Eike Beer authored
The empty line between the short description and the first argument description causes a section to appear twice in the generated manpage. Also the short description should really be short: the script can't handle multiple lines. Signed-off-by:
Randy Dunlap <rdunlap@xenotime.net> Signed-off-by:
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Randy Dunlap authored
Use NULL instead of 0 for pointer value, eliminate sparse warnings. Signed-off-by:
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Jes Sorensen authored
Implement the special memory driver (mspec) based on the do_no_pfn approach. The driver is currently used only on SN2 hardware with special fetchop support but could be beneficial on other architectures using the uncached mode. Signed-off-by:
Jes Sorensen <jes@sgi.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by:
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Jes Sorensen authored
Implement do_no_pfn() for handling mapping of memory without a struct page backing it. This avoids creating fake page table entries for regions which are not backed by real memory. This feature is used by the MSPEC driver and other users, where it is highly undesirable to have a struct page sitting behind the page (for instance if the page is accessed in cached mode via the struct page in parallel to the the driver accessing it uncached, which can result in data corruption on some architectures, such as ia64). This version uses specific NOPFN_{SIGBUS,OOM} return values, rather than expect all negative pfn values would be an error. It also bugs on cow mappings as this would not work with the VM. [akpm@osdl.org: micro-optimise] Signed-off-by: -
Christoph Lameter authored
Now that we have the node in the hot zone of struct zone we can avoid accessing zone_pgdat in zone_statistics. Signed-off-by:
Christoph Lameter <clameter@sgi.com> Signed-off-by:
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Christoph Lameter authored
We do not need to allocate pagesets for unpopulated zones. Signed-off-by:
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Christoph Lameter authored
Add the node in order to optimize zone_to_nid. Signed-off-by:
Paul Jackson <pj@sgi.com> Signed-off-by:
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Christoph Lameter authored
This patch insures that the slab node lists in the NUMA case only contain slabs that belong to that specific node. All slab allocations use GFP_THISNODE when calling into the page allocator. If an allocation fails then we fall back in the slab allocator according to the zonelists appropriate for a certain context. This allows a replication of the behavior of alloc_pages and alloc_pages node in the slab layer. Currently allocations requested from the page allocator may be redirected via cpusets to other nodes. This results in remote pages on nodelists and that in turn results in interrupt latency issues during cache draining. Plus the slab is handing out memory as local when it is really remote. Fallback for slab memory allocations will occur within the slab allocator and not in the page allocator. This is necessary in order to be able to use the existing pools of objects on the nodes that we fall back to before adding more pages to a slab. The fallback function insures that the nodes we fall back to obey cpuset restrictions of the current context. We do not allocate objects from outside of the current cpuset context like before. Note that the implementation of locality constraints within the slab allocator requires importing logic from the page allocator. This is a mischmash that is not that great. Other allocators (uncached allocator, vmalloc, huge pages) face similar problems and have similar minimal reimplementations of the basic fallback logic of the page allocator. There is another way of implementing a slab by avoiding per node lists (see modular slab) but this wont work within the existing slab. V1->V2: - Use NUMA_BUILD to avoid #ifdef CONFIG_NUMA - Exploit GFP_THISNODE being 0 in the NON_NUMA case to avoid another #ifdef [akpm@osdl.org: build fix] Signed-off-by:
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