The patch titled
NOMMU: Make futexes work under NOMMU conditions
has been added to the -mm tree. Its filename is
nommu-make-futexes-work-under-nommu-conditions.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: NOMMU: Make futexes work under NOMMU conditions
From: David Howells <dhowells@xxxxxxxxxx>
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 <dhowells@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
mm/nommu.c | 14 +++++++++-----
1 files changed, 9 insertions(+), 5 deletions(-)
diff -puN mm/nommu.c~nommu-make-futexes-work-under-nommu-conditions mm/nommu.c
--- a/mm/nommu.c~nommu-make-futexes-work-under-nommu-conditions
+++ a/mm/nommu.c
@@ -350,6 +350,15 @@ struct vm_area_struct *find_vma(struct m
EXPORT_SYMBOL(find_vma);
/*
+ * find a VMA
+ * - we don't extend stack VMAs under NOMMU conditions
+ */
+struct vm_area_struct *find_extend_vma(struct mm_struct *mm, unsigned long addr)
+{
+ return find_vma(mm, addr);
+}
+
+/*
* look up the first VMA exactly that exactly matches addr
* - should be called with mm->mmap_sem at least held readlocked
*/
@@ -1153,11 +1162,6 @@ struct page *follow_page(struct vm_area_
return NULL;
}
-struct vm_area_struct *find_extend_vma(struct mm_struct *mm, unsigned long addr)
-{
- return NULL;
-}
-
int remap_pfn_range(struct vm_area_struct *vma, unsigned long from,
unsigned long to, unsigned long size, pgprot_t prot)
{
_
Patches currently in -mm which might be from dhowells@xxxxxxxxxx are
git-block.patch
git-block-hack.patch
git-gfs2.patch
git-nfs.patch
nfs-replace-null-dentries-that-appear-in-readdirs-list-2.patch
binfmt_elf-consistently-use-loff_t.patch
nommu-check-that-access_process_vm-has-a-valid-target.patch
nommu-set-bdi-capabilities-for-dev-mem-and-dev-kmem.patch
nommu-set-bdi-capabilities-for-dev-mem-and-dev-kmem-tidy.patch
nommu-use-find_vma-rather-than-reimplementing-a-vma-search.patch
check-if-start-address-is-in-vma-region-in-nommu-function-get_user_pages.patch
nommu-check-vma-protections.patch
nommu-permit-ptrace-to-ignore-non-prot_write-vmas-in-nommu-mode.patch
nommu-implement-proc-pid-maps-for-nommu.patch
nommu-order-the-per-mm_struct-vma-list.patch
nommu-make-mremap-partially-work-for-nommu-kernels.patch
nommu-add-docs-about-shared-memory.patch
nommu-make-futexes-work-under-nommu-conditions.patch
afs-add-lock-annotations-to-afs_proc_cell_servers_startstop.patch
elf_fdpic_core_dump-dont-take-tasklist_lock.patch
simplify-update_times-avoid-jiffies-jiffies_64-aliasing-problem-2.patch
lib-rwsemc-un-inline-rwsem_down_failed_common.patch
reiserfs-make-sure-all-dentries-refs-are-released-before-calling-kill_block_super-try-2.patch
fs-cache-provide-a-filesystem-specific-syncable-page-bit.patch
fs-cache-generic-filesystem-caching-facility.patch
fs-cache-release-page-private-in-failed-readahead.patch
fs-cache-release-page-private-after-failed-readahead-12.patch
fs-cache-make-kafs-use-fs-cache.patch
fs-cache-make-kafs-use-fs-cache-fix.patch
fs-cache-make-kafs-use-fs-cache-12.patch
fs-cache-make-kafs-use-fs-cache-12-fix.patch
fs-cache-make-kafs-use-fs-cache-vs-streamline-generic_file_-interfaces-and-filemap.patch
nfs-use-local-caching.patch
nfs-use-local-caching-12.patch
nfs-use-local-caching-12-fix.patch
fs-cache-cachefiles-ia64-missing-copy_page-export.patch
fs-cache-cachefiles-a-cache-that-backs-onto-a-mounted-filesystem.patch
fs-cache-cachefiles-a-cache-that-backs-onto-a-mounted-filesystem-cachefiles-printk-format-warning.patch
fs-cache-cachefiles-a-cache-that-backs-onto-a-mounted-filesystem-warning-fixes.patch
fs-cache-cachefiles-a-cache-that-backs-onto-a-mounted-filesystem-cachefiles-cachefiles_write_page-shouldnt-indicate-error-twice.patch
fs-cache-cachefiles-a-cache-that-backs-onto-a-mounted-filesystem-cachefiles-handle-enospc-on-create-mkdir-better.patch
fs-cache-cachefiles-a-cache-that-backs-onto-a-mounted-filesystem-inode-count-maintenance.patch
autofs-make-sure-all-dentries-refs-are-released-before-calling-kill_anon_super.patch
vfs-destroy-the-dentries-contributed-by-a-superblock-on-unmounting.patch
vfs-make-filldir_t-and-struct-kstat-deal-in-64-bit-inode-numbers.patch
vfs-make-filldir_t-and-struct-kstat-deal-in-64-bit-inode-numbers-alpha-fix.patch
nfs-represent-64-bit-fileids-as-64-bit-inode-numbers-on-32-bit-systems.patch
ecryptfs-get_sb_dev-fix.patch
introduce-kernel_execve.patch
rename-the-provided-execve-functions-to-kernel_execve.patch
provide-kernel_execve-on-all-architectures.patch
provide-kernel_execve-on-all-architectures-fix.patch
remove-the-use-of-_syscallx-macros-in-uml.patch
sh64-remove-the-use-of-kernel-syscalls.patch
remove-remaining-errno-and-__kernel_syscalls__-references.patch
reiser4-get_sb_dev-fix.patch
mutex-subsystem-synchro-test-module.patch
-
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