diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2008-11-19 18:51:56 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-11-19 18:51:56 -0800 |
| commit | 4f7dbc7ff4ec19b40ec083f7c54a87d3ece0089d (patch) | |
| tree | c37f34eee23ae96c78f72e445ad20f8fbcab010e /arch/x86/kernel/ds.c | |
| parent | 9f92f4719764acf1c9185a5958200887a43e3483 (diff) | |
| parent | 73f56c0d35e6427081a4eabd620d8b8d8a35bd09 (diff) | |
Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: more general identifier for Phoenix BIOS
AMD IOMMU: check for next_bit also in unmapped area
AMD IOMMU: fix fullflush comparison length
AMD IOMMU: enable device isolation per default
AMD IOMMU: add parameter to disable device isolation
x86, PEBS/DS: fix code flow in ds_request()
x86: add rdtsc barrier to TSC sync check
xen: fix scrub_page()
x86: fix es7000 compiling
x86, bts: fix unlock problem in ds.c
x86, voyager: fix smp generic helper voyager breakage
x86: move iomap.h to the new include location
Diffstat (limited to 'arch/x86/kernel/ds.c')
| -rw-r--r-- | arch/x86/kernel/ds.c | 25 |
1 files changed, 21 insertions, 4 deletions
diff --git a/arch/x86/kernel/ds.c b/arch/x86/kernel/ds.c index 2b69994fd3a8..d1a121443bde 100644 --- a/arch/x86/kernel/ds.c +++ b/arch/x86/kernel/ds.c @@ -236,17 +236,33 @@ static inline struct ds_context *ds_alloc_context(struct task_struct *task) struct ds_context *context = *p_context; if (!context) { + spin_unlock(&ds_lock); + context = kzalloc(sizeof(*context), GFP_KERNEL); - if (!context) + if (!context) { + spin_lock(&ds_lock); return NULL; + } context->ds = kzalloc(ds_cfg.sizeof_ds, GFP_KERNEL); if (!context->ds) { kfree(context); + spin_lock(&ds_lock); return NULL; } + spin_lock(&ds_lock); + /* + * Check for race - another CPU could have allocated + * it meanwhile: + */ + if (*p_context) { + kfree(context->ds); + kfree(context); + return *p_context; + } + *p_context = context; context->this = p_context; @@ -384,14 +400,15 @@ static int ds_request(struct task_struct *task, void *base, size_t size, spin_lock(&ds_lock); - if (!check_tracer(task)) - return -EPERM; - error = -ENOMEM; context = ds_alloc_context(task); if (!context) goto out_unlock; + error = -EPERM; + if (!check_tracer(task)) + goto out_unlock; + error = -EALREADY; if (context->owner[qual] == current) goto out_unlock; |