| Message ID | 20210106011750.13709-3-paulmck@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Export return addresses etc. for better diagnostics | expand |
On 1/6/21 2:17 AM, paulmck@kernel.org wrote: > From: "Paul E. McKenney" <paulmck@kernel.org> > > This commit adds vmalloc() support to mem_dump_obj(). Note that the > vmalloc_dump_obj() function combines the checking and dumping, in > contrast with the split between kmem_valid_obj() and kmem_dump_obj(). > The reason for the difference is that the checking in the vmalloc() > case involves acquiring a global lock, and redundant acquisitions of > global locks should be avoided, even on not-so-fast paths. > > Note that this change causes on-stack variables to be reported as > vmalloc() storage from kernel_clone() or similar, depending on the degree > of inlining that your compiler does. This is likely more helpful than > the earlier "non-paged (local) memory". > > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> > Cc: <linux-mm@kvack.org> > Reported-by: Andrii Nakryiko <andrii@kernel.org> > Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Acked-by: Vlastimil Babka <vbabka@suse.cz>
diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h index 80c0181..c18f475 100644 --- a/include/linux/vmalloc.h +++ b/include/linux/vmalloc.h @@ -246,4 +246,10 @@ pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms) int register_vmap_purge_notifier(struct notifier_block *nb); int unregister_vmap_purge_notifier(struct notifier_block *nb); +#ifdef CONFIG_MMU +bool vmalloc_dump_obj(void *object); +#else +static inline bool vmalloc_dump_obj(void *object) { return false; } +#endif + #endif /* _LINUX_VMALLOC_H */ diff --git a/mm/util.c b/mm/util.c index 92f23d2..5487022 100644 --- a/mm/util.c +++ b/mm/util.c @@ -996,18 +996,20 @@ int __weak memcmp_pages(struct page *page1, struct page *page2) */ void mem_dump_obj(void *object) { + if (kmem_valid_obj(object)) { + kmem_dump_obj(object); + return; + } + if (vmalloc_dump_obj(object)) + return; if (!virt_addr_valid(object)) { if (object == NULL) pr_cont(" NULL pointer.\n"); else if (object == ZERO_SIZE_PTR) pr_cont(" zero-size pointer.\n"); else - pr_cont(" non-paged (local) memory.\n"); - return; - } - if (kmem_valid_obj(object)) { - kmem_dump_obj(object); + pr_cont(" non-paged memory.\n"); return; } - pr_cont(" non-slab memory.\n"); + pr_cont(" non-slab/vmalloc memory.\n"); } diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 4d88fe5..c274ea4 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -3448,6 +3448,18 @@ void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms) } #endif /* CONFIG_SMP */ +bool vmalloc_dump_obj(void *object) +{ + struct vm_struct *vm; + void *objp = (void *)PAGE_ALIGN((unsigned long)object); + + vm = find_vm_area(objp); + if (!vm) + return false; + pr_cont(" vmalloc allocated at %pS\n", vm->caller); + return true; +} + #ifdef CONFIG_PROC_FS static void *s_start(struct seq_file *m, loff_t *pos) __acquires(&vmap_purge_lock)