* [PATCH v4 1/4] mm/vmalloc: don't set area->caller twice
@ 2013-09-03 7:01 Wanpeng Li
2013-09-03 7:01 ` [PATCH v4 2/4] mm/vmalloc: revert "mm/vmalloc.c: emit the failure message before return" Wanpeng Li
` (2 more replies)
0 siblings, 3 replies; 13+ messages in thread
From: Wanpeng Li @ 2013-09-03 7:01 UTC (permalink / raw)
To: Andrew Morton
Cc: Joonsoo Kim, David Rientjes, KOSAKI Motohiro, Zhang Yanfei,
linux-mm, linux-kernel, Wanpeng Li
Changelog:
*v1 -> v2: rebase against mmotm tree
The caller address has already been set in set_vmalloc_vm(), there's no need
to set it again in __vmalloc_area_node.
Reviewed-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
---
mm/vmalloc.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 1074543..d78d117 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1566,7 +1566,6 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
pages = kmalloc_node(array_size, nested_gfp, node);
}
area->pages = pages;
- area->caller = caller;
if (!area->pages) {
remove_vm_area(area->addr);
kfree(area);
--
1.8.1.2
--
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^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH v4 2/4] mm/vmalloc: revert "mm/vmalloc.c: emit the failure message before return" 2013-09-03 7:01 [PATCH v4 1/4] mm/vmalloc: don't set area->caller twice Wanpeng Li @ 2013-09-03 7:01 ` Wanpeng Li 2013-09-03 7:24 ` Zhang Yanfei 2013-09-03 7:01 ` [PATCH v4 3/4] mm/vmalloc: revert "mm/vmalloc.c: check VM_UNINITIALIZED flag in s_show instead of show_numa_info" Wanpeng Li 2013-09-03 7:01 ` [PATCH v4 4/4] mm/vmalloc: don't assume vmap_area w/o VM_VM_AREA flag is vm_map_ram allocation Wanpeng Li 2 siblings, 1 reply; 13+ messages in thread From: Wanpeng Li @ 2013-09-03 7:01 UTC (permalink / raw) To: Andrew Morton Cc: Joonsoo Kim, David Rientjes, KOSAKI Motohiro, Zhang Yanfei, linux-mm, linux-kernel, Wanpeng Li Changelog: *v2 -> v3: revert commit 46c001a2 directly Don't warning twice in __vmalloc_area_node and __vmalloc_node_range if __vmalloc_area_node allocation failure. This patch revert commit 46c001a2 (mm/vmalloc.c: emit the failure message before return). Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> --- mm/vmalloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index d78d117..e3ec8b4 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1635,7 +1635,7 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align, addr = __vmalloc_area_node(area, gfp_mask, prot, node, caller); if (!addr) - goto fail; + return NULL; /* * In this function, newly allocated vm_struct has VM_UNINITIALIZED -- 1.8.1.2 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply related [flat|nested] 13+ messages in thread
* Re: [PATCH v4 2/4] mm/vmalloc: revert "mm/vmalloc.c: emit the failure message before return" 2013-09-03 7:01 ` [PATCH v4 2/4] mm/vmalloc: revert "mm/vmalloc.c: emit the failure message before return" Wanpeng Li @ 2013-09-03 7:24 ` Zhang Yanfei 0 siblings, 0 replies; 13+ messages in thread From: Zhang Yanfei @ 2013-09-03 7:24 UTC (permalink / raw) To: Wanpeng Li Cc: Andrew Morton, Joonsoo Kim, David Rientjes, KOSAKI Motohiro, linux-mm, linux-kernel On 09/03/2013 03:01 PM, Wanpeng Li wrote: > Changelog: > *v2 -> v3: revert commit 46c001a2 directly > > Don't warning twice in __vmalloc_area_node and __vmalloc_node_range if > __vmalloc_area_node allocation failure. This patch revert commit 46c001a2 > (mm/vmalloc.c: emit the failure message before return). > > Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Reviewed-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> > --- > mm/vmalloc.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index d78d117..e3ec8b4 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -1635,7 +1635,7 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align, > > addr = __vmalloc_area_node(area, gfp_mask, prot, node, caller); > if (!addr) > - goto fail; > + return NULL; > > /* > * In this function, newly allocated vm_struct has VM_UNINITIALIZED > -- Thanks. Zhang Yanfei -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 13+ messages in thread
* [PATCH v4 3/4] mm/vmalloc: revert "mm/vmalloc.c: check VM_UNINITIALIZED flag in s_show instead of show_numa_info" 2013-09-03 7:01 [PATCH v4 1/4] mm/vmalloc: don't set area->caller twice Wanpeng Li 2013-09-03 7:01 ` [PATCH v4 2/4] mm/vmalloc: revert "mm/vmalloc.c: emit the failure message before return" Wanpeng Li @ 2013-09-03 7:01 ` Wanpeng Li 2013-09-03 7:24 ` Zhang Yanfei 2013-09-03 7:01 ` [PATCH v4 4/4] mm/vmalloc: don't assume vmap_area w/o VM_VM_AREA flag is vm_map_ram allocation Wanpeng Li 2 siblings, 1 reply; 13+ messages in thread From: Wanpeng Li @ 2013-09-03 7:01 UTC (permalink / raw) To: Andrew Morton Cc: Joonsoo Kim, David Rientjes, KOSAKI Motohiro, Zhang Yanfei, linux-mm, linux-kernel, Wanpeng Li Changelog: *v2 -> v3: revert commit d157a558 directly The VM_UNINITIALIZED/VM_UNLIST flag introduced by commit f5252e00(mm: avoid null pointer access in vm_struct via /proc/vmallocinfo) is used to avoid accessing the pages field with unallocated page when show_numa_info() is called. This patch move the check just before show_numa_info in order that some messages still can be dumped via /proc/vmallocinfo. This patch revert commit d157a558 (mm/vmalloc.c: check VM_UNINITIALIZED flag in s_show instead of show_numa_info); Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> --- mm/vmalloc.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index e3ec8b4..5368b17 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -2562,6 +2562,11 @@ static void show_numa_info(struct seq_file *m, struct vm_struct *v) if (!counters) return; + /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */ + smp_rmb(); + if (v->flags & VM_UNINITIALIZED) + return; + memset(counters, 0, nr_node_ids * sizeof(unsigned int)); for (nr = 0; nr < v->nr_pages; nr++) @@ -2590,11 +2595,6 @@ static int s_show(struct seq_file *m, void *p) v = va->vm; - /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */ - smp_rmb(); - if (v->flags & VM_UNINITIALIZED) - return 0; - seq_printf(m, "0x%pK-0x%pK %7ld", v->addr, v->addr + v->size, v->size); -- 1.8.1.2 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply related [flat|nested] 13+ messages in thread
* Re: [PATCH v4 3/4] mm/vmalloc: revert "mm/vmalloc.c: check VM_UNINITIALIZED flag in s_show instead of show_numa_info" 2013-09-03 7:01 ` [PATCH v4 3/4] mm/vmalloc: revert "mm/vmalloc.c: check VM_UNINITIALIZED flag in s_show instead of show_numa_info" Wanpeng Li @ 2013-09-03 7:24 ` Zhang Yanfei 0 siblings, 0 replies; 13+ messages in thread From: Zhang Yanfei @ 2013-09-03 7:24 UTC (permalink / raw) To: Wanpeng Li Cc: Andrew Morton, Joonsoo Kim, David Rientjes, KOSAKI Motohiro, linux-mm, linux-kernel On 09/03/2013 03:01 PM, Wanpeng Li wrote: > Changelog: > *v2 -> v3: revert commit d157a558 directly > > The VM_UNINITIALIZED/VM_UNLIST flag introduced by commit f5252e00(mm: avoid > null pointer access in vm_struct via /proc/vmallocinfo) is used to avoid > accessing the pages field with unallocated page when show_numa_info() is > called. This patch move the check just before show_numa_info in order that > some messages still can be dumped via /proc/vmallocinfo. This patch revert > commit d157a558 (mm/vmalloc.c: check VM_UNINITIALIZED flag in s_show instead > of show_numa_info); > > Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Reviewed-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> > --- > mm/vmalloc.c | 10 +++++----- > 1 file changed, 5 insertions(+), 5 deletions(-) > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index e3ec8b4..5368b17 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -2562,6 +2562,11 @@ static void show_numa_info(struct seq_file *m, struct vm_struct *v) > if (!counters) > return; > > + /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */ > + smp_rmb(); > + if (v->flags & VM_UNINITIALIZED) > + return; > + > memset(counters, 0, nr_node_ids * sizeof(unsigned int)); > > for (nr = 0; nr < v->nr_pages; nr++) > @@ -2590,11 +2595,6 @@ static int s_show(struct seq_file *m, void *p) > > v = va->vm; > > - /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */ > - smp_rmb(); > - if (v->flags & VM_UNINITIALIZED) > - return 0; > - > seq_printf(m, "0x%pK-0x%pK %7ld", > v->addr, v->addr + v->size, v->size); > > -- Thanks. Zhang Yanfei -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 13+ messages in thread
* [PATCH v4 4/4] mm/vmalloc: don't assume vmap_area w/o VM_VM_AREA flag is vm_map_ram allocation 2013-09-03 7:01 [PATCH v4 1/4] mm/vmalloc: don't set area->caller twice Wanpeng Li 2013-09-03 7:01 ` [PATCH v4 2/4] mm/vmalloc: revert "mm/vmalloc.c: emit the failure message before return" Wanpeng Li 2013-09-03 7:01 ` [PATCH v4 3/4] mm/vmalloc: revert "mm/vmalloc.c: check VM_UNINITIALIZED flag in s_show instead of show_numa_info" Wanpeng Li @ 2013-09-03 7:01 ` Wanpeng Li 2013-09-03 7:41 ` Zhang Yanfei 2013-09-03 7:42 ` Joonsoo Kim 2 siblings, 2 replies; 13+ messages in thread From: Wanpeng Li @ 2013-09-03 7:01 UTC (permalink / raw) To: Andrew Morton Cc: Joonsoo Kim, David Rientjes, KOSAKI Motohiro, Zhang Yanfei, linux-mm, linux-kernel, Wanpeng Li There is a race window between vmap_area free and show vmap_area information. A B remove_vm_area spin_lock(&vmap_area_lock); va->flags &= ~VM_VM_AREA; spin_unlock(&vmap_area_lock); spin_lock(&vmap_area_lock); if (va->flags & (VM_LAZY_FREE | VM_LAZY_FREEZING)) return 0; if (!(va->flags & VM_VM_AREA)) { seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n", (void *)va->va_start, (void *)va->va_end, va->va_end - va->va_start); return 0; } free_unmap_vmap_area(va); flush_cache_vunmap free_unmap_vmap_area_noflush unmap_vmap_area free_vmap_area_noflush va->flags |= VM_LAZY_FREE The assumption is introduced by commit: d4033afd(mm, vmalloc: iterate vmap_area_list, instead of vmlist, in vmallocinfo()). This patch fix it by drop the assumption and keep not dump vm_map_ram allocation information as the logic before that commit. Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> --- mm/vmalloc.c | 7 ------- 1 file changed, 7 deletions(-) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 5368b17..62b7932 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -2586,13 +2586,6 @@ static int s_show(struct seq_file *m, void *p) if (va->flags & (VM_LAZY_FREE | VM_LAZY_FREEING)) return 0; - if (!(va->flags & VM_VM_AREA)) { - seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n", - (void *)va->va_start, (void *)va->va_end, - va->va_end - va->va_start); - return 0; - } - v = va->vm; seq_printf(m, "0x%pK-0x%pK %7ld", -- 1.8.1.2 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply related [flat|nested] 13+ messages in thread
* Re: [PATCH v4 4/4] mm/vmalloc: don't assume vmap_area w/o VM_VM_AREA flag is vm_map_ram allocation 2013-09-03 7:01 ` [PATCH v4 4/4] mm/vmalloc: don't assume vmap_area w/o VM_VM_AREA flag is vm_map_ram allocation Wanpeng Li @ 2013-09-03 7:41 ` Zhang Yanfei 2013-09-03 7:42 ` Joonsoo Kim 1 sibling, 0 replies; 13+ messages in thread From: Zhang Yanfei @ 2013-09-03 7:41 UTC (permalink / raw) To: Wanpeng Li Cc: Andrew Morton, Joonsoo Kim, David Rientjes, KOSAKI Motohiro, linux-mm, linux-kernel On 09/03/2013 03:01 PM, Wanpeng Li wrote: > There is a race window between vmap_area free and show vmap_area information. > > A B > > remove_vm_area > spin_lock(&vmap_area_lock); > va->flags &= ~VM_VM_AREA; Here we also do: va->vm = NULL; And see below.... > spin_unlock(&vmap_area_lock); > spin_lock(&vmap_area_lock); > if (va->flags & (VM_LAZY_FREE | VM_LAZY_FREEZING)) > return 0; > if (!(va->flags & VM_VM_AREA)) { > seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n", > (void *)va->va_start, (void *)va->va_end, > va->va_end - va->va_start); > return 0; > } > free_unmap_vmap_area(va); > flush_cache_vunmap > free_unmap_vmap_area_noflush > unmap_vmap_area > free_vmap_area_noflush > va->flags |= VM_LAZY_FREE > > The assumption is introduced by commit: d4033afd(mm, vmalloc: iterate vmap_area_list, > instead of vmlist, in vmallocinfo()). This patch fix it by drop the assumption and > keep not dump vm_map_ram allocation information as the logic before that commit. > > Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> > --- > mm/vmalloc.c | 7 ------- > 1 file changed, 7 deletions(-) > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index 5368b17..62b7932 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -2586,13 +2586,6 @@ static int s_show(struct seq_file *m, void *p) > if (va->flags & (VM_LAZY_FREE | VM_LAZY_FREEING)) > return 0; > > - if (!(va->flags & VM_VM_AREA)) { > - seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n", > - (void *)va->va_start, (void *)va->va_end, > - va->va_end - va->va_start); > - return 0; > - } > - > v = va->vm; If we remove the if test above, in the window you said above, va->vm is NULL, but below we will still try to access the members of this vm_struct, which will cause problems... Correct me if I am wrong, please. > > seq_printf(m, "0x%pK-0x%pK %7ld", > -- Thanks. Zhang Yanfei -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v4 4/4] mm/vmalloc: don't assume vmap_area w/o VM_VM_AREA flag is vm_map_ram allocation 2013-09-03 7:01 ` [PATCH v4 4/4] mm/vmalloc: don't assume vmap_area w/o VM_VM_AREA flag is vm_map_ram allocation Wanpeng Li 2013-09-03 7:41 ` Zhang Yanfei @ 2013-09-03 7:42 ` Joonsoo Kim 2013-09-03 7:51 ` Wanpeng Li ` (2 more replies) 1 sibling, 3 replies; 13+ messages in thread From: Joonsoo Kim @ 2013-09-03 7:42 UTC (permalink / raw) To: Wanpeng Li Cc: Andrew Morton, David Rientjes, KOSAKI Motohiro, Zhang Yanfei, linux-mm, linux-kernel On Tue, Sep 03, 2013 at 03:01:46PM +0800, Wanpeng Li wrote: > There is a race window between vmap_area free and show vmap_area information. > > A B > > remove_vm_area > spin_lock(&vmap_area_lock); > va->flags &= ~VM_VM_AREA; > spin_unlock(&vmap_area_lock); > spin_lock(&vmap_area_lock); > if (va->flags & (VM_LAZY_FREE | VM_LAZY_FREEZING)) > return 0; > if (!(va->flags & VM_VM_AREA)) { > seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n", > (void *)va->va_start, (void *)va->va_end, > va->va_end - va->va_start); > return 0; > } > free_unmap_vmap_area(va); > flush_cache_vunmap > free_unmap_vmap_area_noflush > unmap_vmap_area > free_vmap_area_noflush > va->flags |= VM_LAZY_FREE > > The assumption is introduced by commit: d4033afd(mm, vmalloc: iterate vmap_area_list, > instead of vmlist, in vmallocinfo()). This patch fix it by drop the assumption and > keep not dump vm_map_ram allocation information as the logic before that commit. > > Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> > --- > mm/vmalloc.c | 7 ------- > 1 file changed, 7 deletions(-) > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index 5368b17..62b7932 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -2586,13 +2586,6 @@ static int s_show(struct seq_file *m, void *p) > if (va->flags & (VM_LAZY_FREE | VM_LAZY_FREEING)) > return 0; > > - if (!(va->flags & VM_VM_AREA)) { > - seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n", > - (void *)va->va_start, (void *)va->va_end, > - va->va_end - va->va_start); > - return 0; > - } > - > v = va->vm; > > seq_printf(m, "0x%pK-0x%pK %7ld", Hello, Wanpeng. Did you test this patch? I guess that, With this patch, if there are some vm_map areas, null pointer deference would occurs, since va->vm may be null for it. And with this patch, if this race really occur, null pointer deference would occurs too, since va->vm is set to null in remove_vm_area(). I think that this is not a right fix for this possible race. Thanks. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v4 4/4] mm/vmalloc: don't assume vmap_area w/o VM_VM_AREA flag is vm_map_ram allocation 2013-09-03 7:42 ` Joonsoo Kim @ 2013-09-03 7:51 ` Wanpeng Li 2013-09-03 7:51 ` Wanpeng Li [not found] ` <52259541.86a02b0a.2e56.ffffde93SMTPIN_ADDED_BROKEN@mx.google.com> 2 siblings, 0 replies; 13+ messages in thread From: Wanpeng Li @ 2013-09-03 7:51 UTC (permalink / raw) To: Joonsoo Kim Cc: Andrew Morton, David Rientjes, KOSAKI Motohiro, Zhang Yanfei, linux-mm, linux-kernel On Tue, Sep 03, 2013 at 04:42:21PM +0900, Joonsoo Kim wrote: >On Tue, Sep 03, 2013 at 03:01:46PM +0800, Wanpeng Li wrote: >> There is a race window between vmap_area free and show vmap_area information. >> >> A B >> >> remove_vm_area >> spin_lock(&vmap_area_lock); >> va->flags &= ~VM_VM_AREA; >> spin_unlock(&vmap_area_lock); >> spin_lock(&vmap_area_lock); >> if (va->flags & (VM_LAZY_FREE | VM_LAZY_FREEZING)) >> return 0; >> if (!(va->flags & VM_VM_AREA)) { >> seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n", >> (void *)va->va_start, (void *)va->va_end, >> va->va_end - va->va_start); >> return 0; >> } >> free_unmap_vmap_area(va); >> flush_cache_vunmap >> free_unmap_vmap_area_noflush >> unmap_vmap_area >> free_vmap_area_noflush >> va->flags |= VM_LAZY_FREE >> >> The assumption is introduced by commit: d4033afd(mm, vmalloc: iterate vmap_area_list, >> instead of vmlist, in vmallocinfo()). This patch fix it by drop the assumption and >> keep not dump vm_map_ram allocation information as the logic before that commit. >> >> Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> >> --- >> mm/vmalloc.c | 7 ------- >> 1 file changed, 7 deletions(-) >> >> diff --git a/mm/vmalloc.c b/mm/vmalloc.c >> index 5368b17..62b7932 100644 >> --- a/mm/vmalloc.c >> +++ b/mm/vmalloc.c >> @@ -2586,13 +2586,6 @@ static int s_show(struct seq_file *m, void *p) >> if (va->flags & (VM_LAZY_FREE | VM_LAZY_FREEING)) >> return 0; >> >> - if (!(va->flags & VM_VM_AREA)) { >> - seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n", >> - (void *)va->va_start, (void *)va->va_end, >> - va->va_end - va->va_start); >> - return 0; >> - } >> - >> v = va->vm; >> >> seq_printf(m, "0x%pK-0x%pK %7ld", > >Hello, Wanpeng. > Hi Joonsoo and Yanfei, >Did you test this patch? > >I guess that, With this patch, if there are some vm_map areas, >null pointer deference would occurs, since va->vm may be null for it. > >And with this patch, if this race really occur, null pointer deference >would occurs too, since va->vm is set to null in remove_vm_area(). > >I think that this is not a right fix for this possible race. > How about append below to this patch? if (va->vm) v = va->vm; else return 0; Regards, Wanpeng Li >Thanks. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v4 4/4] mm/vmalloc: don't assume vmap_area w/o VM_VM_AREA flag is vm_map_ram allocation 2013-09-03 7:42 ` Joonsoo Kim 2013-09-03 7:51 ` Wanpeng Li @ 2013-09-03 7:51 ` Wanpeng Li [not found] ` <52259541.86a02b0a.2e56.ffffde93SMTPIN_ADDED_BROKEN@mx.google.com> 2 siblings, 0 replies; 13+ messages in thread From: Wanpeng Li @ 2013-09-03 7:51 UTC (permalink / raw) To: Joonsoo Kim Cc: Andrew Morton, David Rientjes, KOSAKI Motohiro, Zhang Yanfei, linux-mm, linux-kernel On Tue, Sep 03, 2013 at 04:42:21PM +0900, Joonsoo Kim wrote: >On Tue, Sep 03, 2013 at 03:01:46PM +0800, Wanpeng Li wrote: >> There is a race window between vmap_area free and show vmap_area information. >> >> A B >> >> remove_vm_area >> spin_lock(&vmap_area_lock); >> va->flags &= ~VM_VM_AREA; >> spin_unlock(&vmap_area_lock); >> spin_lock(&vmap_area_lock); >> if (va->flags & (VM_LAZY_FREE | VM_LAZY_FREEZING)) >> return 0; >> if (!(va->flags & VM_VM_AREA)) { >> seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n", >> (void *)va->va_start, (void *)va->va_end, >> va->va_end - va->va_start); >> return 0; >> } >> free_unmap_vmap_area(va); >> flush_cache_vunmap >> free_unmap_vmap_area_noflush >> unmap_vmap_area >> free_vmap_area_noflush >> va->flags |= VM_LAZY_FREE >> >> The assumption is introduced by commit: d4033afd(mm, vmalloc: iterate vmap_area_list, >> instead of vmlist, in vmallocinfo()). This patch fix it by drop the assumption and >> keep not dump vm_map_ram allocation information as the logic before that commit. >> >> Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> >> --- >> mm/vmalloc.c | 7 ------- >> 1 file changed, 7 deletions(-) >> >> diff --git a/mm/vmalloc.c b/mm/vmalloc.c >> index 5368b17..62b7932 100644 >> --- a/mm/vmalloc.c >> +++ b/mm/vmalloc.c >> @@ -2586,13 +2586,6 @@ static int s_show(struct seq_file *m, void *p) >> if (va->flags & (VM_LAZY_FREE | VM_LAZY_FREEING)) >> return 0; >> >> - if (!(va->flags & VM_VM_AREA)) { >> - seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n", >> - (void *)va->va_start, (void *)va->va_end, >> - va->va_end - va->va_start); >> - return 0; >> - } >> - >> v = va->vm; >> >> seq_printf(m, "0x%pK-0x%pK %7ld", > >Hello, Wanpeng. > Hi Joonsoo and Yanfei, >Did you test this patch? > >I guess that, With this patch, if there are some vm_map areas, >null pointer deference would occurs, since va->vm may be null for it. > >And with this patch, if this race really occur, null pointer deference >would occurs too, since va->vm is set to null in remove_vm_area(). > >I think that this is not a right fix for this possible race. > How about append below to this patch? if (va->vm) v = va->vm; else return 0; Regards, Wanpeng Li >Thanks. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 13+ messages in thread
[parent not found: <52259541.86a02b0a.2e56.ffffde93SMTPIN_ADDED_BROKEN@mx.google.com>]
* Re: [PATCH v4 4/4] mm/vmalloc: don't assume vmap_area w/o VM_VM_AREA flag is vm_map_ram allocation [not found] ` <52259541.86a02b0a.2e56.ffffde93SMTPIN_ADDED_BROKEN@mx.google.com> @ 2013-09-03 8:59 ` Joonsoo Kim 2013-09-03 9:08 ` Wanpeng Li 2013-09-03 9:08 ` Wanpeng Li 0 siblings, 2 replies; 13+ messages in thread From: Joonsoo Kim @ 2013-09-03 8:59 UTC (permalink / raw) To: Wanpeng Li Cc: Andrew Morton, David Rientjes, KOSAKI Motohiro, Zhang Yanfei, linux-mm, linux-kernel On Tue, Sep 03, 2013 at 03:51:39PM +0800, Wanpeng Li wrote: > On Tue, Sep 03, 2013 at 04:42:21PM +0900, Joonsoo Kim wrote: > >On Tue, Sep 03, 2013 at 03:01:46PM +0800, Wanpeng Li wrote: > >> There is a race window between vmap_area free and show vmap_area information. > >> > >> A B > >> > >> remove_vm_area > >> spin_lock(&vmap_area_lock); > >> va->flags &= ~VM_VM_AREA; > >> spin_unlock(&vmap_area_lock); > >> spin_lock(&vmap_area_lock); > >> if (va->flags & (VM_LAZY_FREE | VM_LAZY_FREEZING)) > >> return 0; > >> if (!(va->flags & VM_VM_AREA)) { > >> seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n", > >> (void *)va->va_start, (void *)va->va_end, > >> va->va_end - va->va_start); > >> return 0; > >> } > >> free_unmap_vmap_area(va); > >> flush_cache_vunmap > >> free_unmap_vmap_area_noflush > >> unmap_vmap_area > >> free_vmap_area_noflush > >> va->flags |= VM_LAZY_FREE > >> > >> The assumption is introduced by commit: d4033afd(mm, vmalloc: iterate vmap_area_list, > >> instead of vmlist, in vmallocinfo()). This patch fix it by drop the assumption and > >> keep not dump vm_map_ram allocation information as the logic before that commit. > >> > >> Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> > >> --- > >> mm/vmalloc.c | 7 ------- > >> 1 file changed, 7 deletions(-) > >> > >> diff --git a/mm/vmalloc.c b/mm/vmalloc.c > >> index 5368b17..62b7932 100644 > >> --- a/mm/vmalloc.c > >> +++ b/mm/vmalloc.c > >> @@ -2586,13 +2586,6 @@ static int s_show(struct seq_file *m, void *p) > >> if (va->flags & (VM_LAZY_FREE | VM_LAZY_FREEING)) > >> return 0; > >> > >> - if (!(va->flags & VM_VM_AREA)) { > >> - seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n", > >> - (void *)va->va_start, (void *)va->va_end, > >> - va->va_end - va->va_start); > >> - return 0; > >> - } > >> - > >> v = va->vm; > >> > >> seq_printf(m, "0x%pK-0x%pK %7ld", > > > >Hello, Wanpeng. > > > > Hi Joonsoo and Yanfei, > > >Did you test this patch? > > > >I guess that, With this patch, if there are some vm_map areas, > >null pointer deference would occurs, since va->vm may be null for it. > > > >And with this patch, if this race really occur, null pointer deference > >would occurs too, since va->vm is set to null in remove_vm_area(). > > > >I think that this is not a right fix for this possible race. > > > > How about append below to this patch? > > if (va->vm) > v = va->vm; > else > return 0; Hello, I think that appending below code is better to represent it's purpose. Maybe some comment is needed. /* blablabla */ if (!(va->flags & VM_VM_AREA)) return 0; And maybe we can remove below code snippet, since either VM_LAZY_FREE or VM_LAZY_FREEING is not possible for !VM_VM_AREA case. if (va->flags & (VM_LAZY_FREE | VM_LAZY_FREEING)) return 0; Thanks. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v4 4/4] mm/vmalloc: don't assume vmap_area w/o VM_VM_AREA flag is vm_map_ram allocation 2013-09-03 8:59 ` Joonsoo Kim @ 2013-09-03 9:08 ` Wanpeng Li 2013-09-03 9:08 ` Wanpeng Li 1 sibling, 0 replies; 13+ messages in thread From: Wanpeng Li @ 2013-09-03 9:08 UTC (permalink / raw) To: Joonsoo Kim Cc: Andrew Morton, David Rientjes, KOSAKI Motohiro, Zhang Yanfei, linux-mm, linux-kernel On Tue, Sep 03, 2013 at 05:59:59PM +0900, Joonsoo Kim wrote: >On Tue, Sep 03, 2013 at 03:51:39PM +0800, Wanpeng Li wrote: >> On Tue, Sep 03, 2013 at 04:42:21PM +0900, Joonsoo Kim wrote: >> >On Tue, Sep 03, 2013 at 03:01:46PM +0800, Wanpeng Li wrote: >> >> There is a race window between vmap_area free and show vmap_area information. >> >> >> >> A B >> >> >> >> remove_vm_area >> >> spin_lock(&vmap_area_lock); >> >> va->flags &= ~VM_VM_AREA; >> >> spin_unlock(&vmap_area_lock); >> >> spin_lock(&vmap_area_lock); >> >> if (va->flags & (VM_LAZY_FREE | VM_LAZY_FREEZING)) >> >> return 0; >> >> if (!(va->flags & VM_VM_AREA)) { >> >> seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n", >> >> (void *)va->va_start, (void *)va->va_end, >> >> va->va_end - va->va_start); >> >> return 0; >> >> } >> >> free_unmap_vmap_area(va); >> >> flush_cache_vunmap >> >> free_unmap_vmap_area_noflush >> >> unmap_vmap_area >> >> free_vmap_area_noflush >> >> va->flags |= VM_LAZY_FREE >> >> >> >> The assumption is introduced by commit: d4033afd(mm, vmalloc: iterate vmap_area_list, >> >> instead of vmlist, in vmallocinfo()). This patch fix it by drop the assumption and >> >> keep not dump vm_map_ram allocation information as the logic before that commit. >> >> >> >> Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> >> >> --- >> >> mm/vmalloc.c | 7 ------- >> >> 1 file changed, 7 deletions(-) >> >> >> >> diff --git a/mm/vmalloc.c b/mm/vmalloc.c >> >> index 5368b17..62b7932 100644 >> >> --- a/mm/vmalloc.c >> >> +++ b/mm/vmalloc.c >> >> @@ -2586,13 +2586,6 @@ static int s_show(struct seq_file *m, void *p) >> >> if (va->flags & (VM_LAZY_FREE | VM_LAZY_FREEING)) >> >> return 0; >> >> >> >> - if (!(va->flags & VM_VM_AREA)) { >> >> - seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n", >> >> - (void *)va->va_start, (void *)va->va_end, >> >> - va->va_end - va->va_start); >> >> - return 0; >> >> - } >> >> - >> >> v = va->vm; >> >> >> >> seq_printf(m, "0x%pK-0x%pK %7ld", >> > >> >Hello, Wanpeng. >> > >> >> Hi Joonsoo and Yanfei, >> >> >Did you test this patch? >> > >> >I guess that, With this patch, if there are some vm_map areas, >> >null pointer deference would occurs, since va->vm may be null for it. >> > >> >And with this patch, if this race really occur, null pointer deference >> >would occurs too, since va->vm is set to null in remove_vm_area(). >> > >> >I think that this is not a right fix for this possible race. >> > >> >> How about append below to this patch? >> >> if (va->vm) >> v = va->vm; >> else >> return 0; > >Hello, > >I think that appending below code is better to represent it's purpose. >Maybe some comment is needed. > > /* blablabla */ > if (!(va->flags & VM_VM_AREA)) > return 0; > Looks reasonable to me. ;-) >And maybe we can remove below code snippet, since >either VM_LAZY_FREE or VM_LAZY_FREEING is not possible for !VM_VM_AREA case. > > if (va->flags & (VM_LAZY_FREE | VM_LAZY_FREEING)) > return 0; > Agreed. I will fold these in my patch and add your suggested-by. Thanks. Regards, Wanpeng Li >Thanks. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v4 4/4] mm/vmalloc: don't assume vmap_area w/o VM_VM_AREA flag is vm_map_ram allocation 2013-09-03 8:59 ` Joonsoo Kim 2013-09-03 9:08 ` Wanpeng Li @ 2013-09-03 9:08 ` Wanpeng Li 1 sibling, 0 replies; 13+ messages in thread From: Wanpeng Li @ 2013-09-03 9:08 UTC (permalink / raw) To: Joonsoo Kim Cc: Andrew Morton, David Rientjes, KOSAKI Motohiro, Zhang Yanfei, linux-mm, linux-kernel On Tue, Sep 03, 2013 at 05:59:59PM +0900, Joonsoo Kim wrote: >On Tue, Sep 03, 2013 at 03:51:39PM +0800, Wanpeng Li wrote: >> On Tue, Sep 03, 2013 at 04:42:21PM +0900, Joonsoo Kim wrote: >> >On Tue, Sep 03, 2013 at 03:01:46PM +0800, Wanpeng Li wrote: >> >> There is a race window between vmap_area free and show vmap_area information. >> >> >> >> A B >> >> >> >> remove_vm_area >> >> spin_lock(&vmap_area_lock); >> >> va->flags &= ~VM_VM_AREA; >> >> spin_unlock(&vmap_area_lock); >> >> spin_lock(&vmap_area_lock); >> >> if (va->flags & (VM_LAZY_FREE | VM_LAZY_FREEZING)) >> >> return 0; >> >> if (!(va->flags & VM_VM_AREA)) { >> >> seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n", >> >> (void *)va->va_start, (void *)va->va_end, >> >> va->va_end - va->va_start); >> >> return 0; >> >> } >> >> free_unmap_vmap_area(va); >> >> flush_cache_vunmap >> >> free_unmap_vmap_area_noflush >> >> unmap_vmap_area >> >> free_vmap_area_noflush >> >> va->flags |= VM_LAZY_FREE >> >> >> >> The assumption is introduced by commit: d4033afd(mm, vmalloc: iterate vmap_area_list, >> >> instead of vmlist, in vmallocinfo()). This patch fix it by drop the assumption and >> >> keep not dump vm_map_ram allocation information as the logic before that commit. >> >> >> >> Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> >> >> --- >> >> mm/vmalloc.c | 7 ------- >> >> 1 file changed, 7 deletions(-) >> >> >> >> diff --git a/mm/vmalloc.c b/mm/vmalloc.c >> >> index 5368b17..62b7932 100644 >> >> --- a/mm/vmalloc.c >> >> +++ b/mm/vmalloc.c >> >> @@ -2586,13 +2586,6 @@ static int s_show(struct seq_file *m, void *p) >> >> if (va->flags & (VM_LAZY_FREE | VM_LAZY_FREEING)) >> >> return 0; >> >> >> >> - if (!(va->flags & VM_VM_AREA)) { >> >> - seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n", >> >> - (void *)va->va_start, (void *)va->va_end, >> >> - va->va_end - va->va_start); >> >> - return 0; >> >> - } >> >> - >> >> v = va->vm; >> >> >> >> seq_printf(m, "0x%pK-0x%pK %7ld", >> > >> >Hello, Wanpeng. >> > >> >> Hi Joonsoo and Yanfei, >> >> >Did you test this patch? >> > >> >I guess that, With this patch, if there are some vm_map areas, >> >null pointer deference would occurs, since va->vm may be null for it. >> > >> >And with this patch, if this race really occur, null pointer deference >> >would occurs too, since va->vm is set to null in remove_vm_area(). >> > >> >I think that this is not a right fix for this possible race. >> > >> >> How about append below to this patch? >> >> if (va->vm) >> v = va->vm; >> else >> return 0; > >Hello, > >I think that appending below code is better to represent it's purpose. >Maybe some comment is needed. > > /* blablabla */ > if (!(va->flags & VM_VM_AREA)) > return 0; > Looks reasonable to me. ;-) >And maybe we can remove below code snippet, since >either VM_LAZY_FREE or VM_LAZY_FREEING is not possible for !VM_VM_AREA case. > > if (va->flags & (VM_LAZY_FREE | VM_LAZY_FREEING)) > return 0; > Agreed. I will fold these in my patch and add your suggested-by. Thanks. Regards, Wanpeng Li >Thanks. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 13+ messages in thread
end of thread, other threads:[~2013-09-03 9:08 UTC | newest]
Thread overview: 13+ messages (download: mbox.gz follow: Atom feed
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2013-09-03 7:01 [PATCH v4 1/4] mm/vmalloc: don't set area->caller twice Wanpeng Li
2013-09-03 7:01 ` [PATCH v4 2/4] mm/vmalloc: revert "mm/vmalloc.c: emit the failure message before return" Wanpeng Li
2013-09-03 7:24 ` Zhang Yanfei
2013-09-03 7:01 ` [PATCH v4 3/4] mm/vmalloc: revert "mm/vmalloc.c: check VM_UNINITIALIZED flag in s_show instead of show_numa_info" Wanpeng Li
2013-09-03 7:24 ` Zhang Yanfei
2013-09-03 7:01 ` [PATCH v4 4/4] mm/vmalloc: don't assume vmap_area w/o VM_VM_AREA flag is vm_map_ram allocation Wanpeng Li
2013-09-03 7:41 ` Zhang Yanfei
2013-09-03 7:42 ` Joonsoo Kim
2013-09-03 7:51 ` Wanpeng Li
2013-09-03 7:51 ` Wanpeng Li
[not found] ` <52259541.86a02b0a.2e56.ffffde93SMTPIN_ADDED_BROKEN@mx.google.com>
2013-09-03 8:59 ` Joonsoo Kim
2013-09-03 9:08 ` Wanpeng Li
2013-09-03 9:08 ` Wanpeng Li
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