* [PATCH] mm: fix wrong vmap address calculations with odd NR_CPUS values
@ 2011-08-14 12:52 Stefan Richter
2011-08-14 13:10 ` Stefan Richter
0 siblings, 1 reply; 3+ messages in thread
From: Stefan Richter @ 2011-08-14 12:52 UTC (permalink / raw)
To: Linus Torvalds, Andrew Morton
Cc: Nick Piggin, Clemens Ladisch, Pavel Kysilka, Matias A. Fonzo,
linux-mm, inux-kernel
Date: Tue, 21 Jun 2011 22:09:50 +0200
From: Clemens Ladisch <clemens@ladisch.de>
Commit db64fe02258f (mm: rewrite vmap layer) introduced code that does
address calculations under the assumption that VMAP_BLOCK_SIZE is
a power of two. However, this might not be true if CONFIG_NR_CPUS is
not set to a power of two.
Wrong vmap_block index/offset values could lead to memory corruption.
However, this has never been observed in practice (or never been
diagnosed correctly); what caught this was the BUG_ON in vb_alloc() that
checks for inconsistent vmap_block indices.
To fix this, ensure that VMAP_BLOCK_SIZE always is a power of two.
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=31572
Reported-by: Pavel Kysilka <goldenfish@linuxsoft.cz>
Reported-by: Matias A. Fonzo <selk@dragora.org>
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: 2.6.28+ <stable@kernel.org>
---
This fixes instant and fully repeatable crashes if NR_CPUS is not a power
of two and vm_map_ram() or something like that is executed, for example
firewire-ohci probe in its 2.6.38+ incarnation.
mm/vmalloc.c | 7 ++++---
1 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 1d34d75..d3d451b 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -732,9 +732,10 @@ static void free_unmap_vmap_area_addr(unsigned long addr)
#define VMAP_BBMAP_BITS_MIN (VMAP_MAX_ALLOC*2)
#define VMAP_MIN(x, y) ((x) < (y) ? (x) : (y)) /* can't use min() */
#define VMAP_MAX(x, y) ((x) > (y) ? (x) : (y)) /* can't use max() */
-#define VMAP_BBMAP_BITS VMAP_MIN(VMAP_BBMAP_BITS_MAX, \
- VMAP_MAX(VMAP_BBMAP_BITS_MIN, \
- VMALLOC_PAGES / NR_CPUS / 16))
+#define VMAP_BBMAP_BITS \
+ VMAP_MIN(VMAP_BBMAP_BITS_MAX, \
+ VMAP_MAX(VMAP_BBMAP_BITS_MIN, \
+ VMALLOC_PAGES / roundup_pow_of_two(NR_CPUS) / 16))
#define VMAP_BLOCK_SIZE (VMAP_BBMAP_BITS * PAGE_SIZE)
--
1.7.3.2
--
Stefan Richter
-=====-==-== =--- -===-
http://arcgraph.de/sr/
--
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/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH] mm: fix wrong vmap address calculations with odd NR_CPUS values
2011-08-14 12:52 [PATCH] mm: fix wrong vmap address calculations with odd NR_CPUS values Stefan Richter
@ 2011-08-14 13:10 ` Stefan Richter
0 siblings, 0 replies; 3+ messages in thread
From: Stefan Richter @ 2011-08-14 13:10 UTC (permalink / raw)
To: Linus Torvalds, Andrew Morton
Cc: Nick Piggin, Clemens Ladisch, Pavel Kysilka, Matias A. Fonzo,
linux-mm, linux-kernel
From: Clemens Ladisch <clemens@ladisch.de>
Date: Tue, 21 Jun 2011 22:09:50 +0200
Commit db64fe02258f (mm: rewrite vmap layer) introduced code that does
address calculations under the assumption that VMAP_BLOCK_SIZE is
a power of two. However, this might not be true if CONFIG_NR_CPUS is
not set to a power of two.
Wrong vmap_block index/offset values could lead to memory corruption.
However, this has never been observed in practice (or never been
diagnosed correctly); what caught this was the BUG_ON in vb_alloc() that
checks for inconsistent vmap_block indices.
To fix this, ensure that VMAP_BLOCK_SIZE always is a power of two.
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=31572
Reported-by: Pavel Kysilka <goldenfish@linuxsoft.cz>
Reported-by: Matias A. Fonzo <selk@dragora.org>
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: 2.6.28+ <stable@kernel.org>
---
Resend with corrected Cc list; sorry.
This fixes instant and fully repeatable crashes if NR_CPUS is not a power
of two and vm_map_ram() or something like that is executed, for example
firewire-ohci probe in its 2.6.38+ incarnation.
mm/vmalloc.c | 7 ++++---
1 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 1d34d75..d3d451b 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -732,9 +732,10 @@ static void free_unmap_vmap_area_addr(unsigned long addr)
#define VMAP_BBMAP_BITS_MIN (VMAP_MAX_ALLOC*2)
#define VMAP_MIN(x, y) ((x) < (y) ? (x) : (y)) /* can't use min() */
#define VMAP_MAX(x, y) ((x) > (y) ? (x) : (y)) /* can't use max() */
-#define VMAP_BBMAP_BITS VMAP_MIN(VMAP_BBMAP_BITS_MAX, \
- VMAP_MAX(VMAP_BBMAP_BITS_MIN, \
- VMALLOC_PAGES / NR_CPUS / 16))
+#define VMAP_BBMAP_BITS \
+ VMAP_MIN(VMAP_BBMAP_BITS_MAX, \
+ VMAP_MAX(VMAP_BBMAP_BITS_MIN, \
+ VMALLOC_PAGES / roundup_pow_of_two(NR_CPUS) / 16))
#define VMAP_BLOCK_SIZE (VMAP_BBMAP_BITS * PAGE_SIZE)
--
1.7.3.2
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH] mm: fix wrong vmap address calculations with odd NR_CPUS values
@ 2011-08-14 13:10 ` Stefan Richter
0 siblings, 0 replies; 3+ messages in thread
From: Stefan Richter @ 2011-08-14 13:10 UTC (permalink / raw)
To: Linus Torvalds, Andrew Morton
Cc: Nick Piggin, Clemens Ladisch, Pavel Kysilka, Matias A. Fonzo,
linux-mm, linux-kernel
From: Clemens Ladisch <clemens@ladisch.de>
Date: Tue, 21 Jun 2011 22:09:50 +0200
Commit db64fe02258f (mm: rewrite vmap layer) introduced code that does
address calculations under the assumption that VMAP_BLOCK_SIZE is
a power of two. However, this might not be true if CONFIG_NR_CPUS is
not set to a power of two.
Wrong vmap_block index/offset values could lead to memory corruption.
However, this has never been observed in practice (or never been
diagnosed correctly); what caught this was the BUG_ON in vb_alloc() that
checks for inconsistent vmap_block indices.
To fix this, ensure that VMAP_BLOCK_SIZE always is a power of two.
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=31572
Reported-by: Pavel Kysilka <goldenfish@linuxsoft.cz>
Reported-by: Matias A. Fonzo <selk@dragora.org>
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: 2.6.28+ <stable@kernel.org>
---
Resend with corrected Cc list; sorry.
This fixes instant and fully repeatable crashes if NR_CPUS is not a power
of two and vm_map_ram() or something like that is executed, for example
firewire-ohci probe in its 2.6.38+ incarnation.
mm/vmalloc.c | 7 ++++---
1 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 1d34d75..d3d451b 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -732,9 +732,10 @@ static void free_unmap_vmap_area_addr(unsigned long addr)
#define VMAP_BBMAP_BITS_MIN (VMAP_MAX_ALLOC*2)
#define VMAP_MIN(x, y) ((x) < (y) ? (x) : (y)) /* can't use min() */
#define VMAP_MAX(x, y) ((x) > (y) ? (x) : (y)) /* can't use max() */
-#define VMAP_BBMAP_BITS VMAP_MIN(VMAP_BBMAP_BITS_MAX, \
- VMAP_MAX(VMAP_BBMAP_BITS_MIN, \
- VMALLOC_PAGES / NR_CPUS / 16))
+#define VMAP_BBMAP_BITS \
+ VMAP_MIN(VMAP_BBMAP_BITS_MAX, \
+ VMAP_MAX(VMAP_BBMAP_BITS_MIN, \
+ VMALLOC_PAGES / roundup_pow_of_two(NR_CPUS) / 16))
#define VMAP_BLOCK_SIZE (VMAP_BBMAP_BITS * PAGE_SIZE)
--
1.7.3.2
--
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/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply related [flat|nested] 3+ messages in thread
end of thread, other threads:[~2011-08-14 13:11 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2011-08-14 12:52 [PATCH] mm: fix wrong vmap address calculations with odd NR_CPUS values Stefan Richter
2011-08-14 13:10 ` Stefan Richter
2011-08-14 13:10 ` Stefan Richter
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.