Messages in this thread Patch in this message | | | Date | Wed, 22 Jul 2015 08:26:05 -0700 | From | tip-bot for Toshi Kani <> | Subject | [tip:x86/urgent] mm: Fix bugs in region_is_ram() |
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Commit-ID: 8c38de992be9aed0b34c4fab8f972c83d3b00dc4 Gitweb: http://git.kernel.org/tip/8c38de992be9aed0b34c4fab8f972c83d3b00dc4 Author: Toshi Kani <toshi.kani@hp.com> AuthorDate: Thu, 16 Jul 2015 17:23:16 -0600 Committer: Thomas Gleixner <tglx@linutronix.de> CommitDate: Wed, 22 Jul 2015 17:20:34 +0200
mm: Fix bugs in region_is_ram()
region_is_ram() looks up the iomem_resource table to check if a target range is in RAM. However, it always returns with -1 due to invalid range checks. It always breaks the loop at the first entry of the table.
Another issue is that it compares p->flags and flags, but it always fails. flags is declared as int, which makes it as a negative value with IORESOURCE_BUSY (0x80000000) set while p->flags is unsigned long.
Fix the range check and flags so that region_is_ram() works as advertised.
Signed-off-by: Toshi Kani <toshi.kani@hp.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Cc: Mike Travis <travis@sgi.com> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Roland Dreier <roland@purestorage.com> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/1437088996-28511-4-git-send-email-toshi.kani@hp.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- kernel/resource.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/kernel/resource.c b/kernel/resource.c index 90552aa..fed052a 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -504,13 +504,13 @@ int region_is_ram(resource_size_t start, unsigned long size) { struct resource *p; resource_size_t end = start + size - 1; - int flags = IORESOURCE_MEM | IORESOURCE_BUSY; + unsigned long flags = IORESOURCE_MEM | IORESOURCE_BUSY; const char *name = "System RAM"; int ret = -1; read_lock(&resource_lock); for (p = iomem_resource.child; p ; p = p->sibling) { - if (end < p->start) + if (p->end < start) continue; if (p->start <= start && end <= p->end) { @@ -521,7 +521,7 @@ int region_is_ram(resource_size_t start, unsigned long size) ret = 1; break; } - if (p->end < start) + if (end < p->start) break; /* not found */ } read_unlock(&resource_lock);
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