From: Bjorn Helgaas bhelgaas@google.com
[ Upstream commit a98959fdbda1849a01b2150bb635ed559ec06700 ]
find_next_iomem_res() finds an iomem resource that covers part of a range described by "start, end". All callers expect that range to be inclusive, i.e., both start and end are included, but find_next_iomem_res() doesn't handle the end address correctly.
If it finds an iomem resource that contains exactly the end address, it skips it, e.g., if "start, end" is [0x0-0x10000] and there happens to be an iomem resource [mem 0x10000-0x10000] (the single byte at 0x10000), we skip it:
find_next_iomem_res(...) { start = 0x0; end = 0x10000; for (p = next_resource(...)) { # p->start = 0x10000; # p->end = 0x10000; # we *should* return this resource, but this condition is false: if ((p->end >= start) && (p->start < end)) break;
Adjust find_next_iomem_res() so it allows a resource that includes the single byte at the end of the range. This is a corner case that we probably don't see in practice.
Fixes: 58c1b5b07907 ("[PATCH] memory hotadd fixes: find_next_system_ram catch range fix") Signed-off-by: Bjorn Helgaas bhelgaas@google.com Signed-off-by: Borislav Petkov bp@suse.de CC: Andrew Morton akpm@linux-foundation.org CC: Brijesh Singh brijesh.singh@amd.com CC: Dan Williams dan.j.williams@intel.com CC: H. Peter Anvin hpa@zytor.com CC: Lianbo Jiang lijiang@redhat.com CC: Takashi Iwai tiwai@suse.de CC: Thomas Gleixner tglx@linutronix.de CC: Tom Lendacky thomas.lendacky@amd.com CC: Vivek Goyal vgoyal@redhat.com CC: Yaowei Bai baiyaowei@cmss.chinamobile.com CC: bhe@redhat.com CC: dan.j.williams@intel.com CC: dyoung@redhat.com CC: kexec@lists.infradead.org CC: mingo@redhat.com CC: x86-ml x86@kernel.org Link: http://lkml.kernel.org/r/153805812254.1157.16736368485811773752.stgit@bhelga... Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/resource.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/resource.c b/kernel/resource.c index 30e1bc68503b5..155ec873ea4d1 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -319,7 +319,7 @@ int release_resource(struct resource *old) EXPORT_SYMBOL(release_resource);
/* - * Finds the lowest iomem resource existing within [res->start.res->end). + * Finds the lowest iomem resource existing within [res->start..res->end]. * The caller must specify res->start, res->end, res->flags, and optionally * desc. If found, returns 0, res is overwritten, if not found, returns -1. * This function walks the whole tree and not just first level children until @@ -352,7 +352,7 @@ static int find_next_iomem_res(struct resource *res, unsigned long desc, p = NULL; break; } - if ((p->end >= start) && (p->start < end)) + if ((p->end >= start) && (p->start <= end)) break; }