From 9a80dfccade1dac74a5dfa39ceb85101804b5313 Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Thu, 27 Sep 2018 09:22:02 -0500 Subject: [PATCH] resource: Include resource end in walk_*() interfaces [ 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 Signed-off-by: Borislav Petkov CC: Andrew Morton CC: Brijesh Singh CC: Dan Williams CC: H. Peter Anvin CC: Lianbo Jiang CC: Takashi Iwai CC: Thomas Gleixner CC: Tom Lendacky CC: Vivek Goyal CC: Yaowei Bai 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 Link: http://lkml.kernel.org/r/153805812254.1157.16736368485811773752.stgit@bhelgaas-glaptop.roam.corp.google.com Signed-off-by: Sasha Levin --- kernel/resource.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/resource.c b/kernel/resource.c index 30e1bc68503b..155ec873ea4d 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; } -- GitLab