Re: [PATCH 2/3] resource: Include resource end in walk_*() interfaces
On Thu, Sep 27, 2018 at 09:22:02AM -0500, Bjorn Helgaas wrote: > From: Bjorn Helgaas > > 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 [0x0-0x1] and there happens to be an > iomem resource [mem 0x1-0x1] (the single byte at 0x1), we skip > it: > > find_next_iomem_res(...) > { > start = 0x0; > end = 0x1; > for (p = next_resource(...)) { > # p->start = 0x1; > # p->end = 0x1; > # 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. This is how one should write commit messages! Thanks for that - it was a joy - for a change - to read it :-) > > Fixes: 58c1b5b07907 ("[PATCH] memory hotadd fixes: find_next_system_ram catch > range fix") > Signed-off-by: Bjorn Helgaas > --- > kernel/resource.c |4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) Reviewed-by: Borislav Petkov > 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). What I'm still wondering about is, why was it ever even considered to have a non-inclusive range. Looking at the git history, especially 58c1b5b07907 and 2842f11419704 - it looks like it was an omission and then users started using it with inclusive ranges. Thx. -- Regards/Gruss, Boris. SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg) ___ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
[PATCH 2/3] resource: Include resource end in walk_*() interfaces
From: Bjorn Helgaas 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 [0x0-0x1] and there happens to be an iomem resource [mem 0x1-0x1] (the single byte at 0x1), we skip it: find_next_iomem_res(...) { start = 0x0; end = 0x1; for (p = next_resource(...)) { # p->start = 0x1; # p->end = 0x1; # 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 --- 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; } ___ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
[PATCH 2/3] resource: Include resource end in walk_*() interfaces
From: Bjorn Helgaas 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 [0x0-0x1] and there happens to be an iomem resource [mem 0x1-0x1] (the single byte at 0x1), we skip it: find_next_iomem_res(...) { start = 0x0; end = 0x1; for (p = next_resource(...)) { # p->start = 0x1; # p->end = 0x1; # 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 --- 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; } ___ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec