From: Dave Hansen <dave.han...@linux.intel.com>

[ Upstream commit 5cd401ace914dc68556c6d2fcae0c349444d5f86 ]

walk_system_ram_range() can return an error code either becuase
*it* failed, or because the 'func' that it calls returned an
error.  The memory hotplug does the following:

        ret = walk_system_ram_range(..., func);
        if (ret)
                return ret;

and 'ret' makes it out to userspace, eventually.  The problem
s, walk_system_ram_range() failues that result from *it* failing
(as opposed to 'func') return -1.  That leads to a very odd
-EPERM (-1) return code out to userspace.

Make walk_system_ram_range() return -EINVAL for internal
failures to keep userspace less confused.

This return code is compatible with all the callers that I
audited.

Signed-off-by: Dave Hansen <dave.han...@linux.intel.com>
Reviewed-by: Bjorn Helgaas <bhelg...@google.com>
Acked-by: Michael Ellerman <m...@ellerman.id.au> (powerpc)
Cc: Dan Williams <dan.j.willi...@intel.com>
Cc: Dave Jiang <dave.ji...@intel.com>
Cc: Ross Zwisler <zwis...@kernel.org>
Cc: Vishal Verma <vishal.l.ve...@intel.com>
Cc: Tom Lendacky <thomas.lenda...@amd.com>
Cc: Andrew Morton <a...@linux-foundation.org>
Cc: Michal Hocko <mho...@suse.com>
Cc: linux-nvd...@lists.01.org
Cc: linux-kernel@vger.kernel.org
Cc: linux...@kvack.org
Cc: Huang Ying <ying.hu...@intel.com>
Cc: Fengguang Wu <fengguang...@intel.com>
Cc: Borislav Petkov <b...@suse.de>
Cc: Yaowei Bai <baiyao...@cmss.chinamobile.com>
Cc: Takashi Iwai <ti...@suse.de>
Cc: Jerome Glisse <jgli...@redhat.com>
Cc: Benjamin Herrenschmidt <b...@kernel.crashing.org>
Cc: Paul Mackerras <pau...@samba.org>
Cc: linuxppc-...@lists.ozlabs.org
Cc: Keith Busch <keith.bu...@intel.com>
Signed-off-by: Dan Williams <dan.j.willi...@intel.com>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
 kernel/resource.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/resource.c b/kernel/resource.c
index 915c02e8e5dd..ca7ed5158cff 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -382,7 +382,7 @@ static int __walk_iomem_res_desc(resource_size_t start, 
resource_size_t end,
                                 int (*func)(struct resource *, void *))
 {
        struct resource res;
-       int ret = -1;
+       int ret = -EINVAL;
 
        while (start < end &&
               !find_next_iomem_res(start, end, flags, desc, first_lvl, &res)) {
@@ -462,7 +462,7 @@ int walk_system_ram_range(unsigned long start_pfn, unsigned 
long nr_pages,
        unsigned long flags;
        struct resource res;
        unsigned long pfn, end_pfn;
-       int ret = -1;
+       int ret = -EINVAL;
 
        start = (u64) start_pfn << PAGE_SHIFT;
        end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
-- 
2.19.1

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