5.0-stable review patch. If anyone has any objections, please let me know.
------------------
[ 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.hansen@xxxxxxxxxxxxxxx>
Reviewed-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Acked-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> (powerpc)
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Dave Jiang <dave.jiang@xxxxxxxxx>
Cc: Ross Zwisler <zwisler@xxxxxxxxxx>
Cc: Vishal Verma <vishal.l.verma@xxxxxxxxx>
Cc: Tom Lendacky <thomas.lendacky@xxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: linux-nvdimm@xxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: linux-mm@xxxxxxxxx
Cc: Huang Ying <ying.huang@xxxxxxxxx>
Cc: Fengguang Wu <fengguang.wu@xxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxx>
Cc: Yaowei Bai <baiyaowei@xxxxxxxxxxxxxxxxxxxx>
Cc: Takashi Iwai <tiwai@xxxxxxx>
Cc: Jerome Glisse <jglisse@xxxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
Cc: Keith Busch <keith.busch@xxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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
