Le 25/02/2019 à 19:57, Dave Hansen a écrit :
From: Dave Hansen <dave.han...@linux.intel.com>
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.
This changes both the generic mm/ and powerpc-specific
implementations to have the same return value.
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-ker...@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-dev@lists.ozlabs.org
Cc: Keith Busch <keith.bu...@intel.com>
---
b/arch/powerpc/mm/mem.c | 2 +-
walk_system_ram_range() was droped in commit
https://git.kernel.orghttps://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=26b523356f49a0117c8f9e32ca98aa6d6e496e1a
Christophe
b/kernel/resource.c | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)
diff -puN
arch/powerpc/mm/mem.c~memory-hotplug-walk_system_ram_range-returns-neg-1
arch/powerpc/mm/mem.c
--- a/arch/powerpc/mm/mem.c~memory-hotplug-walk_system_ram_range-returns-neg-1
2019-02-25 10:56:47.452908034 -0800
+++ b/arch/powerpc/mm/mem.c 2019-02-25 10:56:47.458908034 -0800
@@ -189,7 +189,7 @@ walk_system_ram_range(unsigned long star
struct memblock_region *reg;
unsigned long end_pfn = start_pfn + nr_pages;
unsigned long tstart, tend;
- int ret = -1;
+ int ret = -EINVAL;
for_each_memblock(memory, reg) {
tstart = max(start_pfn, memblock_region_memory_base_pfn(reg));
diff -puN kernel/resource.c~memory-hotplug-walk_system_ram_range-returns-neg-1
kernel/resource.c
--- a/kernel/resource.c~memory-hotplug-walk_system_ram_range-returns-neg-1
2019-02-25 10:56:47.454908034 -0800
+++ b/kernel/resource.c 2019-02-25 10:56:47.459908034 -0800
@@ -382,7 +382,7 @@ static int __walk_iomem_res_desc(resourc
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
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;
_
