From 0f91df0c0fae1a88f11be3eabb1f20f73a88c90a Mon Sep 17 00:00:00 2001 From: Sumanth Korikkar Date: Wed, 10 Jan 2024 15:01:27 +0100 Subject: [PATCH] mm/memory_hotplug: fix memmap_on_memory sysfs value retrieval commit 11684134140bb708b6e6de969a060535630b1b53 upstream. set_memmap_mode() stores the kernel parameter memmap mode as an integer. However, the get_memmap_mode() function utilizes param_get_bool() to fetch the value as a boolean, leading to potential endianness issue. On Big-endian architectures, the memmap_on_memory is consistently displayed as 'N' regardless of its actual status. To address this endianness problem, the solution involves obtaining the mode as an integer. This adjustment ensures the proper display of the memmap_on_memory parameter, presenting it as one of the following options: Force, Y, or N. Link: https://lkml.kernel.org/r/20240110140127.241451-1-sumanthk@linux.ibm.com Fixes: 2d1f649c7c08 ("mm/memory_hotplug: support memmap_on_memory when memmap is not aligned to pageblocks") Signed-off-by: Sumanth Korikkar Suggested-by: Gerald Schaefer Acked-by: David Hildenbrand Cc: Alexander Gordeev Cc: Aneesh Kumar K.V Cc: Heiko Carstens Cc: Michal Hocko Cc: Oscar Salvador Cc: Vasily Gorbik Cc: [6.6+] Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- mm/memory_hotplug.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 7a5fc89a86528..c9c2ad5e2681e 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -101,9 +101,11 @@ static int set_memmap_mode(const char *val, const struct kernel_param *kp) static int get_memmap_mode(char *buffer, const struct kernel_param *kp) { - if (*((int *)kp->arg) == MEMMAP_ON_MEMORY_FORCE) - return sprintf(buffer, "force\n"); - return param_get_bool(buffer, kp); + int mode = *((int *)kp->arg); + + if (mode == MEMMAP_ON_MEMORY_FORCE) + return sprintf(buffer, "force\n"); + return sprintf(buffer, "%c\n", mode ? 'Y' : 'N'); } static const struct kernel_param_ops memmap_mode_ops = {