From: Sheng Yong <shengyong1@xxxxxxxxxx> [ Upstream commit ac92985864e187a1735502f6a02f54eaa655b2aa ] When setting /sys/fs/f2fs/<DEV>/iostat_enable with non-bool value, UBSAN reports the following warning. [ 7562.295484] ================================================================================ [ 7562.296531] UBSAN: Undefined behaviour in fs/f2fs/f2fs.h:2776:10 [ 7562.297651] load of value 64 is not a valid value for type '_Bool' [ 7562.298642] CPU: 1 PID: 7487 Comm: dd Not tainted 4.20.0-rc4+ #79 [ 7562.298653] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 7562.298662] Call Trace: [ 7562.298760] dump_stack+0x46/0x5b [ 7562.298811] ubsan_epilogue+0x9/0x40 [ 7562.298830] __ubsan_handle_load_invalid_value+0x72/0x90 [ 7562.298863] f2fs_file_write_iter+0x29f/0x3f0 [ 7562.298905] __vfs_write+0x115/0x160 [ 7562.298922] vfs_write+0xa7/0x190 [ 7562.298934] ksys_write+0x50/0xc0 [ 7562.298973] do_syscall_64+0x4a/0xe0 [ 7562.298992] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 7562.299001] RIP: 0033:0x7fa45ec19c00 [ 7562.299004] Code: 73 01 c3 48 8b 0d 88 92 2c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d dd eb 2c 00 00 75 10 b8 01 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 ce 8f 01 00 48 89 04 24 [ 7562.299044] RSP: 002b:00007ffca52b49e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 7562.299052] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fa45ec19c00 [ 7562.299059] RDX: 0000000000000400 RSI: 000000000093f000 RDI: 0000000000000001 [ 7562.299065] RBP: 000000000093f000 R08: 0000000000000004 R09: 0000000000000000 [ 7562.299071] R10: 00007ffca52b47b0 R11: 0000000000000246 R12: 0000000000000400 [ 7562.299077] R13: 000000000093f000 R14: 000000000093f400 R15: 0000000000000000 [ 7562.299091] ================================================================================ So, if iostat_enable is enabled, set its value as true. Signed-off-by: Sheng Yong <shengyong1@xxxxxxxxxx> Reviewed-by: Chao Yu <yuchao0@xxxxxxxxxx> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- fs/f2fs/sysfs.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c index 81c0e5337443..98887187af4c 100644 --- a/fs/f2fs/sysfs.c +++ b/fs/f2fs/sysfs.c @@ -273,10 +273,16 @@ static ssize_t __sbi_store(struct f2fs_attr *a, return count; } - *ui = t; - if (!strcmp(a->attr.name, "iostat_enable") && *ui == 0) - f2fs_reset_iostat(sbi); + if (!strcmp(a->attr.name, "iostat_enable")) { + sbi->iostat_enable = !!t; + if (!sbi->iostat_enable) + f2fs_reset_iostat(sbi); + return count; + } + + *ui = (unsigned int)t; + return count; } -- 2.19.1