[PATCH v22 1/9] kdump: return -ENOENT if required cmdline option does not exist

[Zhen Lei]

According to the current crashkernel=Y,low support in other ARCHes, it's
an optional command-line option. When it doesn't exist, kernel will try
to allocate minimum required memory below 4G automatically.

However, __parse_crashkernel() returns '-EINVAL' for all error cases. It
can't distinguish the nonexistent option from invalid option.

Change __parse_crashkernel() to return '-ENOENT' for the nonexistent option
case. With this change, crashkernel,low memory will take the default
value if crashkernel=,low is not specified; while crashkernel reservation
will fail and bail out if an invalid option is specified.

Signed-off-by: Zhen Lei <thunder.leizhen at huawei.com>
---
 kernel/crash_core.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/kernel/crash_core.c b/kernel/crash_core.c
index 256cf6db573cd09..4d57c03714f4e13 100644
--- a/kernel/crash_core.c
+++ b/kernel/crash_core.c
@@ -243,9 +243,8 @@ static int __init __parse_crashkernel(char *cmdline,
 	*crash_base = 0;
 
 	ck_cmdline = get_last_crashkernel(cmdline, name, suffix);
-
 	if (!ck_cmdline)
-		return -EINVAL;
+		return -ENOENT;
 
 	ck_cmdline += strlen(name);
 
-- 
2.25.1