From: "Zhu, Yi" <yi.zhu@intel.com>
In arch/i386/kernel/setup.c:
__early_param("acpi", early_acpi);
In drivers/acpi/osl.c:
__setup("acpi_os_name=", acpi_os_name_setup);
So if one passes kernel parameter in the bootloader as below,
"acpi=force acpi_os_name=my_override_name"
the "acpi_os_name=" parameter will take the setup func for "acpi",
because they begin with the same string "acpi".
Vanilla kernel doesn't have the problem now because most of the parameter
strings have a trailing '=', so "acpi_os_name" won't take the setup func for
"acpi=". But a safer way is to checkup the parameter string when parsing it
as the patch did.
---
25-akpm/init/main.c | 6 +++++-
1 files changed, 5 insertions(+), 1 deletion(-)
diff -puN init/main.c~kernel-parameter-parsing-fix init/main.c
--- 25/init/main.c~kernel-parameter-parsing-fix 2004-05-22 18:57:21.186616536 -0700
+++ 25-akpm/init/main.c 2004-05-22 18:57:21.189616080 -0700
@@ -151,11 +151,15 @@ static int __init obsolete_checksetup(ch
{
struct obs_kernel_param *p;
extern struct obs_kernel_param __setup_start, __setup_end;
+ char *ptr;
+ int len = strlen(line);
+ if ((ptr = strchr(line, '=')))
+ len = ptr - line;
p = &__setup_start;
do {
int n = strlen(p->str);
- if (!strncmp(line, p->str, n)) {
+ if (len <= n && !strncmp(line, p->str, n)) {
if (!p->setup_func) {
printk(KERN_WARNING "Parameter %s is obsolete, ignored\n", p->str);
return 1;
_