On Fri 2020-10-16 20:09:07, Matteo Croce wrote:
From: Matteo Croce mcroce@microsoft.com
The kernel cmdline reboot= argument allows to specify the CPU used for rebooting, with the syntax `s####` among the other flags, e.g.
reboot=soft,s4 reboot=warm,s31,force
In the early days the parsing was done with simple_strtoul(), later deprecated in favor of the safer kstrtoint() which handles overflow.
But kstrtoint() returns -EINVAL if there are non-digit characters in a string, so if this flag is not the last given, it's silently ignored as well as the subsequent ones.
To fix it, revert the usage of simple_strtoul(), which is no longer deprecated, and restore the old behaviour.
While at it, merge two identical code blocks into one.
Fixes: 616feab75397 ("kernel/reboot.c: convert simple_strtoul to kstrtoint") Signed-off-by: Matteo Croce mcroce@microsoft.com
diff --git a/kernel/reboot.c b/kernel/reboot.c index c4e7965c39b9..475f790bbd75 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -552,25 +552,19 @@ static int __init reboot_setup(char *str) case 's': {
int rc;if (isdigit(*(str+1))) {rc = kstrtoint(str+1, 0, &reboot_cpu);if (rc)return rc;if (reboot_cpu >= num_possible_cpus()) {reboot_cpu = 0;return -ERANGE;}} else if (str[1] == 'm' && str[2] == 'p' &&isdigit(*(str+3))) {rc = kstrtoint(str+3, 0, &reboot_cpu);if (rc)return rc;if (reboot_cpu >= num_possible_cpus()) {reboot_cpu = 0;
int cpu;/** reboot_cpu is s[mp]#### with #### being the processor* to be used for rebooting. Skip 's' or 'smp' prefix.*/str += str[1] == 'm' && str[2] == 'p' ? 3 : 1;if (isdigit(str[0])) {cpu = simple_strtoul(str, NULL, 10);
The original code did not force the base 10. And even the code before the commit 616feab75397 ("kernel/reboot.c: convert simple_strtoul to kstrtoint") did not force the base 10.
I am not sure if people use it. But sometimes it might be easier to define the CPU number in hexa format.
With using simple_strtoul(str, NULL, 0):
Reviewed-by: Petr Mladek pmladek@suse.com
Best Regards, Petr