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authorMatteo Croce <mcroce@microsoft.com>2020-12-16 07:46:53 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2020-12-16 09:46:19 +0300
commitf9a90501faac55ddbea93c1f73497857f1997227 (patch)
tree37a3b1d168877a6d6d3dd61a8d4eb217086175fe /kernel
parentd3c227978a130ee18716d3496cf82621d8cda28c (diff)
downloadlinux-f9a90501faac55ddbea93c1f73497857f1997227.tar.xz
reboot: refactor and comment the cpu selection code
Small improvements to the code, without changing the way it works: - use a local variable, to avoid a small time lapse where reboot_cpu can have an invalid value - comment the code which is not easy to understand at a glance - merge two identical code blocks into one - replace pointer arithmetics with equivalent array syntax Link: https://lkml.kernel.org/r/20201103214025.116799-4-mcroce@linux.microsoft.com Signed-off-by: Matteo Croce <mcroce@microsoft.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Fabian Frederick <fabf@skynet.be> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Kees Cook <keescook@chromium.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Robin Holt <robinmholt@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/reboot.c30
1 files changed, 17 insertions, 13 deletions
diff --git a/kernel/reboot.c b/kernel/reboot.c
index 2a18b76ffc06..aa3bfd6c673b 100644
--- a/kernel/reboot.c
+++ b/kernel/reboot.c
@@ -553,20 +553,24 @@ static int __init reboot_setup(char *str)
break;
case 's':
- if (isdigit(*(str+1)))
- reboot_cpu = simple_strtoul(str+1, NULL, 0);
- else if (str[1] == 'm' && str[2] == 'p' &&
- isdigit(*(str+3)))
- reboot_cpu = simple_strtoul(str+3, NULL, 0);
- else
+ /*
+ * 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])) {
+ int cpu = simple_strtoul(str, NULL, 0);
+
+ if (cpu >= num_possible_cpus()) {
+ pr_err("Ignoring the CPU number in reboot= option. "
+ "CPU %d exceeds possible cpu number %d\n",
+ cpu, num_possible_cpus());
+ break;
+ }
+ reboot_cpu = cpu;
+ } else
*mode = REBOOT_SOFT;
- if (reboot_cpu >= num_possible_cpus()) {
- pr_err("Ignoring the CPU number in reboot= option. "
- "CPU %d exceeds possible cpu number %d\n",
- reboot_cpu, num_possible_cpus());
- reboot_cpu = 0;
- break;
- }
break;
case 'g':