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| author | Matteo Croce <mcroce@microsoft.com> | 2020-12-15 20:46:53 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-12-15 22:46:19 -0800 |
| commit | f9a90501faac55ddbea93c1f73497857f1997227 (patch) | |
| tree | 37a3b1d168877a6d6d3dd61a8d4eb217086175fe | |
| parent | d3c227978a130ee18716d3496cf82621d8cda28c (diff) | |
| download | linux-f9a90501faac55ddbea93c1f73497857f1997227.tar.gz linux-f9a90501faac55ddbea93c1f73497857f1997227.tar.bz2 linux-f9a90501faac55ddbea93c1f73497857f1997227.zip | |
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>
| -rw-r--r-- | kernel/reboot.c | 30 |
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': |