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| author |  Yury Norov <yury.norov@gmail.com>
| 2022-09-20 06:13:12 -0700 |
|---|---|---|
| committer | Yury Norov <yury.norov@gmail.com>
| 2022-09-20 16:11:44 -0700 |
| commit | 546a073d628111e3338af689938407e77d5dc38f (patch) | |
| tree | a10422c8025db39ef7540a85e61bacfe1ff400ae /lib/Kconfig | |
| parent | lib/cpumask: deprecate nr_cpumask_bits (diff) | |
| download | linux-546a073d628111e3338af689938407e77d5dc38f.tar.gz linux-546a073d628111e3338af689938407e77d5dc38f.tar.bz2 linux-546a073d628111e3338af689938407e77d5dc38f.zip | |
powerpc/64: don't refer nr_cpu_ids in asm code when it's undefined
generic_secondary_common_init() calls LOAD_REG_ADDR(r7, nr_cpu_ids)
conditionally on CONFIG_SMP. However, if 'NR_CPUS == 1', kernel doesn't
use the nr_cpu_ids, and in C code, it's just:
#if NR_CPUS == 1
#define nr_cpu_ids
...
This series makes declaration of nr_cpu_ids conditional on NR_CPUS == 1,
and that reveals the issue, because compiler can't link the
LOAD_REG_ADDR(r7, nr_cpu_ids) against nonexisting symbol.
Current code looks unsafe for those who build kernel with CONFIG_SMP=y and
NR_CPUS == 1. This is weird configuration, but not disallowed.
Fix the linker error by replacing LOAD_REG_ADDR() with LOAD_REG_IMMEDIATE()
conditionally on NR_CPUS == 1.
As the following patch adds CONFIG_FORCE_NR_CPUS option that has the
similar effect on nr_cpu_ids, make the generic_secondary_common_init()
conditional on it too.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Diffstat (limited to 'lib/Kconfig')
0 files changed, 0 insertions, 0 deletions