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| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2024-12-05 17:06:02 +0100 |
|---|---|---|
| committer | Petr Pavlu <petr.pavlu@suse.com> | 2024-12-23 10:46:38 +0100 |
| commit | 0b7a66a2c864859fbf9bb16229c03172eef02c05 (patch) | |
| tree | 4962b5542ccf4fc7c19093e05d7ba1221be5fc9a | |
| parent | 4bbf9020becbfd8fc2c3da790855b7042fad455b (diff) | |
| download | linux-0b7a66a2c864859fbf9bb16229c03172eef02c05.tar.gz linux-0b7a66a2c864859fbf9bb16229c03172eef02c05.tar.bz2 linux-0b7a66a2c864859fbf9bb16229c03172eef02c05.zip | |
preempt: Move PREEMPT_RT before PREEMPT in vermagic.
Since the dynamic preemption has been enabled for PREEMPT_RT we have now
CONFIG_PREEMPT and CONFIG_PREEMPT_RT set simultaneously. This affects
the vermagic strings which comes now PREEMPT with PREEMPT_RT enabled.
The PREEMPT_RT module usually can not be loaded on a PREEMPT kernel
because some symbols are missing.
However if the symbols are fine then it continues and it crashes later.
The problem is that the struct module has a different layout and the
num_exentries or init members are at a different position leading to a
crash later on. This is not necessary caught by the size check in
elf_validity_cache_index_mod() because the mem member has an alignment
requirement of __module_memory_align which is big enough keep the total
size unchanged. Therefore we should keep the string accurate instead of
removing it.
Move the PREEMPT_RT check before the PREEMPT so that it takes precedence
if both symbols are enabled.
Fixes: 35772d627b55c ("sched: Enable PREEMPT_DYNAMIC for PREEMPT_RT")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
Link: https://lore.kernel.org/r/20241205160602.3lIAsJRT@linutronix.de
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
| -rw-r--r-- | include/linux/vermagic.h | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/include/linux/vermagic.h b/include/linux/vermagic.h index a54046bf37e5..939ceabcaf06 100644 --- a/include/linux/vermagic.h +++ b/include/linux/vermagic.h @@ -15,10 +15,10 @@ #else #define MODULE_VERMAGIC_SMP "" #endif -#ifdef CONFIG_PREEMPT_BUILD -#define MODULE_VERMAGIC_PREEMPT "preempt " -#elif defined(CONFIG_PREEMPT_RT) +#ifdef CONFIG_PREEMPT_RT #define MODULE_VERMAGIC_PREEMPT "preempt_rt " +#elif defined(CONFIG_PREEMPT_BUILD) +#define MODULE_VERMAGIC_PREEMPT "preempt " #else #define MODULE_VERMAGIC_PREEMPT "" #endif |