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2 commits

Author SHA1 Message Date
Sebastian Andrzej Siewior
77993b595a locking: Allow to include asm/spinlock_types.h from linux/spinlock_types_raw.h
The printk header file includes ratelimit_types.h for its __ratelimit()
based usage. It is required for the static initializer used in
printk_ratelimited(). It uses a raw_spinlock_t and includes the
spinlock_types.h.

PREEMPT_RT substitutes spinlock_t with a rtmutex based implementation and so
its spinlock_t implmentation (provided by spinlock_rt.h) includes rtmutex.h and
atomic.h which leads to recursive includes where defines are missing.

By including only the raw_spinlock_t defines it avoids the atomic.h
related includes at this stage.

An example on powerpc:

|  CALL    scripts/atomic/check-atomics.sh
|In file included from include/linux/bug.h:5,
|                 from include/linux/page-flags.h:10,
|                 from kernel/bounds.c:10:
|arch/powerpc/include/asm/page_32.h: In function ‘clear_page’:
|arch/powerpc/include/asm/bug.h:87:4: error: implicit declaration of function â=80=98__WARNâ=80=99 [-Werror=3Dimplicit-function-declaration]
|   87 |    __WARN();    \
|      |    ^~~~~~
|arch/powerpc/include/asm/page_32.h:48:2: note: in expansion of macro ‘WARN_ONâ€=99
|   48 |  WARN_ON((unsigned long)addr & (L1_CACHE_BYTES - 1));
|      |  ^~~~~~~
|arch/powerpc/include/asm/bug.h:58:17: error: invalid application of ‘sizeofâ€=99 to incomplete type ‘struct bug_entryâ€=99
|   58 |     "i" (sizeof(struct bug_entry)), \
|      |                 ^~~~~~
|arch/powerpc/include/asm/bug.h:89:3: note: in expansion of macro ‘BUG_ENTRYâ€=99
|   89 |   BUG_ENTRY(PPC_TLNEI " %4, 0",   \
|      |   ^~~~~~~~~
|arch/powerpc/include/asm/page_32.h:48:2: note: in expansion of macro ‘WARN_ONâ€=99
|   48 |  WARN_ON((unsigned long)addr & (L1_CACHE_BYTES - 1));
|      |  ^~~~~~~
|In file included from arch/powerpc/include/asm/ptrace.h:298,
|                 from arch/powerpc/include/asm/hw_irq.h:12,
|                 from arch/powerpc/include/asm/irqflags.h:12,
|                 from include/linux/irqflags.h:16,
|                 from include/asm-generic/cmpxchg-local.h:6,
|                 from arch/powerpc/include/asm/cmpxchg.h:526,
|                 from arch/powerpc/include/asm/atomic.h:11,
|                 from include/linux/atomic.h:7,
|                 from include/linux/rwbase_rt.h:6,
|                 from include/linux/rwlock_types.h:55,
|                 from include/linux/spinlock_types.h:74,
|                 from include/linux/ratelimit_types.h:7,
|                 from include/linux/printk.h:10,
|                 from include/asm-generic/bug.h:22,
|                 from arch/powerpc/include/asm/bug.h:109,
|                 from include/linux/bug.h:5,
|                 from include/linux/page-flags.h:10,
|                 from kernel/bounds.c:10:
|include/linux/thread_info.h: In function â=80=98copy_overflowâ=80=99:
|include/linux/thread_info.h:210:2: error: implicit declaration of function â=80=98WARNâ=80=99 [-Werror=3Dimplicit-function-declaration]
|  210 |  WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
|      |  ^~~~

The WARN / BUG include pulls in printk.h and then ptrace.h expects WARN
(from bug.h) which is not yet complete. Even hw_irq.h has WARN_ON()
statements.

On POWERPC64 there are missing atomic64 defines while building 32bit
VDSO:
|  VDSO32C arch/powerpc/kernel/vdso32/vgettimeofday.o
|In file included from include/linux/atomic.h:80,
|                 from include/linux/rwbase_rt.h:6,
|                 from include/linux/rwlock_types.h:55,
|                 from include/linux/spinlock_types.h:74,
|                 from include/linux/ratelimit_types.h:7,
|                 from include/linux/printk.h:10,
|                 from include/linux/kernel.h:19,
|                 from arch/powerpc/include/asm/page.h:11,
|                 from arch/powerpc/include/asm/vdso/gettimeofday.h:5,
|                 from include/vdso/datapage.h:137,
|                 from lib/vdso/gettimeofday.c:5,
|                 from <command-line>:
|include/linux/atomic-arch-fallback.h: In function ‘arch_atomic64_incâ€=99:
|include/linux/atomic-arch-fallback.h:1447:2: error: implicit declaration of function ‘arch_atomic64_add’; did you mean ‘arch_atomic_add’? [-Werror=3Dimpl
|icit-function-declaration]
| 1447 |  arch_atomic64_add(1, v);
|      |  ^~~~~~~~~~~~~~~~~
|      |  arch_atomic_add

The generic fallback is not included, atomics itself are not used. If
kernel.h does not include printk.h then it comes later from the bug.h
include.

Allow asm/spinlock_types.h to be included from
linux/spinlock_types_raw.h.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20211129174654.668506-12-bigeasy@linutronix.de
2021-12-07 15:14:12 +01:00
Herbert Xu
b4a461e72b printk: Make linux/printk.h self-contained
As it stands if you include printk.h by itself it will fail to
compile because it requires definitions from ratelimit.h.  However,
simply including ratelimit.h from printk.h does not work due to
inclusion loops involving sched.h and kernel.h.

This patch solves this by moving bits from ratelimit.h into a new
header file which can then be included by printk.h without any
worries about header loops.

The build bot then revealed some intriguing failures arising out
of this patch.  On s390 there is an inclusion loop with asm/bug.h
and linux/kernel.h that triggers a compile failure, because kernel.h
will cause asm-generic/bug.h to be included before s390's own
asm/bug.h has finished processing.  This has been fixed by not
including kernel.h in arch/s390/include/asm/bug.h.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Petr Mladek <pmladek@suse.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Link: https://lore.kernel.org/r/20200721062248.GA18383@gondor.apana.org.au
2020-07-27 17:46:24 +09:00