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lockdep: fix static memory detection even more 

On the parisc architecture, lockdep reports for all static objects which
are in the __initdata section (e.g. "setup_done" in devtmpfs,
"kthreadd_done" in init/main.c) this warning:

	INFO: trying to register non-static key.

The warning itself is wrong, because those objects are in the __initdata
section, but the section itself is on parisc outside of range from
_stext to _end, which is why the static_obj() functions returns a wrong
answer.

While fixing this issue, I noticed that the whole existing check can
be simplified a lot.
Instead of checking against the _stext and _end symbols (which include
code areas too) just check for the .data and .bss segments (since we check a
data object). This can be done with the existing is_kernel_core_data()
macro.

In addition objects in the __initdata section can be checked with
init_section_contains(), and is_kernel_rodata() allows keys to be in the
_ro_after_init section.

This partly reverts and simplifies commit bac59d18c7 ("x86/setup: Fix static
memory detection").

Link: https://lkml.kernel.org/r/ZNqrLRaOi/3wPAdp@p100
Fixes: bac59d18c7 ("x86/setup: Fix static memory detection")
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Helge Deller 2023-08-15 00:31:09 +02:00 committed by Andrew Morton
parent 6655360923
commit 0a6b58c5cd
2 changed files with 14 additions and 40 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
arch/x86/include/asm/sections.h
View File

@ -2,8 +2,6 @@
#ifndef _ASM_X86_SECTIONS_H
#define _ASM_X86_SECTIONS_H
#define arch_is_kernel_initmem_freed arch_is_kernel_initmem_freed
#include <asm-generic/sections.h>
#include <asm/extable.h>
@ -18,20 +16,4 @@ extern char __end_of_kernel_reserve[];
extern unsigned long _brk_start, _brk_end;
static inline bool arch_is_kernel_initmem_freed(unsigned long addr)
{
/*
* If _brk_start has not been cleared, brk allocation is incomplete,
* and we can not make assumptions about its use.
*/
if (_brk_start)
return 0;
/*
* After brk allocation is complete, space between _brk_end and _end
* is available for allocation.
*/
return addr >= _brk_end && addr < (unsigned long)&_end;
}
#endif /* _ASM_X86_SECTIONS_H */

36
kernel/locking/lockdep.c
View File

@ -819,34 +819,26 @@ static int very_verbose(struct lock_class *class)
* Is this the address of a static object:
*/
#ifdef __KERNEL__
/*
* Check if an address is part of freed initmem. After initmem is freed,
* memory can be allocated from it, and such allocations would then have
* addresses within the range [_stext, _end].
*/
#ifndef arch_is_kernel_initmem_freed
static int arch_is_kernel_initmem_freed(unsigned long addr)
{
if (system_state < SYSTEM_FREEING_INITMEM)
return 0;
return init_section_contains((void *)addr, 1);
}
#endif
static int static_obj(const void *obj)
{
unsigned long start = (unsigned long) &_stext,
end = (unsigned long) &_end,
addr = (unsigned long) obj;
unsigned long addr = (unsigned long) obj;
if (arch_is_kernel_initmem_freed(addr))
return 0;
if (is_kernel_core_data(addr))
return 1;
/*
* static variable?
* keys are allowed in the __ro_after_init section.
*/
if ((addr >= start) && (addr < end))
if (is_kernel_rodata(addr))
return 1;
/*
* in initdata section and used during bootup only?
* NOTE: On some platforms the initdata section is
* outside of the _stext ... _end range.
*/
if (system_state < SYSTEM_FREEING_INITMEM &&
init_section_contains((void *)addr, 1))
return 1;
/*