6.4-stable review patch. If anyone has any objections, please let me know.
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From: Helge Deller deller@gmx.de
commit 0a6b58c5cd0dfd7961e725212f0fc8dfc5d96195 upstream.
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 bac59d18c701 ("x86/setup: Fix static memory detection").
Link: https://lkml.kernel.org/r/ZNqrLRaOi/3wPAdp@p100 Fixes: bac59d18c701 ("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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/include/asm/sections.h | 18 ------------------ kernel/locking/lockdep.c | 36 ++++++++++++++---------------------- 2 files changed, 14 insertions(+), 40 deletions(-)
--- a/arch/x86/include/asm/sections.h +++ b/arch/x86/include/asm/sections.h @@ -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 */ --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -817,34 +817,26 @@ static int very_verbose(struct lock_clas * 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; + + /* + * keys are allowed in the __ro_after_init section. + */ + if (is_kernel_rodata(addr)) + return 1;
/* - * static variable? + * in initdata section and used during bootup only? + * NOTE: On some platforms the initdata section is + * outside of the _stext ... _end range. */ - if ((addr >= start) && (addr < end)) + if (system_state < SYSTEM_FREEING_INITMEM && + init_section_contains((void *)addr, 1)) return 1;
/*