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		e4f674229c
		
	
	
	
	
		
			
			I recently added a patch to let folks pass a "reason" string dump_page() which gets dumped out along with the page's data. This essentially saves the bug-reader a trip in to the source to figure out why we BUG_ON()'d. The new VM_BUG_ON_PAGE() passes in NULL for "reason". It seems like we might as well pass the BUG_ON() condition if we have it. This will bloat kernels a bit with ~160 new strings, but this is all under a debugging option anyway. page:ffffea0008560280 count:1 mapcount:0 mapping:(null) index:0x0 page flags: 0xbfffc0000000001(locked) page dumped because: VM_BUG_ON_PAGE(PageLocked(page)) ------------[ cut here ]------------ kernel BUG at /home/davehans/linux.git/mm/filemap.c:464! invalid opcode: 0000 [#1] SMP CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.14.0+ #251 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 ... [akpm@linux-foundation.org: include stringify.h] Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Davidlohr Bueso <davidlohr@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
		
			
				
	
	
		
			36 lines
		
	
	
	
		
			964 B
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			36 lines
		
	
	
	
		
			964 B
		
	
	
	
		
			C
		
	
	
	
	
	
| #ifndef LINUX_MM_DEBUG_H
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| #define LINUX_MM_DEBUG_H 1
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| 
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| #include <linux/stringify.h>
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| 
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| struct page;
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| 
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| extern void dump_page(struct page *page, const char *reason);
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| extern void dump_page_badflags(struct page *page, const char *reason,
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| 			       unsigned long badflags);
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| 
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| #ifdef CONFIG_DEBUG_VM
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| #define VM_BUG_ON(cond) BUG_ON(cond)
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| #define VM_BUG_ON_PAGE(cond, page)					\
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| 	do {								\
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| 		if (unlikely(cond)) {					\
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| 			dump_page(page, "VM_BUG_ON_PAGE(" __stringify(cond)")");\
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| 			BUG();						\
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| 		}							\
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| 	} while (0)
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| #define VM_WARN_ON(cond) WARN_ON(cond)
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| #define VM_WARN_ON_ONCE(cond) WARN_ON_ONCE(cond)
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| #else
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| #define VM_BUG_ON(cond) BUILD_BUG_ON_INVALID(cond)
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| #define VM_BUG_ON_PAGE(cond, page) VM_BUG_ON(cond)
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| #define VM_WARN_ON(cond) BUILD_BUG_ON_INVALID(cond)
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| #define VM_WARN_ON_ONCE(cond) BUILD_BUG_ON_INVALID(cond)
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| #endif
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| 
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| #ifdef CONFIG_DEBUG_VIRTUAL
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| #define VIRTUAL_BUG_ON(cond) BUG_ON(cond)
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| #else
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| #define VIRTUAL_BUG_ON(cond) do { } while (0)
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| #endif
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| 
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| #endif
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