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	The fix for BZ#21270 (commit 158d5fa0e1) added a mask to avoid offset larger
than 1^44 to be used along __NR_mmap2.  However mips64n32 users __NR_mmap,
as mips64n64, but still defines off_t as old non-LFS type (other ILP32, such
x32, defines off_t being equal to off64_t).  This leads to use the same
mask meant only for __NR_mmap2 call for __NR_mmap, thus limiting the maximum
offset it can use with mmap64.
This patch fixes by setting the high mask only for __NR_mmap2 usage. The
posix/tst-mmap-offset.c already tests it and also fails for mips64n32. The
patch also change the test to check for an arch-specific header that defines
the maximum supported offset.
Checked on x86_64-linux-gnu, i686-linux-gnu, and I also tests tst-mmap-offset
on qemu simulated mips64 with kernel 3.2.0 kernel for both mips-linux-gnu and
mips64-n32-linux-gnu.
	[BZ #24699]
	* posix/tst-mmap-offset.c: Mention BZ #24699.
	(do_test_bz21270): Rename to do_test_large_offset and use
	mmap64_maximum_offset to check for maximum expected offset value.
	* sysdeps/generic/mmap_info.h: New file.
	* sysdeps/unix/sysv/linux/mips/mmap_info.h: Likewise.
	* sysdeps/unix/sysv/linux/mmap64.c (MMAP_OFF_HIGH_MASK): Define iff
	__NR_mmap2 is used.
		
	
		
			
				
	
	
		
			14 lines
		
	
	
		
			425 B
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			14 lines
		
	
	
		
			425 B
		
	
	
	
		
			C
		
	
	
	
	
	
| /* mips64n32 uses __NR_mmap for mmap64 while still having sizeof (off_t)
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|    smaller than sizeof (off64_t).  So it allows mapping large offsets
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|    using mmap64 than 32-bit archs which uses __NR_mmap2.  */
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| 
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| static inline uint64_t
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| mmap64_maximum_offset (long int page_shift)
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| {
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| #if _MIPS_SIM == _ABIN32 || _MIPS_SIM == _ABI64
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|   return UINT64_MAX;
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| #else
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|   return (UINT64_C(1) << (page_shift + (8 * sizeof (off_t)))) - 1;
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| #endif
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| }
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