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1f27a050fc
To cope with the changes in:12c89130a5("x86/asm/memcpy_mcsafe: Add write-protection-fault handling")60622d6822("x86/asm/memcpy_mcsafe: Return bytes remaining")bd131544aa("x86/asm/memcpy_mcsafe: Add labels for __memcpy_mcsafe() write fault handling")da7bc9c57e("x86/asm/memcpy_mcsafe: Remove loop unrolling") This needed introducing a file with a copy of the mcsafe_handle_tail() function, that is used in the new memcpy_64.S file, as well as a dummy mcsafe_test.h header. Testing it: $ nm ~/bin/perf | grep mcsafe 0000000000484130 T mcsafe_handle_tail 0000000000484300 T __memcpy_mcsafe $ $ perf bench mem memcpy # Running 'mem/memcpy' benchmark: # function 'default' (Default memcpy() provided by glibc) # Copying 1MB bytes ... 44.389205 GB/sec # function 'x86-64-unrolled' (unrolled memcpy() in arch/x86/lib/memcpy_64.S) # Copying 1MB bytes ... 22.710756 GB/sec # function 'x86-64-movsq' (movsq-based memcpy() in arch/x86/lib/memcpy_64.S) # Copying 1MB bytes ... 42.459239 GB/sec # function 'x86-64-movsb' (movsb-based memcpy() in arch/x86/lib/memcpy_64.S) # Copying 1MB bytes ... 42.459239 GB/sec $ This silences this perf tools build warning: Warning: Kernel ABI header at 'tools/arch/x86/lib/memcpy_64.S' differs from latest version at 'arch/x86/lib/memcpy_64.S' Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Mika Penttilä <mika.penttila@nextfour.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Wang Nan <wangnan0@huawei.com> Link: https://lkml.kernel.org/n/tip-igdpciheradk3gb3qqal52d0@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
25 lines
647 B
C
25 lines
647 B
C
/*
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* From code in arch/x86/lib/usercopy_64.c, copied to keep tools/ copy
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* of the kernel's arch/x86/lib/memcpy_64.s used in 'perf bench mem memcpy'
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* happy.
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*/
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#include <linux/types.h>
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unsigned long __memcpy_mcsafe(void *dst, const void *src, size_t cnt);
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unsigned long mcsafe_handle_tail(char *to, char *from, unsigned len);
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unsigned long mcsafe_handle_tail(char *to, char *from, unsigned len)
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{
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for (; len; --len, to++, from++) {
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/*
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* Call the assembly routine back directly since
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* memcpy_mcsafe() may silently fallback to memcpy.
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*/
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unsigned long rem = __memcpy_mcsafe(to, from, 1);
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if (rem)
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break;
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}
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return len;
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}
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