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author | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
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committer | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
commit | 871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch) | |
tree | 8718f573808810c2a1e8cb8fb6ac469093ca2784 /arch/tile/lib/memcpy_user_64.c | |
parent | 9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff) | |
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Moved, renamed, and deleted files
The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.
Diffstat (limited to 'arch/tile/lib/memcpy_user_64.c')
-rw-r--r-- | arch/tile/lib/memcpy_user_64.c | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/arch/tile/lib/memcpy_user_64.c b/arch/tile/lib/memcpy_user_64.c new file mode 100644 index 00000000..37440caa --- /dev/null +++ b/arch/tile/lib/memcpy_user_64.c @@ -0,0 +1,92 @@ +/* + * Copyright 2011 Tilera Corporation. All Rights Reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation, version 2. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or + * NON INFRINGEMENT. See the GNU General Public License for + * more details. + * + * Do memcpy(), but trap and return "n" when a load or store faults. + * + * Note: this idiom only works when memcpy() compiles to a leaf function. + * Here leaf function not only means it does not have calls, but also + * requires no stack operations (sp, stack frame pointer) and no + * use of callee-saved registers, else "jrp lr" will be incorrect since + * unwinding stack frame is bypassed. Since memcpy() is not complex so + * these conditions are satisfied here, but we need to be careful when + * modifying this file. This is not a clean solution but is the best + * one so far. + * + * Also note that we are capturing "n" from the containing scope here. + */ + +#define _ST(p, inst, v) \ + ({ \ + asm("1: " #inst " %0, %1;" \ + ".pushsection .coldtext.memcpy,\"ax\";" \ + "2: { move r0, %2; jrp lr };" \ + ".section __ex_table,\"a\";" \ + ".quad 1b, 2b;" \ + ".popsection" \ + : "=m" (*(p)) : "r" (v), "r" (n)); \ + }) + +#define _LD(p, inst) \ + ({ \ + unsigned long __v; \ + asm("1: " #inst " %0, %1;" \ + ".pushsection .coldtext.memcpy,\"ax\";" \ + "2: { move r0, %2; jrp lr };" \ + ".section __ex_table,\"a\";" \ + ".quad 1b, 2b;" \ + ".popsection" \ + : "=r" (__v) : "m" (*(p)), "r" (n)); \ + __v; \ + }) + +#define USERCOPY_FUNC __copy_to_user_inatomic +#define ST1(p, v) _ST((p), st1, (v)) +#define ST2(p, v) _ST((p), st2, (v)) +#define ST4(p, v) _ST((p), st4, (v)) +#define ST8(p, v) _ST((p), st, (v)) +#define LD1 LD +#define LD2 LD +#define LD4 LD +#define LD8 LD +#include "memcpy_64.c" + +#define USERCOPY_FUNC __copy_from_user_inatomic +#define ST1 ST +#define ST2 ST +#define ST4 ST +#define ST8 ST +#define LD1(p) _LD((p), ld1u) +#define LD2(p) _LD((p), ld2u) +#define LD4(p) _LD((p), ld4u) +#define LD8(p) _LD((p), ld) +#include "memcpy_64.c" + +#define USERCOPY_FUNC __copy_in_user_inatomic +#define ST1(p, v) _ST((p), st1, (v)) +#define ST2(p, v) _ST((p), st2, (v)) +#define ST4(p, v) _ST((p), st4, (v)) +#define ST8(p, v) _ST((p), st, (v)) +#define LD1(p) _LD((p), ld1u) +#define LD2(p) _LD((p), ld2u) +#define LD4(p) _LD((p), ld4u) +#define LD8(p) _LD((p), ld) +#include "memcpy_64.c" + +unsigned long __copy_from_user_zeroing(void *to, const void __user *from, + unsigned long n) +{ + unsigned long rc = __copy_from_user_inatomic(to, from, n); + if (unlikely(rc)) + memset(to + n - rc, 0, rc); + return rc; +} |