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| author | Peter Zijlstra <peterz@infradead.org> | 2021-11-10 11:01:22 +0100 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2021-12-11 09:09:50 +0100 |
| commit | d5d797dcbd781cb7c526ad32f31c7fd96babfdb2 (patch) | |
| tree | dd64239b122e8ab932f750b121d88bdacbff9120 /arch/x86/lib/usercopy_32.c | |
| parent | 13e4bf1bddcb65dd028aaa492789e8d61efaafa1 (diff) | |
| download | lwn-d5d797dcbd781cb7c526ad32f31c7fd96babfdb2.tar.gz lwn-d5d797dcbd781cb7c526ad32f31c7fd96babfdb2.zip | |
x86/usercopy: Remove .fixup usage
Typically usercopy does whole word copies followed by a number of byte
copies to finish the tail. This means that on exception it needs to
compute the remaining length as: words*sizeof(long) + bytes.
Create a new extable handler to do just this.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20211110101326.081701085@infradead.org
Diffstat (limited to 'arch/x86/lib/usercopy_32.c')
| -rw-r--r-- | arch/x86/lib/usercopy_32.c | 28 |
1 files changed, 5 insertions, 23 deletions
diff --git a/arch/x86/lib/usercopy_32.c b/arch/x86/lib/usercopy_32.c index 1eb15060c436..422257c350c6 100644 --- a/arch/x86/lib/usercopy_32.c +++ b/arch/x86/lib/usercopy_32.c @@ -42,11 +42,7 @@ do { \ " movl %2,%0\n" \ "1: rep; stosb\n" \ "2: " ASM_CLAC "\n" \ - ".section .fixup,\"ax\"\n" \ - "3: lea 0(%2,%0,4),%0\n" \ - " jmp 2b\n" \ - ".previous\n" \ - _ASM_EXTABLE_UA(0b, 3b) \ + _ASM_EXTABLE_TYPE_REG(0b, 2b, EX_TYPE_UCOPY_LEN4, %2) \ _ASM_EXTABLE_UA(1b, 2b) \ : "=&c"(size), "=&D" (__d0) \ : "r"(size & 3), "0"(size / 4), "1"(addr), "a"(0)); \ @@ -148,10 +144,6 @@ __copy_user_intel(void __user *to, const void *from, unsigned long size) "36: movl %%eax, %0\n" "37: rep; movsb\n" "100:\n" - ".section .fixup,\"ax\"\n" - "101: lea 0(%%eax,%0,4),%0\n" - " jmp 100b\n" - ".previous\n" _ASM_EXTABLE_UA(1b, 100b) _ASM_EXTABLE_UA(2b, 100b) _ASM_EXTABLE_UA(3b, 100b) @@ -189,7 +181,7 @@ __copy_user_intel(void __user *to, const void *from, unsigned long size) _ASM_EXTABLE_UA(35b, 100b) _ASM_EXTABLE_UA(36b, 100b) _ASM_EXTABLE_UA(37b, 100b) - _ASM_EXTABLE_UA(99b, 101b) + _ASM_EXTABLE_TYPE_REG(99b, 100b, EX_TYPE_UCOPY_LEN4, %%eax) : "=&c"(size), "=&D" (d0), "=&S" (d1) : "1"(to), "2"(from), "0"(size) : "eax", "edx", "memory"); @@ -254,10 +246,6 @@ static unsigned long __copy_user_intel_nocache(void *to, " movl %%eax,%0\n" "7: rep; movsb\n" "8:\n" - ".section .fixup,\"ax\"\n" - "9: lea 0(%%eax,%0,4),%0\n" - " jmp 8b\n" - ".previous\n" _ASM_EXTABLE_UA(0b, 8b) _ASM_EXTABLE_UA(1b, 8b) _ASM_EXTABLE_UA(2b, 8b) @@ -276,7 +264,7 @@ static unsigned long __copy_user_intel_nocache(void *to, _ASM_EXTABLE_UA(81b, 8b) _ASM_EXTABLE_UA(14b, 8b) _ASM_EXTABLE_UA(91b, 8b) - _ASM_EXTABLE_UA(6b, 9b) + _ASM_EXTABLE_TYPE_REG(6b, 8b, EX_TYPE_UCOPY_LEN4, %%eax) _ASM_EXTABLE_UA(7b, 8b) : "=&c"(size), "=&D" (d0), "=&S" (d1) : "1"(to), "2"(from), "0"(size) @@ -314,14 +302,8 @@ do { \ " movl %3,%0\n" \ "1: rep; movsb\n" \ "2:\n" \ - ".section .fixup,\"ax\"\n" \ - "5: addl %3,%0\n" \ - " jmp 2b\n" \ - "3: lea 0(%3,%0,4),%0\n" \ - " jmp 2b\n" \ - ".previous\n" \ - _ASM_EXTABLE_UA(4b, 5b) \ - _ASM_EXTABLE_UA(0b, 3b) \ + _ASM_EXTABLE_TYPE_REG(4b, 2b, EX_TYPE_UCOPY_LEN1, %3) \ + _ASM_EXTABLE_TYPE_REG(0b, 2b, EX_TYPE_UCOPY_LEN4, %3) \ _ASM_EXTABLE_UA(1b, 2b) \ : "=&c"(size), "=&D" (__d0), "=&S" (__d1), "=r"(__d2) \ : "3"(size), "0"(size), "1"(to), "2"(from) \ |