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Now passes runtime tests for BP. No regressions for non-BP. This has a new optimization: don't write back to SAVE_PTR when returning NULL. OK? 2000-07-26 Greg McGary <greg@mcgary.org> * sysdeps/i386/strtok.S: Fix bounds checks to pass tests. (SAVE_PTR): New macro. (save_ptr): Expand size as BP. (strtok): Don't bother to write into SAVE_PTR when returning NULL. * sysdeps/i386/i686/strtok.S: Likewise. * sysdeps/i386/bp-asm.h (RETURN_BOUNDED_POINTER, RETURN_NULL_BOUNDED_POINTER): Use %ecx as the scratch register. Index: sysdeps/i386/strtok.S =================================================================== RCS file: /cvs/glibc/libc/sysdeps/i386/strtok.S,v retrieving revision 1.9 diff -u -p -B -w -r1.9 strtok.S --- strtok.S 2000/06/26 22:14:59 1.9 +++ strtok.S 2000/07/26 08:19:39 @@ -39,14 +39,26 @@ We do a common implementation here. */ -#ifndef USE_AS_STRTOK_R +#ifdef USE_AS_STRTOK_R +# define SAVE_PTR 0(%ecx) +#else .bss .local save_ptr ASM_TYPE_DIRECTIVE (save_ptr, @object) .size save_ptr, 4 save_ptr: +# if __BOUNDED_POINTERS__ + .space 12 +# else .space 4 +# endif +# ifdef PIC +# define SAVE_PTR save_ptr@GOTOFF(%ebx) +# else +# define SAVE_PTR save_ptr +# endif + #define FUNCTION strtok #endif @@ -62,10 +74,9 @@ ENTRY (BP_SYM (FUNCTION)) movl STR(%esp), %edx movl DELIM(%esp), %eax - CHECK_BOUNDS_LOW (%edx, STR(%esp)) CHECK_BOUNDS_LOW (%eax, DELIM(%esp)) -#if !defined (USE_AS_STRTOK_R) && defined (PIC) +#if !defined USE_AS_STRTOK_R && defined PIC pushl %ebx /* Save PIC register. */ call L(here) L(here): @@ -76,7 +87,22 @@ L(here): /* If the pointer is NULL we have to use the stored value of the last run. */ cmpl $0, %edx - jne L(0) +#if __BOUNDED_POINTERS__ + movl SAVE(%esp), %ecx + je L(0) + /* Save bounds of incoming non-NULL STR into save area. */ + movl 4+STR(%esp), %eax + movl %eax, 4+SAVE_PTR + movl 8+STR(%esp), %eax + movl %eax, 8+SAVE_PTR + CHECK_BOUNDS_LOW (%edx, SAVE_PTR) + jmp L(1) +L(0): movl SAVE_PTR, %edx + CHECK_BOUNDS_LOW (%edx, SAVE_PTR) + jmp L(1) +#else + jne L(1) +#endif #ifdef USE_AS_STRTOK_R /* The value is stored in the third argument. */ @@ -85,14 +111,10 @@ L(here): #else /* The value is in the local variable defined above. But we have to take care for PIC code. */ -# ifndef PIC - movl save_ptr, %edx -# else - movl save_ptr@GOTOFF(%ebx), %edx -# endif + movl SAVE_PTR, %edx #endif -L(0): +L(1): /* First we create a table with flags for all possible characters. For the ASCII (7bit/8bit) or ISO-8859-X character sets which are supported by the C string functions we have 256 characters. @@ -195,7 +217,7 @@ L(2): movb (%eax), %cl /* get byte from L(1_3): incl %eax /* adjust pointer for bounds check */ L(1_2): incl %eax /* ditto */ L(1_1): incl %eax /* ditto */ -L(1_0): CHECK_BOUNDS_HIGH (%eax, DELIM(%esp), jb) +L(1_0): CHECK_BOUNDS_HIGH (%eax, DELIM(%esp), jbe) #else L(1_3):; L(1_2):; L(1_1): /* fall through */ #endif @@ -273,25 +295,17 @@ L(8): /* Remove the stopset table. */ incl %edx L(11): -L(return): /* Store the pointer to the next character. */ #ifdef USE_AS_STRTOK_R movl SAVE(%esp), %ecx - movl %edx, (%ecx) -#else -# ifndef PIC - movl %edx, save_ptr -# else - movl %edx, save_ptr@GOTOFF(%ebx) - popl %ebx -# endif #endif -#if __BOUNDED_POINTERS__ - testl %eax, %eax - jz L(ret) - CHECK_BOUNDS_HIGH (%eax, STR(%esp), jb) - RETURN_BOUNDED_POINTER (STR(%esp)) -L(ret): + movl %edx, SAVE_PTR + CHECK_BOUNDS_HIGH (%edx, SAVE_PTR, jb) + RETURN_BOUNDED_POINTER (SAVE_PTR) + +L(epilogue): +#if !defined USE_AS_STRTOK_R && defined PIC + popl %ebx #endif LEAVE RET_PTR @@ -299,6 +313,6 @@ L(ret): L(returnNULL): xorl %eax, %eax RETURN_NULL_BOUNDED_POINTER - jmp L(return) + jmp L(epilogue) END (BP_SYM (FUNCTION)) Index: sysdeps/i386/i686/strtok.S =================================================================== RCS file: /cvs/glibc/libc/sysdeps/i386/i686/strtok.S,v retrieving revision 1.4 diff -u -p -B -w -r1.4 strtok.S --- strtok.S 2000/06/26 22:15:00 1.4 +++ strtok.S 2000/07/26 08:19:39 @@ -39,30 +39,48 @@ We do a common implementation here. */ -#ifndef USE_AS_STRTOK_R +#ifdef USE_AS_STRTOK_R +# define SAVE_PTR 0(%ecx) +#else .bss .local save_ptr ASM_TYPE_DIRECTIVE (save_ptr, @object) .size save_ptr, 4 save_ptr: +# if __BOUNDED_POINTERS__ + .space 12 +# else .space 4 +# endif -#define FUNCTION BP_SYM (strtok) +# ifdef PIC +# define SAVE_PTR save_ptr@GOTOFF(%ebx) +# else +# define SAVE_PTR save_ptr #endif - .text +# define FUNCTION strtok +#endif #if !defined USE_AS_STRTOK_R && defined PIC -0: movl (%esp), %ebx - ret +# define PARMS LINKAGE+256+4 /* space for table and saved PIC register */ +#else +# define PARMS LINKAGE+256 /* space for table */ #endif - -#define PARMS LINKAGE /* no space for saved regs */ #define RTN PARMS #define STR RTN+RTN_SIZE #define DELIM STR+PTR_SIZE +#ifdef USE_AS_STRTOK_R #define SAVE DELIM+PTR_SIZE +#endif + + .text +#if !defined USE_AS_STRTOK_R && defined PIC +0: movl (%esp), %ebx + ret +#endif + ENTRY (BP_SYM (FUNCTION)) ENTER @@ -89,36 +107,39 @@ ENTRY (BP_SYM (FUNCTION)) /* Note: %ecx = 0 !!! */ movl %edx, %edi -#if !defined USE_AS_STRTOK_R && defined PIC - movl 264(%esp), %edx /* Get start of string. */ -#else - movl 260(%esp), %edx /* Get start of string. */ -#endif + movl STR(%esp), %edx /* Get start of string. */ #ifdef USE_AS_STRTOK_R /* The value is stored in the third argument. */ - movl 268(%esp), %eax + movl SAVE(%esp), %eax movl (%eax), %eax #else /* The value is in the local variable defined above. But we have to take care for PIC code. */ -# ifndef PIC - movl save_ptr, %eax -# else - movl save_ptr@GOTOFF(%ebx), %eax -# endif + movl SAVE_PTR, %eax #endif /* If the pointer is NULL we have to use the stored value of the last run. */ cmpl $0, %edx cmove %eax, %edx - -#if !defined USE_AS_STRTOK_R && defined PIC - movl 268(%esp), %eax /* Get start of delimiter set. */ -#else - movl 264(%esp), %eax /* Get start of delimiter set. */ +#if __BOUNDED_POINTERS__ +# ifdef USE_AS_STRTOK_R + movl SAVE(%esp), %ecx /* borrow %ecx for a moment */ #endif + je L(0) + /* Save bounds of incoming non-NULL STR into save area. */ + movl 4+STR(%esp), %eax + movl %eax, 4+SAVE_PTR + movl 8+STR(%esp), %eax + movl %eax, 8+SAVE_PTR +L(0): CHECK_BOUNDS_LOW (%edx, SAVE_PTR) +# ifdef USE_AS_STRTOK_R + xorl %ecx, %ecx /* restore %ecx to zero */ +# endif +#endif + movl DELIM(%esp), %eax /* Get start of delimiter set. */ + CHECK_BOUNDS_LOW (%eax, DELIM(%esp)) /* For understanding the following code remember that %ecx == 0 now. Although all the following instruction only modify %cl we always @@ -126,17 +147,17 @@ ENTRY (BP_SYM (FUNCTION)) L(2): movb (%eax), %cl /* get byte from stopset */ testb %cl, %cl /* is NUL char? */ - jz L(1) /* yes => start compare loop */ + jz L(1_1) /* yes => start compare loop */ movb %cl, (%esp,%ecx) /* set corresponding byte in stopset table */ movb 1(%eax), %cl /* get byte from stopset */ testb $0xff, %cl /* is NUL char? */ - jz L(1) /* yes => start compare loop */ + jz L(1_2) /* yes => start compare loop */ movb %cl, (%esp,%ecx) /* set corresponding byte in stopset table */ movb 2(%eax), %cl /* get byte from stopset */ testb $0xff, %cl /* is NUL char? */ - jz L(1) /* yes => start compare loop */ + jz L(1_3) /* yes => start compare loop */ movb %cl, (%esp,%ecx) /* set corresponding byte in stopset table */ movb 3(%eax), %cl /* get byte from stopset */ @@ -145,7 +166,16 @@ L(2): movb (%eax), %cl /* get byte from testb $0xff, %cl /* is NUL char? */ jnz L(2) /* no => process next dword from stopset */ -L(1): leal -4(%edx), %eax /* prepare loop */ +#if __BOUNDED_POINTERS__ + jmp L(1_0) /* pointer is correct for bounds check */ +L(1_3): incl %eax /* adjust pointer for bounds check */ +L(1_2): incl %eax /* ditto */ +L(1_1): incl %eax /* ditto */ +L(1_0): CHECK_BOUNDS_HIGH (%eax, DELIM(%esp), jbe) +#else +L(1_3):; L(1_2):; L(1_1): /* fall through */ +#endif + leal -4(%edx), %eax /* prepare loop */ /* We use a neat trick for the following loop. Normally we would have to test for two termination conditions @@ -204,10 +234,7 @@ L(7): addl $4, %edx /* adjust pointer f L(10): incl %edx L(9): incl %edx -L(8): /* Remove the stopset table. */ - addl $256, %esp - - cmpl %eax, %edx +L(8): cmpl %eax, %edx je L(returnNULL) /* There was no token anymore. */ movb $0, (%edx) /* Terminate string. */ @@ -217,22 +244,26 @@ L(8): /* Remove the stopset table. */ leal 1(%edx), %ecx cmovne %ecx, %edx -L(return): /* Store the pointer to the next character. */ #ifdef USE_AS_STRTOK_R - movl 12(%esp), %ecx - movl %edx, (%ecx) -#else -# ifndef PIC - movl %edx, save_ptr -# else - movl %edx, save_ptr@GOTOFF(%ebx) - popl %ebx + movl SAVE(%esp), %ecx # endif + movl %edx, SAVE_PTR + CHECK_BOUNDS_HIGH (%edx, SAVE_PTR, jb) + RETURN_BOUNDED_POINTER (SAVE_PTR) + +L(epilogue): + /* Remove the stopset table. */ + addl $256, %esp +#if !defined USE_AS_STRTOK_R && defined PIC + popl %ebx #endif - ret + LEAVE + RET_PTR L(returnNULL): xorl %eax, %eax - jmp L(return) + RETURN_NULL_BOUNDED_POINTER + jmp L(epilogue) + END (BP_SYM (FUNCTION))
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