From: sandmann AT clio DOT rice DOT edu (Charles Sandmann) Message-Id: <10108121754.AA12952@clio.rice.edu> Subject: Latest crt0 patches (+block sizing for core) To: djgpp-workers AT delorie DOT com (DJGPP developers) Date: Sun, 12 Aug 2001 12:54:59 -0500 (CDT) X-Mailer: ELM [version 2.5 PL2] Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Reply-To: djgpp-workers AT delorie DOT com Here are the latest crt0 diffs. They include memory handle sizing for dumps, fixes for address space wraps, and fixes for too many memory handles. Documentation updates included. 4 patched files. If there are no new comments I'd like to get these into cvs. *** crt0.S_203 Wed Aug 1 20:28:48 2001 --- crt0.S Sat Aug 11 19:42:50 2001 *************** *** 46,49 **** --- 46,50 ---- .long ___djgpp_memory_handle_list+8 /* Next free, first for stub */ .comm ___djgpp_memory_handle_list, 2048 /* Enough for 256 handles */ + .comm ___djgpp_memory_handle_size, 1024 /* Enough for 256 handles */ #endif *************** *** 145,155 **** int $0x31 /* set access rights for alias */ ! /* Maybe set our DS limit to 4Gb in size if flag set */ ! testb $0x80, __crt0_startup_flags /* include/crt0.h */ ! jz 2f movw $0xffff, %cx movl %ecx, %edx movw $0x0008, %ax /* reset alias limit to -1 */ int $0x31 movw %cs, %bx movw $0x0008, %ax /* reset CS limit to -1 */ --- 146,163 ---- int $0x31 /* set access rights for alias */ ! /* Test set the limit on the alias to 4Gb (it may be reset on stack malloc) */ movw $0xffff, %cx movl %ecx, %edx movw $0x0008, %ax /* reset alias limit to -1 */ int $0x31 + lsl %ebx, %ebx /* Should be -1 */ + incl %ebx + jz 16f + andb $0x7f, __crt0_startup_flags /* clear it if failure */ + orb $0x80, __crt0_startup_flags+1 /* Wrap is *BAD* */ + jmp 2f + /* Maybe set our DS limit to 4Gb in size if flag set */ + 16: testb $0x80, __crt0_startup_flags /* include/crt0.h */ + jz 2f movw %cs, %bx movw $0x0008, %ax /* reset CS limit to -1 */ *************** *** 158,165 **** movw $0x0008, %ax /* reset DS limit to -1 */ int $0x31 - lsl %ebx, %ebx /* Should be -1 */ - incl %ebx - jz 2f - andb $0x7f, __crt0_startup_flags /* clear it if failure */ 2: #ifdef MULTIBLOCK --- 166,169 ---- *************** *** 234,237 **** --- 238,242 ---- movl STUBINFO_INITIAL_SIZE, %eax movl %eax, __what_size_dpmi_thinks_we_are + movl %eax, ___djgpp_memory_handle_size /* Maybe lock the initial block, expects BX:CX */ *************** *** 482,485 **** --- 487,491 ---- movl %edi, ___djgpp_memory_handle_list /* store new handle */ movw %si, ___djgpp_memory_handle_list+2 + movl %edx, ___djgpp_memory_handle_size movl %ecx, ___djgpp_base_address /* store new base address */ movw %bx, ___djgpp_base_address+2 *************** *** 500,506 **** /* Current allocation not large enough, get another block */ 10: movl %ecx, %eax /* Add amt */ ! pushl %eax /* Save orig */ ! addl $0x0000ffff, %eax /* round up to 64K block */ ! andl $0xffff0000, %eax movl %eax, %edx /* Save size */ movl %eax, %ecx --- 506,527 ---- /* Current allocation not large enough, get another block */ 10: movl %ecx, %eax /* Add amt */ ! 14: pushl %eax /* Save orig */ ! ! /* Prevent handle exhaustion: Block size of later allocated handles is larger. ! Block Size = 2^(16+handle#/32) which allows 512Mb on default 256 handles. */ ! ! movl ___djgpp_memory_handle_pointer, %ecx ! xorl %edx, %edx ! subl $___djgpp_memory_handle_list, %ecx /* 8*hand# */ ! shrl $8, %ecx /* hand#/32, tuneable, big shifts = old way */ ! incl %edx /* EDX = 1 */ ! addb $16, %cl /* 2^16=64K */ ! shll %cl, %edx ! decl %edx ! movl %edx, %ecx ! notl %edx ! addl %ecx, %eax /* Round up to block */ ! andl %edx, %eax ! movl %eax, %edx /* Save size */ movl %eax, %ecx *************** *** 512,521 **** jc brk_error - pushl %edx /* Size */ - call lock_memory - pushw %bx pushw %cx popl %ecx /* Linear address */ subl ___djgpp_base_address, %ecx /* New dpmi size */ cmpl %ecx, __what_size_dpmi_thinks_we_are /* Back to back ? */ --- 533,547 ---- jc brk_error pushw %bx pushw %cx popl %ecx /* Linear address */ + cmpl ___djgpp_base_address, %ecx /* New dpmi size */ + jns 15f /* Ignore this block */ + testb $0x80, __crt0_startup_flags+1 /* include/crt0.h */ + jnz 14b + 15: + pushl %edx /* Size */ + call lock_memory + subl ___djgpp_base_address, %ecx /* New dpmi size */ cmpl %ecx, __what_size_dpmi_thinks_we_are /* Back to back ? */ *************** *** 532,535 **** --- 558,567 ---- movw %si, 2(%ebx) movl %ecx, 4(%ebx) + /* Handle Offset / 2 = Offset into Size Array */ + movl %ebx, %edi + subl $___djgpp_memory_handle_list, %edi + shrl $1, %edi + addl $___djgpp_memory_handle_size, %edi + movl %edx, (%edi) addl $8, %ebx cmpl $___djgpp_memory_handle_list+2040, %ebx /* At end? */ *** crt0.h_203 Sun Jul 26 08:33:36 1998 --- crt0.h Sat Aug 11 19:46:34 2001 *************** *** 164,167 **** --- 164,177 ---- #define _CRT0_FLAG_KEEP_QUOTES 0x4000 + /* If set, non-move sbrk() should discard (ignore) memory blocks which are + ** returned by DPMI which would require address wrap to access (at addresses + ** below the CS/DS base address). This bit is automatically set on Win NT + ** systems which require it. It may be manually set on other systems which + ** don't require it to retain a more normal memory space layout and better + ** memory protection. This bit can be set but should never be cleared. + */ + + #define _CRT0_DISABLE_SBRK_ADDRESS_WRAP 0x8000 + /*****************************************************************************\ * Access to the memory handles used by the non-move sbrk algorithm. *************** *** 177,180 **** --- 187,191 ---- extern __djgpp_sbrk_handle __djgpp_memory_handle_list[256]; __djgpp_sbrk_handle *__djgpp_memory_handle(unsigned address); + extern unsigned __djgpp_memory_handle_size[256]; #endif /* !_POSIX_SOURCE */ *** crt0.txh_203 Sat Mar 20 16:15:24 1999 --- crt0.txh Sat Aug 11 21:43:06 2001 *************** *** 100,104 **** #include ! extern __djgpp_sbrk_handle __djgpp_memory_handle_list[256]; @end example --- 100,111 ---- #include ! for(i=0; i<256; i++) { ! int h, a, s; ! h = __djgpp_memory_handle_list[i].handle; ! a = __djgpp_memory_handle_list[i].address; ! s = __djgpp_memory_handle_size[i]; ! if(a == 0 && i != 0) break; ! printf("handle[%d]=0x%x base=0x%x size=0x%x\n",i,h,a,s); ! } @end example *************** *** 111,114 **** --- 118,148 ---- @subheading Portability + + @portability !ansi, !posix + + @c ---------------------------------------------------------------------- + @node __djgpp_memory_handle_size, memory + @subheading Syntax + + @example + #include + + for(i=0; i<256; i++) { + int h, a, s; + h = __djgpp_memory_handle_list[i].handle; + a = __djgpp_memory_handle_list[i].address; + s = __djgpp_memory_handle_size[i]; + if(a == 0 && i != 0) break; + printf("handle[%d]=0x%x base=0x%x size=0x%x\n",i,h,a,s); + } + @end example + + @subheading Description + + This array contains a list of the sizes of the memory handles allocated + by sbrk() in addition to the handle allocated by the stub. These + values are normally not needed unless you are dumping the memory blocks. + + @subheading Portability @portability !ansi, !posix *** crt1.txh_203 Sat Mar 20 16:48:18 1999 --- crt1.txh Sat Aug 11 21:50:06 2001 *************** *** 187,191 **** @code{sbrk} expectations. This mode should not be used with hardware interrupts, near pointers, and may cause problems with QDPMI virtual ! memory. On NT, this is the recommended algorithm. If your program requires a specific @code{sbrk} behavior, you --- 187,191 ---- @code{sbrk} expectations. This mode should not be used with hardware interrupts, near pointers, and may cause problems with QDPMI virtual ! memory. If your program requires a specific @code{sbrk} behavior, you *************** *** 193,196 **** --- 193,205 ---- change in different libc releases. + @item _CRT0_DISABLE_SBRK_ADDRESS_WRAP + + If set, non-move @code{sbrk} should discard (ignore) memory blocks which are + returned by DPMI which would require address wrap to access (at addresses + below the CS/DS base address). This bit is automatically set on Windows NT + systems which require it. It may be manually set on other systems which + don't require it to retain a more normal memory space layout and better + memory protection. This bit can be set but should never be cleared. + @item _CRT0_FLAG_LOCK_MEMORY