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Diffstat (limited to 'gdb/i386-dep.c')
| -rw-r--r-- | gdb/i386-dep.c | 1203 |
1 files changed, 1203 insertions, 0 deletions
diff --git a/gdb/i386-dep.c b/gdb/i386-dep.c new file mode 100644 index 0000000..23a553a --- /dev/null +++ b/gdb/i386-dep.c @@ -0,0 +1,1203 @@ +/* Low level interface to ptrace, for GDB when running on the Intel 386. + Copyright (C) 1988 Free Software Foundation, Inc. + +GDB is distributed in the hope that it will be useful, but WITHOUT ANY +WARRANTY. No author or distributor accepts responsibility to anyone +for the consequences of using it or for whether it serves any +particular purpose or works at all, unless he says so in writing. +Refer to the GDB General Public License for full details. + +Everyone is granted permission to copy, modify and redistribute GDB, +but only under the conditions described in the GDB General Public +License. A copy of this license is supposed to have been given to you +along with GDB so you can know your rights and responsibilities. It +should be in a file named COPYING. Among other things, the copyright +notice and this notice must be preserved on all copies. + +In other words, go ahead and share GDB, but don't try to stop +anyone else from sharing it farther. Help stamp out software hoarding! +*/ + +#include "defs.h" +#include "param.h" +#include "frame.h" +#include "inferior.h" + +#ifdef USG +#include <sys/types.h> +#endif + +#include <stdio.h> +#include <sys/param.h> +#include <sys/dir.h> +#include <signal.h> +#include <sys/user.h> +#include <sys/ioctl.h> +#include <fcntl.h> + +#ifdef COFF_ENCAPSULATE +#include "a.out.encap.h" +#else +#include <a.out.h> +#endif + +#ifndef N_SET_MAGIC +#ifdef COFF_FORMAT +#define N_SET_MAGIC(exec, val) ((exec).magic = (val)) +#else +#define N_SET_MAGIC(exec, val) ((exec).a_magic = (val)) +#endif +#endif + +#include <sys/file.h> +#include <sys/stat.h> + +#include <sys/reg.h> + +extern int errno; + +/* This function simply calls ptrace with the given arguments. + It exists so that all calls to ptrace are isolated in this + machine-dependent file. */ +int +call_ptrace (request, pid, arg3, arg4) + int request, pid, arg3, arg4; +{ + return ptrace (request, pid, arg3, arg4); +} + +kill_inferior () +{ + if (remote_debugging) + return; + if (inferior_pid == 0) + return; + ptrace (8, inferior_pid, 0, 0); + wait (0); + inferior_died (); +} + +/* This is used when GDB is exiting. It gives less chance of error.*/ + +kill_inferior_fast () +{ + if (remote_debugging) + return; + if (inferior_pid == 0) + return; + ptrace (8, inferior_pid, 0, 0); + wait (0); +} + +/* Resume execution of the inferior process. + If STEP is nonzero, single-step it. + If SIGNAL is nonzero, give it that signal. */ + +void +resume (step, signal) + int step; + int signal; +{ + errno = 0; + if (remote_debugging) + remote_resume (step, signal); + else + { + ptrace (step ? 9 : 7, inferior_pid, 1, signal); + if (errno) + perror_with_name ("ptrace"); + } +} + +void +fetch_inferior_registers () +{ + register int regno; + register unsigned int regaddr; + char buf[MAX_REGISTER_RAW_SIZE]; + register int i; + + struct user u; + unsigned int offset = (char *) &u.u_ar0 - (char *) &u; + offset = ptrace (3, inferior_pid, offset, 0) - KERNEL_U_ADDR; + + for (regno = 0; regno < NUM_REGS; regno++) + { + regaddr = register_addr (regno, offset); + for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (int)) + { + *(int *) &buf[i] = ptrace (3, inferior_pid, regaddr, 0); + regaddr += sizeof (int); + } + supply_register (regno, buf); + } +} + +/* Store our register values back into the inferior. + If REGNO is -1, do this for all registers. + Otherwise, REGNO specifies which register (so we can save time). */ + +store_inferior_registers (regno) + int regno; +{ + register unsigned int regaddr; + char buf[80]; + + struct user u; + unsigned int offset = (char *) &u.u_ar0 - (char *) &u; + offset = ptrace (3, inferior_pid, offset, 0) - KERNEL_U_ADDR; + + if (regno >= 0) + { + regaddr = register_addr (regno, offset); + errno = 0; + ptrace (6, inferior_pid, regaddr, read_register (regno)); + if (errno != 0) + { + sprintf (buf, "writing register number %d", regno); + perror_with_name (buf); + } + } + else for (regno = 0; regno < NUM_REGS; regno++) + { + regaddr = register_addr (regno, offset); + errno = 0; + ptrace (6, inferior_pid, regaddr, read_register (regno)); + if (errno != 0) + { + sprintf (buf, "writing register number %d", regno); + perror_with_name (buf); + } + } +} + +/* Copy LEN bytes from inferior's memory starting at MEMADDR + to debugger memory starting at MYADDR. + On failure (cannot read from inferior, usually because address is out + of bounds) returns the value of errno. */ + +int +read_inferior_memory (memaddr, myaddr, len) + CORE_ADDR memaddr; + char *myaddr; + int len; +{ + register int i; + /* Round starting address down to longword boundary. */ + register CORE_ADDR addr = memaddr & - sizeof (int); + /* Round ending address up; get number of longwords that makes. */ + register int count + = (((memaddr + len) - addr) + sizeof (int) - 1) / sizeof (int); + /* Allocate buffer of that many longwords. */ + register int *buffer = (int *) alloca (count * sizeof (int)); + extern int errno; + + /* Read all the longwords */ + for (i = 0; i < count; i++, addr += sizeof (int)) + { + errno = 0; + if (remote_debugging) + buffer[i] = remote_fetch_word (addr); + else + buffer[i] = ptrace (1, inferior_pid, addr, 0); + if (errno) + return errno; + } + + /* Copy appropriate bytes out of the buffer. */ + bcopy ((char *) buffer + (memaddr & (sizeof (int) - 1)), myaddr, len); + return 0; +} + +/* Copy LEN bytes of data from debugger memory at MYADDR + to inferior's memory at MEMADDR. + On failure (cannot write the inferior) + returns the value of errno. */ + +int +write_inferior_memory (memaddr, myaddr, len) + CORE_ADDR memaddr; + char *myaddr; + int len; +{ + register int i; + /* Round starting address down to longword boundary. */ + register CORE_ADDR addr = memaddr & - sizeof (int); + /* Round ending address up; get number of longwords that makes. */ + register int count + = (((memaddr + len) - addr) + sizeof (int) - 1) / sizeof (int); + /* Allocate buffer of that many longwords. */ + register int *buffer = (int *) alloca (count * sizeof (int)); + extern int errno; + + /* Fill start and end extra bytes of buffer with existing memory data. */ + + if (remote_debugging) + buffer[0] = remote_fetch_word (addr); + else + buffer[0] = ptrace (1, inferior_pid, addr, 0); + + if (count > 1) + { + if (remote_debugging) + buffer[count - 1] + = remote_fetch_word (addr + (count - 1) * sizeof (int)); + else + buffer[count - 1] + = ptrace (1, inferior_pid, + addr + (count - 1) * sizeof (int), 0); + } + + /* Copy data to be written over corresponding part of buffer */ + + bcopy (myaddr, (char *) buffer + (memaddr & (sizeof (int) - 1)), len); + + /* Write the entire buffer. */ + + for (i = 0; i < count; i++, addr += sizeof (int)) + { + errno = 0; + if (remote_debugging) + remote_store_word (addr, buffer[i]); + else + ptrace (4, inferior_pid, addr, buffer[i]); + if (errno) + return errno; + } + + return 0; +} + +/* Work with core dump and executable files, for GDB. + This code would be in core.c if it weren't machine-dependent. */ + +#ifndef N_TXTADDR +#define N_TXTADDR(hdr) 0 +#endif /* no N_TXTADDR */ + +#ifndef N_DATADDR +#define N_DATADDR(hdr) hdr.a_text +#endif /* no N_DATADDR */ + +/* Make COFF and non-COFF names for things a little more compatible + to reduce conditionals later. */ + +#ifndef COFF_FORMAT +#define AOUTHDR struct exec +#endif + +extern char *sys_siglist[]; + + +/* Hook for `exec_file_command' command to call. */ + +extern void (*exec_file_display_hook) (); + +/* File names of core file and executable file. */ + +extern char *corefile; +extern char *execfile; + +/* Descriptors on which core file and executable file are open. + Note that the execchan is closed when an inferior is created + and reopened if the inferior dies or is killed. */ + +extern int corechan; +extern int execchan; + +/* Last modification time of executable file. + Also used in source.c to compare against mtime of a source file. */ + +extern int exec_mtime; + +/* Virtual addresses of bounds of the two areas of memory in the core file. */ + +extern CORE_ADDR data_start; +extern CORE_ADDR data_end; +extern CORE_ADDR stack_start; +extern CORE_ADDR stack_end; + +/* Virtual addresses of bounds of two areas of memory in the exec file. + Note that the data area in the exec file is used only when there is no core file. */ + +extern CORE_ADDR text_start; +extern CORE_ADDR text_end; + +extern CORE_ADDR exec_data_start; +extern CORE_ADDR exec_data_end; + +/* Address in executable file of start of text area data. */ + +extern int text_offset; + +/* Address in executable file of start of data area data. */ + +extern int exec_data_offset; + +/* Address in core file of start of data area data. */ + +extern int data_offset; + +/* Address in core file of start of stack area data. */ + +extern int stack_offset; + +#ifdef COFF_FORMAT +/* various coff data structures */ + +extern FILHDR file_hdr; +extern SCNHDR text_hdr; +extern SCNHDR data_hdr; + +#endif /* not COFF_FORMAT */ + +/* a.out header saved in core file. */ + +extern AOUTHDR core_aouthdr; + +/* a.out header of exec file. */ + +extern AOUTHDR exec_aouthdr; + +extern void validate_files (); + +core_file_command (filename, from_tty) + char *filename; + int from_tty; +{ + int val; + extern char registers[]; + + /* Discard all vestiges of any previous core file + and mark data and stack spaces as empty. */ + + if (corefile) + free (corefile); + corefile = 0; + + if (corechan >= 0) + close (corechan); + corechan = -1; + + data_start = 0; + data_end = 0; + stack_start = STACK_END_ADDR; + stack_end = STACK_END_ADDR; + + /* Now, if a new core file was specified, open it and digest it. */ + + if (filename) + { + if (have_inferior_p ()) + error ("To look at a core file, you must kill the inferior with \"kill\"."); + corechan = open (filename, O_RDONLY, 0); + if (corechan < 0) + perror_with_name (filename); + /* 4.2-style (and perhaps also sysV-style) core dump file. */ + { + struct user u; + + int reg_offset; + + val = myread (corechan, &u, sizeof u); + if (val < 0) + perror_with_name (filename); + data_start = exec_data_start; + + data_end = data_start + NBPG * u.u_dsize; + stack_start = stack_end - NBPG * u.u_ssize; + data_offset = NBPG * UPAGES; + stack_offset = NBPG * (UPAGES + u.u_dsize); + reg_offset = (int) u.u_ar0 - KERNEL_U_ADDR; + + /* I don't know where to find this info. + So, for now, mark it as not available. */ +/* N_SET_MAGIC (core_aouthdr, 0); */ + bzero ((char *) &core_aouthdr, sizeof core_aouthdr); + + /* Read the register values out of the core file and store + them where `read_register' will find them. */ + + { + register int regno; + + for (regno = 0; regno < NUM_REGS; regno++) + { + char buf[MAX_REGISTER_RAW_SIZE]; + + val = lseek (corechan, register_addr (regno, reg_offset), 0); + if (val < 0) + perror_with_name (filename); + + val = myread (corechan, buf, sizeof buf); + if (val < 0) + perror_with_name (filename); + supply_register (regno, buf); + } + } + } + if (filename[0] == '/') + corefile = savestring (filename, strlen (filename)); + else + { + corefile = concat (current_directory, "/", filename); + } + + set_current_frame ( create_new_frame (read_register (FP_REGNUM), + read_pc ())); + select_frame (get_current_frame (), 0); + validate_files (); + } + else if (from_tty) + printf ("No core file now.\n"); +} + +exec_file_command (filename, from_tty) + char *filename; + int from_tty; +{ + int val; + + /* Eliminate all traces of old exec file. + Mark text segment as empty. */ + + if (execfile) + free (execfile); + execfile = 0; + data_start = 0; + data_end -= exec_data_start; + text_start = 0; + text_end = 0; + exec_data_start = 0; + exec_data_end = 0; + if (execchan >= 0) + close (execchan); + execchan = -1; + + /* Now open and digest the file the user requested, if any. */ + + if (filename) + { + execchan = openp (getenv ("PATH"), 1, filename, O_RDONLY, 0, + &execfile); + if (execchan < 0) + perror_with_name (filename); + +#ifdef COFF_FORMAT + { + int aout_hdrsize; + int num_sections; + + if (read_file_hdr (execchan, &file_hdr) < 0) + error ("\"%s\": not in executable format.", execfile); + + aout_hdrsize = file_hdr.f_opthdr; + num_sections = file_hdr.f_nscns; + + if (read_aout_hdr (execchan, &exec_aouthdr, aout_hdrsize) < 0) + error ("\"%s\": can't read optional aouthdr", execfile); + + if (read_section_hdr (execchan, _TEXT, &text_hdr, num_sections) < 0) + error ("\"%s\": can't read text section header", execfile); + + if (read_section_hdr (execchan, _DATA, &data_hdr, num_sections) < 0) + error ("\"%s\": can't read data section header", execfile); + + text_start = exec_aouthdr.text_start; + text_end = text_start + exec_aouthdr.tsize; + text_offset = text_hdr.s_scnptr; + exec_data_start = exec_aouthdr.data_start; + exec_data_end = exec_data_start + exec_aouthdr.dsize; + exec_data_offset = data_hdr.s_scnptr; + data_start = exec_data_start; + data_end += exec_data_start; + exec_mtime = file_hdr.f_timdat; + } +#else /* not COFF_FORMAT */ + { + struct stat st_exec; + +#ifdef HEADER_SEEK_FD + HEADER_SEEK_FD (execchan); +#endif + + val = myread (execchan, &exec_aouthdr, sizeof (AOUTHDR)); + + if (val < 0) + perror_with_name (filename); + + text_start = N_TXTADDR (exec_aouthdr); + exec_data_start = N_DATADDR (exec_aouthdr); + + text_offset = N_TXTOFF (exec_aouthdr); + exec_data_offset = N_TXTOFF (exec_aouthdr) + exec_aouthdr.a_text; + + text_end = text_start + exec_aouthdr.a_text; + exec_data_end = exec_data_start + exec_aouthdr.a_data; + data_start = exec_data_start; + data_end += exec_data_start; + + fstat (execchan, &st_exec); + exec_mtime = st_exec.st_mtime; + } +#endif /* not COFF_FORMAT */ + + validate_files (); + } + else if (from_tty) + printf ("No exec file now.\n"); + + /* Tell display code (if any) about the changed file name. */ + if (exec_file_display_hook) + (*exec_file_display_hook) (filename); +} + +/* helper functions for m-i386.h */ + +/* stdio style buffering to minimize calls to ptrace */ +static CORE_ADDR codestream_next_addr; +static CORE_ADDR codestream_addr; +static unsigned char codestream_buf[sizeof (int)]; +static int codestream_off; +static int codestream_cnt; + +#define codestream_tell() (codestream_addr + codestream_off) +#define codestream_peek() (codestream_cnt == 0 ? \ + codestream_fill(1): codestream_buf[codestream_off]) +#define codestream_get() (codestream_cnt-- == 0 ? \ + codestream_fill(0) : codestream_buf[codestream_off++]) + +static unsigned char +codestream_fill (peek_flag) +{ + codestream_addr = codestream_next_addr; + codestream_next_addr += sizeof (int); + codestream_off = 0; + codestream_cnt = sizeof (int); + read_memory (codestream_addr, + (unsigned char *)codestream_buf, + sizeof (int)); + + if (peek_flag) + return (codestream_peek()); + else + return (codestream_get()); +} + +static void +codestream_seek (place) +{ + codestream_next_addr = place & -sizeof (int); + codestream_cnt = 0; + codestream_fill (1); + while (codestream_tell() != place) + codestream_get (); +} + +static void +codestream_read (buf, count) + unsigned char *buf; +{ + unsigned char *p; + int i; + p = buf; + for (i = 0; i < count; i++) + *p++ = codestream_get (); +} + +/* next instruction is a jump, move to target */ +static +i386_follow_jump () +{ + int long_delta; + short short_delta; + char byte_delta; + int data16; + int pos; + + pos = codestream_tell (); + + data16 = 0; + if (codestream_peek () == 0x66) + { + codestream_get (); + data16 = 1; + } + + switch (codestream_get ()) + { + case 0xe9: + /* relative jump: if data16 == 0, disp32, else disp16 */ + if (data16) + { + codestream_read ((unsigned char *)&short_delta, 2); + pos += short_delta + 3; /* include size of jmp inst */ + } + else + { + codestream_read ((unsigned char *)&long_delta, 4); + pos += long_delta + 5; + } + break; + case 0xeb: + /* relative jump, disp8 (ignore data16) */ + codestream_read ((unsigned char *)&byte_delta, 1); + pos += byte_delta + 2; + break; + } + codestream_seek (pos + data16); +} + +/* + * find & return amound a local space allocated, and advance codestream to + * first register push (if any) + * + * if entry sequence doesn't make sense, return -1, and leave + * codestream pointer random + */ +static long +i386_get_frame_setup (pc) +{ + unsigned char op; + + codestream_seek (pc); + + i386_follow_jump (); + + op = codestream_get (); + + if (op == 0x58) /* popl %eax */ + { + /* + * this function must start with + * + * popl %eax 0x58 + * xchgl %eax, (%esp) 0x87 0x04 0x24 + * or xchgl %eax, 0(%esp) 0x87 0x44 0x24 0x00 + * + * (the system 5 compiler puts out the second xchg + * inst, and the assembler doesn't try to optimize it, + * so the 'sib' form gets generated) + * + * this sequence is used to get the address of the return + * buffer for a function that returns a structure + */ + int pos; + unsigned char buf[4]; + static unsigned char proto1[3] = { 0x87,0x04,0x24 }; + static unsigned char proto2[4] = { 0x87,0x44,0x24,0x00 }; + pos = codestream_tell (); + codestream_read (buf, 4); + if (bcmp (buf, proto1, 3) == 0) + pos += 3; + else if (bcmp (buf, proto2, 4) == 0) + pos += 4; + + codestream_seek (pos); + op = codestream_get (); /* update next opcode */ + } + + if (op == 0x55) /* pushl %esp */ + { + /* check for movl %esp, %ebp - can be written two ways */ + switch (codestream_get ()) + { + case 0x8b: + if (codestream_get () != 0xec) + return (-1); + break; + case 0x89: + if (codestream_get () != 0xe5) + return (-1); + break; + default: + return (-1); + } + /* check for stack adjustment + * + * subl $XXX, %esp + * + * note: you can't subtract a 16 bit immediate + * from a 32 bit reg, so we don't have to worry + * about a data16 prefix + */ + op = codestream_peek (); + if (op == 0x83) + { + /* subl with 8 bit immed */ + codestream_get (); + if (codestream_get () != 0xec) + return (-1); + /* subl with signed byte immediate + * (though it wouldn't make sense to be negative) + */ + return (codestream_get()); + } + else if (op == 0x81) + { + /* subl with 32 bit immed */ + int locals; + codestream_get(); + if (codestream_get () != 0xec) + return (-1); + /* subl with 32 bit immediate */ + codestream_read ((unsigned char *)&locals, 4); + return (locals); + } + else + { + return (0); + } + } + else if (op == 0xc8) + { + /* enter instruction: arg is 16 bit unsigned immed */ + unsigned short slocals; + codestream_read ((unsigned char *)&slocals, 2); + codestream_get (); /* flush final byte of enter instruction */ + return (slocals); + } + return (-1); +} + +/* + * parse the first few instructions of the function to see + * what registers were stored. + * + * We handle these cases: + * + * The startup sequence can be at the start of the function, + * or the function can start with a branch to startup code at the end. + * + * %ebp can be set up with either the 'enter' instruction, or + * 'pushl %ebp, movl %esp, %ebp' (enter is too slow to be useful, + * but was once used in the sys5 compiler) + * + * Local space is allocated just below the saved %ebp by either the + * 'enter' instruction, or by 'subl $<size>, %esp'. 'enter' has + * a 16 bit unsigned argument for space to allocate, and the + * 'addl' instruction could have either a signed byte, or + * 32 bit immediate. + * + * Next, the registers used by this function are pushed. In + * the sys5 compiler they will always be in the order: %edi, %esi, %ebx + * (and sometimes a harmless bug causes it to also save but not restore %eax); + * however, the code below is willing to see the pushes in any order, + * and will handle up to 8 of them. + * + * If the setup sequence is at the end of the function, then the + * next instruction will be a branch back to the start. + */ + +i386_frame_find_saved_regs (fip, fsrp) + struct frame_info *fip; + struct frame_saved_regs *fsrp; +{ + unsigned long locals; + unsigned char *p; + unsigned char op; + CORE_ADDR dummy_bottom; + CORE_ADDR adr; + int i; + + bzero (fsrp, sizeof *fsrp); + + /* if frame is the end of a dummy, compute where the + * beginning would be + */ + dummy_bottom = fip->frame - 4 - NUM_REGS*4 - CALL_DUMMY_LENGTH; + + /* check if the PC is in the stack, in a dummy frame */ + if (dummy_bottom <= fip->pc && fip->pc <= fip->frame) + { + /* all regs were saved by push_call_dummy () */ + adr = fip->frame - 4; + for (i = 0; i < NUM_REGS; i++) + { + fsrp->regs[i] = adr; + adr -= 4; + } + return; + } + + locals = i386_get_frame_setup (get_pc_function_start (fip->pc)); + + if (locals >= 0) + { + adr = fip->frame - 4 - locals; + for (i = 0; i < 8; i++) + { + op = codestream_get (); + if (op < 0x50 || op > 0x57) + break; + fsrp->regs[op - 0x50] = adr; + adr -= 4; + } + } + + fsrp->regs[PC_REGNUM] = fip->frame + 4; + fsrp->regs[FP_REGNUM] = fip->frame; +} + +/* return pc of first real instruction */ +i386_skip_prologue (pc) +{ + unsigned char op; + int i; + + if (i386_get_frame_setup (pc) < 0) + return (pc); + + /* found valid frame setup - codestream now points to + * start of push instructions for saving registers + */ + + /* skip over register saves */ + for (i = 0; i < 8; i++) + { + op = codestream_peek (); + /* break if not pushl inst */ + if (op < 0x50 || op > 0x57) + break; + codestream_get (); + } + + i386_follow_jump (); + + return (codestream_tell ()); +} + +i386_push_dummy_frame () +{ + CORE_ADDR sp = read_register (SP_REGNUM); + int regnum; + + sp = push_word (sp, read_register (PC_REGNUM)); + sp = push_word (sp, read_register (FP_REGNUM)); + write_register (FP_REGNUM, sp); + for (regnum = 0; regnum < NUM_REGS; regnum++) + sp = push_word (sp, read_register (regnum)); + write_register (SP_REGNUM, sp); +} + +i386_pop_frame () +{ + FRAME frame = get_current_frame (); + CORE_ADDR fp; + int regnum; + struct frame_saved_regs fsr; + struct frame_info *fi; + + fi = get_frame_info (frame); + fp = fi->frame; + get_frame_saved_regs (fi, &fsr); + for (regnum = 0; regnum < NUM_REGS; regnum++) + { + CORE_ADDR adr; + adr = fsr.regs[regnum]; + if (adr) + write_register (regnum, read_memory_integer (adr, 4)); + } + write_register (FP_REGNUM, read_memory_integer (fp, 4)); + write_register (PC_REGNUM, read_memory_integer (fp + 4, 4)); + write_register (SP_REGNUM, fp + 8); + flush_cached_frames (); + set_current_frame ( create_new_frame (read_register (FP_REGNUM), + read_pc ())); +} + +/* this table must line up with REGISTER_NAMES in m-i386.h */ +/* symbols like 'EAX' come from <sys/reg.h> */ +static int regmap[] = +{ + EAX, ECX, EDX, EBX, + UESP, EBP, ESI, EDI, + EIP, EFL, CS, SS, + DS, ES, FS, GS, +}; + +/* blockend is the value of u.u_ar0, and points to the + * place where GS is stored + */ +i386_register_u_addr (blockend, regnum) +{ +#if 0 + /* this will be needed if fp registers are reinstated */ + /* for now, you can look at them with 'info float' + * sys5 wont let you change them with ptrace anyway + */ + if (regnum >= FP0_REGNUM && regnum <= FP7_REGNUM) + { + int ubase, fpstate; + struct user u; + ubase = blockend + 4 * (SS + 1) - KSTKSZ; + fpstate = ubase + ((char *)&u.u_fpstate - (char *)&u); + return (fpstate + 0x1c + 10 * (regnum - FP0_REGNUM)); + } + else +#endif + return (blockend + 4 * regmap[regnum]); + +} + +i387_to_double (from, to) + char *from; + char *to; +{ + long *lp; + /* push extended mode on 387 stack, then pop in double mode + * + * first, set exception masks so no error is generated - + * number will be rounded to inf or 0, if necessary + */ + asm ("pushl %eax"); /* grab a stack slot */ + asm ("fstcw (%esp)"); /* get 387 control word */ + asm ("movl (%esp),%eax"); /* save old value */ + asm ("orl $0x3f,%eax"); /* mask all exceptions */ + asm ("pushl %eax"); + asm ("fldcw (%esp)"); /* load new value into 387 */ + + asm ("movl 8(%ebp),%eax"); + asm ("fldt (%eax)"); /* push extended number on 387 stack */ + asm ("fwait"); + asm ("movl 12(%ebp),%eax"); + asm ("fstpl (%eax)"); /* pop double */ + asm ("fwait"); + + asm ("popl %eax"); /* flush modified control word */ + asm ("fnclex"); /* clear exceptions */ + asm ("fldcw (%esp)"); /* restore original control word */ + asm ("popl %eax"); /* flush saved copy */ +} + +double_to_i387 (from, to) + char *from; + char *to; +{ + /* push double mode on 387 stack, then pop in extended mode + * no errors are possible because every 64-bit pattern + * can be converted to an extended + */ + asm ("movl 8(%ebp),%eax"); + asm ("fldl (%eax)"); + asm ("fwait"); + asm ("movl 12(%ebp),%eax"); + asm ("fstpt (%eax)"); + asm ("fwait"); +} + +struct env387 +{ + unsigned short control; + unsigned short r0; + unsigned short status; + unsigned short r1; + unsigned short tag; + unsigned short r2; + unsigned long eip; + unsigned short code_seg; + unsigned short opcode; + unsigned long operand; + unsigned short operand_seg; + unsigned short r3; + unsigned char regs[8][10]; +}; + +static +print_387_control_word (control) +unsigned short control; +{ + printf ("control 0x%04x: ", control); + printf ("compute to "); + switch ((control >> 8) & 3) + { + case 0: printf ("24 bits; "); break; + case 1: printf ("(bad); "); break; + case 2: printf ("53 bits; "); break; + case 3: printf ("64 bits; "); break; + } + printf ("round "); + switch ((control >> 10) & 3) + { + case 0: printf ("NEAREST; "); break; + case 1: printf ("DOWN; "); break; + case 2: printf ("UP; "); break; + case 3: printf ("CHOP; "); break; + } + if (control & 0x3f) + { + printf ("mask:"); + if (control & 0x0001) printf (" INVALID"); + if (control & 0x0002) printf (" DENORM"); + if (control & 0x0004) printf (" DIVZ"); + if (control & 0x0008) printf (" OVERF"); + if (control & 0x0010) printf (" UNDERF"); + if (control & 0x0020) printf (" LOS"); + printf (";"); + } + printf ("\n"); + if (control & 0xe080) printf ("warning: reserved bits on 0x%x\n", + control & 0xe080); +} + +static +print_387_status_word (status) + unsigned short status; +{ + printf ("status 0x%04x: ", status); + if (status & 0xff) + { + printf ("exceptions:"); + if (status & 0x0001) printf (" INVALID"); + if (status & 0x0002) printf (" DENORM"); + if (status & 0x0004) printf (" DIVZ"); + if (status & 0x0008) printf (" OVERF"); + if (status & 0x0010) printf (" UNDERF"); + if (status & 0x0020) printf (" LOS"); + if (status & 0x0040) printf (" FPSTACK"); + printf ("; "); + } + printf ("flags: %d%d%d%d; ", + (status & 0x4000) != 0, + (status & 0x0400) != 0, + (status & 0x0200) != 0, + (status & 0x0100) != 0); + + printf ("top %d\n", (status >> 11) & 7); +} + +static +print_387_status (status, ep) + unsigned short status; + struct env387 *ep; +{ + int i; + int bothstatus; + int top; + int fpreg; + unsigned char *p; + + bothstatus = ((status != 0) && (ep->status != 0)); + if (status != 0) + { + if (bothstatus) + printf ("u: "); + print_387_status_word (status); + } + + if (ep->status != 0) + { + if (bothstatus) + printf ("e: "); + print_387_status_word (ep->status); + } + + print_387_control_word (ep->control); + printf ("last exception: "); + printf ("opcode 0x%x; ", ep->opcode); + printf ("pc 0x%x:0x%x; ", ep->code_seg, ep->eip); + printf ("operand 0x%x:0x%x\n", ep->operand_seg, ep->operand); + + top = (ep->status >> 11) & 7; + + printf ("regno tag msb lsb value\n"); + for (fpreg = 7; fpreg >= 0; fpreg--) + { + double val; + + printf ("%s %d: ", fpreg == top ? "=>" : " ", fpreg); + + switch ((ep->tag >> (fpreg * 2)) & 3) + { + case 0: printf ("valid "); break; + case 1: printf ("zero "); break; + case 2: printf ("trap "); break; + case 3: printf ("empty "); break; + } + for (i = 9; i >= 0; i--) + printf ("%02x", ep->regs[fpreg][i]); + + i387_to_double (ep->regs[fpreg], (char *)&val); + printf (" %g\n", val); + } + if (ep->r0) + printf ("warning: reserved0 is 0x%x\n", ep->r0); + if (ep->r1) + printf ("warning: reserved1 is 0x%x\n", ep->r1); + if (ep->r2) + printf ("warning: reserved2 is 0x%x\n", ep->r2); + if (ep->r3) + printf ("warning: reserved3 is 0x%x\n", ep->r3); +} + +i386_float_info () +{ + struct user u; /* just for address computations */ + int i; + /* fpstate defined in <sys/user.h> */ + struct fpstate *fpstatep; + char buf[sizeof (struct fpstate) + 2 * sizeof (int)]; + unsigned int uaddr; + char fpvalid; + unsigned int rounded_addr; + unsigned int rounded_size; + extern int corechan; + int skip; + + uaddr = (char *)&u.u_fpvalid - (char *)&u; + if (have_inferior_p()) + { + unsigned int data; + unsigned int mask; + + rounded_addr = uaddr & -sizeof (int); + data = ptrace (3, inferior_pid, rounded_addr, 0); + mask = 0xff << ((uaddr - rounded_addr) * 8); + + fpvalid = ((data & mask) != 0); + } + else + { + if (lseek (corechan, uaddr, 0) < 0) + perror ("seek on core file"); + if (myread (corechan, &fpvalid, 1) < 0) + perror ("read on core file"); + + } + + if (fpvalid == 0) + { + printf ("no floating point status saved\n"); + return; + } + + uaddr = (char *)&u.u_fpstate - (char *)&u; + if (have_inferior_p ()) + { + int *ip; + + rounded_addr = uaddr & -sizeof (int); + rounded_size = (((uaddr + sizeof (struct fpstate)) - uaddr) + + sizeof (int) - 1) / sizeof (int); + skip = uaddr - rounded_addr; + + ip = (int *)buf; + for (i = 0; i < rounded_size; i++) + { + *ip++ = ptrace (3, inferior_pid, rounded_addr, 0); + rounded_addr += sizeof (int); + } + } + else + { + if (lseek (corechan, uaddr, 0) < 0) + perror_with_name ("seek on core file"); + if (myread (corechan, buf, sizeof (struct fpstate)) < 0) + perror_with_name ("read from core file"); + skip = 0; + } + + fpstatep = (struct fpstate *)(buf + skip); + print_387_status (fpstatep->status, (struct env387 *)fpstatep->state); +} + |