#ifndef _I386_USER_H #define _I386_USER_H #include <asm/page.h> #include <linux/ptrace.h> /* Core file format: The core file is written in such a way that gdb can understand it and provide useful information to the user (under linux we use the 'trad-core' bfd). There are quite a number of obstacles to being able to view the contents of the floating point registers, and until these are solved you will not be able to view the contents of them. Actually, you can read in the core file and look at the contents of the user struct to find out what the floating point registers contain. The actual file contents are as follows: UPAGE: 1 page consisting of a user struct that tells gdb what is present in the file. Directly after this is a copy of the task_struct, which is currently not used by gdb, but it may come in useful at some point. All of the registers are stored as part of the upage. The upage should always be only one page. DATA: The data area is stored. We use current->end_text to current->brk to pick up all of the user variables, plus any memory that may have been malloced. No attempt is made to determine if a page is demand-zero or if a page is totally unused, we just cover the entire range. All of the addresses are rounded in such a way that an integral number of pages is written. STACK: We need the stack information in order to get a meaningful backtrace. We need to write the data from (esp) to current->start_stack, so we round each of these off in order to be able to write an integer number of pages. The minimum core file size is 3 pages, or 12288 bytes. */ struct user_i387_struct { long cwd; long swd; long twd; long fip; long fcs; long foo; long fos; long st_space[20]; /* 8*10 bytes for each FP-reg = 80 bytes */ }; /* When the kernel dumps core, it starts by dumping the user struct - this will be used by gdb to figure out where the data and stack segments are within the file, and what virtual addresses to use. */ struct user{ /* We start with the registers, to mimic the way that "memory" is returned from the ptrace(3,...) function. */ struct pt_regs regs; /* Where the registers are actually stored */ /* ptrace does not yet supply these. Someday.... */ int u_fpvalid; /* True if math co-processor being used. */ /* for this mess. Not yet used. */ struct user_i387_struct i387; /* Math Co-processor registers. */ /* The rest of this junk is to help gdb figure out what goes where */ unsigned long int u_tsize; /* Text segment size (pages). */ unsigned long int u_dsize; /* Data segment size (pages). */ unsigned long int u_ssize; /* Stack segment size (pages). */ unsigned long start_code; /* Starting virtual address of text. */ unsigned long start_stack; /* Starting virtual address of stack area. This is actually the bottom of the stack, the top of the stack is always found in the esp register. */ long int signal; /* Signal that caused the core dump. */ int reserved; /* No longer used */ struct pt_regs * u_ar0; /* Used by gdb to help find the values for */ /* the registers. */ struct user_i387_struct* u_fpstate; /* Math Co-processor pointer. */ unsigned long magic; /* To uniquely identify a core file */ char u_comm[32]; /* User command that was responsible */ int u_debugreg[8]; }; #define NBPG PAGE_SIZE #define UPAGES 1 #define HOST_TEXT_START_ADDR (u.start_code) #define HOST_STACK_END_ADDR (u.start_stack + u.u_ssize * NBPG) #endif /* _I386_USER_H */