int
main()
{
int left = 0, right = 657;
stab_binsearch(stabs, &left, &right, N_SO, 0xf0100184);
printf("left = %d, right = %d\n", left, right);
return 0;
}
// debuginfo_eip(addr, info)
//
// Fill in the 'info' structure with information about the specified
// instruction address, 'addr'. Returns 0 if information was found, and
// negative if not. But even if it returns negative it has stored some
// information into '*info'.
//
int
debuginfo_eip(uintptr_t addr, struct Eipdebuginfo *info)
{
const struct Stab *stabs, *stab_end;
const char *stabstr, *stabstr_end;
int lfile, rfile, lfun, rfun, lline, rline;
// Initialize *info
info->eip_file = "<unknown>";
info->eip_line = 0;
info->eip_fn_name = "<unknown>";
info->eip_fn_namelen = 9;
info->eip_fn_addr = addr;
info->eip_fn_narg = 0;
// Find the relevant set of stabs
if (addr >= ULIM) {
stabs = __STAB_BEGIN__;
stab_end = __STAB_END__;
stabstr = __STABSTR_BEGIN__;
stabstr_end = __STABSTR_END__;
} else {
// The user-application linker script, user/user.ld,
// puts information about the application's stabs (equivalent
// to __STAB_BEGIN__, __STAB_END__, __STABSTR_BEGIN__, and
// __STABSTR_END__) in a structure located at virtual address
// USTABDATA.
const struct UserStabData *usd = (const struct UserStabData *) USTABDATA;
// Make sure this memory is valid.
// Return -1 if it is not. Hint: Call user_mem_check.
// LAB 3: Your code here.
if(user_mem_check(curenv, usd, sizeof(struct UserStabData), PTE_U) < 0)
{
return -1;
}
stabs = usd->stabs;
stab_end = usd->stab_end;
stabstr = usd->stabstr;
stabstr_end = usd->stabstr_end;
// Make sure the STABS and string table memory is valid.
// LAB 3: Your code here.
if(user_mem_check(curenv, stabs, stab_end-stabs, PTE_U) < 0)
{
return -1;
}
if(user_mem_check(curenv, stabstr, stabstr_end-stabstr, PTE_U) < 0)
{
return -1;
}
}
// String table validity checks
if (stabstr_end <= stabstr || stabstr_end[-1] != 0)
return -1;
// Now we find the right stabs that define the function containing
// 'eip'. First, we find the basic source file containing 'eip'.
// Then, we look in that source file for the function. Then we look
// for the line number.
// Search the entire set of stabs for the source file (type N_SO).
lfile = 0;
rfile = (stab_end - stabs) - 1;
stab_binsearch(stabs, &lfile, &rfile, N_SO, addr);
if (lfile == 0)
return -1;
// Search within that file's stabs for the function definition
// (N_FUN).
lfun = lfile;
rfun = rfile;
stab_binsearch(stabs, &lfun, &rfun, N_FUN, addr);
if (lfun <= rfun) {
// stabs[lfun] points to the function name
// in the string table, but check bounds just in case.
if (stabs[lfun].n_strx < stabstr_end - stabstr)
info->eip_fn_name = stabstr + stabs[lfun].n_strx;
info->eip_fn_addr = stabs[lfun].n_value;
addr -= info->eip_fn_addr;
// Search within the function definition for the line number.
lline = lfun;
rline = rfun;
} else {
// Couldn't find function stab! Maybe we're in an assembly
// file. Search the whole file for the line number.
info->eip_fn_addr = addr;
lline = lfile;
rline = rfile;
}
// Ignore stuff after the colon.
info->eip_fn_namelen = strfind(info->eip_fn_name, ':') - info->eip_fn_name;
// Search within [lline, rline] for the line number stab.
// If found, set info->eip_line to the right line number.
// If not found, return -1.
//
// Hint:
// There's a particular stabs type used for line numbers.
// Look at the STABS documentation and <inc/stab.h> to find
// which one.
// Your code here.
stab_binsearch(stabs, &lline, &rline, N_SLINE, addr);
if (lline <= rline)
{
info->eip_line = stabs[lline].n_desc;
}
else
{
return -1;
}
// Search backwards from the line number for the relevant filename
// stab.
// We can't just use the "lfile" stab because inlined functions
// can interpolate code from a different file!
// Such included source files use the N_SOL stab type.
while (lline >= lfile
&& stabs[lline].n_type != N_SOL
&& (stabs[lline].n_type != N_SO || !stabs[lline].n_value))
lline--;
if (lline >= lfile && stabs[lline].n_strx < stabstr_end - stabstr)
info->eip_file = stabstr + stabs[lline].n_strx;
// Set eip_fn_narg to the number of arguments taken by the function,
// or 0 if there was no containing function.
if (lfun < rfun)
for (lline = lfun + 1;
lline < rfun && stabs[lline].n_type == N_PSYM;
lline++)
info->eip_fn_narg++;
return 0;
}
// debuginfo_eip(addr, info)
//
// Fill in the 'info' structure with information about the specified
// instruction address, 'addr'. Returns 0 if information was found, and
// negative if not. But even if it returns negative it has stored some
// information into '*info'.
//
int
debuginfo_eip(uintptr_t addr, struct Eipdebuginfo *info)
{
const struct Stab *stabs, *stab_end;
const char *stabstr, *stabstr_end;
int lfile, rfile, lfun, rfun, lline, rline;
// Initialize *info
info->eip_file = "<unknown>";
info->eip_line = 0;
info->eip_fn_name = "<unknown>";
info->eip_fn_namelen = 9;
info->eip_fn_addr = addr;
info->eip_fn_narg = 0;
// Find the relevant set of stabs
if (addr >= ULIM) {
stabs = __STAB_BEGIN__;
stab_end = __STAB_END__;
stabstr = __STABSTR_BEGIN__;
stabstr_end = __STABSTR_END__;
} else {
// Can't search for user-level addresses yet!
panic("User address");
}
// String table validity checks
if (stabstr_end <= stabstr || stabstr_end[-1] != 0)
return -1;
// Now we find the right stabs that define the function containing
// 'eip'. First, we find the basic source file containing 'eip'.
// Then, we look in that source file for the function. Then we look
// for the line number.
// Search the entire set of stabs for the source file (type N_SO).
lfile = 0;
rfile = (stab_end - stabs) - 1;
stab_binsearch(stabs, &lfile, &rfile, N_SO, addr);
if (lfile == 0)
return -1;
// Search within that file's stabs for the function definition
// (N_FUN).
lfun = lfile;
rfun = rfile;
stab_binsearch(stabs, &lfun, &rfun, N_FUN, addr);
if (lfun <= rfun) {
// stabs[lfun] points to the function name
// in the string table, but check bounds just in case.
if (stabs[lfun].n_strx < stabstr_end - stabstr)
info->eip_fn_name = stabstr + stabs[lfun].n_strx;
info->eip_fn_addr = stabs[lfun].n_value;
addr -= info->eip_fn_addr;
// Search within the function definition for the line number.
lline = lfun;
rline = rfun;
} else {
// Couldn't find function stab! Maybe we're in an assembly
// file. Search the whole file for the line number.
info->eip_fn_addr = addr;
lline = lfile;
rline = rfile;
}
// Ignore stuff after the colon.
info->eip_fn_namelen = strfind(info->eip_fn_name, ':') - info->eip_fn_name;
// Search within [lline, rline] for the line number stab.
// If found, set info->eip_line to the right line number.
// If not found, return -1.
//
// Hint:
// There's a particular stabs type used for line numbers.
// Look at the STABS documentation and <inc/stab.h> to find
// which one.
// Your code here.
stab_binsearch(stabs, &lline, &rline, N_SLINE, addr);
info.eip_line = (lline <= rline)?
stabs[rrline].n_desc:
-1;
// Search backwards from the line number for the relevant filename
// stab.
// We can't just use the "lfile" stab because inlined functions
// can interpolate code from a different file!
// Such included source files use the N_SOL stab type.
while (lline >= lfile
&& stabs[lline].n_type != N_SOL
&& (stabs[lline].n_type != N_SO || !stabs[lline].n_value))
lline--;
if (lline >= lfile && stabs[lline].n_strx < stabstr_end - stabstr)
info->eip_file = stabstr + stabs[lline].n_strx;
// Set eip_fn_narg to the number of arguments taken by the function,
// or 0 if there was no containing function.
if (lfun < rfun)
for (lline = lfun + 1;
lline < rfun && stabs[lline].n_type == N_PSYM;
lline++)
info->eip_fn_narg++;
return 0;
}
