static int
handle_cfi (Dwfl *dwfl, const char *which, Dwarf_CFI *cfi,
GElf_Addr pc, struct stuff *stuff)
{
int result = dwarf_cfi_addrframe (cfi, pc - stuff->bias, &stuff->frame);
if (result != 0)
{
error (0, 0, "dwarf_addrframe (%s): %s", which, dwfl_errmsg (-1));
return 1;
}
Dwarf_Addr start = pc;
Dwarf_Addr end = pc;
bool signalp;
int ra_regno = dwarf_frame_info (stuff->frame, &start, &end, &signalp);
if (ra_regno >= 0)
{
start += stuff->bias;
end += stuff->bias;
}
printf ("%s has %#" PRIx64 " => [%#" PRIx64 ", %#" PRIx64 "):\n",
which, pc, start, end);
if (ra_regno < 0)
printf ("\treturn address register unavailable (%s)\n",
dwarf_errmsg (0));
else
printf ("\treturn address in reg%u%s\n",
ra_regno, signalp ? " (signal frame)" : "");
Dwarf_Op *cfa_ops;
size_t cfa_nops;
result = dwarf_frame_cfa (stuff->frame, &cfa_ops, &cfa_nops);
printf ("\tCFA ");
print_detail (result, cfa_ops, cfa_nops, stuff->bias);
(void) dwfl_module_register_names (dwfl_addrmodule (dwfl, pc),
&print_register, stuff);
return 0;
}
/*
* Return:
* 0 if return address for the program counter @pc is on stack
* 1 if return address is in LR and no new stack frame was allocated
* 2 if return address is in LR and a new frame was allocated (but not
* yet used)
* -1 in case of errors
*/
static int check_return_addr(struct dso *dso, u64 map_start, Dwarf_Addr pc)
{
int rc = -1;
Dwfl *dwfl;
Dwfl_Module *mod;
Dwarf_Frame *frame;
int ra_regno;
Dwarf_Addr start = pc;
Dwarf_Addr end = pc;
bool signalp;
const char *exec_file = dso->long_name;
dwfl = dso->dwfl;
if (!dwfl) {
dwfl = dwfl_begin(&offline_callbacks);
if (!dwfl) {
pr_debug("dwfl_begin() failed: %s\n", dwarf_errmsg(-1));
return -1;
}
mod = dwfl_report_elf(dwfl, exec_file, exec_file, -1,
map_start, false);
if (!mod) {
pr_debug("dwfl_report_elf() failed %s\n",
dwarf_errmsg(-1));
/*
* We normally cache the DWARF debug info and never
* call dwfl_end(). But to prevent fd leak, free in
* case of error.
*/
dwfl_end(dwfl);
goto out;
}
dso->dwfl = dwfl;
}
mod = dwfl_addrmodule(dwfl, pc);
if (!mod) {
pr_debug("dwfl_addrmodule() failed, %s\n", dwarf_errmsg(-1));
goto out;
}
/*
* To work with split debug info files (eg: glibc), check both
* .eh_frame and .debug_frame sections of the ELF header.
*/
frame = get_eh_frame(mod, pc);
if (!frame) {
frame = get_dwarf_frame(mod, pc);
if (!frame)
goto out;
}
ra_regno = dwarf_frame_info(frame, &start, &end, &signalp);
if (ra_regno < 0) {
pr_debug("Return address register unavailable: %s\n",
dwarf_errmsg(-1));
goto out;
}
rc = check_return_reg(ra_regno, frame);
out:
return rc;
}
