static int __report_module(struct addr_location *al, u64 ip,
struct unwind_info *ui)
{
Dwfl_Module *mod;
struct dso *dso = NULL;
thread__find_addr_location(ui->thread, ui->machine,
PERF_RECORD_MISC_USER,
MAP__FUNCTION, ip, al);
if (al->map)
dso = al->map->dso;
if (!dso)
return 0;
mod = dwfl_addrmodule(ui->dwfl, ip);
if (!mod)
mod = dwfl_report_elf(ui->dwfl, dso->short_name,
dso->long_name, -1, al->map->start,
false);
return mod && dwfl_addrmodule(ui->dwfl, ip) == mod ? 0 : -1;
}
/*
* 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;
}
