diff options
Diffstat (limited to 'nptl_db/td_thr_tlsbase.c')
| -rw-r--r-- | nptl_db/td_thr_tlsbase.c | 172 |
1 files changed, 170 insertions, 2 deletions
diff --git a/nptl_db/td_thr_tlsbase.c b/nptl_db/td_thr_tlsbase.c index 7092e31c5d..24a489ad46 100644 --- a/nptl_db/td_thr_tlsbase.c +++ b/nptl_db/td_thr_tlsbase.c @@ -17,14 +17,118 @@ <http://www.gnu.org/licenses/>. */ #include "thread_dbP.h" +#include <link.h> +/* Get the DTV slotinfo list head entry from the dynamic loader state + into *LISTHEAD. */ +static td_err_e +dtv_slotinfo_list (td_thragent_t *ta, + psaddr_t *listhead) +{ + td_err_e err; + psaddr_t head; + + if (ta->ta_addr__rtld_global == 0 + && td_mod_lookup (ta->ph, LD_SO, SYM__rtld_global, + &ta->ta_addr__rtld_global) != PS_OK) + ta->ta_addr__rtld_global = (void*)-1; + + if (ta->ta_addr__rtld_global != (void*)-1) + { + err = DB_GET_FIELD (head, ta, ta->ta_addr__rtld_global, + rtld_global, _dl_tls_dtv_slotinfo_list, 0); + if (err != TD_OK) + return err; + } + else + { + if (ta->ta_addr__dl_tls_dtv_slotinfo_list == 0 + && td_mod_lookup (ta->ph, NULL, SYM__dl_tls_dtv_slotinfo_list, + &ta->ta_addr__dl_tls_dtv_slotinfo_list) != PS_OK) + return TD_ERR; + + err = _td_fetch_value (ta, ta->ta_var__dl_tls_dtv_slotinfo_list, + SYM_DESC__dl_tls_dtv_slotinfo_list, + 0, ta->ta_addr__dl_tls_dtv_slotinfo_list, &head); + if (err != TD_OK) + return err; + } + + *listhead = head; + return TD_OK; +} + +/* Get the address of the DTV slotinfo entry for MODID into + *DTVSLOTINFO. */ +static td_err_e +dtv_slotinfo (td_thragent_t *ta, + unsigned long int modid, + psaddr_t *dtvslotinfo) +{ + td_err_e err; + psaddr_t slot, temp; + size_t slbase = 0; + + err = dtv_slotinfo_list (ta, &slot); + if (err != TD_OK) + return err; + + while (slot) + { + /* Get the number of entries in this list entry's array. */ + err = DB_GET_FIELD (temp, ta, slot, dtv_slotinfo_list, len, 0); + if (err != TD_OK) + return err; + size_t len = (uintptr_t)temp; + + /* Did we find the list entry for modid? */ + if (modid < slbase + len) + break; + + /* We didn't, so get the next list entry. */ + slbase += len; + err = DB_GET_FIELD (temp, ta, slot, dtv_slotinfo_list, + next, 0); + if (err != TD_OK) + return err; + slot = temp; + } + + /* We reached the end of the list and found nothing. */ + if (!slot) + return TD_ERR; + + /* Take the slotinfo for modid from the list entry. */ + err = DB_GET_FIELD_ADDRESS (temp, ta, slot, dtv_slotinfo_list, + slotinfo, modid - slbase); + if (err != TD_OK) + return err; + slot = temp; + + *dtvslotinfo = slot; + return TD_OK; +} + +/* Return in *BASE the base address of the TLS block for MODID within + TH. + + It should return success and yield the correct pointer in any + circumstance where the TLS block for the module and thread + requested has already been initialized. + + It should fail with TD_TLSDEFER only when the thread could not + possibly have observed any values in that TLS block. That way, the + debugger can fall back to showing initial values from the PT_TLS + segment (and refusing attempts to mutate) for the TD_TLSDEFER case, + and never fail to make the values the program will actually see + available to the user of the debugger. */ td_err_e td_thr_tlsbase (const td_thrhandle_t *th, unsigned long int modid, psaddr_t *base) { td_err_e err; - psaddr_t dtv, dtvslot, dtvptr; + psaddr_t dtv, dtvslot, dtvptr, temp; if (modid < 1) return TD_NOTLS; @@ -50,11 +154,75 @@ td_thr_tlsbase (const td_thrhandle_t *th, return TD_TLSDEFER; } + err = dtv_slotinfo (th->th_ta_p, modid, &temp); + if (err != TD_OK) + return err; + + psaddr_t slot; + err = DB_GET_STRUCT (slot, th->th_ta_p, temp, dtv_slotinfo); + if (err != TD_OK) + return err; + + /* Take the link_map from the slotinfo. */ + psaddr_t map; + err = DB_GET_FIELD_LOCAL (map, th->th_ta_p, slot, dtv_slotinfo, map, 0); + if (err != TD_OK) + return err; + if (!map) + return TD_ERR; + + /* Ok, the modid is good, now find out what DTV generation it + requires. */ + err = DB_GET_FIELD_LOCAL (temp, th->th_ta_p, slot, dtv_slotinfo, gen, 0); + if (err != TD_OK) + return err; + size_t modgen = (uintptr_t)temp; + /* Get the DTV pointer from the thread descriptor. */ err = DB_GET_FIELD (dtv, th->th_ta_p, pd, pthread, dtvp, 0); if (err != TD_OK) return err; + psaddr_t dtvgenloc; + /* Get the DTV generation count at dtv[0].counter. */ + err = DB_GET_FIELD_ADDRESS (dtvgenloc, th->th_ta_p, dtv, dtv, dtv, 0); + if (err != TD_OK) + return err; + err = DB_GET_FIELD (temp, th->th_ta_p, dtvgenloc, dtv_t, counter, 0); + if (err != TD_OK) + return err; + size_t dtvgen = (uintptr_t)temp; + + /* Is the DTV current enough? */ + if (dtvgen < modgen) + { + try_static_tls: + /* If the module uses Static TLS, we're still good. */ + err = DB_GET_FIELD (temp, th->th_ta_p, map, link_map, l_tls_offset, 0); + if (err != TD_OK) + return err; + ptrdiff_t tlsoff = (uintptr_t)temp; + + if (tlsoff != FORCED_DYNAMIC_TLS_OFFSET + && tlsoff != NO_TLS_OFFSET) + { + psaddr_t tp = pd; + +#if TLS_TCB_AT_TP + dtvptr = tp - tlsoff; +#elif TLS_DTV_AT_TP + dtvptr = tp + tlsoff + TLS_PRE_TCB_SIZE; +#else +# error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined" +#endif + + *base = dtvptr; + return TD_OK; + } + + return TD_TLSDEFER; + } + /* Find the corresponding entry in the DTV. */ err = DB_GET_FIELD_ADDRESS (dtvslot, th->th_ta_p, dtv, dtv, dtv, modid); if (err != TD_OK) @@ -68,7 +236,7 @@ td_thr_tlsbase (const td_thrhandle_t *th, /* It could be that the memory for this module is not allocated for the given thread. */ if ((uintptr_t) dtvptr & 1) - return TD_TLSDEFER; + goto try_static_tls; *base = dtvptr; return TD_OK; |