diff options
Diffstat (limited to 'gdb/amd64-linux-tdep.c')
| -rw-r--r-- | gdb/amd64-linux-tdep.c | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/gdb/amd64-linux-tdep.c b/gdb/amd64-linux-tdep.c index 494e744..e5a2ab9 100644 --- a/gdb/amd64-linux-tdep.c +++ b/gdb/amd64-linux-tdep.c @@ -33,7 +33,9 @@ #include "amd64-linux-tdep.h" #include "i386-linux-tdep.h" #include "linux-tdep.h" +#include "svr4-tls-tdep.h" #include "gdbsupport/x86-xstate.h" +#include "inferior.h" #include "amd64-tdep.h" #include "solib-svr4.h" @@ -1832,6 +1834,39 @@ amd64_linux_remove_non_address_bits_watchpoint (gdbarch *gdbarch, return (addr & amd64_linux_lam_untag_mask ()); } +/* Fetch and return the TLS DTV (dynamic thread vector) address for PTID. + Throw a suitable TLS error if something goes wrong. */ + +static CORE_ADDR +amd64_linux_get_tls_dtv_addr (struct gdbarch *gdbarch, ptid_t ptid, + enum svr4_tls_libc libc) +{ + /* On x86-64, the thread pointer is found in the fsbase register. */ + regcache *regcache + = get_thread_arch_regcache (current_inferior (), ptid, gdbarch); + target_fetch_registers (regcache, AMD64_FSBASE_REGNUM); + ULONGEST fsbase; + if (regcache->cooked_read (AMD64_FSBASE_REGNUM, &fsbase) != REG_VALID) + throw_error (TLS_GENERIC_ERROR, _("Unable to fetch thread pointer")); + + /* The thread pointer (fsbase) points at the TCB (thread control + block). The first two members of this struct are both pointers, + where the first will be a pointer to the TCB (i.e. it points at + itself) and the second will be a pointer to the DTV (dynamic + thread vector). There are many other fields too, but the one + we care about here is the DTV pointer. Compute the address + of the DTV pointer, fetch it, and convert it to an address. */ + CORE_ADDR dtv_ptr_addr = fsbase + gdbarch_ptr_bit (gdbarch) / TARGET_CHAR_BIT; + gdb::byte_vector buf (gdbarch_ptr_bit (gdbarch) / TARGET_CHAR_BIT); + if (target_read_memory (dtv_ptr_addr, buf.data (), buf.size ()) != 0) + throw_error (TLS_GENERIC_ERROR, _("Unable to fetch DTV address")); + + const struct builtin_type *builtin = builtin_type (gdbarch); + CORE_ADDR dtv_addr = gdbarch_pointer_to_address + (gdbarch, builtin->builtin_data_ptr, buf.data ()); + return dtv_addr; +} + static void amd64_linux_init_abi_common(struct gdbarch_info info, struct gdbarch *gdbarch, int num_disp_step_buffers) @@ -1862,6 +1897,9 @@ amd64_linux_init_abi_common(struct gdbarch_info info, struct gdbarch *gdbarch, /* Enable TLS support. */ set_gdbarch_fetch_tls_load_module_address (gdbarch, svr4_fetch_objfile_link_map); + set_gdbarch_get_thread_local_address (gdbarch, + svr4_tls_get_thread_local_address); + svr4_tls_register_tls_methods (info, gdbarch, amd64_linux_get_tls_dtv_addr); /* GNU/Linux uses SVR4-style shared libraries. */ set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target); |