From f5424cfa7e9337a6cb02a1f83c9feea0995c5350 Mon Sep 17 00:00:00 2001 From: John Baldwin Date: Tue, 12 Mar 2019 13:39:02 -0700 Subject: [PATCH] Support TLS variables on FreeBSD/amd64. Use the fs_base register to fetch the address of a thread's tcb and calculate the address of the DTV array. This value is then passed to fbsd_get_thread_local_address to compute the final variable address. Note that fs_base is currently only available via the native target as core dumps on FreeBSD do not store the value of fs_base. gdb/ChangeLog: * amd64-fbsd-tdep.c (amd64fbsd_get_thread_local_address): New. (amd64fbsd_init_abi): Install gdbarch "fetch_tls_load_module_address" and "get_thread_local_address" methods. --- gdb/ChangeLog | 7 +++++++ gdb/amd64-fbsd-tdep.c | 25 +++++++++++++++++++++++++ 2 files changed, 32 insertions(+) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index ae7203a03da..2268dd2ca64 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,10 @@ +2019-03-12 John Baldwin + + * amd64-fbsd-tdep.c (amd64fbsd_get_thread_local_address): New. + (amd64fbsd_init_abi): Install gdbarch + "fetch_tls_load_module_address" and "get_thread_local_address" + methods. + 2019-03-12 John Baldwin * fbsd-tdep.c (fbsd_pspace_data_handle): New variable. diff --git a/gdb/amd64-fbsd-tdep.c b/gdb/amd64-fbsd-tdep.c index 403e65022d5..7e2e9edf21d 100644 --- a/gdb/amd64-fbsd-tdep.c +++ b/gdb/amd64-fbsd-tdep.c @@ -204,6 +204,26 @@ amd64fbsd_iterate_over_regset_sections (struct gdbarch *gdbarch, &amd64fbsd_xstateregset, "XSAVE extended state", cb_data); } +/* Implement the get_thread_local_address gdbarch method. */ + +static CORE_ADDR +amd64fbsd_get_thread_local_address (struct gdbarch *gdbarch, ptid_t ptid, + CORE_ADDR lm_addr, CORE_ADDR offset) +{ + struct regcache *regcache; + + regcache = get_thread_arch_regcache (ptid, gdbarch); + + target_fetch_registers (regcache, AMD64_FSBASE_REGNUM); + + ULONGEST fsbase; + if (regcache->cooked_read (AMD64_FSBASE_REGNUM, &fsbase) != REG_VALID) + error (_("Unable to fetch %%fsbase")); + + CORE_ADDR dtv_addr = fsbase + gdbarch_ptr_bit (gdbarch) / 8; + return fbsd_get_thread_local_address (gdbarch, dtv_addr, lm_addr, offset); +} + static void amd64fbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) { @@ -241,6 +261,11 @@ amd64fbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) /* FreeBSD uses SVR4-style shared libraries. */ set_solib_svr4_fetch_link_map_offsets (gdbarch, svr4_lp64_fetch_link_map_offsets); + + set_gdbarch_fetch_tls_load_module_address (gdbarch, + svr4_fetch_objfile_link_map); + set_gdbarch_get_thread_local_address (gdbarch, + amd64fbsd_get_thread_local_address); } void -- 2.30.2