From ed810cc7d3252bd8bfdb4303ee6b44293fe6214e Mon Sep 17 00:00:00 2001 From: John Baldwin Date: Mon, 20 Jul 2020 09:09:58 -0700 Subject: [PATCH] Implement the skip_solib_resolver gdbarch hook for FreeBSD architectures. The ELF runtime linker on all FreeBSD architectures uses the "_rtld_bind" entry point for unresolved PTL entries. FreeBSD/mips has an additional entry point called "_mips_rtld_bind". gdb/ChangeLog: * fbsd-tdep.c (fbsd_skip_solib_resolver): New function. (fbsd_init_abi): Install gdbarch "skip_solib_resolver" method. * fbsd-tdep.h (fbsd_skip_solib_resolver): New prototype. * mips-fbsd-tdep.c (mips_fbsd_skip_solib_resolver): New function. (mips_fbsd_init_abi): Install gdbarch "skip_solib_resolver" method. --- gdb/ChangeLog | 9 +++++++++ gdb/fbsd-tdep.c | 14 ++++++++++++++ gdb/fbsd-tdep.h | 5 +++++ gdb/mips-fbsd-tdep.c | 16 ++++++++++++++++ 4 files changed, 44 insertions(+) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 30ef2c8e35a..fad4608002f 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,12 @@ +2020-07-20 John Baldwin + + * fbsd-tdep.c (fbsd_skip_solib_resolver): New function. + (fbsd_init_abi): Install gdbarch "skip_solib_resolver" method. + * fbsd-tdep.h (fbsd_skip_solib_resolver): New prototype. + * mips-fbsd-tdep.c (mips_fbsd_skip_solib_resolver): New function. + (mips_fbsd_init_abi): Install gdbarch "skip_solib_resolver" + method. + 2020-07-20 Ludovic Courtès * guile/scm-math.c (vlscm_integer_fits_p): Use 'uintmax_t' diff --git a/gdb/fbsd-tdep.c b/gdb/fbsd-tdep.c index 557c5d3d737..ca397fa8e0f 100644 --- a/gdb/fbsd-tdep.c +++ b/gdb/fbsd-tdep.c @@ -21,6 +21,7 @@ #include "auxv.h" #include "gdbcore.h" #include "inferior.h" +#include "objfiles.h" #include "regcache.h" #include "regset.h" #include "gdbthread.h" @@ -2071,6 +2072,18 @@ fbsd_get_thread_local_address (struct gdbarch *gdbarch, CORE_ADDR dtv_addr, return addr + offset; } +/* See fbsd-tdep.h. */ + +CORE_ADDR +fbsd_skip_solib_resolver (struct gdbarch *gdbarch, CORE_ADDR pc) +{ + struct bound_minimal_symbol msym = lookup_bound_minimal_symbol ("_rtld_bind"); + if (msym.minsym != nullptr && BMSYMBOL_VALUE_ADDRESS (msym) == pc) + return frame_unwind_caller_pc (get_current_frame ()); + + return 0; +} + /* To be called from GDB_OSABI_FREEBSD handlers. */ void @@ -2085,6 +2098,7 @@ fbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) set_gdbarch_get_siginfo_type (gdbarch, fbsd_get_siginfo_type); set_gdbarch_gdb_signal_from_target (gdbarch, fbsd_gdb_signal_from_target); set_gdbarch_gdb_signal_to_target (gdbarch, fbsd_gdb_signal_to_target); + set_gdbarch_skip_solib_resolver (gdbarch, fbsd_skip_solib_resolver); /* `catch syscall' */ set_xml_syscall_file_name (gdbarch, "syscalls/freebsd.xml"); diff --git a/gdb/fbsd-tdep.h b/gdb/fbsd-tdep.h index 5dd82032991..e8e49dc25f7 100644 --- a/gdb/fbsd-tdep.h +++ b/gdb/fbsd-tdep.h @@ -71,4 +71,9 @@ extern CORE_ADDR fbsd_get_thread_local_address (struct gdbarch *gdbarch, CORE_ADDR lm_addr, CORE_ADDR offset); +/* Implement the "skip_solib_resolver" gdbarch method. */ + +extern CORE_ADDR fbsd_skip_solib_resolver (struct gdbarch *gdbarch, + CORE_ADDR pc); + #endif /* fbsd-tdep.h */ diff --git a/gdb/mips-fbsd-tdep.c b/gdb/mips-fbsd-tdep.c index abaf7f2474a..ba666f1dc54 100644 --- a/gdb/mips-fbsd-tdep.c +++ b/gdb/mips-fbsd-tdep.c @@ -462,6 +462,20 @@ static const struct tramp_frame mips64_fbsd_sigframe = /* Shared library support. */ +/* FreeBSD/mips can use an alternate routine in the runtime linker to + resolve functions. */ + +static CORE_ADDR +mips_fbsd_skip_solib_resolver (struct gdbarch *gdbarch, CORE_ADDR pc) +{ + struct bound_minimal_symbol msym + = lookup_bound_minimal_symbol ("_mips_rtld_bind"); + if (msym.minsym != nullptr && BMSYMBOL_VALUE_ADDRESS (msym) == pc) + return frame_unwind_caller_pc (get_current_frame ()); + + return fbsd_skip_solib_resolver (gdbarch, pc); +} + /* FreeBSD/mips uses a slightly different `struct link_map' than the other FreeBSD platforms as it includes an additional `l_off' member. */ @@ -546,6 +560,8 @@ mips_fbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) set_gdbarch_iterate_over_regset_sections (gdbarch, mips_fbsd_iterate_over_regset_sections); + set_gdbarch_skip_solib_resolver (gdbarch, mips_fbsd_skip_solib_resolver); + /* FreeBSD/mips has SVR4-style shared libraries. */ set_solib_svr4_fetch_link_map_offsets (gdbarch, (gdbarch_ptr_bit (gdbarch) == 32 ? -- 2.30.2