From b3a7d1711e4557811865333a0ac96fc16b750869 Mon Sep 17 00:00:00 2001 From: Andrew Burgess Date: Thu, 4 Jul 2019 21:02:43 +0100 Subject: [PATCH] gdb/riscv: Don't use default bfd to define required features When we initialise a gdbarch object we perform a check to try and detect if the user is doing something silly; trying to run an RV64 binary on an RV32 target. To perform this check we compare the xlen from the target description with the xlen specified in the headers on the ELF being debugged. If there is no ELF being debugged then we (currently) try to use the bfd_arch_info from the gdbarch_info object, which will have been set to the default architecture if no bfd is currently being debugged. For RISC-V the default architecture is RV64. What this means is that if a user tries to connect to an RV32 target without specifying the BFD to debug then GDB will assume RV64. The sanity check mentioned above will failed (xlen difference) and GDB will throw an error. The error causes GDB to disconnect from the remote target. After this commit GDB no longer relies on the default bfd architecture. If the user tries to connect without specifying the bfd then GDB will simply make use of the xlen extracted from the target description in order to find or create a suitable gdbarch object. gdb/ChangeLog: * riscv-tdep.c (riscv_features_from_gdbarch_info): Don't modify required features based on default bfd type when no specific bfd is present. --- gdb/ChangeLog | 6 ++++++ gdb/riscv-tdep.c | 12 ------------ 2 files changed, 6 insertions(+), 12 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 2f406ae2bd..854eeb5b0e 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,9 @@ +2019-07-09 Andrew Burgess + + * riscv-tdep.c (riscv_features_from_gdbarch_info): Don't modify + required features based on default bfd type when no specific bfd + is present. + 2019-07-08 Philippe Waroquiers * NEWS: Mention that GDB printf and eval commands can now print diff --git a/gdb/riscv-tdep.c b/gdb/riscv-tdep.c index bae987cf66..828beea7e2 100644 --- a/gdb/riscv-tdep.c +++ b/gdb/riscv-tdep.c @@ -2917,18 +2917,6 @@ riscv_features_from_gdbarch_info (const struct gdbarch_info info) else if (e_flags & EF_RISCV_FLOAT_ABI_SINGLE) features.flen = 4; } - else - { - const struct bfd_arch_info *binfo = info.bfd_arch_info; - - if (binfo->bits_per_word == 32) - features.xlen = 4; - else if (binfo->bits_per_word == 64) - features.xlen = 8; - else - internal_error (__FILE__, __LINE__, _("unknown bits_per_word %d"), - binfo->bits_per_word); - } return features; } -- 2.34.1