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Diffstat (limited to 'gdb/amd64-obsd-nat.c')
| -rw-r--r-- | gdb/amd64-obsd-nat.c | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/gdb/amd64-obsd-nat.c b/gdb/amd64-obsd-nat.c new file mode 100644 index 0000000..7256dec --- /dev/null +++ b/gdb/amd64-obsd-nat.c @@ -0,0 +1,144 @@ +/* Native-dependent code for OpenBSD/amd64. + + Copyright (C) 2003-2016 Free Software Foundation, Inc. + + This file is part of GDB. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. */ + +#include "defs.h" +#include "gdbcore.h" +#include "regcache.h" +#include "target.h" + +#include "amd64-tdep.h" +#include "amd64-nat.h" +#include "obsd-nat.h" + +/* Mapping between the general-purpose registers in OpenBSD/amd64 + `struct reg' format and GDB's register cache layout for + OpenBSD/i386. + + Note that most (if not all) OpenBSD/amd64 registers are 64-bit, + while the OpenBSD/i386 registers are all 32-bit, but since we're + little-endian we get away with that. */ + +/* From <machine/reg.h>. */ +static int amd64obsd32_r_reg_offset[] = +{ + 14 * 8, /* %eax */ + 3 * 8, /* %ecx */ + 2 * 8, /* %edx */ + 13 * 8, /* %ebx */ + 15 * 8, /* %esp */ + 12 * 8, /* %ebp */ + 1 * 8, /* %esi */ + 0 * 8, /* %edi */ + 16 * 8, /* %eip */ + 17 * 8, /* %eflags */ + 18 * 8, /* %cs */ + 19 * 8, /* %ss */ + 20 * 8, /* %ds */ + 21 * 8, /* %es */ + 22 * 8, /* %fs */ + 23 * 8 /* %gs */ +}; + + +/* Support for debugging kernel virtual memory images. */ + +#include <sys/types.h> +#include <machine/frame.h> +#include <machine/pcb.h> + +#include "bsd-kvm.h" + +static int +amd64obsd_supply_pcb (struct regcache *regcache, struct pcb *pcb) +{ + struct switchframe sf; + int regnum; + + /* The following is true for OpenBSD 3.5: + + The pcb contains the stack pointer at the point of the context + switch in cpu_switch(). At that point we have a stack frame as + described by `struct switchframe', which for OpenBSD 3.5 has the + following layout: + + interrupt level + %r15 + %r14 + %r13 + %r12 + %rbp + %rbx + return address + + Together with %rsp in the pcb, this accounts for all callee-saved + registers specified by the psABI. From this information we + reconstruct the register state as it would look when we just + returned from cpu_switch(). + + For core dumps the pcb is saved by savectx(). In that case the + stack frame only contains the return address, and there is no way + to recover the other registers. */ + + /* The stack pointer shouldn't be zero. */ + if (pcb->pcb_rsp == 0) + return 0; + + /* Read the stack frame, and check its validity. */ + read_memory (pcb->pcb_rsp, (gdb_byte *) &sf, sizeof sf); + if (sf.sf_rbp == pcb->pcb_rbp) + { + /* Yes, we have a frame that matches cpu_switch(). */ + pcb->pcb_rsp += sizeof (struct switchframe); + regcache_raw_supply (regcache, 12, &sf.sf_r12); + regcache_raw_supply (regcache, 13, &sf.sf_r13); + regcache_raw_supply (regcache, 14, &sf.sf_r14); + regcache_raw_supply (regcache, 15, &sf.sf_r15); + regcache_raw_supply (regcache, AMD64_RBX_REGNUM, &sf.sf_rbx); + regcache_raw_supply (regcache, AMD64_RIP_REGNUM, &sf.sf_rip); + } + else + { + /* No, the pcb must have been last updated by savectx(). */ + pcb->pcb_rsp += 8; + regcache_raw_supply (regcache, AMD64_RIP_REGNUM, &sf); + } + + regcache_raw_supply (regcache, AMD64_RSP_REGNUM, &pcb->pcb_rsp); + regcache_raw_supply (regcache, AMD64_RBP_REGNUM, &pcb->pcb_rbp); + + return 1; +} + + +/* Provide a prototype to silence -Wmissing-prototypes. */ +void _initialize_amd64obsd_nat (void); + +void +_initialize_amd64obsd_nat (void) +{ + amd64_native_gregset32_reg_offset = amd64obsd32_r_reg_offset; + amd64_native_gregset32_num_regs = ARRAY_SIZE (amd64obsd32_r_reg_offset); + amd64_native_gregset64_reg_offset = amd64obsd_r_reg_offset; + + /* Add some extra features to the common *BSD/amd64 target. */ + obsd_add_target (amd64bsd_target ()); + + /* Support debugging kernel virtual memory images. */ + bsd_kvm_add_target (amd64obsd_supply_pcb); +} |