OpenE2K
/
binutils-gdb
12
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

RISC-V: Linux signal frame support. 

Add support for recognizing signal trampolines, parsing the signal frame,
and reading register values from it.

	gdb/
	* riscv-linux-tdep.c: Include tramp-frame.h and trad-frame.h.
	(riscv_linux_sigframe_init): Declare.
	(RISCV_INST_LI_A7_SIGRETURN, RISCV_INT_ECALL): New.
	(riscv_linux_sigframe): New.
	(SIGFRAME_SIGINFO_SIZE, UCONTEXT_MCONTEXT_OFFSET): New.
	(riscv_linux_sigframe_init): Define.
	(riscv_linux_init_abi): Call tramp_frame_prepend_unwinder.
This commit is contained in:
Jim Wilson 2018-10-26 10:32:58 -07:00
parent 8a61382623
commit 77c6f5fcda
2 changed files with 88 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
gdb/ChangeLog
View File

@ -1,5 +1,13 @@
2018-10-26 Jim Wilson <jimw@sifive.com>
* riscv-linux-tdep.c: Include tramp-frame.h and trad-frame.h.
(riscv_linux_sigframe_init): Declare.
(RISCV_INST_LI_A7_SIGRETURN, RISCV_INT_ECALL): New.
(riscv_linux_sigframe): New.
(SIGFRAME_SIGINFO_SIZE, UCONTEXT_MCONTEXT_OFFSET): New.
(riscv_linux_sigframe_init): Define.
(riscv_linux_init_abi): Call tramp_frame_prepend_unwinder.
* riscv-tdep.c (riscv_isa_xlen): Refer to riscv-tdep.h comment.
(riscv_isa_flen): Likewise. Drop static.
* riscv-tdep.h (riscv_isa_xlen): Move riscv-tdep.c comment to here.

80
gdb/riscv-linux-tdep.c
View File

@ -23,6 +23,8 @@
#include "linux-tdep.h"
#include "solib-svr4.h"
#include "regset.h"
#include "tramp-frame.h"
#include "trad-frame.h"
/* Define the general register mapping. The kernel puts the PC at offset 0,
gdb puts it at offset 32. Register x0 is always 0 and can be ignored.
@ -56,6 +58,82 @@ riscv_linux_iterate_over_regset_sections (struct gdbarch *gdbarch,
/* TODO: Add FP register support. */
}
/* Signal trampoline support. */
static void riscv_linux_sigframe_init (const struct tramp_frame *self,
struct frame_info *this_frame,
struct trad_frame_cache *this_cache,
CORE_ADDR func);
#define RISCV_INST_LI_A7_SIGRETURN 0x08b00893
#define RISCV_INST_ECALL 0x00000073
static const struct tramp_frame riscv_linux_sigframe = {
SIGTRAMP_FRAME,
4,
{
{ RISCV_INST_LI_A7_SIGRETURN, ULONGEST_MAX },
{ RISCV_INST_ECALL, ULONGEST_MAX },
{ TRAMP_SENTINEL_INSN }
},
riscv_linux_sigframe_init,
NULL
};
/* Runtime signal frames look like this:
struct rt_sigframe {
struct siginfo info;
struct ucontext uc;
};
struct ucontext {
unsigned long __uc_flags;
struct ucontext *uclink;
stack_t uc_stack;
sigset_t uc_sigmask;
char __glibc_reserved[1024 / 8 - sizeof (sigset_t)];
mcontext_t uc_mcontext;
}; */
#define SIGFRAME_SIGINFO_SIZE 128
#define UCONTEXT_MCONTEXT_OFFSET 176
static void
riscv_linux_sigframe_init (const struct tramp_frame *self,
struct frame_info *this_frame,
struct trad_frame_cache *this_cache,
CORE_ADDR func)
{
struct gdbarch *gdbarch = get_frame_arch (this_frame);
int xlen = riscv_isa_xlen (gdbarch);
int flen = riscv_isa_flen (gdbarch);
CORE_ADDR frame_sp = get_frame_sp (this_frame);
CORE_ADDR mcontext_base;
CORE_ADDR regs_base;
mcontext_base = frame_sp + SIGFRAME_SIGINFO_SIZE + UCONTEXT_MCONTEXT_OFFSET;
/* Handle the integer registers. The first one is PC, followed by x1
through x31. */
regs_base = mcontext_base;
trad_frame_set_reg_addr (this_cache, RISCV_PC_REGNUM, regs_base);
for (int i = 1; i < 32; i++)
trad_frame_set_reg_addr (this_cache, RISCV_ZERO_REGNUM + i,
regs_base + (i * xlen));
/* Handle the FP registers. First comes the 32 FP registers, followed by
fcsr. */
regs_base += 32 * xlen;
for (int i = 0; i < 32; i++)
trad_frame_set_reg_addr (this_cache, RISCV_FIRST_FP_REGNUM + i,
regs_base + (i * flen));
regs_base += 32 * flen;
trad_frame_set_reg_addr (this_cache, RISCV_CSR_FCSR_REGNUM, regs_base);
/* Choice of the bottom of the sigframe is somewhat arbitrary. */
trad_frame_set_id (this_cache, frame_id_build (frame_sp, func));
}
/* Initialize RISC-V Linux ABI info. */
static void
@ -82,6 +160,8 @@ riscv_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
set_gdbarch_iterate_over_regset_sections
(gdbarch, riscv_linux_iterate_over_regset_sections);
tramp_frame_prepend_unwinder (gdbarch, &riscv_linux_sigframe);
}
/* Initialize RISC-V Linux target support. */