mirror of
https://sourceware.org/git/binutils-gdb.git
synced 2024-12-15 04:31:49 +08:00
arc: Add support for signal frames for Linux targets
Implement functions needed to unwind signal frames on ARC Linux targets. gdb/ChangeLog * arc-linux-tdep.c (arc_linux_sc_reg_offsets): New static variable. (arc_linux_is_sigtramp): New function. (arc_linux_sigcontext_addr): Likewise. (arc_linux_init_osabi): Use them.
This commit is contained in:
Anton Kolesov
Shahab Vahedi
parent
b4e3cd0440
commit
d4af727286
@ -1,3 +1,10 @@
|
||||
2020-12-22 Anton Kolesov <anton.kolesov@synopsys.com>
|
||||
|
||||
* arc-linux-tdep.c (arc_linux_sc_reg_offsets): New static variable.
|
||||
(arc_linux_is_sigtramp): New function.
|
||||
(arc_linux_sigcontext_addr): Likewise.
|
||||
(arc_linux_init_osabi): Use them.
|
||||
|
||||
2020-12-22 Anton Kolesov <anton.kolesov@synopsys.com>
|
||||
|
||||
* arc-tdep.c (arc_make_sigtramp_frame_cache): New function.
|
||||
|
||||
@ -33,6 +33,60 @@
|
||||
|
||||
#define REGOFF(offset) (offset * ARC_REGISTER_SIZE)
|
||||
|
||||
/* arc_linux_sc_reg_offsets[i] is the offset of register i in the `struct
|
||||
sigcontext'. Array index is an internal GDB register number, as defined in
|
||||
arc-tdep.h:arc_regnum.
|
||||
|
||||
From <include/uapi/asm/sigcontext.h> and <include/uapi/asm/ptrace.h>.
|
||||
|
||||
The layout of this struct is tightly bound to "arc_regnum" enum
|
||||
in arc-tdep.h. Any change of order in there, must be reflected
|
||||
here as well. */
|
||||
static const int arc_linux_sc_reg_offsets[] = {
|
||||
/* R0 - R12. */
|
||||
REGOFF (22), REGOFF (21), REGOFF (20), REGOFF (19),
|
||||
REGOFF (18), REGOFF (17), REGOFF (16), REGOFF (15),
|
||||
REGOFF (14), REGOFF (13), REGOFF (12), REGOFF (11),
|
||||
REGOFF (10),
|
||||
|
||||
/* R13 - R25. */
|
||||
ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER,
|
||||
ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER,
|
||||
ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER,
|
||||
ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER,
|
||||
ARC_OFFSET_NO_REGISTER,
|
||||
|
||||
REGOFF (9), /* R26 (GP) */
|
||||
REGOFF (8), /* FP */
|
||||
REGOFF (23), /* SP */
|
||||
ARC_OFFSET_NO_REGISTER, /* ILINK */
|
||||
ARC_OFFSET_NO_REGISTER, /* R30 */
|
||||
REGOFF (7), /* BLINK */
|
||||
|
||||
/* R32 - R59. */
|
||||
ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER,
|
||||
ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER,
|
||||
ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER,
|
||||
ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER,
|
||||
ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER,
|
||||
ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER,
|
||||
ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER,
|
||||
ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER,
|
||||
ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER, ARC_OFFSET_NO_REGISTER,
|
||||
ARC_OFFSET_NO_REGISTER,
|
||||
|
||||
REGOFF (4), /* LP_COUNT */
|
||||
ARC_OFFSET_NO_REGISTER, /* RESERVED */
|
||||
ARC_OFFSET_NO_REGISTER, /* LIMM */
|
||||
ARC_OFFSET_NO_REGISTER, /* PCL */
|
||||
|
||||
REGOFF (6), /* PC */
|
||||
REGOFF (5), /* STATUS32 */
|
||||
REGOFF (2), /* LP_START */
|
||||
REGOFF (3), /* LP_END */
|
||||
REGOFF (1), /* BTA */
|
||||
};
|
||||
|
||||
/* arc_linux_core_reg_offsets[i] is the offset in the .reg section of GDB
|
||||
regnum i. Array index is an internal GDB register number, as defined in
|
||||
arc-tdep.h:arc_regnum.
|
||||
@ -87,6 +141,127 @@ static const int arc_linux_core_reg_offsets[] = {
|
||||
REGOFF (6) /* ERET */
|
||||
};
|
||||
|
||||
/* Is THIS_FRAME a sigtramp function - the function that returns from
|
||||
signal handler into normal execution flow? This is the case if the PC is
|
||||
either at the start of, or in the middle of the two instructions:
|
||||
|
||||
mov r8, __NR_rt_sigreturn ; __NR_rt_sigreturn == 139
|
||||
trap_s 0 ; `swi' for ARC700
|
||||
|
||||
On ARC uClibc Linux this function is called __default_rt_sa_restorer.
|
||||
|
||||
Returns TRUE if this is a sigtramp frame. */
|
||||
|
||||
static bool
|
||||
arc_linux_is_sigtramp (struct frame_info *this_frame)
|
||||
{
|
||||
struct gdbarch *gdbarch = get_frame_arch (this_frame);
|
||||
CORE_ADDR pc = get_frame_pc (this_frame);
|
||||
|
||||
if (arc_debug)
|
||||
{
|
||||
debug_printf ("arc-linux: arc_linux_is_sigtramp, pc=%s\n",
|
||||
paddress(gdbarch, pc));
|
||||
}
|
||||
|
||||
static const gdb_byte insns_be_hs[] = {
|
||||
0x20, 0x8a, 0x12, 0xc2, /* mov r8,nr_rt_sigreturn */
|
||||
0x78, 0x1e /* trap_s 0 */
|
||||
};
|
||||
static const gdb_byte insns_be_700[] = {
|
||||
0x20, 0x8a, 0x12, 0xc2, /* mov r8,nr_rt_sigreturn */
|
||||
0x22, 0x6f, 0x00, 0x3f /* swi */
|
||||
};
|
||||
|
||||
gdb_byte arc_sigtramp_insns[sizeof (insns_be_700)];
|
||||
size_t insns_sz;
|
||||
if (arc_mach_is_arcv2 (gdbarch))
|
||||
{
|
||||
insns_sz = sizeof (insns_be_hs);
|
||||
memcpy (arc_sigtramp_insns, insns_be_hs, insns_sz);
|
||||
}
|
||||
else
|
||||
{
|
||||
insns_sz = sizeof (insns_be_700);
|
||||
memcpy (arc_sigtramp_insns, insns_be_700, insns_sz);
|
||||
}
|
||||
if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_LITTLE)
|
||||
{
|
||||
/* On little endian targets, ARC code section is in what is called
|
||||
"middle endian", where half-words are in the big-endian order,
|
||||
only bytes inside the halfwords are in the little endian order.
|
||||
As a result it is very easy to convert big endian instruction to
|
||||
little endian, since it is needed to swap bytes in the halfwords,
|
||||
so there is no need to have information on whether that is a
|
||||
4-byte instruction or 2-byte. */
|
||||
gdb_assert ((insns_sz % 2) == 0);
|
||||
for (int i = 0; i < insns_sz; i += 2)
|
||||
std::swap (arc_sigtramp_insns[i], arc_sigtramp_insns[i+1]);
|
||||
}
|
||||
|
||||
gdb_byte buf[insns_sz];
|
||||
|
||||
/* Read the memory at the PC. Since we are stopped, any breakpoint must
|
||||
have been removed. */
|
||||
if (!safe_frame_unwind_memory (this_frame, pc, buf, insns_sz))
|
||||
{
|
||||
/* Failed to unwind frame. */
|
||||
return FALSE;
|
||||
}
|
||||
|
||||
/* Is that code the sigtramp instruction sequence? */
|
||||
if (memcmp (buf, arc_sigtramp_insns, insns_sz) == 0)
|
||||
return TRUE;
|
||||
|
||||
/* No - look one instruction earlier in the code... */
|
||||
if (!safe_frame_unwind_memory (this_frame, pc - 4, buf, insns_sz))
|
||||
{
|
||||
/* Failed to unwind frame. */
|
||||
return FALSE;
|
||||
}
|
||||
|
||||
return (memcmp (buf, arc_sigtramp_insns, insns_sz) == 0);
|
||||
}
|
||||
|
||||
/* Get sigcontext structure of sigtramp frame - it contains saved
|
||||
registers of interrupted frame.
|
||||
|
||||
Stack pointer points to the rt_sigframe structure, and sigcontext can
|
||||
be found as in:
|
||||
|
||||
struct rt_sigframe {
|
||||
struct siginfo info;
|
||||
struct ucontext uc;
|
||||
...
|
||||
};
|
||||
|
||||
struct ucontext {
|
||||
unsigned long uc_flags;
|
||||
struct ucontext *uc_link;
|
||||
stack_t uc_stack;
|
||||
struct sigcontext uc_mcontext;
|
||||
sigset_t uc_sigmask;
|
||||
};
|
||||
|
||||
sizeof (struct siginfo) == 0x80
|
||||
offsetof (struct ucontext, uc_mcontext) == 0x14
|
||||
|
||||
GDB cannot include linux headers and use offsetof () because those are
|
||||
target headers and GDB might be built for a different run host. There
|
||||
doesn't seem to be an established mechanism to figure out those offsets
|
||||
via gdbserver, so the only way is to hardcode values in the GDB,
|
||||
meaning that GDB will be broken if values will change. That seems to
|
||||
be a very unlikely scenario and other arches (aarch64, alpha, amd64,
|
||||
etc) in GDB hardcode values. */
|
||||
|
||||
static CORE_ADDR
|
||||
arc_linux_sigcontext_addr (struct frame_info *this_frame)
|
||||
{
|
||||
const int ucontext_offset = 0x80;
|
||||
const int sigcontext_offset = 0x14;
|
||||
return get_frame_sp (this_frame) + ucontext_offset + sigcontext_offset;
|
||||
}
|
||||
|
||||
/* Implement the "cannot_fetch_register" gdbarch method. */
|
||||
|
||||
static int
|
||||
@ -430,6 +605,12 @@ arc_linux_init_osabi (struct gdbarch_info info, struct gdbarch *gdbarch)
|
||||
if (arc_debug)
|
||||
debug_printf ("arc-linux: GNU/Linux OS/ABI initialization.\n");
|
||||
|
||||
/* Fill in target-dependent info in ARC-private structure. */
|
||||
tdep->is_sigtramp = arc_linux_is_sigtramp;
|
||||
tdep->sigcontext_addr = arc_linux_sigcontext_addr;
|
||||
tdep->sc_reg_offset = arc_linux_sc_reg_offsets;
|
||||
tdep->sc_num_regs = ARRAY_SIZE (arc_linux_sc_reg_offsets);
|
||||
|
||||
/* If we are using Linux, we have in uClibc
|
||||
(libc/sysdeps/linux/arc/bits/setjmp.h):
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user