]>
Commit | Line | Data |
---|---|---|
e430824f | 1 | /* DWARF2 EH unwinding support for Nios II Linux. |
a5544970 | 2 | Copyright (C) 2008-2019 Free Software Foundation, Inc. |
e430824f CLT |
3 | |
4 | This file is free software; you can redistribute it and/or modify it | |
5 | under the terms of the GNU General Public License as published by the | |
6 | Free Software Foundation; either version 3, or (at your option) any | |
7 | later version. | |
8 | ||
9 | This file is distributed in the hope that it will be useful, but | |
10 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
12 | General Public License for more details. | |
13 | ||
14 | Under Section 7 of GPL version 3, you are granted additional | |
15 | permissions described in the GCC Runtime Library Exception, version | |
16 | 3.1, as published by the Free Software Foundation. | |
17 | ||
18 | You should have received a copy of the GNU General Public License and | |
19 | a copy of the GCC Runtime Library Exception along with this program; | |
20 | see the files COPYING3 and COPYING.RUNTIME respectively. If not, see | |
21 | <http://www.gnu.org/licenses/>. */ | |
22 | ||
23 | #ifndef inhibit_libc | |
24 | ||
25 | /* Do code reading to identify a signal frame, and set the frame | |
26 | state data appropriately. See unwind-dw2.c for the structs. | |
27 | The corresponding bits in the Linux kernel are in | |
28 | arch/nios2/kernel/signal.c. */ | |
29 | ||
30 | #include <signal.h> | |
31 | #include <asm/unistd.h> | |
32 | ||
33 | /* Exactly the same layout as the kernel structures, unique names. */ | |
34 | struct nios2_mcontext { | |
35 | int version; | |
36 | int gregs[32]; | |
37 | }; | |
38 | ||
39 | struct nios2_ucontext { | |
40 | unsigned long uc_flags; | |
883312dc | 41 | ucontext_t *uc_link; |
e430824f CLT |
42 | stack_t uc_stack; |
43 | struct nios2_mcontext uc_mcontext; | |
44 | sigset_t uc_sigmask; /* mask last for extensibility */ | |
45 | }; | |
46 | ||
47 | #define MD_FALLBACK_FRAME_STATE_FOR nios2_fallback_frame_state | |
48 | ||
49 | static _Unwind_Reason_Code | |
50 | nios2_fallback_frame_state (struct _Unwind_Context *context, | |
51 | _Unwind_FrameState *fs) | |
52 | { | |
53 | u_int32_t *pc = (u_int32_t *) context->ra; | |
54 | _Unwind_Ptr new_cfa; | |
55 | ||
56 | /* The expected sequence of instructions is: | |
57 | movi r2,(rt_sigreturn) | |
58 | trap | |
59 | Check for the trap first. */ | |
60 | if (pc[1] != 0x003b683a) | |
61 | return _URC_END_OF_STACK; | |
62 | ||
63 | #define NIOS2_REG(NUM,NAME) \ | |
64 | (fs->regs.reg[NUM].how = REG_SAVED_OFFSET, \ | |
65 | fs->regs.reg[NUM].loc.offset = (_Unwind_Ptr)&(regs->NAME) - new_cfa) | |
66 | ||
67 | if (pc[0] == (0x00800004 | (__NR_rt_sigreturn << 6))) | |
68 | { | |
69 | struct rt_sigframe { | |
e430824f CLT |
70 | siginfo_t info; |
71 | struct nios2_ucontext uc; | |
a9ce4e4a | 72 | } *rt_ = context->cfa; |
e430824f CLT |
73 | struct nios2_mcontext *regs = &rt_->uc.uc_mcontext; |
74 | int i; | |
75 | ||
76 | /* MCONTEXT_VERSION is defined to 2 in the kernel. */ | |
77 | if (regs->version != 2) | |
78 | return _URC_END_OF_STACK; | |
79 | ||
80 | /* The CFA is the user's incoming stack pointer value. */ | |
81 | new_cfa = (_Unwind_Ptr)regs->gregs[28]; | |
82 | fs->regs.cfa_how = CFA_REG_OFFSET; | |
53d68b9f | 83 | fs->regs.cfa_reg = __LIBGCC_STACK_POINTER_REGNUM__; |
e430824f CLT |
84 | fs->regs.cfa_offset = new_cfa - (_Unwind_Ptr) context->cfa; |
85 | ||
86 | /* The sequential registers. */ | |
87 | for (i = 1; i < 24; i++) | |
88 | NIOS2_REG (i, gregs[i-1]); | |
89 | ||
90 | /* The random registers. The kernel stores these in a funny order | |
91 | in the gregs array. */ | |
92 | NIOS2_REG (RA_REGNO, gregs[23]); | |
93 | NIOS2_REG (FP_REGNO, gregs[24]); | |
94 | NIOS2_REG (GP_REGNO, gregs[25]); | |
95 | NIOS2_REG (EA_REGNO, gregs[27]); | |
96 | ||
97 | fs->retaddr_column = EA_REGNO; | |
98 | fs->signal_frame = 1; | |
99 | ||
100 | return _URC_NO_REASON; | |
101 | } | |
102 | #undef NIOS2_REG | |
103 | return _URC_END_OF_STACK; | |
104 | } | |
105 | #endif |