1 /* Common target dependent code for GNU/Linux on ARM systems. 2 3 Copyright (C) 1999-2016 Free Software Foundation, Inc. 4 5 This file is part of GDB. 6 7 This program is free software; you can redistribute it and/or modify 8 it under the terms of the GNU General Public License as published by 9 the Free Software Foundation; either version 3 of the License, or 10 (at your option) any later version. 11 12 This program is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 19 20 #ifndef ARM_LINUX_H 21 #define ARM_LINUX_H 22 23 /* The index to access CSPR in user_regs defined in GLIBC. */ 24 #define ARM_CPSR_GREGNUM 16 25 26 /* There are a couple of different possible stack layouts that 27 we need to support. 28 29 Before version 2.6.18, the kernel used completely independent 30 layouts for non-RT and RT signals. For non-RT signals the stack 31 began directly with a struct sigcontext. For RT signals the stack 32 began with two redundant pointers (to the siginfo and ucontext), 33 and then the siginfo and ucontext. 34 35 As of version 2.6.18, the non-RT signal frame layout starts with 36 a ucontext and the RT signal frame starts with a siginfo and then 37 a ucontext. Also, the ucontext now has a designated save area 38 for coprocessor registers. 39 40 For RT signals, it's easy to tell the difference: we look for 41 pinfo, the pointer to the siginfo. If it has the expected 42 value, we have an old layout. If it doesn't, we have the new 43 layout. 44 45 For non-RT signals, it's a bit harder. We need something in one 46 layout or the other with a recognizable offset and value. We can't 47 use the return trampoline, because ARM usually uses SA_RESTORER, 48 in which case the stack return trampoline is not filled in. 49 We can't use the saved stack pointer, because sigaltstack might 50 be in use. So for now we guess the new layout... */ 51 52 /* There are three words (trap_no, error_code, oldmask) in 53 struct sigcontext before r0. */ 54 #define ARM_SIGCONTEXT_R0 0xc 55 56 /* There are five words (uc_flags, uc_link, and three for uc_stack) 57 in the ucontext_t before the sigcontext. */ 58 #define ARM_UCONTEXT_SIGCONTEXT 0x14 59 60 /* There are three elements in an rt_sigframe before the ucontext: 61 pinfo, puc, and info. The first two are pointers and the third 62 is a struct siginfo, with size 128 bytes. We could follow puc 63 to the ucontext, but it's simpler to skip the whole thing. */ 64 #define ARM_OLD_RT_SIGFRAME_SIGINFO 0x8 65 #define ARM_OLD_RT_SIGFRAME_UCONTEXT 0x88 66 67 #define ARM_NEW_RT_SIGFRAME_UCONTEXT 0x80 68 69 #define ARM_NEW_SIGFRAME_MAGIC 0x5ac3c35a 70 71 int 72 arm_linux_sigreturn_next_pc_offset (unsigned long sp, 73 unsigned long sp_data, 74 unsigned long svc_number, 75 int is_sigreturn); 76 77 struct arm_get_next_pcs; 78 79 CORE_ADDR arm_linux_get_next_pcs_fixup (struct arm_get_next_pcs *self, 80 CORE_ADDR pc); 81 #endif /* ARM_LINUX_H */ 82