xref: /linux/arch/parisc/kernel/signal32.h (revision 4f2c0a4acffbec01079c28f839422e64ddeff004)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  *    Copyright (C) 2001 Matthew Wilcox <willy at parisc-linux.org>
4  *    Copyright (C) 2003 Carlos O'Donell <carlos at parisc-linux.org>
5  */
6 #ifndef _PARISC64_KERNEL_SIGNAL32_H
7 #define _PARISC64_KERNEL_SIGNAL32_H
8 
9 #include <linux/compat.h>
10 
11 /* 32-bit ucontext as seen from an 64-bit kernel */
12 struct compat_ucontext {
13         compat_uint_t uc_flags;
14         compat_uptr_t uc_link;
15         compat_stack_t uc_stack;        /* struct compat_sigaltstack (12 bytes)*/
16         /* FIXME: Pad out to get uc_mcontext to start at an 8-byte aligned boundary */
17         compat_uint_t pad[1];
18         struct compat_sigcontext uc_mcontext;
19         compat_sigset_t uc_sigmask;     /* mask last for extensibility */
20 };
21 
22 /* ELF32 signal handling */
23 
24 /* In a deft move of uber-hackery, we decide to carry the top half of all
25  * 64-bit registers in a non-portable, non-ABI, hidden structure.
26  * Userspace can read the hidden structure if it *wants* but is never
27  * guaranteed to be in the same place. In fact the uc_sigmask from the
28  * ucontext_t structure may push the hidden register file downards
29  */
30 struct compat_regfile {
31         /* Upper half of all the 64-bit registers that were truncated
32            on a copy to a 32-bit userspace */
33         compat_int_t rf_gr[32];
34         compat_int_t rf_iasq[2];
35         compat_int_t rf_iaoq[2];
36         compat_int_t rf_sar;
37 };
38 
39 struct compat_rt_sigframe {
40 	unsigned int tramp[2]; /* holds original return address */
41 	compat_siginfo_t info;
42 	struct compat_ucontext uc;
43 	/* Hidden location of truncated registers, *must* be last. */
44 	struct compat_regfile regs;
45 };
46 
47 /*
48  * The 32-bit ABI wants at least 48 bytes for a function call frame:
49  * 16 bytes for arg0-arg3, and 32 bytes for magic (the only part of
50  * which Linux/parisc uses is sp-20 for the saved return pointer...)
51  * Then, the stack pointer must be rounded to a cache line (64 bytes).
52  */
53 #define SIGFRAME32              64
54 #define FUNCTIONCALLFRAME32     48
55 #define PARISC_RT_SIGFRAME_SIZE32 (((sizeof(struct compat_rt_sigframe) + FUNCTIONCALLFRAME32) + SIGFRAME32) & -SIGFRAME32)
56 
57 long restore_sigcontext32(struct compat_sigcontext __user *sc,
58 		struct compat_regfile __user *rf,
59 		struct pt_regs *regs);
60 long setup_sigcontext32(struct compat_sigcontext __user *sc,
61 		struct compat_regfile __user *rf,
62 		struct pt_regs *regs, int in_syscall);
63 
64 #endif
65