arch/parisc/kernel/signal32.h

   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 #define COMPAT_SIGRETURN_TRAMP 4
  40 #define COMPAT_SIGRESTARTBLOCK_TRAMP 5
  41 #define COMPAT_TRAMP_SIZE (COMPAT_SIGRETURN_TRAMP + \
  42                                 COMPAT_SIGRESTARTBLOCK_TRAMP)
  43
  44 struct compat_rt_sigframe {
  45         /* XXX: Must match trampoline size in arch/parisc/kernel/signal.c
  46                 Secondary to that it must protect the ERESTART_RESTARTBLOCK
  47                 trampoline we left on the stack (we were bad and didn't
  48                 change sp so we could run really fast.) */
  49         compat_uint_t tramp[COMPAT_TRAMP_SIZE];
  50         compat_siginfo_t info;
  51         struct compat_ucontext uc;
  52         /* Hidden location of truncated registers, *must* be last. */
  53         struct compat_regfile regs;
  54 };
  55
  56 /*
  57  * The 32-bit ABI wants at least 48 bytes for a function call frame:
  58  * 16 bytes for arg0-arg3, and 32 bytes for magic (the only part of
  59  * which Linux/parisc uses is sp-20 for the saved return pointer...)
  60  * Then, the stack pointer must be rounded to a cache line (64 bytes).
  61  */
  62 #define SIGFRAME32              64
  63 #define FUNCTIONCALLFRAME32     48
  64 #define PARISC_RT_SIGFRAME_SIZE32 (((sizeof(struct compat_rt_sigframe) + FUNCTIONCALLFRAME32) + SIGFRAME32) & -SIGFRAME32)
  65
  66 long restore_sigcontext32(struct compat_sigcontext __user *sc,
  67                 struct compat_regfile __user *rf,
  68                 struct pt_regs *regs);
  69 long setup_sigcontext32(struct compat_sigcontext __user *sc,
  70                 struct compat_regfile __user *rf,
  71                 struct pt_regs *regs, int in_syscall);
  72
  73 #endif