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 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