/* Low-level siginfo manipulation for amd64. Copyright (C) 2002-2021 Free Software Foundation, Inc. This file is part of GDB. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. */ #include "gdbsupport/common-defs.h" #include <signal.h> #include "amd64-linux-siginfo.h" #define GDB_SI_SIZE 128 /* The types below define the most complete kernel siginfo types known for the architecture, independent of the system/libc headers. They are named from a 64-bit kernel's perspective: | layout | type | |--------+----------------------| | 64-bit | nat_siginfo_t | | 32-bit | compat_siginfo_t | | x32 | compat_x32_siginfo_t | */ #ifndef __ILP32__ typedef int nat_int_t; typedef unsigned long nat_uptr_t; typedef int nat_time_t; typedef int nat_timer_t; /* For native 64-bit, clock_t in _sigchld is 64-bit. */ typedef long nat_clock_t; union nat_sigval_t { nat_int_t sival_int; nat_uptr_t sival_ptr; }; struct nat_siginfo_t { int si_signo; int si_errno; int si_code; union { int _pad[((128 / sizeof (int)) - 4)]; /* kill() */ struct { unsigned int _pid; unsigned int _uid; } _kill; /* POSIX.1b timers */ struct { nat_timer_t _tid; int _overrun; nat_sigval_t _sigval; } _timer; /* POSIX.1b signals */ struct { unsigned int _pid; unsigned int _uid; nat_sigval_t _sigval; } _rt; /* SIGCHLD */ struct { unsigned int _pid; unsigned int _uid; int _status; nat_clock_t _utime; nat_clock_t _stime; } _sigchld; /* SIGILL, SIGFPE, SIGSEGV, SIGBUS */ struct { nat_uptr_t _addr; short int _addr_lsb; struct { nat_uptr_t _lower; nat_uptr_t _upper; } si_addr_bnd; } _sigfault; /* SIGPOLL */ struct { int _band; int _fd; } _sigpoll; } _sifields; }; #endif /* __ILP32__ */ /* These types below (compat_*) define a siginfo type that is layout compatible with the siginfo type exported by the 32-bit userspace support. */ typedef int compat_int_t; typedef unsigned int compat_uptr_t; typedef int compat_time_t; typedef int compat_timer_t; typedef int compat_clock_t; struct compat_timeval { compat_time_t tv_sec; int tv_usec; }; union compat_sigval_t { compat_int_t sival_int; compat_uptr_t sival_ptr; }; struct compat_siginfo_t { int si_signo; int si_errno; int si_code; union { int _pad[((128 / sizeof (int)) - 3)]; /* kill() */ struct { unsigned int _pid; unsigned int _uid; } _kill; /* POSIX.1b timers */ struct { compat_timer_t _tid; int _overrun; compat_sigval_t _sigval; } _timer; /* POSIX.1b signals */ struct { unsigned int _pid; unsigned int _uid; compat_sigval_t _sigval; } _rt; /* SIGCHLD */ struct { unsigned int _pid; unsigned int _uid; int _status; compat_clock_t _utime; compat_clock_t _stime; } _sigchld; /* SIGILL, SIGFPE, SIGSEGV, SIGBUS */ struct { unsigned int _addr; short int _addr_lsb; struct { unsigned int _lower; unsigned int _upper; } si_addr_bnd; } _sigfault; /* SIGPOLL */ struct { int _band; int _fd; } _sigpoll; } _sifields; }; /* For x32, clock_t in _sigchld is 64bit aligned at 4 bytes. */ typedef long __attribute__ ((__aligned__ (4))) compat_x32_clock_t; struct __attribute__ ((__aligned__ (8))) compat_x32_siginfo_t { int si_signo; int si_errno; int si_code; union { int _pad[((128 / sizeof (int)) - 3)]; /* kill() */ struct { unsigned int _pid; unsigned int _uid; } _kill; /* POSIX.1b timers */ struct { compat_timer_t _tid; int _overrun; compat_sigval_t _sigval; } _timer; /* POSIX.1b signals */ struct { unsigned int _pid; unsigned int _uid; compat_sigval_t _sigval; } _rt; /* SIGCHLD */ struct { unsigned int _pid; unsigned int _uid; int _status; compat_x32_clock_t _utime; compat_x32_clock_t _stime; } _sigchld; /* SIGILL, SIGFPE, SIGSEGV, SIGBUS */ struct { unsigned int _addr; unsigned int _addr_lsb; } _sigfault; /* SIGPOLL */ struct { int _band; int _fd; } _sigpoll; } _sifields; }; /* To simplify usage of siginfo fields. */ #define cpt_si_pid _sifields._kill._pid #define cpt_si_uid _sifields._kill._uid #define cpt_si_timerid _sifields._timer._tid #define cpt_si_overrun _sifields._timer._overrun #define cpt_si_status _sifields._sigchld._status #define cpt_si_utime _sifields._sigchld._utime #define cpt_si_stime _sifields._sigchld._stime #define cpt_si_ptr _sifields._rt._sigval.sival_ptr #define cpt_si_addr _sifields._sigfault._addr #define cpt_si_addr_lsb _sifields._sigfault._addr_lsb #define cpt_si_lower _sifields._sigfault.si_addr_bnd._lower #define cpt_si_upper _sifields._sigfault.si_addr_bnd._upper #define cpt_si_band _sifields._sigpoll._band #define cpt_si_fd _sifields._sigpoll._fd /* glibc at least up to 2.3.2 doesn't have si_timerid, si_overrun. In their place is si_timer1,si_timer2. */ #ifndef si_timerid #define si_timerid si_timer1 #endif #ifndef si_overrun #define si_overrun si_timer2 #endif #ifndef SEGV_BNDERR #define SEGV_BNDERR 3 #endif /* The type of the siginfo object the kernel returns in PTRACE_GETSIGINFO. If gdb is built as a x32 program, we get a x32 siginfo. */ #ifdef __ILP32__ typedef compat_x32_siginfo_t ptrace_siginfo_t; #else typedef nat_siginfo_t ptrace_siginfo_t; #endif /* Convert the system provided siginfo into compatible siginfo. */ static void compat_siginfo_from_siginfo (compat_siginfo_t *to, const siginfo_t *from) { ptrace_siginfo_t from_ptrace; memcpy (&from_ptrace, from, sizeof (from_ptrace)); memset (to, 0, sizeof (*to)); to->si_signo = from_ptrace.si_signo; to->si_errno = from_ptrace.si_errno; to->si_code = from_ptrace.si_code; if (to->si_code == SI_TIMER) { to->cpt_si_timerid = from_ptrace.cpt_si_timerid; to->cpt_si_overrun = from_ptrace.cpt_si_overrun; to->cpt_si_ptr = from_ptrace.cpt_si_ptr; } else if (to->si_code == SI_USER) { to->cpt_si_pid = from_ptrace.cpt_si_pid; to->cpt_si_uid = from_ptrace.cpt_si_uid; } else if (to->si_code == SEGV_BNDERR && to->si_signo == SIGSEGV) { to->cpt_si_addr = from_ptrace.cpt_si_addr; to->cpt_si_lower = from_ptrace.cpt_si_lower; to->cpt_si_upper = from_ptrace.cpt_si_upper; } else if (to->si_code < 0) { to->cpt_si_pid = from_ptrace.cpt_si_pid; to->cpt_si_uid = from_ptrace.cpt_si_uid; to->cpt_si_ptr = from_ptrace.cpt_si_ptr; } else { switch (to->si_signo) { case SIGCHLD: to->cpt_si_pid = from_ptrace.cpt_si_pid; to->cpt_si_uid = from_ptrace.cpt_si_uid; to->cpt_si_status = from_ptrace.cpt_si_status; to->cpt_si_utime = from_ptrace.cpt_si_utime; to->cpt_si_stime = from_ptrace.cpt_si_stime; break; case SIGILL: case SIGFPE: case SIGSEGV: case SIGBUS: to->cpt_si_addr = from_ptrace.cpt_si_addr; break; case SIGPOLL: to->cpt_si_band = from_ptrace.cpt_si_band; to->cpt_si_fd = from_ptrace.cpt_si_fd; break; default: to->cpt_si_pid = from_ptrace.cpt_si_pid; to->cpt_si_uid = from_ptrace.cpt_si_uid; to->cpt_si_ptr = from_ptrace.cpt_si_ptr; break; } } } /* Convert the compatible siginfo into system siginfo. */ static void siginfo_from_compat_siginfo (siginfo_t *to, const compat_siginfo_t *from) { ptrace_siginfo_t to_ptrace; memset (&to_ptrace, 0, sizeof (to_ptrace)); to_ptrace.si_signo = from->si_signo; to_ptrace.si_errno = from->si_errno; to_ptrace.si_code = from->si_code; if (to_ptrace.si_code == SI_TIMER) { to_ptrace.cpt_si_timerid = from->cpt_si_timerid; to_ptrace.cpt_si_overrun = from->cpt_si_overrun; to_ptrace.cpt_si_ptr = from->cpt_si_ptr; } else if (to_ptrace.si_code == SI_USER) { to_ptrace.cpt_si_pid = from->cpt_si_pid; to_ptrace.cpt_si_uid = from->cpt_si_uid; } if (to_ptrace.si_code < 0) { to_ptrace.cpt_si_pid = from->cpt_si_pid; to_ptrace.cpt_si_uid = from->cpt_si_uid; to_ptrace.cpt_si_ptr = from->cpt_si_ptr; } else { switch (to_ptrace.si_signo) { case SIGCHLD: to_ptrace.cpt_si_pid = from->cpt_si_pid; to_ptrace.cpt_si_uid = from->cpt_si_uid; to_ptrace.cpt_si_status = from->cpt_si_status; to_ptrace.cpt_si_utime = from->cpt_si_utime; to_ptrace.cpt_si_stime = from->cpt_si_stime; break; case SIGILL: case SIGFPE: case SIGSEGV: case SIGBUS: to_ptrace.cpt_si_addr = from->cpt_si_addr; to_ptrace.cpt_si_addr_lsb = from->cpt_si_addr_lsb; break; case SIGPOLL: to_ptrace.cpt_si_band = from->cpt_si_band; to_ptrace.cpt_si_fd = from->cpt_si_fd; break; default: to_ptrace.cpt_si_pid = from->cpt_si_pid; to_ptrace.cpt_si_uid = from->cpt_si_uid; to_ptrace.cpt_si_ptr = from->cpt_si_ptr; break; } } memcpy (to, &to_ptrace, sizeof (to_ptrace)); } /* Convert the system provided siginfo into compatible x32 siginfo. */ static void compat_x32_siginfo_from_siginfo (compat_x32_siginfo_t *to, const siginfo_t *from) { ptrace_siginfo_t from_ptrace; memcpy (&from_ptrace, from, sizeof (from_ptrace)); memset (to, 0, sizeof (*to)); to->si_signo = from_ptrace.si_signo; to->si_errno = from_ptrace.si_errno; to->si_code = from_ptrace.si_code; if (to->si_code == SI_TIMER) { to->cpt_si_timerid = from_ptrace.cpt_si_timerid; to->cpt_si_overrun = from_ptrace.cpt_si_overrun; to->cpt_si_ptr = from_ptrace.cpt_si_ptr; } else if (to->si_code == SI_USER) { to->cpt_si_pid = from_ptrace.cpt_si_pid; to->cpt_si_uid = from_ptrace.cpt_si_uid; } else if (to->si_code < 0) { to->cpt_si_pid = from_ptrace.cpt_si_pid; to->cpt_si_uid = from_ptrace.cpt_si_uid; to->cpt_si_ptr = from_ptrace.cpt_si_ptr; } else { switch (to->si_signo) { case SIGCHLD: to->cpt_si_pid = from_ptrace.cpt_si_pid; to->cpt_si_uid = from_ptrace.cpt_si_uid; to->cpt_si_status = from_ptrace.cpt_si_status; memcpy (&to->cpt_si_utime, &from_ptrace.cpt_si_utime, sizeof (to->cpt_si_utime)); memcpy (&to->cpt_si_stime, &from_ptrace.cpt_si_stime, sizeof (to->cpt_si_stime)); break; case SIGILL: case SIGFPE: case SIGSEGV: case SIGBUS: to->cpt_si_addr = from_ptrace.cpt_si_addr; break; case SIGPOLL: to->cpt_si_band = from_ptrace.cpt_si_band; to->cpt_si_fd = from_ptrace.cpt_si_fd; break; default: to->cpt_si_pid = from_ptrace.cpt_si_pid; to->cpt_si_uid = from_ptrace.cpt_si_uid; to->cpt_si_ptr = from_ptrace.cpt_si_ptr; break; } } } /* Convert the compatible x32 siginfo into system siginfo. */ static void siginfo_from_compat_x32_siginfo (siginfo_t *to, const compat_x32_siginfo_t *from) { ptrace_siginfo_t to_ptrace; memset (&to_ptrace, 0, sizeof (to_ptrace)); to_ptrace.si_signo = from->si_signo; to_ptrace.si_errno = from->si_errno; to_ptrace.si_code = from->si_code; if (to_ptrace.si_code == SI_TIMER) { to_ptrace.cpt_si_timerid = from->cpt_si_timerid; to_ptrace.cpt_si_overrun = from->cpt_si_overrun; to_ptrace.cpt_si_ptr = from->cpt_si_ptr; } else if (to_ptrace.si_code == SI_USER) { to_ptrace.cpt_si_pid = from->cpt_si_pid; to_ptrace.cpt_si_uid = from->cpt_si_uid; } if (to_ptrace.si_code < 0) { to_ptrace.cpt_si_pid = from->cpt_si_pid; to_ptrace.cpt_si_uid = from->cpt_si_uid; to_ptrace.cpt_si_ptr = from->cpt_si_ptr; } else { switch (to_ptrace.si_signo) { case SIGCHLD: to_ptrace.cpt_si_pid = from->cpt_si_pid; to_ptrace.cpt_si_uid = from->cpt_si_uid; to_ptrace.cpt_si_status = from->cpt_si_status; memcpy (&to_ptrace.cpt_si_utime, &from->cpt_si_utime, sizeof (to_ptrace.cpt_si_utime)); memcpy (&to_ptrace.cpt_si_stime, &from->cpt_si_stime, sizeof (to_ptrace.cpt_si_stime)); break; case SIGILL: case SIGFPE: case SIGSEGV: case SIGBUS: to_ptrace.cpt_si_addr = from->cpt_si_addr; break; case SIGPOLL: to_ptrace.cpt_si_band = from->cpt_si_band; to_ptrace.cpt_si_fd = from->cpt_si_fd; break; default: to_ptrace.cpt_si_pid = from->cpt_si_pid; to_ptrace.cpt_si_uid = from->cpt_si_uid; to_ptrace.cpt_si_ptr = from->cpt_si_ptr; break; } } memcpy (to, &to_ptrace, sizeof (to_ptrace)); } /* Convert a ptrace siginfo object, into/from the siginfo in the layout of the inferiors' architecture. Returns true if any conversion was done; false otherwise. If DIRECTION is 1, then copy from INF to PTRACE. If DIRECTION is 0, then copy from NATIVE to INF. */ int amd64_linux_siginfo_fixup_common (siginfo_t *ptrace, gdb_byte *inf, int direction, enum amd64_siginfo_fixup_mode mode) { if (mode == FIXUP_32) { if (direction == 0) compat_siginfo_from_siginfo ((compat_siginfo_t *) inf, ptrace); else siginfo_from_compat_siginfo (ptrace, (compat_siginfo_t *) inf); return 1; } else if (mode == FIXUP_X32) { if (direction == 0) compat_x32_siginfo_from_siginfo ((compat_x32_siginfo_t *) inf, ptrace); else siginfo_from_compat_x32_siginfo (ptrace, (compat_x32_siginfo_t *) inf); return 1; } return 0; } /* Sanity check for the siginfo structure sizes. */ gdb_static_assert (sizeof (siginfo_t) == GDB_SI_SIZE); #ifndef __ILP32__ gdb_static_assert (sizeof (nat_siginfo_t) == GDB_SI_SIZE); #endif gdb_static_assert (sizeof (compat_x32_siginfo_t) == GDB_SI_SIZE); gdb_static_assert (sizeof (compat_siginfo_t) == GDB_SI_SIZE); gdb_static_assert (sizeof (ptrace_siginfo_t) == GDB_SI_SIZE);