linux_dsm_epyc7002/arch/x86/include/asm/compat.h
Dmitry Safonov 7b2dd36828 x86/coredump: Always use user_regs_struct for compat_elf_gregset_t
Commit:

  90954e7b94 ("x86/coredump: Use pr_reg size, rather that TIF_IA32 flag")

changed the coredumping code to construct the elf coredump file according
to register set size - and that's good: if binary crashes with 32-bit code
selector, generate 32-bit ELF core, otherwise - 64-bit core.

That was made for restoring 32-bit applications on x86_64: we want
32-bit application after restore to generate 32-bit ELF dump on crash.

All was quite good and recently I started reworking 32-bit applications
dumping part of CRIU: now it has two parasites (32 and 64) for seizing
compat/native tasks, after rework it'll have one parasite, working in
64-bit mode, to which 32-bit prologue long-jumps during infection.

And while it has worked for my work machine, in VM with
!CONFIG_X86_X32_ABI during reworking I faced that segfault in 32-bit
binary, that has long-jumped to 64-bit mode results in dereference
of garbage:

 32-victim[19266]: segfault at f775ef65 ip 00000000f775ef65 sp 00000000f776aa50 error 14
 BUG: unable to handle kernel paging request at ffffffffffffffff
 IP: [<ffffffff81332ce0>] strlen+0x0/0x20
 [...]
 Call Trace:
  [] elf_core_dump+0x11a9/0x1480
  [] do_coredump+0xa6b/0xe60
  [] get_signal+0x1a8/0x5c0
  [] do_signal+0x23/0x660
  [] exit_to_usermode_loop+0x34/0x65
  [] prepare_exit_to_usermode+0x2f/0x40
  [] retint_user+0x8/0x10

That's because we have 64-bit registers set (with according total size)
and we're writing it to elf_thread_core_info which has smaller size
on !CONFIG_X86_X32_ABI. That lead to overwriting ELF notes part.

Tested on 32-, 64-bit ELF crashes and on 32-bit binaries that have
jumped with 64-bit code selector - all is readable with gdb.

Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Fixes: 90954e7b94 ("x86/coredump: Use pr_reg size, rather that TIF_IA32 flag")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-11-24 06:01:05 +01:00

335 lines
7.4 KiB
C

#ifndef _ASM_X86_COMPAT_H
#define _ASM_X86_COMPAT_H
/*
* Architecture specific compatibility types
*/
#include <linux/types.h>
#include <linux/sched.h>
#include <asm/processor.h>
#include <asm/user32.h>
#include <asm/unistd.h>
#define COMPAT_USER_HZ 100
#define COMPAT_UTS_MACHINE "i686\0\0"
typedef u32 compat_size_t;
typedef s32 compat_ssize_t;
typedef s32 compat_time_t;
typedef s32 compat_clock_t;
typedef s32 compat_pid_t;
typedef u16 __compat_uid_t;
typedef u16 __compat_gid_t;
typedef u32 __compat_uid32_t;
typedef u32 __compat_gid32_t;
typedef u16 compat_mode_t;
typedef u32 compat_ino_t;
typedef u16 compat_dev_t;
typedef s32 compat_off_t;
typedef s64 compat_loff_t;
typedef u16 compat_nlink_t;
typedef u16 compat_ipc_pid_t;
typedef s32 compat_daddr_t;
typedef u32 compat_caddr_t;
typedef __kernel_fsid_t compat_fsid_t;
typedef s32 compat_timer_t;
typedef s32 compat_key_t;
typedef s32 compat_int_t;
typedef s32 compat_long_t;
typedef s64 __attribute__((aligned(4))) compat_s64;
typedef u32 compat_uint_t;
typedef u32 compat_ulong_t;
typedef u32 compat_u32;
typedef u64 __attribute__((aligned(4))) compat_u64;
typedef u32 compat_uptr_t;
struct compat_timespec {
compat_time_t tv_sec;
s32 tv_nsec;
};
struct compat_timeval {
compat_time_t tv_sec;
s32 tv_usec;
};
struct compat_stat {
compat_dev_t st_dev;
u16 __pad1;
compat_ino_t st_ino;
compat_mode_t st_mode;
compat_nlink_t st_nlink;
__compat_uid_t st_uid;
__compat_gid_t st_gid;
compat_dev_t st_rdev;
u16 __pad2;
u32 st_size;
u32 st_blksize;
u32 st_blocks;
u32 st_atime;
u32 st_atime_nsec;
u32 st_mtime;
u32 st_mtime_nsec;
u32 st_ctime;
u32 st_ctime_nsec;
u32 __unused4;
u32 __unused5;
};
struct compat_flock {
short l_type;
short l_whence;
compat_off_t l_start;
compat_off_t l_len;
compat_pid_t l_pid;
};
#define F_GETLK64 12 /* using 'struct flock64' */
#define F_SETLK64 13
#define F_SETLKW64 14
/*
* IA32 uses 4 byte alignment for 64 bit quantities,
* so we need to pack this structure.
*/
struct compat_flock64 {
short l_type;
short l_whence;
compat_loff_t l_start;
compat_loff_t l_len;
compat_pid_t l_pid;
} __attribute__((packed));
struct compat_statfs {
int f_type;
int f_bsize;
int f_blocks;
int f_bfree;
int f_bavail;
int f_files;
int f_ffree;
compat_fsid_t f_fsid;
int f_namelen; /* SunOS ignores this field. */
int f_frsize;
int f_flags;
int f_spare[4];
};
#define COMPAT_RLIM_OLD_INFINITY 0x7fffffff
#define COMPAT_RLIM_INFINITY 0xffffffff
typedef u32 compat_old_sigset_t; /* at least 32 bits */
#define _COMPAT_NSIG 64
#define _COMPAT_NSIG_BPW 32
typedef u32 compat_sigset_word;
typedef union compat_sigval {
compat_int_t sival_int;
compat_uptr_t sival_ptr;
} compat_sigval_t;
typedef struct compat_siginfo {
int si_signo;
int si_errno;
int si_code;
union {
int _pad[128/sizeof(int) - 3];
/* kill() */
struct {
unsigned int _pid; /* sender's pid */
unsigned int _uid; /* sender's uid */
} _kill;
/* POSIX.1b timers */
struct {
compat_timer_t _tid; /* timer id */
int _overrun; /* overrun count */
compat_sigval_t _sigval; /* same as below */
int _sys_private; /* not to be passed to user */
int _overrun_incr; /* amount to add to overrun */
} _timer;
/* POSIX.1b signals */
struct {
unsigned int _pid; /* sender's pid */
unsigned int _uid; /* sender's uid */
compat_sigval_t _sigval;
} _rt;
/* SIGCHLD */
struct {
unsigned int _pid; /* which child */
unsigned int _uid; /* sender's uid */
int _status; /* exit code */
compat_clock_t _utime;
compat_clock_t _stime;
} _sigchld;
/* SIGCHLD (x32 version) */
struct {
unsigned int _pid; /* which child */
unsigned int _uid; /* sender's uid */
int _status; /* exit code */
compat_s64 _utime;
compat_s64 _stime;
} _sigchld_x32;
/* SIGILL, SIGFPE, SIGSEGV, SIGBUS */
struct {
unsigned int _addr; /* faulting insn/memory ref. */
short int _addr_lsb; /* Valid LSB of the reported address. */
union {
/* used when si_code=SEGV_BNDERR */
struct {
compat_uptr_t _lower;
compat_uptr_t _upper;
} _addr_bnd;
/* used when si_code=SEGV_PKUERR */
compat_u32 _pkey;
};
} _sigfault;
/* SIGPOLL */
struct {
int _band; /* POLL_IN, POLL_OUT, POLL_MSG */
int _fd;
} _sigpoll;
struct {
unsigned int _call_addr; /* calling insn */
int _syscall; /* triggering system call number */
unsigned int _arch; /* AUDIT_ARCH_* of syscall */
} _sigsys;
} _sifields;
} compat_siginfo_t;
#define COMPAT_OFF_T_MAX 0x7fffffff
#define COMPAT_LOFF_T_MAX 0x7fffffffffffffffL
struct compat_ipc64_perm {
compat_key_t key;
__compat_uid32_t uid;
__compat_gid32_t gid;
__compat_uid32_t cuid;
__compat_gid32_t cgid;
unsigned short mode;
unsigned short __pad1;
unsigned short seq;
unsigned short __pad2;
compat_ulong_t unused1;
compat_ulong_t unused2;
};
struct compat_semid64_ds {
struct compat_ipc64_perm sem_perm;
compat_time_t sem_otime;
compat_ulong_t __unused1;
compat_time_t sem_ctime;
compat_ulong_t __unused2;
compat_ulong_t sem_nsems;
compat_ulong_t __unused3;
compat_ulong_t __unused4;
};
struct compat_msqid64_ds {
struct compat_ipc64_perm msg_perm;
compat_time_t msg_stime;
compat_ulong_t __unused1;
compat_time_t msg_rtime;
compat_ulong_t __unused2;
compat_time_t msg_ctime;
compat_ulong_t __unused3;
compat_ulong_t msg_cbytes;
compat_ulong_t msg_qnum;
compat_ulong_t msg_qbytes;
compat_pid_t msg_lspid;
compat_pid_t msg_lrpid;
compat_ulong_t __unused4;
compat_ulong_t __unused5;
};
struct compat_shmid64_ds {
struct compat_ipc64_perm shm_perm;
compat_size_t shm_segsz;
compat_time_t shm_atime;
compat_ulong_t __unused1;
compat_time_t shm_dtime;
compat_ulong_t __unused2;
compat_time_t shm_ctime;
compat_ulong_t __unused3;
compat_pid_t shm_cpid;
compat_pid_t shm_lpid;
compat_ulong_t shm_nattch;
compat_ulong_t __unused4;
compat_ulong_t __unused5;
};
/*
* The type of struct elf_prstatus.pr_reg in compatible core dumps.
*/
typedef struct user_regs_struct compat_elf_gregset_t;
/* Full regset -- prstatus on x32, otherwise on ia32 */
#define PRSTATUS_SIZE(S, R) (R != sizeof(S.pr_reg) ? 144 : 296)
#define SET_PR_FPVALID(S, V, R) \
do { *(int *) (((void *) &((S)->pr_reg)) + R) = (V); } \
while (0)
#ifdef CONFIG_X86_X32_ABI
#define COMPAT_USE_64BIT_TIME \
(!!(task_pt_regs(current)->orig_ax & __X32_SYSCALL_BIT))
#endif
/*
* A pointer passed in from user mode. This should not
* be used for syscall parameters, just declare them
* as pointers because the syscall entry code will have
* appropriately converted them already.
*/
static inline void __user *compat_ptr(compat_uptr_t uptr)
{
return (void __user *)(unsigned long)uptr;
}
static inline compat_uptr_t ptr_to_compat(void __user *uptr)
{
return (u32)(unsigned long)uptr;
}
static inline void __user *arch_compat_alloc_user_space(long len)
{
compat_uptr_t sp;
if (test_thread_flag(TIF_IA32)) {
sp = task_pt_regs(current)->sp;
} else {
/* -128 for the x32 ABI redzone */
sp = task_pt_regs(current)->sp - 128;
}
return (void __user *)round_down(sp - len, 16);
}
static inline bool in_x32_syscall(void)
{
#ifdef CONFIG_X86_X32_ABI
if (task_pt_regs(current)->orig_ax & __X32_SYSCALL_BIT)
return true;
#endif
return false;
}
static inline bool in_compat_syscall(void)
{
return in_ia32_syscall() || in_x32_syscall();
}
#define in_compat_syscall in_compat_syscall /* override the generic impl */
#endif /* _ASM_X86_COMPAT_H */