linux/arch/x86/include/asm/ia32.h
H. Peter Anvin 31796ac4e8 x32: Fix alignment fail in struct compat_siginfo
Adding struct _sigchld_x32 caused a misalignment cascade in struct
siginfo, because union _sifields is located on an 4-byte boundary
(8-byte misaligned.)

Adding new fields that are 8-byte aligned caused the intermediate
structures to also be aligned to 8 bytes, thereby adding padding in
unexpected places.

Thus, change s64 to compat_s64 here, which makes it "misaligned on
paper".  In reality these fields *are* actually aligned (there are 3
preceeding ints outside the union and 3 inside struct _sigchld_x32),
but because of the intervening union and struct it is not possible for
gcc to avoid padding without breaking the ABI.

Reported-and-tested-by: H. J. Lu <hjl.tools@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1329696488-16970-1-git-send-email-hpa@zytor.com
2012-03-14 14:27:52 -07:00

164 lines
3.6 KiB
C

#ifndef _ASM_X86_IA32_H
#define _ASM_X86_IA32_H
#ifdef CONFIG_IA32_EMULATION
#include <linux/compat.h>
/*
* 32 bit structures for IA32 support.
*/
#include <asm/sigcontext32.h>
/* signal.h */
struct sigaction32 {
unsigned int sa_handler; /* Really a pointer, but need to deal
with 32 bits */
unsigned int sa_flags;
unsigned int sa_restorer; /* Another 32 bit pointer */
compat_sigset_t sa_mask; /* A 32 bit mask */
};
struct old_sigaction32 {
unsigned int sa_handler; /* Really a pointer, but need to deal
with 32 bits */
compat_old_sigset_t sa_mask; /* A 32 bit mask */
unsigned int sa_flags;
unsigned int sa_restorer; /* Another 32 bit pointer */
};
typedef struct sigaltstack_ia32 {
unsigned int ss_sp;
int ss_flags;
unsigned int ss_size;
} stack_ia32_t;
struct ucontext_ia32 {
unsigned int uc_flags;
unsigned int uc_link;
stack_ia32_t uc_stack;
struct sigcontext_ia32 uc_mcontext;
compat_sigset_t uc_sigmask; /* mask last for extensibility */
};
struct ucontext_x32 {
unsigned int uc_flags;
unsigned int uc_link;
stack_ia32_t uc_stack;
unsigned int uc__pad0; /* needed for alignment */
struct sigcontext uc_mcontext; /* the 64-bit sigcontext type */
compat_sigset_t uc_sigmask; /* mask last for extensibility */
};
/* This matches struct stat64 in glibc2.2, hence the absolutely
* insane amounts of padding around dev_t's.
*/
struct stat64 {
unsigned long long st_dev;
unsigned char __pad0[4];
#define STAT64_HAS_BROKEN_ST_INO 1
unsigned int __st_ino;
unsigned int st_mode;
unsigned int st_nlink;
unsigned int st_uid;
unsigned int st_gid;
unsigned long long st_rdev;
unsigned char __pad3[4];
long long st_size;
unsigned int st_blksize;
long long st_blocks;/* Number 512-byte blocks allocated */
unsigned st_atime;
unsigned st_atime_nsec;
unsigned st_mtime;
unsigned st_mtime_nsec;
unsigned st_ctime;
unsigned st_ctime_nsec;
unsigned long long st_ino;
} __attribute__((packed));
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. */
} _sigfault;
/* SIGPOLL */
struct {
int _band; /* POLL_IN, POLL_OUT, POLL_MSG */
int _fd;
} _sigpoll;
} _sifields;
} compat_siginfo_t;
#define IA32_STACK_TOP IA32_PAGE_OFFSET
#ifdef __KERNEL__
struct linux_binprm;
extern int ia32_setup_arg_pages(struct linux_binprm *bprm,
unsigned long stack_top, int exec_stack);
struct mm_struct;
extern void ia32_pick_mmap_layout(struct mm_struct *mm);
#endif
#endif /* !CONFIG_IA32_SUPPORT */
#endif /* _ASM_X86_IA32_H */