vserver 2.0 rc7
[linux-2.6.git] / arch / i386 / kernel / entry.S
index 0e7e68b..a991d4e 100644 (file)
@@ -47,6 +47,7 @@
 #include <asm/segment.h>
 #include <asm/smp.h>
 #include <asm/page.h>
+#include <asm/desc.h>
 #include "irq_vectors.h"
 
 #define nr_syscalls ((syscall_table_size)/4)
@@ -78,7 +79,7 @@ VM_MASK               = 0x00020000
 #define preempt_stop           cli
 #else
 #define preempt_stop
-#define resume_kernel          restore_all
+#define resume_kernel          restore_nocheck
 #endif
 
 #define SAVE_ALL \
@@ -122,24 +123,6 @@ VM_MASK            = 0x00020000
 .previous
 
 
-#define RESTORE_ALL    \
-       RESTORE_REGS    \
-       addl $4, %esp;  \
-1:     iret;           \
-.section .fixup,"ax";   \
-2:     sti;            \
-       movl $(__USER_DS), %edx; \
-       movl %edx, %ds; \
-       movl %edx, %es; \
-       movl $11,%eax;  \
-       call do_exit;   \
-.previous;             \
-.section __ex_table,"a";\
-       .align 4;       \
-       .long 1b,2b;    \
-.previous
-
-
 ENTRY(ret_from_fork)
        pushl %eax
        call schedule_tail
@@ -163,7 +146,7 @@ ret_from_intr:
        movl EFLAGS(%esp), %eax         # mix EFLAGS and CS
        movb CS(%esp), %al
        testl $(VM_MASK | 3), %eax
-       jz resume_kernel                # returning to kernel or vm86-space
+       jz resume_kernel
 ENTRY(resume_userspace)
        cli                             # make sure we don't miss an interrupt
                                        # setting need_resched or sigpending
@@ -178,7 +161,7 @@ ENTRY(resume_userspace)
 ENTRY(resume_kernel)
        cli
        cmpl $0,TI_preempt_count(%ebp)  # non-zero preempt_count ?
-       jnz restore_all
+       jnz restore_nocheck
 need_resched:
        movl TI_flags(%ebp), %ecx       # need_resched set ?
        testb $_TIF_NEED_RESCHED, %cl
@@ -219,7 +202,8 @@ sysenter_past_esp:
        SAVE_ALL
        GET_THREAD_INFO(%ebp)
 
-       testb $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT),TI_flags(%ebp)
+       /* Note, _TIF_SECCOMP is bit number 8, and so it needs testw and not testb */
+       testw $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SECCOMP),TI_flags(%ebp)
        jnz syscall_trace_entry
        cmpl $(nr_syscalls), %eax
        jae syscall_badsys
@@ -243,7 +227,8 @@ ENTRY(system_call)
        SAVE_ALL
        GET_THREAD_INFO(%ebp)
                                        # system call tracing in operation
-       testb $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT),TI_flags(%ebp)
+       /* Note, _TIF_SECCOMP is bit number 8, and so it needs testw and not testb */
+       testw $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SECCOMP),TI_flags(%ebp)
        jnz syscall_trace_entry
        cmpl $(nr_syscalls), %eax
        jae syscall_badsys
@@ -257,8 +242,57 @@ syscall_exit:
        movl TI_flags(%ebp), %ecx
        testw $_TIF_ALLWORK_MASK, %cx   # current->work
        jne syscall_exit_work
+
 restore_all:
-       RESTORE_ALL
+       movl EFLAGS(%esp), %eax         # mix EFLAGS, SS and CS
+       # Warning: OLDSS(%esp) contains the wrong/random values if we
+       # are returning to the kernel.
+       # See comments in process.c:copy_thread() for details.
+       movb OLDSS(%esp), %ah
+       movb CS(%esp), %al
+       andl $(VM_MASK | (4 << 8) | 3), %eax
+       cmpl $((4 << 8) | 3), %eax
+       je ldt_ss                       # returning to user-space with LDT SS
+restore_nocheck:
+       RESTORE_REGS
+       addl $4, %esp
+1:     iret
+.section .fixup,"ax"
+iret_exc:
+       sti
+       pushl $0                        # no error code
+       pushl $do_iret_error
+       jmp error_code
+.previous
+.section __ex_table,"a"
+       .align 4
+       .long 1b,iret_exc
+.previous
+
+ldt_ss:
+       larl OLDSS(%esp), %eax
+       jnz restore_nocheck
+       testl $0x00400000, %eax         # returning to 32bit stack?
+       jnz restore_nocheck             # allright, normal return
+       /* If returning to userspace with 16bit stack,
+        * try to fix the higher word of ESP, as the CPU
+        * won't restore it.
+        * This is an "official" bug of all the x86-compatible
+        * CPUs, which we can try to work around to make
+        * dosemu and wine happy. */
+       subl $8, %esp           # reserve space for switch16 pointer
+       cli
+       movl %esp, %eax
+       /* Set up the 16bit stack frame with switch32 pointer on top,
+        * and a switch16 pointer on top of the current frame. */
+       call setup_x86_bogus_stack
+       RESTORE_REGS
+       lss 20+4(%esp), %esp    # switch to 16bit stack
+1:     iret
+.section __ex_table,"a"
+       .align 4
+       .long 1b,iret_exc
+.previous
 
        # perform work that needs to be done immediately before resumption
        ALIGN
@@ -334,6 +368,27 @@ syscall_badsys:
        movl $-ENOSYS,EAX(%esp)
        jmp resume_userspace
 
+#define FIXUP_ESPFIX_STACK \
+       movl %esp, %eax; \
+       /* switch to 32bit stack using the pointer on top of 16bit stack */ \
+       lss %ss:CPU_16BIT_STACK_SIZE-8, %esp; \
+       /* copy data from 16bit stack to 32bit stack */ \
+       call fixup_x86_bogus_stack; \
+       /* put ESP to the proper location */ \
+       movl %eax, %esp;
+#define UNWIND_ESPFIX_STACK \
+       pushl %eax; \
+       movl %ss, %eax; \
+       /* see if on 16bit stack */ \
+       cmpw $__ESPFIX_SS, %ax; \
+       jne 28f; \
+       movl $__KERNEL_DS, %edx; \
+       movl %edx, %ds; \
+       movl %edx, %es; \
+       /* switch to 32bit stack */ \
+       FIXUP_ESPFIX_STACK \
+28:    popl %eax;
+
 /*
  * Build the entry stubs and pointer table with
  * some assembler magic.
@@ -388,7 +443,9 @@ error_code:
        pushl %ecx
        pushl %ebx
        cld
-       movl %es, %ecx
+       pushl %es
+       UNWIND_ESPFIX_STACK
+       popl %ecx
        movl ES(%esp), %edi             # get the function address
        movl ORIG_EAX(%esp), %edx       # get the error code
        movl %eax, ORIG_EAX(%esp)
@@ -457,8 +514,6 @@ debug_stack_correct:
        xorl %edx,%edx                  # error code 0
        movl %esp,%eax                  # pt_regs pointer
        call do_debug
-       testl %eax,%eax
-       jnz restore_all
        jmp ret_from_exception
 
 /*
@@ -470,6 +525,11 @@ debug_stack_correct:
  * fault happened on the sysenter path.
  */
 ENTRY(nmi)
+       pushl %eax
+       movl %ss, %eax
+       cmpw $__ESPFIX_SS, %ax
+       popl %eax
+       je nmi_16bit_stack
        cmpl $sysenter_entry,(%esp)
        je nmi_stack_fixup
        pushl %eax
@@ -489,7 +549,7 @@ nmi_stack_correct:
        xorl %edx,%edx          # zero error code
        movl %esp,%eax          # pt_regs pointer
        call do_nmi
-       RESTORE_ALL
+       jmp restore_all
 
 nmi_stack_fixup:
        FIX_STACK(12,nmi_stack_correct, 1)
@@ -505,14 +565,35 @@ nmi_debug_stack_fixup:
        FIX_STACK(24,nmi_stack_correct, 1)
        jmp nmi_stack_correct
 
+nmi_16bit_stack:
+       /* create the pointer to lss back */
+       pushl %ss
+       pushl %esp
+       movzwl %sp, %esp
+       addw $4, (%esp)
+       /* copy the iret frame of 12 bytes */
+       .rept 3
+       pushl 16(%esp)
+       .endr
+       pushl %eax
+       SAVE_ALL
+       FIXUP_ESPFIX_STACK              # %eax == %esp
+       xorl %edx,%edx                  # zero error code
+       call do_nmi
+       RESTORE_REGS
+       lss 12+4(%esp), %esp            # back to 16bit stack
+1:     iret
+.section __ex_table,"a"
+       .align 4
+       .long 1b,iret_exc
+.previous
+
 ENTRY(int3)
        pushl $-1                       # mark this as an int
        SAVE_ALL
        xorl %edx,%edx          # zero error code
        movl %esp,%eax          # pt_regs pointer
        call do_int3
-       testl %eax,%eax
-       jnz restore_all
        jmp ret_from_exception
 
 ENTRY(overflow)
@@ -571,296 +652,6 @@ ENTRY(spurious_interrupt_bug)
        pushl $do_spurious_interrupt_bug
        jmp error_code
 
-.data
-ENTRY(sys_call_table)
-       .long sys_restart_syscall       /* 0 - old "setup()" system call, used for restarting */
-       .long sys_exit
-       .long sys_fork
-       .long sys_read
-       .long sys_write
-       .long sys_open          /* 5 */
-       .long sys_close
-       .long sys_waitpid
-       .long sys_creat
-       .long sys_link
-       .long sys_unlink        /* 10 */
-       .long sys_execve
-       .long sys_chdir
-       .long sys_time
-       .long sys_mknod
-       .long sys_chmod         /* 15 */
-       .long sys_lchown16
-       .long sys_ni_syscall    /* old break syscall holder */
-       .long sys_stat
-       .long sys_lseek
-       .long sys_getpid        /* 20 */
-       .long sys_mount
-       .long sys_oldumount
-       .long sys_setuid16
-       .long sys_getuid16
-       .long sys_stime         /* 25 */
-       .long sys_ptrace
-       .long sys_alarm
-       .long sys_fstat
-       .long sys_pause
-       .long sys_utime         /* 30 */
-       .long sys_ni_syscall    /* old stty syscall holder */
-       .long sys_ni_syscall    /* old gtty syscall holder */
-       .long sys_access
-       .long sys_nice
-       .long sys_ni_syscall    /* 35 - old ftime syscall holder */
-       .long sys_sync
-       .long sys_kill
-       .long sys_rename
-       .long sys_mkdir
-       .long sys_rmdir         /* 40 */
-       .long sys_dup
-       .long sys_pipe
-       .long sys_times
-       .long sys_ni_syscall    /* old prof syscall holder */
-       .long sys_brk           /* 45 */
-       .long sys_setgid16
-       .long sys_getgid16
-       .long sys_signal
-       .long sys_geteuid16
-       .long sys_getegid16     /* 50 */
-       .long sys_acct
-       .long sys_umount        /* recycled never used phys() */
-       .long sys_ni_syscall    /* old lock syscall holder */
-       .long sys_ioctl
-       .long sys_fcntl         /* 55 */
-       .long sys_ni_syscall    /* old mpx syscall holder */
-       .long sys_setpgid
-       .long sys_ni_syscall    /* old ulimit syscall holder */
-       .long sys_olduname
-       .long sys_umask         /* 60 */
-       .long sys_chroot
-       .long sys_ustat
-       .long sys_dup2
-       .long sys_getppid
-       .long sys_getpgrp       /* 65 */
-       .long sys_setsid
-       .long sys_sigaction
-       .long sys_sgetmask
-       .long sys_ssetmask
-       .long sys_setreuid16    /* 70 */
-       .long sys_setregid16
-       .long sys_sigsuspend
-       .long sys_sigpending
-       .long sys_sethostname
-       .long sys_setrlimit     /* 75 */
-       .long sys_old_getrlimit
-       .long sys_getrusage
-       .long sys_gettimeofday
-       .long sys_settimeofday
-       .long sys_getgroups16   /* 80 */
-       .long sys_setgroups16
-       .long old_select
-       .long sys_symlink
-       .long sys_lstat
-       .long sys_readlink      /* 85 */
-       .long sys_uselib
-       .long sys_swapon
-       .long sys_reboot
-       .long old_readdir
-       .long old_mmap          /* 90 */
-       .long sys_munmap
-       .long sys_truncate
-       .long sys_ftruncate
-       .long sys_fchmod
-       .long sys_fchown16      /* 95 */
-       .long sys_getpriority
-       .long sys_setpriority
-       .long sys_ni_syscall    /* old profil syscall holder */
-       .long sys_statfs
-       .long sys_fstatfs       /* 100 */
-       .long sys_ioperm
-       .long sys_socketcall
-       .long sys_syslog
-       .long sys_setitimer
-       .long sys_getitimer     /* 105 */
-       .long sys_newstat
-       .long sys_newlstat
-       .long sys_newfstat
-       .long sys_uname
-       .long sys_iopl          /* 110 */
-       .long sys_vhangup
-       .long sys_ni_syscall    /* old "idle" system call */
-       .long sys_vm86old
-       .long sys_wait4
-       .long sys_swapoff       /* 115 */
-       .long sys_sysinfo
-       .long sys_ipc
-       .long sys_fsync
-       .long sys_sigreturn
-       .long sys_clone         /* 120 */
-       .long sys_setdomainname
-       .long sys_newuname
-       .long sys_modify_ldt
-       .long sys_adjtimex
-       .long sys_mprotect      /* 125 */
-       .long sys_sigprocmask
-       .long sys_ni_syscall    /* old "create_module" */ 
-       .long sys_init_module
-       .long sys_delete_module
-       .long sys_ni_syscall    /* 130: old "get_kernel_syms" */
-       .long sys_quotactl
-       .long sys_getpgid
-       .long sys_fchdir
-       .long sys_bdflush
-       .long sys_sysfs         /* 135 */
-       .long sys_personality
-       .long sys_ni_syscall    /* reserved for afs_syscall */
-       .long sys_setfsuid16
-       .long sys_setfsgid16
-       .long sys_llseek        /* 140 */
-       .long sys_getdents
-       .long sys_select
-       .long sys_flock
-       .long sys_msync
-       .long sys_readv         /* 145 */
-       .long sys_writev
-       .long sys_getsid
-       .long sys_fdatasync
-       .long sys_sysctl
-       .long sys_mlock         /* 150 */
-       .long sys_munlock
-       .long sys_mlockall
-       .long sys_munlockall
-       .long sys_sched_setparam
-       .long sys_sched_getparam   /* 155 */
-       .long sys_sched_setscheduler
-       .long sys_sched_getscheduler
-       .long sys_sched_yield
-       .long sys_sched_get_priority_max
-       .long sys_sched_get_priority_min  /* 160 */
-       .long sys_sched_rr_get_interval
-       .long sys_nanosleep
-       .long sys_mremap
-       .long sys_setresuid16
-       .long sys_getresuid16   /* 165 */
-       .long sys_vm86
-       .long sys_ni_syscall    /* Old sys_query_module */
-       .long sys_poll
-       .long sys_nfsservctl
-       .long sys_setresgid16   /* 170 */
-       .long sys_getresgid16
-       .long sys_prctl
-       .long sys_rt_sigreturn
-       .long sys_rt_sigaction
-       .long sys_rt_sigprocmask        /* 175 */
-       .long sys_rt_sigpending
-       .long sys_rt_sigtimedwait
-       .long sys_rt_sigqueueinfo
-       .long sys_rt_sigsuspend
-       .long sys_pread64       /* 180 */
-       .long sys_pwrite64
-       .long sys_chown16
-       .long sys_getcwd
-       .long sys_capget
-       .long sys_capset        /* 185 */
-       .long sys_sigaltstack
-       .long sys_sendfile
-       .long sys_ni_syscall    /* reserved for streams1 */
-       .long sys_ni_syscall    /* reserved for streams2 */
-       .long sys_vfork         /* 190 */
-       .long sys_getrlimit
-       .long sys_mmap2
-       .long sys_truncate64
-       .long sys_ftruncate64
-       .long sys_stat64        /* 195 */
-       .long sys_lstat64
-       .long sys_fstat64
-       .long sys_lchown
-       .long sys_getuid
-       .long sys_getgid        /* 200 */
-       .long sys_geteuid
-       .long sys_getegid
-       .long sys_setreuid
-       .long sys_setregid
-       .long sys_getgroups     /* 205 */
-       .long sys_setgroups
-       .long sys_fchown
-       .long sys_setresuid
-       .long sys_getresuid
-       .long sys_setresgid     /* 210 */
-       .long sys_getresgid
-       .long sys_chown
-       .long sys_setuid
-       .long sys_setgid
-       .long sys_setfsuid      /* 215 */
-       .long sys_setfsgid
-       .long sys_pivot_root
-       .long sys_mincore
-       .long sys_madvise
-       .long sys_getdents64    /* 220 */
-       .long sys_fcntl64
-       .long sys_ni_syscall    /* reserved for TUX */
-       .long sys_ni_syscall
-       .long sys_gettid
-       .long sys_readahead     /* 225 */
-       .long sys_setxattr
-       .long sys_lsetxattr
-       .long sys_fsetxattr
-       .long sys_getxattr
-       .long sys_lgetxattr     /* 230 */
-       .long sys_fgetxattr
-       .long sys_listxattr
-       .long sys_llistxattr
-       .long sys_flistxattr
-       .long sys_removexattr   /* 235 */
-       .long sys_lremovexattr
-       .long sys_fremovexattr
-       .long sys_tkill
-       .long sys_sendfile64
-       .long sys_futex         /* 240 */
-       .long sys_sched_setaffinity
-       .long sys_sched_getaffinity
-       .long sys_set_thread_area
-       .long sys_get_thread_area
-       .long sys_io_setup      /* 245 */
-       .long sys_io_destroy
-       .long sys_io_getevents
-       .long sys_io_submit
-       .long sys_io_cancel
-       .long sys_fadvise64     /* 250 */
-       .long sys_ni_syscall
-       .long sys_exit_group
-       .long sys_lookup_dcookie
-       .long sys_epoll_create
-       .long sys_epoll_ctl     /* 255 */
-       .long sys_epoll_wait
-       .long sys_remap_file_pages
-       .long sys_set_tid_address
-       .long sys_timer_create
-       .long sys_timer_settime         /* 260 */
-       .long sys_timer_gettime
-       .long sys_timer_getoverrun
-       .long sys_timer_delete
-       .long sys_clock_settime
-       .long sys_clock_gettime         /* 265 */
-       .long sys_clock_getres
-       .long sys_clock_nanosleep
-       .long sys_statfs64
-       .long sys_fstatfs64     
-       .long sys_tgkill        /* 270 */
-       .long sys_utimes
-       .long sys_fadvise64_64
-       .long sys_vserver
-       .long sys_mbind
-       .long sys_get_mempolicy
-       .long sys_set_mempolicy
-       .long sys_mq_open
-       .long sys_mq_unlink
-       .long sys_mq_timedsend
-       .long sys_mq_timedreceive       /* 280 */
-       .long sys_mq_notify
-       .long sys_mq_getsetattr
-       .long sys_ni_syscall            /* reserved for kexec */
-       .long sys_waitid
-       .long sys_ni_syscall            /* 285 */ /* available */
-       .long sys_add_key
-       .long sys_request_key
-       .long sys_keyctl
+#include "syscall_table.S"
 
 syscall_table_size=(.-sys_call_table)