Merge tag 'nmiforkvm' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux...

[linux-2.6-microblaze.git] / arch / s390 / kernel / entry.S

diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index 9b48196..21900e1 100644 (file)
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -52,7 +52,7 @@ _TIF_TRACE    = (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SECCOMP | \
                   _TIF_SYSCALL_TRACEPOINT)
 _CIF_WORK      = (_CIF_MCCK_PENDING | _CIF_ASCE_PRIMARY | \
                   _CIF_ASCE_SECONDARY | _CIF_FPU)
-_PIF_WORK      = (_PIF_PER_TRAP)
+_PIF_WORK      = (_PIF_PER_TRAP | _PIF_SYSCALL_RESTART)
 
 #define BASED(name) name-cleanup_critical(%r13)
 
@@ -232,12 +232,17 @@ ENTRY(sie64a)
        lctlg   %c1,%c1,__LC_USER_ASCE          # load primary asce
 .Lsie_done:
 # some program checks are suppressing. C code (e.g. do_protection_exception)
-# will rewind the PSW by the ILC, which is 4 bytes in case of SIE. Other
-# instructions between sie64a and .Lsie_done should not cause program
-# interrupts. So lets use a nop (47 00 00 00) as a landing pad.
+# will rewind the PSW by the ILC, which is often 4 bytes in case of SIE. There
+# are some corner cases (e.g. runtime instrumentation) where ILC is unpredictable.
+# Other instructions between sie64a and .Lsie_done should not cause program
+# interrupts. So lets use 3 nops as a landing pad for all possible rewinds.
 # See also .Lcleanup_sie
-.Lrewind_pad:
-       nop     0
+.Lrewind_pad6:
+       nopr    7
+.Lrewind_pad4:
+       nopr    7
+.Lrewind_pad2:
+       nopr    7
        .globl sie_exit
 sie_exit:
        lg      %r14,__SF_EMPTY+8(%r15)         # load guest register save area
@@ -250,7 +255,9 @@ sie_exit:
        stg     %r14,__SF_EMPTY+16(%r15)        # set exit reason code
        j       sie_exit
 
-       EX_TABLE(.Lrewind_pad,.Lsie_fault)
+       EX_TABLE(.Lrewind_pad6,.Lsie_fault)
+       EX_TABLE(.Lrewind_pad4,.Lsie_fault)
+       EX_TABLE(.Lrewind_pad2,.Lsie_fault)
        EX_TABLE(sie_exit,.Lsie_fault)
 EXPORT_SYMBOL(sie64a)
 EXPORT_SYMBOL(sie_exit)
@@ -313,6 +320,7 @@ ENTRY(system_call)
        lg      %r14,__LC_VDSO_PER_CPU
        lmg     %r0,%r10,__PT_R0(%r11)
        mvc     __LC_RETURN_PSW(16),__PT_PSW(%r11)
+.Lsysc_exit_timer:
        stpt    __LC_EXIT_TIMER
        mvc     __VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER
        lmg     %r11,%r15,__PT_R11(%r11)
@@ -327,6 +335,8 @@ ENTRY(system_call)
        jo      .Lsysc_mcck_pending
        TSTMSK  __TI_flags(%r12),_TIF_NEED_RESCHED
        jo      .Lsysc_reschedule
+       TSTMSK  __PT_FLAGS(%r11),_PIF_SYSCALL_RESTART
+       jo      .Lsysc_syscall_restart
 #ifdef CONFIG_UPROBES
        TSTMSK  __TI_flags(%r12),_TIF_UPROBE
        jo      .Lsysc_uprobe_notify
@@ -340,6 +350,8 @@ ENTRY(system_call)
        jo      .Lsysc_patch_pending    # handle live patching just before
                                        # signals and possible syscall restart
 #endif
+       TSTMSK  __PT_FLAGS(%r11),_PIF_SYSCALL_RESTART
+       jo      .Lsysc_syscall_restart
        TSTMSK  __TI_flags(%r12),_TIF_SIGPENDING
        jo      .Lsysc_sigpending
        TSTMSK  __TI_flags(%r12),_TIF_NOTIFY_RESUME
@@ -440,6 +452,15 @@ ENTRY(system_call)
        larl    %r14,.Lsysc_return
        jg      do_per_trap
 
+#
+# _PIF_SYSCALL_RESTART is set, repeat the current system call
+#
+.Lsysc_syscall_restart:
+       ni      __PT_FLAGS+7(%r11),255-_PIF_SYSCALL_RESTART
+       lmg     %r1,%r7,__PT_R1(%r11)   # load svc arguments
+       lg      %r2,__PT_ORIG_GPR2(%r11)
+       j       .Lsysc_do_svc
+
 #
 # call tracehook_report_syscall_entry/tracehook_report_syscall_exit before
 # and after the system call
@@ -624,6 +645,7 @@ ENTRY(io_int_handler)
        lg      %r14,__LC_VDSO_PER_CPU
        lmg     %r0,%r10,__PT_R0(%r11)
        mvc     __LC_RETURN_PSW(16),__PT_PSW(%r11)
+.Lio_exit_timer:
        stpt    __LC_EXIT_TIMER
        mvc     __VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER
        lmg     %r11,%r15,__PT_R11(%r11)
@@ -873,9 +895,7 @@ ENTRY(save_fpu_regs)
        oi      __LC_CPU_FLAGS+7,_CIF_FPU
        br      %r14
 .Lsave_fpu_regs_end:
-#if IS_ENABLED(CONFIG_KVM)
 EXPORT_SYMBOL(save_fpu_regs)
-#endif
 
 /*
  * Load floating-point controls and floating-point or vector registers.
@@ -1181,15 +1201,23 @@ cleanup_critical:
        br      %r14
 
 .Lcleanup_sysc_restore:
+       # check if stpt has been executed
        clg     %r9,BASED(.Lcleanup_sysc_restore_insn)
+       jh      0f
+       mvc     __LC_EXIT_TIMER(8),__LC_ASYNC_ENTER_TIMER
+       cghi    %r11,__LC_SAVE_AREA_ASYNC
        je      0f
+       mvc     __LC_EXIT_TIMER(8),__LC_MCCK_ENTER_TIMER
+0:     clg     %r9,BASED(.Lcleanup_sysc_restore_insn+8)
+       je      1f
        lg      %r9,24(%r11)            # get saved pointer to pt_regs
        mvc     __LC_RETURN_PSW(16),__PT_PSW(%r9)
        mvc     0(64,%r11),__PT_R8(%r9)
        lmg     %r0,%r7,__PT_R0(%r9)
-0:     lmg     %r8,%r9,__LC_RETURN_PSW
+1:     lmg     %r8,%r9,__LC_RETURN_PSW
        br      %r14
 .Lcleanup_sysc_restore_insn:
+       .quad   .Lsysc_exit_timer
        .quad   .Lsysc_done - 4
 
 .Lcleanup_io_tif:
@@ -1197,15 +1225,20 @@ cleanup_critical:
        br      %r14
 
 .Lcleanup_io_restore:
+       # check if stpt has been executed
        clg     %r9,BASED(.Lcleanup_io_restore_insn)
-       je      0f
+       jh      0f
+       mvc     __LC_EXIT_TIMER(8),__LC_MCCK_ENTER_TIMER
+0:     clg     %r9,BASED(.Lcleanup_io_restore_insn+8)
+       je      1f
        lg      %r9,24(%r11)            # get saved r11 pointer to pt_regs
        mvc     __LC_RETURN_PSW(16),__PT_PSW(%r9)
        mvc     0(64,%r11),__PT_R8(%r9)
        lmg     %r0,%r7,__PT_R0(%r9)
-0:     lmg     %r8,%r9,__LC_RETURN_PSW
+1:     lmg     %r8,%r9,__LC_RETURN_PSW
        br      %r14
 .Lcleanup_io_restore_insn:
+       .quad   .Lio_exit_timer
        .quad   .Lio_done - 4
 
 .Lcleanup_idle: