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2008-05-07[S390] s390-kvm: leave sie context on work. Removes preemption requirementChristian Borntraeger
From: Martin Schwidefsky <schwidefsky@de.ibm.com> This patch fixes a bug with cpu bound guest on kvm-s390. Sometimes it was impossible to deliver a signal to a spinning guest. We used preemption as a circumvention. The preemption notifiers called vcpu_load, which checked for pending signals and triggered a host intercept. But even with preemption, a sigkill was not delivered immediately. This patch changes the low level host interrupt handler to check for the SIE instruction, if TIF_WORK is set. In that case we change the instruction pointer of the return PSW to rerun the vcpu_run loop. The kvm code sees an intercept reason 0 if that happens. This patch adds accounting for these types of intercept as well. The advantages: - works with and without preemption - signals are delivered immediately - much better host latencies without preemption Acked-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-05-07[S390] s390: Optimize user and work TIF checkMartin Schwidefsky
On return from syscall or interrupt, we have to check if we return to userspace (likely) and if there is work todo (less likely) to decide if we handle the work. We can optimize this check: we first check for the less likely work case and then check for userspace. This patch is also a preparation for an additional patch, that fixes a bug in KVM dealing with cpu bound guests. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-04-30signals: s390: renumber TIF_RESTORE_SIGMASKRoland McGrath
TIF_RESTORE_SIGMASK no longer needs to be in the _TIF_WORK_* masks. Those low bits are scarce, and are all used up now. Renumber TIF_RESTORE_SIGMASK to free one up. Signed-off-by: Roland McGrath <roland@redhat.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: "Luck, Tony" <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-17[S390] kernel: show last breaking-event-address on oopsChristian Borntraeger
Newer s390 models have a breaking-event-address-recording register. Each time an instruction causes a break in the sequential instruction execution, the address is saved in that hardware register. On a program interrupt the address is copied to the lowcore address 272-279, which makes it software accessible. This patch changes the program check handler and the stack overflow checker to copy the value into the pt_regs argument. The oops output is enhanced to show the last known breaking address. It might give additional information if the stack trace is corrupted. The feature is only available on 64 bit. The new oops output looks like: [---------snip----------] Modules linked in: vmcp sunrpc qeth_l2 dm_mod qeth ccwgroup CPU: 2 Not tainted 2.6.24zlive-host #8 Process modprobe (pid: 4788, task: 00000000bf3d8718, ksp: 00000000b2b0b8e0) Krnl PSW : 0704200180000000 000003e000020028 (vmcp_init+0x28/0xe4 [vmcp]) R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:0 CC:2 PM:0 EA:3 Krnl GPRS: 0000000004000002 000003e000020000 0000000000000000 0000000000000001 000000000015734c ffffffffffffffff 000003e0000b3b00 0000000000000000 000003e00007ca30 00000000b5bb5d40 00000000b5bb5800 000003e0000b3b00 000003e0000a2000 00000000003ecf50 00000000b2b0bd50 00000000b2b0bcb0 Krnl Code: 000003e000020018: c0c000040ff4 larl %r12,3e0000a2000 000003e00002001e: e3e0f0000024 stg %r14,0(%r15) 000003e000020024: a7f40001 brc 15,3e000020026 >000003e000020028: e310c0100004 lg %r1,16(%r12) 000003e00002002e: c020000413dc larl %r2,3e0000a27e6 000003e000020034: c0a00004aee6 larl %r10,3e0000b5e00 000003e00002003a: a7490001 lghi %r4,1 000003e00002003e: a75900f0 lghi %r5,240 Call Trace: ([<000000000014b300>] blocking_notifier_call_chain+0x2c/0x40) [<000000000015735c>] sys_init_module+0x19d8/0x1b08 [<0000000000110afc>] sysc_noemu+0x10/0x16 [<000002000011cda2>] 0x2000011cda2 Last Breaking-Event-Address: [<000003e000020024>] vmcp_init+0x24/0xe4 [vmcp] [---------snip----------] Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2008-02-05[S390] Fix couple of section mismatches.Heiko Carstens
Fix couple of section mismatches. And since we touch the code anyway change the IPL code to use C99 initializers. Cc: Michael Holzheu <holzheu@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-11-20[S390] Fix kernel preemption.Heiko Carstens
When returning from IRQ handling and TIF_NEED_RESCHED is set we must call preempt_schedule_irq() instead of schedule(). Otherwise the BKL might be unlocked in schedule() and therfore everything that relies on the BKL is broken. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-11-20[S390] Fix irq tracing and lockdep_sys_exit calls.Heiko Carstens
Current support for TRACE_IRQFLAGS and lockdep_sys_exit is broken. IRQ flag tracing is broken for program checks. Even worse is that the newly introduced calls to lockdep_sys_exit are in the critical section code which is not supposed to call any C functions. In addition the checks if locks are still held are also done when returning to kernel code which is broken as well. Fix all this by disabling interrupts and machine checks at the exit paths and then do the appropriate checks and calls. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-10-11lockdep: s390: connect the sysexit hookHeiko Carstens
Run the lockdep_sys_exit hook before returning to user space. Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-07-27[S390] Fix IRQ tracing.Heiko Carstens
If a machine check is pending and the external or I/O interrupt handler returns to userspace io_mcck_pending is going to call s390_handle_mcck. Before this happens a call to TRACE_IRQS_ON was already made since we know that we are going back to userspace and hence interrupts will be enabled. So there was an indication that interrupts are enabled while in reality they are still disabled. s390_handle_mcck will do a local_irq_save/restore pair and confuse lockdep which later complains about inconsistent irq tracing. To solve this just call trace_hardirqs_off before calling s390_handle_mcck and trace_hardirqs_on afterwards. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-07-10[S390] system call optimization.Martin Schwidefsky
After the in-kernel system call has been remove the system call path can be optimized. The problem state bit of the old psw is always set between system_call and sysc_do_svc. SAVE_ALL_SVC uses this information to avoid two instructions. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-06-19[S390] Fix yet another two section mismatches.Heiko Carstens
WARNING: arch/s390/kernel/built-in.o(.text+0xb92a): Section mismatch: reference to .init.text:start_secondary (between 'restart_addr' and 'stack_overflow') WARNING: arch/s390/appldata/built-in.o(.data+0xdc): Section mismatch: reference to .init.text: (between 'appldata_nb' and 'appldata_timer_lock') Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-04-27[S390] System call cleanup.Martin Schwidefsky
Remove system call glue for sys_clone, sys_fork, sys_vfork, sys_execve, sys_sigreturn, sys_rt_sigreturn and sys_sigaltstack. Call do_execve from kernel_execve directly, move pt_regs to the right place and branch to sysc_return to start the user space program. This removes the last in-kernel system call. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2006-09-28[S390] Whitespace cleanup.Heiko Carstens
Huge s390 assembly files whitespace cleanup. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2006-09-20[S390] Kernel stack overflow handling.Heiko Carstens
Substract the size of the initial stack frame from the correct register. Otherwise we will end up in a program check loop. Fix the offset into the save area as well. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2006-09-20[S390] add kprobes support.Michael Grundy
Signed-off-by: Michael Grundy <grundym@us.ibm.com> Signed-off-by: David Wilder <dwilder@us.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2006-07-03[PATCH] lockdep: irqtrace subsystem, s390 supportHeiko Carstens
irqtrace support for s390. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-01[PATCH] s390: put sys_call_table into .rodata section and write protect itHeiko Carstens
Put s390's syscall tables into .rodata section and write protect this section to prevent misuse of it. Suggested by Arjan van de Ven <arjan@infradead.org>. Cc: Arjan van de Ven <arjan@infradead.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-30Remove obsolete #include <linux/config.h>Jörn Engel
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-29[S390] remove export of sys_call_tableMartin Schwidefsky
Remove export of the sys_call_table symbol to prevent the misuse of it. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2006-06-29[S390] virtual cpu accounting vs. machine checks.Martin Schwidefsky
If a machine checks interrupts the external or the i/o interrupt handler before they have completed the cpu time calculations, the accounting goes wrong. After the cpu returned from the machine check handler to the interrupted interrupt handler, a negative cpu time delta can occur. If the accumulated cpu time in lowcore is small enough this value can get negative as well. The next jiffy interrupt will pick up that negative value, shift it by 12 and add the now huge positive value to the cpu time of the process. To solve this the machine check handler is modified not to change any of the timestamps in the lowcore if the machine check interrupted kernel context. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2006-02-01[PATCH] s390: Add support for new syscalls/TIF_RESTORE_SIGMASKHeiko Carstens
Add support for the new *at, pselect6 and ppoll system calls. This includes adding required support for TIF_RESTORE_SIGMASK. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06[PATCH] s390: cleanup KconfigMartin Schwidefsky
Sanitize some s390 Kconfig options. We have ARCH_S390, ARCH_S390X, ARCH_S390_31, 64BIT, S390_SUPPORT and COMPAT. Replace these 6 options by S390, 64BIT and COMPAT. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07[PATCH] s390: signal deliveryHeiko Carstens
Always create all signal frames for pending signals before returning to userspace, not just a single one. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-17[PATCH] s390: kernel stack corruptionPeter Oberparleiter
When an asynchronous interruption occurs during the execution of the 'critical section' within the generic interruption handling code (entry.S), a faulty check for a userspace PSW may result in a corrupted kernel stack pointer which subsequently triggers a stack overflow check. Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-09kbuild: m68k,parisc,ppc,ppc64,s390,xtensa use generic asm-offsets.h supportSam Ravnborg
Delete obsoleted parts form arch makefiles and rename to asm-offsets.h Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2005-09-05[PATCH] s390: compat system callsHeiko Carstens
Use TIF bit to tell if a process is running in 31 bit mode instead of checking the addressing mode bits of the PSW. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] s390: machine check handler bugsMartin Schwidefsky
The new machine check handler still has a few bugs. 1) The system entry time has to be stored in the machine check handler, 2) the machine check return psw may not be stored at the usual place because it might overwrite the return psw of the interrupted context, 3) the return address for the call to s390_handle_mcck in the i/o interrupt handler is not correct, 4) the system call cleanup has to take the different save area of the machine check handler into account, 5) the machine check handler may not call UPDATE_VTIME before CREATE_STACK_FRAME, and 6) the io leave path needs a critical section cleanup to make sure that the TIF_MCCK_PENDING bit is really checked before switching back to user space. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-27[PATCH] s390: cpu timer reset in machine check handlerHeiko Carstens
Fix wrong move direction of timer values for cpu accounting in case of a machine check that indicates a broken cpu timer. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25[PATCH] s390: improved machine check handlingHeiko Carstens
Improved machine check handling. Kernel is now able to receive machine checks while in kernel mode (system call, interrupt and program check handling). Also register validation is now performed. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!