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* Audit: push audit success and retcode into arch ptrace.hEric Paris2012-01-171-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The audit system previously expected arches calling to audit_syscall_exit to supply as arguments if the syscall was a success and what the return code was. Audit also provides a helper AUDITSC_RESULT which was supposed to simplify things by converting from negative retcodes to an audit internal magic value stating success or failure. This helper was wrong and could indicate that a valid pointer returned to userspace was a failed syscall. The fix is to fix the layering foolishness. We now pass audit_syscall_exit a struct pt_reg and it in turns calls back into arch code to collect the return value and to determine if the syscall was a success or failure. We also define a generic is_syscall_success() macro which determines success/failure based on if the value is < -MAX_ERRNO. This works for arches like x86 which do not use a separate mechanism to indicate syscall failure. We make both the is_syscall_success() and regs_return_value() static inlines instead of macros. The reason is because the audit function must take a void* for the regs. (uml calls theirs struct uml_pt_regs instead of just struct pt_regs so audit_syscall_exit can't take a struct pt_regs). Since the audit function takes a void* we need to use static inlines to cast it back to the arch correct structure to dereference it. The other major change is that on some arches, like ia64, MIPS and ppc, we change regs_return_value() to give us the negative value on syscall failure. THE only other user of this macro, kretprobe_example.c, won't notice and it makes the value signed consistently for the audit functions across all archs. In arch/sh/kernel/ptrace_64.c I see that we were using regs[9] in the old audit code as the return value. But the ptrace_64.h code defined the macro regs_return_value() as regs[3]. I have no idea which one is correct, but this patch now uses the regs_return_value() function, so it now uses regs[3]. For powerpc we previously used regs->result but now use the regs_return_value() function which uses regs->gprs[3]. regs->gprs[3] is always positive so the regs_return_value(), much like ia64 makes it negative before calling the audit code when appropriate. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: H. Peter Anvin <hpa@zytor.com> [for x86 portion] Acked-by: Tony Luck <tony.luck@intel.com> [for ia64] Acked-by: Richard Weinberger <richard@nod.at> [for uml] Acked-by: David S. Miller <davem@davemloft.net> [for sparc] Acked-by: Ralf Baechle <ralf@linux-mips.org> [for mips] Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [for ppc]
* [S390] cleanup trap handlingMartin Schwidefsky2011-12-271-1/+2
| | | | | | | | | | | | Move the program interruption code and the translation exception identifier to the pt_regs structure as 'int_code' and 'int_parm_long' and make the first level interrupt handler in entry[64].S store the two values. That makes it possible to drop 'prot_addr' and 'trap_no' from the thread_struct and to reduce the number of arguments to a lot of functions. Finally un-inline do_trap. Overall this saves 5812 bytes in the .text section of the 64 bit kernel. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] allow all addressing modesMartin Schwidefsky2011-10-301-1/+1
| | | | | | | | | | | | | | | | | The user space program can change its addressing mode between the 24-bit, 31-bit and the 64-bit mode if the kernel is 64 bit. Currently the kernel always forces the standard amode on signal delivery and signal return and on ptrace: 64-bit for a 64-bit process, 31-bit for a compat process and 31-bit kernels. Change the signal and ptrace code to allow the full range of addressing modes. Signal handlers are run in the standard addressing mode for the process. One caveat is that even an 31-bit compat process can switch to the 64-bit mode. The next signal will switch back into the 31-bit mode and there is no room in the 31-bit compat signal frame to store the information that the program came from the 64-bit mode. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] cleanup psw related bits and piecesMartin Schwidefsky2011-10-301-14/+6
| | | | | | | | | | Split out addressing mode bits from PSW_BASE_BITS, rename PSW_BASE_BITS to PSW_MASK_BASE, get rid of psw_user32_bits, remove unused function enabled_wait(), introduce PSW_MASK_USER, and drop PSW_MASK_MERGE macros. Change psw_kernel_bits / psw_user_bits to contain only the bits that are always set in the respective mode. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] addressing mode limits and psw address wrappingMartin Schwidefsky2011-10-301-0/+4
| | | | | | | | | An instruction with an address right below the adress limit for the current addressing mode will wrap. The instruction restart logic in the protection fault handler and the signal code need to follow the wrapping rules to find the correct instruction address. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] signal race with restarting system callsMartin Schwidefsky2011-10-301-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For a ERESTARTNOHAND/ERESTARTSYS/ERESTARTNOINTR restarting system call do_signal will prepare the restart of the system call with a rewind of the PSW before calling get_signal_to_deliver (where the debugger might take control). For A ERESTART_RESTARTBLOCK restarting system call do_signal will set -EINTR as return code. There are two issues with this approach: 1) strace never sees ERESTARTNOHAND, ERESTARTSYS, ERESTARTNOINTR or ERESTART_RESTARTBLOCK as the rewinding already took place or the return code has been changed to -EINTR 2) if get_signal_to_deliver does not return with a signal to deliver the restart via the repeat of the svc instruction is left in place. This opens a race if another signal is made pending before the system call instruction can be reexecuted. The original system call will be restarted even if the second signal would have ended the system call with -EINTR. These two issues can be solved by dropping the early rewind of the system call before get_signal_to_deliver has been called and by using the TIF_RESTART_SVC magic to do the restart if no signal has to be delivered. The only situation where the system call restart via the repeat of the svc instruction is appropriate is when a SA_RESTART signal is delivered to user space. Unfortunately this breaks inferior calls by the debugger again. The system call number and the length of the system call instruction is lost over the inferior call and user space will see ERESTARTNOHAND/ ERESTARTSYS/ERESTARTNOINTR/ERESTART_RESTARTBLOCK. To correct this a new ptrace interface is added to save/restore the system call number and system call instruction length. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* ptrace: unify show_regs() prototypeMike Frysinger2011-07-261-1/+0
| | | | | | | | | [ poleg@redhat.com: no need to declare show_regs() in ptrace.h, sched.h does this ] Signed-off-by: Mike Frysinger <vapier@gentoo.org> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [S390] ptrace cleanupMartin Schwidefsky2011-01-051-1/+51
| | | | | | | Overhaul program event recording and the code dealing with the ptrace user space interface. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] remove ieee_instruction_pointer from thread_structMartin Schwidefsky2010-10-251-2/+1
| | | | | | | | | The ieee_instruction_pointer can not be read from user space anymore since git commit 613e1def6b52c399a8b72a5e11bc2e57d2546fb8, the ptrace interface always returns zero. Remove it from the thread_struct. It is still present in the user_regs_struct for compatability reasons. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] add breaking event address for user spaceMartin Schwidefsky2010-05-171-1/+2
| | | | | | | | | | | Copy the last breaking event address from the lowcore to a new field in the thread_struct on each system entry. Add a new ptrace request PTRACE_GET_LAST_BREAK and a new utrace regset REGSET_LAST_BREAK to query the last breaking event. This is useful for debugging wild branches in user space code. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* ptrace: move user_enable_single_step & co prototypes to linux/ptrace.hChristoph Hellwig2010-03-121-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While in theory user_enable_single_step/user_disable_single_step/ user_enable_blockstep could also be provided as an inline or macro there's no good reason to do so, and having the prototype in one places keeps code size and confusion down. Roland said: The original thought there was that user_enable_single_step() et al might well be only an instruction or three on a sane machine (as if we have any of those!), and since there is only one call site inlining would be beneficial. But I agree that there is no strong reason to care about inlining it. As to the arch changes, there is only one thought I'd add to the record. It was always my thinking that for an arch where PTRACE_SINGLESTEP does text-modifying breakpoint insertion, user_enable_single_step() should not be provided. That is, arch_has_single_step()=>true means that there is an arch facility with "pure" semantics that does not have any unexpected side effects. Inserting a breakpoint might do very unexpected strange things in multi-threaded situations. Aside from that, it is a peculiar side effect that user_{enable,disable}_single_step() should cause COW de-sharing of text pages and so forth. For PTRACE_SINGLESTEP, all these peculiarities are the status quo ante for that arch, so having arch_ptrace() itself do those is one thing. But for building other things in the future, it is nicer to have a uniform "pure" semantics that arch-independent code can expect. OTOH, all such arch issues are really up to the arch maintainer. As of today, there is nothing but ptrace using user_enable_single_step() et al so it's a distinction without a practical difference. If/when there are other facilities that use user_enable_single_step() and might care, the affected arch's can revisit the question when someone cares about the quality of the arch support for said new facility. Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@redhat.com> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* s390: Add pt_regs register and stack access APIHeiko Carstens2010-02-171-1/+12
| | | | | | | | | | This API is needed for the kprobe-based event tracer. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> LKML-Reference: <20100212123840.GB27548@osiris.boeblingen.de.ibm.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
* [S390] 64-bit register support for 31-bit processesHeiko Carstens2009-10-061-0/+4
| | | | | | | | From: Heiko Carstens <heiko.carstens@de.ibm.com> From: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] s390: move machine flags to lowcoreChristian Ehrhardt2009-04-141-2/+0
| | | | | | | | | | | Currently the storage of the machine flags is a globally exported unsigned long long variable. By moving the storage location into the lowcore struct we allow assembler code to check machine_flags directly even without needing a register. Addtionally the lowcore and therefore the machine flags too will be in cache most of the time. Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] Expose a constant for the number of words representing the CRsDan Smith2009-03-261-1/+3
| | | | | | | | | We need to use this value in the checkpoint/restart code and would like to have a constant instead of a magic '3'. Cc: linux-s390@vger.kernel.org Signed-off-by: Dan Smith <danms@us.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] ptrace: no extern declarations for userspaceHeiko Carstens2009-01-091-2/+5
| | | | | | | | | /include/asm/ptrace.h:275: extern's make no sense in userspace /include/asm/ptrace.h:279: extern's make no sense in userspace /include/asm/ptrace.h:280: extern's make no sense in userspace Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* Merge branch 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6Linus Torvalds2008-11-301-1/+1
|\ | | | | | | | | | | | | | | | | * 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6: [S390] Update default configuration. [S390] Fix alignment of initial kernel stack. [S390] pgtable.h: Fix oops in unmap_vmas for KVM processes [S390] fix/cleanup sched_clock [S390] fix system call parameter functions.
| * [S390] fix system call parameter functions.Martin Schwidefsky2008-11-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | syscall_get_nr() currently returns a valid result only if the call chain of the traced process includes do_syscall_trace_enter(). But collect_syscall() can be called for any sleeping task, the result of syscall_get_nr() in general is completely bogus. To make syscall_get_nr() work for any sleeping task the traps field in pt_regs is replace with svcnr - the system call number the process is executing. If svcnr == 0 the process is not on a system call path. The syscall_get_arguments and syscall_set_arguments use regs->gprs[2] for the first system call parameter. This is incorrect since gprs[2] may have been overwritten with the system call number if the call chain includes do_syscall_trace_enter. Use regs->orig_gprs2 instead. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* | remove __ARCH_WANT_COMPAT_SYS_PTRACEChristoph Hellwig2008-11-301-2/+0
|/ | | | | | | | | | | | | All architectures now use the generic compat_sys_ptrace, as should every new architecture that needs 32bit compat (if we'll ever get another). Remove the now superflous __ARCH_WANT_COMPAT_SYS_PTRACE define, and also kill a comment about __ARCH_SYS_PTRACE that was added after __ARCH_SYS_PTRACE was already gone. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [S390] ptrace changesMartin Schwidefsky2008-10-101-0/+1
| | | | | | | | | * System call parameter and result access functions * Add tracehook calls * Split syscall_trace into two functions do_syscall_trace_enter and do_syscall_trace_exit Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] move include/asm-s390 to arch/s390/include/asmMartin Schwidefsky2008-08-011-0/+499
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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