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* syscalls/x86: Unconditionally enable 'struct pt_regs' based syscalls on x86_64Dominik Brodowski2018-04-051-2/+2
| | | | | | | | | | | | | | | | | | | | | Removing CONFIG_SYSCALL_PTREGS from arch/x86/Kconfig and simply selecting ARCH_HAS_SYSCALL_WRAPPER unconditionally on x86-64 allows us to simplify several codepaths. Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20180405095307.3730-7-linux@dominikbrodowski.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
* syscalls/x86: Use 'struct pt_regs' based syscall calling convention for ↵Dominik Brodowski2018-04-051-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 64-bit syscalls Let's make use of ARCH_HAS_SYSCALL_WRAPPER=y on pure 64-bit x86-64 systems: Each syscall defines a stub which takes struct pt_regs as its only argument. It decodes just those parameters it needs, e.g: asmlinkage long sys_xyzzy(const struct pt_regs *regs) { return SyS_xyzzy(regs->di, regs->si, regs->dx); } This approach avoids leaking random user-provided register content down the call chain. For example, for sys_recv() which is a 4-parameter syscall, the assembly now is (in slightly reordered fashion): <sys_recv>: callq <__fentry__> /* decode regs->di, ->si, ->dx and ->r10 */ mov 0x70(%rdi),%rdi mov 0x68(%rdi),%rsi mov 0x60(%rdi),%rdx mov 0x38(%rdi),%rcx [ SyS_recv() is automatically inlined by the compiler, as it is not [yet] used anywhere else ] /* clear %r9 and %r8, the 5th and 6th args */ xor %r9d,%r9d xor %r8d,%r8d /* do the actual work */ callq __sys_recvfrom /* cleanup and return */ cltq retq The only valid place in an x86-64 kernel which rightfully calls a syscall function on its own -- vsyscall -- needs to be modified to pass struct pt_regs onwards as well. To keep the syscall table generation working independent of SYSCALL_PTREGS being enabled, the stubs are named the same as the "original" syscall stubs, i.e. sys_*(). This patch is based on an original proof-of-concept | From: Linus Torvalds <torvalds@linux-foundation.org> | Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> and was split up and heavily modified by me, in particular to base it on ARCH_HAS_SYSCALL_WRAPPER, to limit it to 64-bit-only for the time being, and to update the vsyscall to the new calling convention. Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20180405095307.3730-4-linux@dominikbrodowski.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/asm: Move 'status' from thread_struct to thread_infoAndy Lutomirski2018-01-301-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The TS_COMPAT bit is very hot and is accessed from code paths that mostly also touch thread_info::flags. Move it into struct thread_info to improve cache locality. The only reason it was in thread_struct is that there was a brief period during which arch-specific fields were not allowed in struct thread_info. Linus suggested further changing: ti->status &= ~(TS_COMPAT|TS_I386_REGS_POKED); to: if (unlikely(ti->status & (TS_COMPAT|TS_I386_REGS_POKED))) ti->status &= ~(TS_COMPAT|TS_I386_REGS_POKED); on the theory that frequently dirtying the cacheline even in pure 64-bit code that never needs to modify status hurts performance. That could be a reasonable followup patch, but I suspect it matters less on top of this patch. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Kernel Hardening <kernel-hardening@lists.openwall.com> Link: https://lkml.kernel.org/r/03148bcc1b217100e6e8ecf6a5468c45cf4304b6.1517164461.git.luto@kernel.org
* x86/asm: Move the thread_info::status field to thread_structAndy Lutomirski2016-09-151-15/+5Star
| | | | | | | | | | | | | | | | | | | | Because sched.h and thread_info.h are a tangled mess, I turned in_compat_syscall() into a macro. If we had current_thread_struct() or similar and we could use it from thread_info.h, then this would be a bit cleaner. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jann Horn <jann@thejh.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/ccc8a1b2f41f9c264a41f771bb4a6539a642ad72.1473801993.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/ptrace: Stop setting TS_COMPAT in ptrace codeAndy Lutomirski2016-07-271-4/+1Star
| | | | | | | | | | | | | | | | | | | | | | | Setting TS_COMPAT in ptrace is wrong: if we happen to do it during syscall entry, then we'll confuse seccomp and audit. (The former isn't a security problem: seccomp is currently entirely insecure if a malicious ptracer is attached.) As a minimal fix, this patch adds a new flag TS_I386_REGS_POKED that handles the ptrace special case. Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Pedro Alves <palves@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/5383ebed38b39fa37462139e337aff7f2314d1ca.1469599803.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/syscalls: Give sys_call_ptr_t a useful typeAndy Lutomirski2015-10-091-1/+3
| | | | | | | | | | | | | | | | | | | Syscalls are asmlinkage functions (on 32-bit kernels), take six args of type unsigned long, and return long. Note that uml could probably be slightly cleaned up on top of this patch. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/4d3ecc4a169388d47009175408b2961961744e6f.1444091585.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/entry/syscalls: Move syscall table declarations into asm/syscalls.hAndy Lutomirski2015-10-091-1/+11
| | | | | | | | | | | | | | | | | | | The header was missing some compat declarations. Also make sys_call_ptr_t have a consistent type. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/3166aaff0fb43897998fcb6ef92991533f8c5c6c.1444091585.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* audit: use uapi/linux/audit.h for AUDIT_ARCH declarationsEric Paris2014-03-201-1/+1
| | | | | | | | | | | | The syscall.h headers were including linux/audit.h but really only needed the uapi/linux/audit.h to get the requisite defines. Switch to the uapi headers. Signed-off-by: Eric Paris <eparis@redhat.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-mips@linux-mips.org Cc: linux-s390@vger.kernel.org Cc: x86@kernel.org
* syscall_get_arch: remove useless function argumentsEric Paris2014-03-201-5/+3Star
| | | | | | | | | | | | | | | | Every caller of syscall_get_arch() uses current for the task and no implementors of the function need args. So just get rid of both of those things. Admittedly, since these are inline functions we aren't wasting stack space, but it just makes the prototypes better. Signed-off-by: Eric Paris <eparis@redhat.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-mips@linux-mips.org Cc: linux390@de.ibm.com Cc: x86@kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-s390@vger.kernel.org Cc: linux-arch@vger.kernel.org
* x86: Fix sys_call_table type in asm/syscall.hAndi Kleen2013-08-061-1/+2
| | | | | | | | | | | | | | Make the sys_call_table type defined in asm/syscall.h match the definition in syscall_64.c v2: include asm/syscall.h in syscall_64.c too. I left uml alone because it doesn't have an syscall.h on its own and including the native one leads to other errors. Signed-off-by: Andi Kleen <ak@linux.intel.com> Link: http://lkml.kernel.org/r/1375740170-7446-2-git-send-email-andi@firstfloor.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: Richard Weinberger <richard@nod.at>
* x86: remove the x32 syscall bitmask from syscall_get_nr()Paul Moore2013-04-021-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit fca460f95e928bae373daa8295877b6905bc62b8 simplified the x32 implementation by creating a syscall bitmask, equal to 0x40000000, that could be applied to x32 syscalls such that the masked syscall number would be the same as a x86_64 syscall. While that patch was a nice way to simplify the code, it went a bit too far by adding the mask to syscall_get_nr(); returning the masked syscall numbers can cause confusion with callers that expect syscall numbers matching the x32 ABI, e.g. unmasked syscall numbers. This patch fixes this by simply removing the mask from syscall_get_nr() while preserving the other changes from the original commit. While there are several syscall_get_nr() callers in the kernel, most simply check that the syscall number is greater than zero, in this case this patch will have no effect. Of those remaining callers, they appear to be few, seccomp and ftrace, and from my testing of seccomp without this patch the original commit definitely breaks things; the seccomp filter does not correctly filter the syscalls due to the difference in syscall numbers in the BPF filter and the value from syscall_get_nr(). Applying this patch restores the seccomp BPF filter functionality on x32. I've tested this patch with the seccomp BPF filters as well as ftrace and everything looks reasonable to me; needless to say general usage seemed fine as well. Signed-off-by: Paul Moore <pmoore@redhat.com> Link: http://lkml.kernel.org/r/20130215172143.12549.10292.stgit@localhost Cc: <stable@vger.kernel.org> Cc: Will Drewry <wad@chromium.org> Cc: H. Peter Anvin <hpa@zytor.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
* arch/x86: add syscall_get_arch to syscall.hWill Drewry2012-04-141-0/+27
| | | | | | | | | | | | | | | | | | Add syscall_get_arch() to export the current AUDIT_ARCH_* based on system call entry path. Signed-off-by: Will Drewry <wad@chromium.org> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Reviewed-by: H. Peter Anvin <hpa@zytor.com> Acked-by: Eric Paris <eparis@redhat.com> Reviewed-by: Kees Cook <keescook@chromium.org> v18: - update comment about x32 tasks - rebase to v3.4-rc2 v17: rebase and reviewed-by v14: rebase/nochanges v13: rebase on to 88ebdda6159ffc15699f204c33feb3e431bf9bdc Signed-off-by: James Morris <james.l.morris@oracle.com>
* x32: Handle the x32 system call flagH. Peter Anvin2012-02-201-2/+3
| | | | | | | | | | | | | | | | | | | x32 shares most system calls with x86-64, but unfortunately some subsystem (the input subsystem is the chief offender) which require is_compat() when operating with a 32-bit userspace. The input system actually has text files in sysfs whose meaning is dependent on sizeof(long) in userspace! We could solve this by having two completely disjoint system call tables; requiring that each system call be duplicated. This patch takes a different approach: we add a flag to the system call number; this flag doesn't affect the system call dispatch but requests compat treatment from affected subsystems for the duration of the system call. The change of cmpq to cmpl is safe since it immediately follows the and. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* x86: Move <asm/asm-offsets.h> from trace_syscalls.c to asm/syscall.hH. Peter Anvin2012-01-071-0/+1
| | | | | | | | | | | | This reverts commit d5e553d6e0a4bdea43adae7373e3fa144b9a1aaa, which caused large numbers of build warnings on PowerPC. This moves the #include <asm/asm-offsets.h> to <asm/syscall.h>, which makes some kind of sense since NR_syscalls is syscalls related. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Link: http://lkml.kernel.org/r/20111214181545.6e13bc954cb7ddce9086e861@canb.auug.org.au
* tracing: Unify arch_syscall_addr() implementationsMike Frysinger2010-02-171-0/+2
| | | | | | | | | | | | | | | | | Most implementations of arch_syscall_addr() are the same, so create a default version in common code and move the one piece that differs (the syscall table) to asm/syscall.h. New arch ports don't have to waste time copying & pasting this simple function. The s390/sparc versions need to be different, so document why. Signed-off-by: Mike Frysinger <vapier@gentoo.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Paul Mundt <lethal@linux-sh.org> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <1264498803-17278-1-git-send-email-vapier@gentoo.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
* x86: syscall_get_nr returns intRoland McGrath2009-09-231-7/+7
| | | | | | | Make syscall_get_nr() return int, so we always sign-extend the low 32 bits of orig_ax in checks. Signed-off-by: Roland McGrath <roland@redhat.com>
* Merge branch 'x86-fixes-for-linus' of ↵Linus Torvalds2008-10-231-52/+54
| | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86: fix section mismatch warning - apic_x2apic_phys x86: fix section mismatch warning - apic_x2apic_cluster x86: fix section mismatch warning - apic_x2apic_uv_x x86: fix section mismatch warning - apic_physflat x86: fix section mismatch warning - apic_flat x86: memtest fix use of reserve_early() x86 syscall.h: fix argument order x86/tlb_uv: remove strange mc146818rtc include x86: remove redundant KERN_DEBUG on pr_debug x86: do_boot_cpu - check if we have ESR register x86: MAINTAINERS change for AMD microcode patch loader x86/proc: fix /proc/cpuinfo cpu offline bug x86: call dmi-quirks for HP Laptops after early-quirks are executed x86, kexec: fix hang on i386 when panic occurs while console_sem is held MCE: Don't run 32bit machine checks with interrupts on x86: SB600: skip IRQ0 override if it is not routed to INT2 of IOAPIC x86: make variables static
* x86: canonicalize remaining header guardsH. Peter Anvin2008-10-231-3/+3
| | | | | | | Canonicalize a few remaining header guards, with the exception for those which are still in subarchitecture directories. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* x86, um: ... and asm-x86 moveAl Viro2008-10-231-0/+211
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: H. Peter Anvin <hpa@zytor.com>