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2015-10-09x86/entry/32: Open-code return tracking from fork and kthreadsAndy Lutomirski1-3/+15
syscall_exit is going away, and return tracing is just a function call now, so open-code the two non-syscall 32-bit users. While we're at it, update the big register layout comment. 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/a6b3c472fda7cda0e368c3ccd553dea7447dfdd2.1444091585.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-09x86/entry/compat: Implement opportunistic SYSRETL for compat syscallsAndy Lutomirski2-5/+60
If CS, SS and IP are as expected and FLAGS is compatible with SYSRETL, then return from fast compat syscalls (both SYSCALL and SYSENTER) using SYSRETL. Unlike native 64-bit opportunistic SYSRET, this is not invisible to user code: RCX and R8-R15 end up in a different state than shown saved in pt_regs. To compensate, we only do this when returning to the vDSO fast syscall return path. This won't interfere with syscall restart, as we won't use SYSRETL when returning to the INT80 restart instruction. 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/aa15e49db33773eb10b73d73466b6d5466d7856a.1444091585.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-09x86/vdso/compat: Wire up SYSENTER and SYSCSALL for compat userspaceAndy Lutomirski2-36/+62
What, you didn't realize that SYSENTER and SYSCALL were actually the same thing? :) Unlike the old code, this actually passes the ptrace_syscall_32 test on AMD systems. 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/b74615af58d785aa02d917213ec64e2022a2c796.1444091585.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-09x86/entry: Add C code for fast system call entriesAndy Lutomirski1-0/+43
This handles both SYSENTER and SYSCALL. The asm glue will take care of the differences. 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/6041a58a9b8ef6d2522ab4350deb1a1945eb563f.1444091585.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-09x86/entry/64/compat: Migrate the body of the syscall entry to CAndy Lutomirski2-39/+19
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/a2f0fce68feeba798a24339b5a7ec1ec2dd9eaf7.1444091585.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-09x86/entry: Add do_syscall_32(), a C function to do 32-bit syscallsAndy Lutomirski1-0/+43
System calls are really quite simple. Add a helper to call a 32-bit system call. 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/a77ed179834c27da436fb4a7fb23c8ee77abc11c.1444091585.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-09x86/syscalls: Give sys_call_ptr_t a useful typeAndy Lutomirski5-9/+11
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>
2015-10-09x86/entry/syscalls: Move syscall table declarations into asm/syscalls.hAndy Lutomirski4-9/+14
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>
2015-10-09x86/entry/64/compat: Set up full pt_regs for all compat syscallsAndy Lutomirski3-40/+20
This is conceptually simpler. More importantly, it eliminates the PTREGSCALL and execve stubs, which were not compatible with the C ABI. This means that C code can call through the compat syscall table. The execve stubs are a bit subtle. They did two things: they cleared some registers and they forced slow-path return. Neither is necessary any more: elf_common_init clears the extra registers and start_thread calls force_iret(). 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/f95b7f7dfaacf88a8cae85bb06226cae53769287.1444091584.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-09x86/entry/64/compat: Remove most of the fast system call machineryAndy Lutomirski1-242/+4
We now have only one code path that calls through the compat syscall table. This will make it much more pleasant to change the pt_regs vs register calling convention, which we need to do to move the call into C. 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/320cda5573cefdc601b955d23fbe8f36c085432d.1444091584.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-09x86/entry/64/compat: Remove audit optimizationsAndy Lutomirski1-96/+2
These audit optimizations are messy and hard to maintain. We'll get a similar effect from opportunistic sysret when fast compat system calls are re-implemented. 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/0bcca79ac7ff835d0e5a38725298865b01347a82.1444091584.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-09x86/entry/64/compat: Disable SYSENTER and SYSCALL32 entriesAndy Lutomirski1-0/+13
We've disabled the vDSO helpers to call them, so turn off the entries entirely (temporarily) in preparation for cleaning them up. 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/8d6e84bf651519289dc532dcc230adfabbd2a3eb.1444091584.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-09x86/vdso/32: Save extra registers in the INT80 vsyscall pathAndy Lutomirski3-1/+26
The goal is to integrate the SYSENTER and SYSCALL32 entry paths with the INT80 path. SYSENTER clobbers ESP and EIP. SYSCALL32 clobbers ECX (and, invisibly, R11). SYSRETL (long mode to compat mode) clobbers ECX and, invisibly, R11. SYSEXIT (which we only need for native 32-bit) clobbers ECX and EDX. This means that we'll need to provide ESP to the kernel in a register (I chose ECX, since it's only needed for SYSENTER) and we need to provide the args that normally live in ECX and EDX in memory. The epilogue needs to restore ECX and EDX, since user code relies on regs being preserved. We don't need to do anything special about EIP, since the kernel already knows where we are. The kernel will eventually need to know where int $0x80 lands, so add a vdso_image entry for it. The only user-visible effect of this code is that ptrace-induced changes to ECX and EDX during fast syscalls will be lost. This is already the case for the SYSENTER path. 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/b860925adbee2d2627a0671fbfe23a7fd04127f8.1444091584.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-09x86/elf/64: Clear more registers in elf_common_init()Andy Lutomirski1-4/+4
Before we start calling execve in contexts that honor the full pt_regs, we need to teach it to initialize all registers. 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/65a38a9edee61a1158cfd230800c61dbd963dac5.1444091584.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-09x86/vdso: Replace hex int80 CFI annotations with GAS directivesAndy Lutomirski1-40/+8
Maintaining the current CFI annotations written in R'lyehian is difficult for most of us. Translate them to something a little closer to English. This will remove the CFI data for kernels built with extremely old versions of binutils. I think this is a fair tradeoff for the ability for mortals to edit the asm. 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/ae3ff4ff5278b4bfc1e1dab368823469866d4b71.1444091584.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-09x86/vdso: Define BUILD_VDSO while building and emit .eh_frame in asmAndy Lutomirski2-5/+12
For the vDSO, user code wants runtime unwind info. Make sure that, if we use .cfi directives, we generate it. 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/16e29ad8855e6508197000d8c41f56adb00d7580.1444091584.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-09x86/asm: Re-add parts of the manual CFI infrastructureAndy Lutomirski2-2/+178
Commit: 131484c8da97 ("x86/debug: Remove perpetually broken, unmaintainable dwarf annotations") removed all the manual DWARF annotations outside the vDSO. It also removed the macros we used for the manual annotations. Re-add these macros so that we can clean up the vDSO annotations. 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/4c70bb98a8b773c8ccfaabf6745e569ff43e7f65.1444091584.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-07x86/vdso: Remove runtime 32-bit vDSO selectionAndy Lutomirski12-279/+21
32-bit userspace will now always see the same vDSO, which is exactly what used to be the int80 vDSO. Subsequent patches will clean it up and make it support SYSENTER and SYSCALL using alternatives. 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/e7e6b3526fa442502e6125fe69486aab50813c32.1444091584.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-07x86/entry/64/compat: After SYSENTER, move STI after the NT fixupAndy Lutomirski1-8/+22
We eventually want to make it all the way into C code before enabling interrupts. We need to rework our flags handling slightly to delay enabling interrupts. 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/35d24d2a9305da3182eab7b2cdfd32902e90962c.1444091584.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-07x86/entry, locking/lockdep: Move lockdep_sys_exit() to ↵Andy Lutomirski3-3/+2
prepare_exit_to_usermode() Rather than worrying about exactly where LOCKDEP_SYS_EXIT should go in the asm code, add it to prepare_exit_from_usermode() and remove all of the asm calls that are followed by prepare_exit_to_usermode(). LOCKDEP_SYS_EXIT now appears only in the syscall fast paths. 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/1736ebe948b845e68120b86b89091f3ec27f5e8e.1444091584.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-07x86/entry/64/compat: Fix SYSENTER's NT flag before user memory accessAndy Lutomirski1-9/+9
Clearing NT is part of the prologue, whereas loading up arg6 makes more sense to think about as part of syscall processing. Reorder them. 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/19eb235828b2d2a52c53459e09f2974e15e65a35.1444091584.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-07selftests/x86: Add a test for ptrace syscall restart and arg modificationAndy Lutomirski3-1/+342
This tests assumptions about how fast syscall works wrt pt_regs and, in particular, what happens if IP is decremented by 2 during a syscall. 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: Shuah Khan <shuahkh@osg.samsung.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/1c44dbfe59000ba135bbf35ccc5d2433a0b31618.1444091584.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-07selftests/x86: Add a test for vDSO unwindingAndy Lutomirski2-1/+210
While the kernel itself doesn't use DWARF unwinding, user code expects to be able to unwind the vDSO. The vsyscall (AT_SYSINFO) entry is manually CFI-annotated, and this tests that it unwinds correctly. I tested the test by incorrectly annotating __kernel_vsyscall, and the test indeed fails if I do that. 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: Shuah Khan <shuahkh@osg.samsung.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/8bf736d1925cdd165c0f980156a4248e55af47a1.1444091584.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-07x86/uaccess: Add unlikely() to __chk_range_not_ok() failure pathsAndy Lutomirski1-3/+3
This should improve code quality a bit. It also shrinks the kernel text: Before: text data bss dec filename 21828379 5194760 1277952 28301091 vmlinux After: text data bss dec filename 21827997 5194760 1277952 28300709 vmlinux ... by 382 bytes. 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/f427b8002d932e5deab9055e0074bb4e7e80ee39.1444091584.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-07x86/uaccess: Tell the compiler that uaccess is unlikely to faultAndy Lutomirski1-4/+4
GCC doesn't realize that get_user(), put_user(), and their __ variants are unlikely to fail. Tell it. I noticed this while playing with the C entry code. Before: text data bss dec filename 21828763 5194760 1277952 28301475 vmlinux.baseline After: text data bss dec filename 21828379 5194760 1277952 28301091 vmlinux.new The generated code shrunk by 384 bytes. 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/dc37bed7024319c3004d950d57151fca6aeacf97.1444091584.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-07Merge branch 'linus' into x86/asm, to pick up fixes before applying new changesIngo Molnar711-4070/+7422
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-07Merge tag 'nfs-for-4.3-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfsLinus Torvalds6-15/+30
Pull NFS client bugfixes from Trond Myklebust: "Highlights include: Bugfixes: - Fix a use-after-free bug in the RPC/RDMA client - Fix a write performance regression - Fix up page writeback accounting - Don't try to reclaim unused state owners - Fix a NFSv4 nograce recovery hang - reset states to use open_stateid when returning delegation voluntarily - Fix a tracepoint NULL-pointer dereference" * tag 'nfs-for-4.3-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: NFS: Fix a tracepoint NULL-pointer dereference nfs4: reset states to use open_stateid when returning delegation voluntarily NFSv4: Fix a nograce recovery hang NFSv4.1: nfs4_opendata_check_deleg needs to handle NFS4_OPEN_CLAIM_DELEG_CUR_FH NFSv4: Don't try to reclaim unused state owners NFS: Fix a write performance regression NFS: Fix up page writeback accounting xprtrdma: disconnect and flush cqs before freeing buffers
2015-10-07Revert "fs: do not prefault sys_write() user buffer pages"Linus Torvalds1-18/+16
This reverts commit 998ef75ddb5709bbea0bf1506cd2717348a3c647. The commit itself does not appear to be buggy per se, but it is exposing a bug in ext4 (and Ted thinks ext3 too, but we solved that by getting rid of it). It's too late in the release cycle to really worry about this, even if Dave Hansen has a patch that may actually fix the underlying ext4 problem. We can (and should) revisit this for the next release. The problem is that moving the prefaulting later now exposes a special case with partially successful writes that isn't handled correctly. And the prefaulting likely isn't normally even that much of a performance issue - it looks like at least one reason Dave saw this in his performance tests is that he also ran them on Skylake that now supports the new SMAP code, which makes the normally very cheap user space prefaulting noticeably more expensive. Bisected-and-acked-by: Ted Ts'o <tytso@mit.edu> Analyzed-and-acked-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-10-06NFS: Fix a tracepoint NULL-pointer dereferenceAnna Schumaker1-1/+1
Running xfstest generic/013 with the tracepoint nfs:nfs4_open_file enabled produces a NULL-pointer dereference when calculating fileid and filehandle of the opened file. Fix this by checking if state is NULL before trying to use the inode pointer. Reported-by: Olga Kornievskaia <aglo@umich.edu> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-10-06Merge tag 'for-linus-4.3b-rc4-tag' of ↵Linus Torvalds5-5/+54
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen bug fixes from David Vrabel: - Fix VM save performance regression with x86 PV guests - Make kexec work in x86 PVHVM guests (if Xen has the soft-reset ABI) - Other minor fixes. * tag 'for-linus-4.3b-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: x86/xen/p2m: hint at the last populated P2M entry x86/xen: Do not clip xen_e820_map to xen_e820_map_entries when sanitizing map x86/xen: Support kexec/kdump in HVM guests by doing a soft reset xen/x86: Don't try to write syscall-related MSRs for PV guests xen: use correct type for HYPERVISOR_memory_op()
2015-10-06Merge branch 'for-linus' of ↵Linus Torvalds11-40/+77
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 fixes from Martin Schwidefsky: "Three bug fixes and an update to the default configuration" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/defconfig: set SCSI_DH=y s390/vtime: correct scaled cputime of partially idle CPUs s390/boot/decompression: disable floating point in decompressor s390/numa: use correct type for node_to_cpumask_map
2015-10-06Merge branch 'for-next' of git://git.samba.org/sfrench/cifs-2.6Linus Torvalds3-36/+2
Pull CIFS fixes from Steve French: "Two fixes for problems pointed out by automated tools. Thanks PaX/grsecurity team and Dan Carpenter (and the Smatch tool)" * 'for-next' of git://git.samba.org/sfrench/cifs-2.6: [CIFS] Update cifs version number [SMB3] Do not fall back to SMBWriteX in set_file_size error cases [SMB3] Missing null tcon check
2015-10-06x86/xen/p2m: hint at the last populated P2M entryDavid Vrabel1-1/+18
With commit 633d6f17cd91ad5bf2370265946f716e42d388c6 (x86/xen: prepare p2m list for memory hotplug) the P2M may be sized to accomdate a much larger amount of memory than the domain currently has. When saving a domain, the toolstack must scan all the P2M looking for populated pages. This results in a performance regression due to the unnecessary scanning. Instead of reporting (via shared_info) the maximum possible size of the P2M, hint at the last PFN which might be populated. This hint is increased as new leaves are added to the P2M (in the expectation that they will be used for populated entries). Signed-off-by: David Vrabel <david.vrabel@citrix.com> Cc: <stable@vger.kernel.org> # 4.0+
2015-10-04Linux 4.3-rc4v4.3-rc4Linus Torvalds1-1/+1
2015-10-04Merge branch 'strscpy' of ↵Linus Torvalds25-37/+188
git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile Pull strscpy string copy function implementation from Chris Metcalf. Chris sent this during the merge window, but I waffled back and forth on the pull request, which is why it's going in only now. The new "strscpy()" function is definitely easier to use and more secure than either strncpy() or strlcpy(), both of which are horrible nasty interfaces that have serious and irredeemable problems. strncpy() has a useless return value, and doesn't NUL-terminate an overlong result. To make matters worse, it pads a short result with zeroes, which is a performance disaster if you have big buffers. strlcpy(), by contrast, is a mis-designed "fix" for strlcpy(), lacking the insane NUL padding, but having a differently broken return value which returns the original length of the source string. Which means that it will read characters past the count from the source buffer, and you have to trust the source to be properly terminated. It also makes error handling fragile, since the test for overflow is unnecessarily subtle. strscpy() avoids both these problems, guaranteeing the NUL termination (but not excessive padding) if the destination size wasn't zero, and making the overflow condition very obvious by returning -E2BIG. It also doesn't read past the size of the source, and can thus be used for untrusted source data too. So why did I waffle about this for so long? Every time we introduce a new-and-improved interface, people start doing these interminable series of trivial conversion patches. And every time that happens, somebody does some silly mistake, and the conversion patch to the improved interface actually makes things worse. Because the patch is mindnumbing and trivial, nobody has the attention span to look at it carefully, and it's usually done over large swatches of source code which means that not every conversion gets tested. So I'm pulling the strscpy() support because it *is* a better interface. But I will refuse to pull mindless conversion patches. Use this in places where it makes sense, but don't do trivial patches to fix things that aren't actually known to be broken. * 'strscpy' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile: tile: use global strscpy() rather than private copy string: provide strscpy() Make asm/word-at-a-time.h available on all architectures
2015-10-04Merge tag 'md/4.3-fixes' of git://neil.brown.name/mdLinus Torvalds7-26/+28
Pull md fixes from Neil Brown: "Assorted fixes for md in 4.3-rc. Two tagged for -stable, and one is really a cleanup to match and improve kmemcache interface. * tag 'md/4.3-fixes' of git://neil.brown.name/md: md/bitmap: don't pass -1 to bitmap_storage_alloc. md/raid1: Avoid raid1 resync getting stuck md: drop null test before destroy functions md: clear CHANGE_PENDING in readonly array md/raid0: apply base queue limits *before* disk_stack_limits md/raid5: don't index beyond end of array in need_this_block(). raid5: update analysis state for failed stripe md: wait for pending superblock updates before switching to read-only
2015-10-04Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linusLinus Torvalds13-144/+82
Pull MIPS updates from Ralf Baechle: "This week's round of MIPS fixes: - Fix JZ4740 build - Fix fallback to GFP_DMA - FP seccomp in case of ENOSYS - Fix bootmem panic - A number of FP and CPS fixes - Wire up new syscalls - Make sure BPF assembler objects can properly be disassembled - Fix BPF assembler code for MIPS I" * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: MIPS: scall: Always run the seccomp syscall filters MIPS: Octeon: Fix kernel panic on startup from memory corruption MIPS: Fix R2300 FP context switch handling MIPS: Fix octeon FP context switch handling MIPS: BPF: Fix load delay slots. MIPS: BPF: Do all exports of symbols with FEXPORT(). MIPS: Fix the build on jz4740 after removing the custom gpio.h MIPS: CPS: #ifdef on CONFIG_MIPS_MT_SMP rather than CONFIG_MIPS_MT MIPS: CPS: Don't include MT code in non-MT kernels. MIPS: CPS: Stop dangling delay slot from has_mt. MIPS: dma-default: Fix 32-bit fall back to GFP_DMA MIPS: Wire up userfaultfd and membarrier syscalls.
2015-10-04Merge branch 'irq-urgent-for-linus' of ↵Linus Torvalds3-3/+21
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq fixes from Thomas Gleixner: "This update contains: - Fix for a long standing race affecting /proc/irq/NNN - One line fix for ARM GICV3-ITS counting the wrong data - Warning silencing in ARM GICV3-ITS. Another GCC trying to be overly clever issue" * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: irqchip/gic-v3-its: Count additional LPIs for the aliased devices irqchip/gic-v3-its: Silence warning when its_lpi_alloc_chunks gets inlined genirq: Fix race in register_irq_proc()
2015-10-04MIPS: scall: Always run the seccomp syscall filtersMarkos Chandras4-73/+42
The MIPS syscall handler code used to return -ENOSYS on invalid syscalls. Whilst this is expected, it caused problems for seccomp filters because the said filters never had the change to run since the code returned -ENOSYS before triggering them. This caused problems on the chromium testsuite for filters looking for invalid syscalls. This has now changed and the seccomp filters are always run even if the syscall is invalid. We return -ENOSYS once we return from the seccomp filters. Moreover, similar codepaths have been merged in the process which simplifies somewhat the overall syscall code. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/11236/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-10-03[CIFS] Update cifs version numberSteve French1-1/+1
Update modinfo cifs.ko version number to 2.08 Signed-off-by: Steve French <steve.french@primarydata.com>
2015-10-03Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds9-65/+69
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: "Fixes all around the map: W+X kernel mapping fix, WCHAN fixes, two build failure fixes for corner case configs, x32 header fix and a speling fix" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/headers/uapi: Fix __BITS_PER_LONG value for x32 builds x86/mm: Set NX on gap between __ex_table and rodata x86/kexec: Fix kexec crash in syscall kexec_file_load() x86/process: Unify 32bit and 64bit implementations of get_wchan() x86/process: Add proper bound checks in 64bit get_wchan() x86, efi, kasan: Fix build failure on !KASAN && KMEMCHECK=y kernels x86/hyperv: Fix the build in the !CONFIG_KEXEC_CORE case x86/cpufeatures: Correct spelling of the HWP_NOTIFY flag
2015-10-03Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds3-3/+3
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fixes from Ingo Molnar: "An abs64() fix in the watchdog driver, and two clocksource driver NO_IRQ assumption fixes" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: clocksource: Fix abs() usage w/ 64bit values clocksource/drivers/keystone: Fix bad NO_IRQ usage clocksource/drivers/rockchip: Fix bad NO_IRQ usage
2015-10-03Merge branch 'core-urgent-for-linus' of ↵Linus Torvalds3-17/+141
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull EFI fixes from Ingo Molnar: "Two EFI fixes: one for x86, one for ARM, fixing a boot crash bug that can trigger under newer EFI firmware" * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: arm64/efi: Fix boot crash by not padding between EFI_MEMORY_RUNTIME regions x86/efi: Fix boot crash by mapping EFI memmap entries bottom-up at runtime, instead of top-down
2015-10-03Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linuxLinus Torvalds34-300/+227
Pull drm fixes from Dave Airlie: "Bunch of fixes all over the place, all pretty small: amdgpu, i915, exynos, one qxl and one vmwgfx. There is also a bunch of mst fixes, I left some cleanups in the series as I didn't think it was worth splitting up the tested series" * 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: (37 commits) drm/dp/mst: add some defines for logical/physical ports drm/dp/mst: drop cancel work sync in the mstb destroy path (v2) drm/dp/mst: split connector registration into two parts (v2) drm/dp/mst: update the link_address_sent before sending the link address (v3) drm/dp/mst: fixup handling hotplug on port removal. drm/dp/mst: don't pass port into the path builder function drm/radeon: drop radeon_fb_helper_set_par drm: handle cursor_set2 in restore_fbdev_mode drm/exynos: Staticize local function in exynos_drm_gem.c drm/exynos: fimd: actually disable dp clock drm/exynos: dp: remove suspend/resume functions drm/qxl: recreate the primary surface when the bo is not primary drm/amdgpu: only print meaningful VM faults drm/amdgpu/cgs: remove import_gpu_mem drm/i915: Call non-locking version of drm_kms_helper_poll_enable(), v2 drm: Add a non-locking version of drm_kms_helper_poll_enable(), v2 drm/vmwgfx: Fix a command submission hang regression drm/exynos: remove unused mode_fixup() code drm/exynos: remove decon_mode_fixup() drm/exynos: remove fimd_mode_fixup() ...
2015-10-02Merge branch 'for-linus' of ↵Linus Torvalds15-49/+74
git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input Pull input layer fixes from Dmitry Torokhov: "Fixes for two recent regressions (in Synaptics PS/2 and uinput drivers) and some more driver fixups" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: Revert "Input: synaptics - fix handling of disabling gesture mode" Input: psmouse - fix data race in __ps2_command Input: elan_i2c - add all valid ic type for i2c/smbus Input: zhenhua - ensure we have BITREVERSE Input: omap4-keypad - fix memory leak Input: serio - fix blocking of parport Input: uinput - fix crash when using ABS events Input: elan_i2c - expand maximum product_id form 0xFF to 0xFFFF Input: elan_i2c - add ic type 0x03 Input: elan_i2c - don't require known iap version Input: imx6ul_tsc - fix controller name Input: imx6ul_tsc - use the preferred method for kzalloc() Input: imx6ul_tsc - check for negative return value Input: imx6ul_tsc - propagate the errors Input: walkera0701 - fix abs() calculations on 64 bit values Input: mms114 - remove unneded semicolons Input: pm8941-pwrkey - remove unneded semicolon Input: fix typo in MT documentation Input: cyapa - fix address of Gen3 devices in device tree documentation
2015-10-02clocksource: Fix abs() usage w/ 64bit valuesJohn Stultz1-1/+1
This patch fixes one cases where abs() was being used with 64-bit nanosecond values, where the result may be capped at 32-bits. This potentially could cause watchdog false negatives on 32-bit systems, so this patch addresses the issue by using abs64(). Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1442279124-7309-2-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-10-02Merge tag 'nfs-rdma-for-4.3-2' of git://git.linux-nfs.org/projects/anna/nfs-rdmaTrond Myklebust2-4/+7
NFS: NFSoRDMA bugfix Fixes a use-after-free bug. Signed-off-by: Anna Schumaker <Anna.Schumaker@netapp.com>
2015-10-02nfs4: reset states to use open_stateid when returning delegation voluntarilyJeff Layton1-0/+3
When the client goes to return a delegation, it should always update any nfs4_state currently set up to use that delegation stateid to instead use the open stateid. It already does do this in some cases, particularly in the state recovery code, but not currently when the delegation is voluntarily returned (e.g. in advance of a RENAME). This causes the client to try to continue using the delegation stateid after the DELEGRETURN, e.g. in LAYOUTGET. Set the nfs4_state back to using the open stateid in nfs4_open_delegation_recall, just before clearing the NFS_DELEGATED_STATE bit. Signed-off-by: Jeff Layton <jeff.layton@primarydata.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-10-02NFSv4: Fix a nograce recovery hangBenjamin Coddington1-0/+2
Since commit 5cae02f42793130e1387f4ec09c4d07056ce9fa5 an OPEN_CONFIRM should have a privileged sequence in the recovery case to allow nograce recovery to proceed for NFSv4.0. Signed-off-by: Benjamin Coddington <bcodding@redhat.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-10-02NFSv4.1: nfs4_opendata_check_deleg needs to handle NFS4_OPEN_CLAIM_DELEG_CUR_FHTrond Myklebust1-2/+8
We need to warn against broken NFSv4.1 servers that try to hand out delegations in response to NFS4_OPEN_CLAIM_DELEG_CUR_FH. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>