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2015-11-04Merge branch 'x86-mm-for-linus' of ↵Linus Torvalds1-0/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 mm changes from Ingo Molnar: "The main changes are: continued PAT work by Toshi Kani, plus a new boot time warning about insecure RWX kernel mappings, by Stephen Smalley. The new CONFIG_DEBUG_WX=y warning is marked default-y if CONFIG_DEBUG_RODATA=y is already eanbled, as a special exception, as these bugs are hard to notice and this check already found several live bugs" * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm: Warn on W^X mappings x86/mm: Fix no-change case in try_preserve_large_page() x86/mm: Fix __split_large_page() to handle large PAT bit x86/mm: Fix try_preserve_large_page() to handle large PAT bit x86/mm: Fix gup_huge_p?d() to handle large PAT bit x86/mm: Fix slow_virt_to_phys() to handle large PAT bit x86/mm: Fix page table dump to show PAT bit x86/asm: Add pud_pgprot() and pmd_pgprot() x86/asm: Fix pud/pmd interfaces to handle large PAT bit x86/asm: Add pud/pmd mask interfaces to handle large PAT bit x86/asm: Move PUD_PAGE macros to page_types.h x86/vdso32: Define PGTABLE_LEVELS to 32bit VDSO
2015-10-09x86/entry/32: Re-implement SYSENTER using the new C pathAndy Lutomirski1-0/+2
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/5b99659e8be70f3dd10cd8970a5c90293d9ad9a7.1444091585.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 Lutomirski1-0/+8
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/vdso/32: Save extra registers in the INT80 vsyscall pathAndy Lutomirski2-1/+25
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/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 Lutomirski1-2/+2
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>
2015-10-07x86/vdso: Remove runtime 32-bit vDSO selectionAndy Lutomirski7-255/+13
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>
2015-09-22x86/vdso32: Define PGTABLE_LEVELS to 32bit VDSOToshi Kani1-0/+2
In case of CONFIG_X86_64, vdso32/vclock_gettime.c fakes a 32-bit non-PAE kernel configuration by re-defining it to CONFIG_X86_32. However, it does not re-define CONFIG_PGTABLE_LEVELS leaving it as 4 levels. This mismatch leads <asm/pgtable_type.h> to NOT include <asm-generic/ pgtable-nopud.h> and <asm-generic/pgtable-nopmd.h>, which will cause compile errors when a later patch enhances <asm/pgtable_type.h> to use PUD_SHIFT and PMD_SHIFT. These -nopud & -nopmd headers define these SHIFTs for the 32-bit non-PAE kernel. Fix it by re-defining CONFIG_PGTABLE_LEVELS to 2 levels. Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Juergen Gross <jgross@suse.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Konrad Wilk <konrad.wilk@oracle.com> Cc: Robert Elliot <elliott@hpe.com> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/1442514264-12475-2-git-send-email-toshi.kani@hpe.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-08-08x86/vdso: Emit a GNU hashAndy Lutomirski1-1/+1
Some dynamic loaders may be slightly faster if a GNU hash is available. Strangely, this seems to have no effect at all on the vdso size. This is unlikely to have any measurable effect on the time it takes to resolve vdso symbols (since there are so few of them). In some contexts, it can be a win for a different reason: if every DSO has a GNU hash section, then libc can avoid calculating SysV hashes at all. Both musl and glibc appear to have this optimization. It's plausible that this breaks some ancient glibc version. If so, then, depending on what glibc versions break, we could either require COMPAT_VDSO for them or consider reverting. Signed-off-by: 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: Isaac Dunham <ibid.ag@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nathan Lynch <nathan_lynch@mentor.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rich Felker <dalias@libc.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: musl@lists.openwall.com <musl@lists.openwall.com> Link: http://lkml.kernel.org/r/fd56cc057a2d62ab31c56a48d04fccb435b3fd4f.1438897382.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-06x86/compat: Don't build the 32-bit VDSO if not neededBrian Gerst2-5/+8
Build the 32-bit vdso only for native 32-bit or 32-bit compat is enabled. x32 should not force it to build. Signed-off-by: Brian Gerst <brgerst@gmail.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> 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> Link: http://lkml.kernel.org/r/1434974121-32575-7-git-send-email-brgerst@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-06x86/asm/tsc: Add rdtsc_ordered() and use it in trivial call sitesAndy Lutomirski1-14/+2
rdtsc_barrier(); rdtsc() is an unnecessary mouthful and requires more thought than should be necessary. Add an rdtsc_ordered() helper and replace the trivial call sites with it. This should not change generated code. The duplication of the fence asm is temporary. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> 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: Huang Rui <ray.huang@amd.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Len Brown <lenb@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kvm ML <kvm@vger.kernel.org> Link: http://lkml.kernel.org/r/dddbf98a2af53312e9aa73a5a2b1622fe5d6f52b.1434501121.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-06x86/asm/tsc: Rename native_read_tsc() to rdtsc()Andy Lutomirski1-1/+1
Now that there is no paravirt TSC, the "native" is inappropriate. The function does RDTSC, so give it the obvious name: rdtsc(). Suggested-by: Borislav Petkov <bp@suse.de> Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> 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: Huang Rui <ray.huang@amd.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Len Brown <lenb@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kvm ML <kvm@vger.kernel.org> Link: http://lkml.kernel.org/r/fd43e16281991f096c1e4d21574d9e1402c62d39.1434501121.git.luto@kernel.org [ Ported it to v4.2-rc1. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-06x86/asm/tsc: Inline native_read_tsc() and remove __native_read_tsc()Andy Lutomirski1-1/+1
In the following commit: cdc7957d1954 ("x86: move native_read_tsc() offline") ... native_read_tsc() was moved out of line, presumably for some now-obsolete vDSO-related reason. Undo it. The entire rdtsc, shl, or sequence is only 11 bytes, and calls via rdtscl() and similar helpers were already inlined. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> 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: Huang Rui <ray.huang@amd.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Len Brown <lenb@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kvm ML <kvm@vger.kernel.org> Link: http://lkml.kernel.org/r/d05ffe2aaf8468ca475ebc00efad7b2fa174af19.1434501121.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-06-03x86/asm/entry, x86/vdso: Move the vDSO code to arch/x86/entry/vdso/Ingo Molnar22-0/+2142
Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Brian Gerst <brgerst@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>