kernel.git/arch/x86/include/asm/elf.h, branch linux-4.6.y

x86/cpufeature: Use enum cpuid_leafs instead of magic numbers

2016-02-01T09:46:48Z

Most of the magic numbers in x86_capability[] have been converted to 'enum cpuid_leafs', and this patch updates the remaining part. Signed-off-by: Huaitong Han Signed-off-by: Borislav Petkov Cc: Alexander Kuleshov Cc: Andrew Morton Cc: Andy Lutomirski Cc: Boris Ostrovsky Cc: Borislav Petkov Cc: Brian Gerst Cc: David Vrabel Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Hector Marco-Gisbert Cc: Jiang Liu Cc: Kees Cook Cc: Konrad Rzeszutek Wilk Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Rusty Russell Cc: Thomas Gleixner Cc: Tony Luck Cc: Viresh Kumar Cc: lguest@lists.ozlabs.org Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1453750913-4781-3-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar

x86/elf/64: Clear more registers in elf_common_init()

2015-10-09T07:41:06Z

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 Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/65a38a9edee61a1158cfd230800c61dbd963dac5.1444091584.git.luto@kernel.org Signed-off-by: Ingo Molnar

x86/vdso: Remove runtime 32-bit vDSO selection

2015-10-07T09:34:08Z

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 Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/e7e6b3526fa442502e6125fe69486aab50813c32.1444091584.git.luto@kernel.org Signed-off-by: Ingo Molnar

x86/compat: Don't build the 32-bit VDSO if not needed

2015-07-06T13:28:56Z

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 Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1434974121-32575-7-git-send-email-brgerst@gmail.com Signed-off-by: Ingo Molnar

x86/compat: Rename 'start_thread_ia32' to 'compat_start_thread'

2015-07-06T13:28:56Z

This function is shared between the 32-bit compat and x32 ABIs. Signed-off-by: Brian Gerst Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1434974121-32575-5-git-send-email-brgerst@gmail.com Signed-off-by: Ingo Molnar

x86/compat: Make mmap_is_ia32() common compat

2015-07-06T13:28:55Z

TIF_ADDR32 is set for both ia32 and x32 tasks, so change from CONFIG_IA32_EMULATION to CONFIG_COMPAT. Use config_enabled() to make the function more readable. Signed-off-by: Brian Gerst Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1434974121-32575-3-git-send-email-brgerst@gmail.com Signed-off-by: Ingo Molnar

mm: fold arch_randomize_brk into ARCH_HAS_ELF_RANDOMIZE

2015-04-14T23:49:05Z

The arch_randomize_brk() function is used on several architectures, even those that don't support ET_DYN ASLR. To avoid bulky extern/#define tricks, consolidate the support under CONFIG_ARCH_HAS_ELF_RANDOMIZE for the architectures that support it, while still handling CONFIG_COMPAT_BRK. Signed-off-by: Kees Cook Cc: Hector Marco-Gisbert Cc: Russell King Reviewed-by: Ingo Molnar Cc: Catalin Marinas Cc: Will Deacon Cc: Ralf Baechle Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: Alexander Viro Cc: Oleg Nesterov Cc: Andy Lutomirski Cc: "David A. Long" Cc: Andrey Ryabinin Cc: Arun Chandran Cc: Yann Droneaud Cc: Min-Hua Chen Cc: Paul Burton Cc: Alex Smith Cc: Markos Chandras Cc: Vineeth Vijayan Cc: Jeff Bailey Cc: Michael Holzheu Cc: Ben Hutchings Cc: Behan Webster Cc: Ismael Ripoll Cc: Jan-Simon Mller Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2015-04-13T20:31:32Z

Pull x86 mm changes from Ingo Molnar: "The main changes in this cycle were: - reduce the x86/32 PAE per task PGD allocation overhead from 4K to 0.032k (Fenghua Yu) - early_ioremap/memunmap() usage cleanups (Juergen Gross) - gbpages support cleanups (Luis R Rodriguez) - improve AMD Bulldozer (family 0x15) ASLR I$ aliasing workaround to increase randomization by 3 bits (per bootup) (Hector Marco-Gisbert) - misc fixlets" * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm: Improve AMD Bulldozer ASLR workaround x86/mm/pat: Initialize __cachemode2pte_tbl[] and __pte2cachemode_tbl[] in a bit more readable fashion init.h: Clean up the __setup()/early_param() macros x86/mm: Simplify probe_page_size_mask() x86/mm: Further simplify 1 GB kernel linear mappings handling x86/mm: Use early_param_on_off() for direct_gbpages init.h: Add early_param_on_off() x86/mm: Simplify enabling direct_gbpages x86/mm: Use IS_ENABLED() for direct_gbpages x86/mm: Unexport set_memory_ro() and set_memory_rw() x86/mm, efi: Use early_ioremap() in arch/x86/platform/efi/efi-bgrt.c x86/mm: Use early_memunmap() instead of early_iounmap() x86/mm/pat: Ensure different messages in STRICT_DEVMEM and PAT cases x86/mm: Reduce PAE-mode per task pgd allocation overhead from 4K to 32 bytes

x86/asm/entry: Clear EXTRA_REGS for all executable formats

2015-04-06T07:24:08Z

On failure, sys_execve() does not clobber EXTRA_REGS, so we can just return to userpsace without saving/restoring them. On success, ELF_PLAT_INIT() in sys_execve() clears all these registers. On other executable formats: - binfmt_flat.c has similar FLAT_PLAT_INIT, but x86 (and everyone else except sh) doesn't define it. - binfmt_elf_fdpic.c has ELF_FDPIC_PLAT_INIT, but x86 (and most others) doesn't define it. - There are no such hooks in binfmt_aout.c et al. We inherit EXTRA_REGS from the prior executable. This inconsistency was not intended. This change removes SAVE/RESTORE_EXTRA_REGS in stub_execve, removes register clearing in ELF_PLAT_INIT(), and instead simply clears them on success in stub_execve. Run-tested. Signed-off-by: Denys Vlasenko Cc: Alexei Starovoitov Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Frederic Weisbecker Cc: H. Peter Anvin Cc: Kees Cook Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Steven Rostedt Cc: Will Drewry Link: http://lkml.kernel.org/r/1428173719-7637-1-git-send-email-dvlasenk@redhat.com Signed-off-by: Ingo Molnar

x86/mm: Improve AMD Bulldozer ASLR workaround

2015-03-31T08:01:17Z

The ASLR implementation needs to special-case AMD F15h processors by clearing out bits [14:12] of the virtual address in order to avoid I$ cross invalidations and thus performance penalty for certain workloads. For details, see: dfb09f9b7ab0 ("x86, amd: Avoid cache aliasing penalties on AMD family 15h") This special case reduces the mmapped file's entropy by 3 bits. The following output is the run on an AMD Opteron 62xx class CPU processor under x86_64 Linux 4.0.0: $ for i in `seq 1 10`; do cat /proc/self/maps | grep "r-xp.*libc" ; done b7588000-b7736000 r-xp 00000000 00:01 4924 /lib/i386-linux-gnu/libc.so.6 b7570000-b771e000 r-xp 00000000 00:01 4924 /lib/i386-linux-gnu/libc.so.6 b75d0000-b777e000 r-xp 00000000 00:01 4924 /lib/i386-linux-gnu/libc.so.6 b75b0000-b775e000 r-xp 00000000 00:01 4924 /lib/i386-linux-gnu/libc.so.6 b7578000-b7726000 r-xp 00000000 00:01 4924 /lib/i386-linux-gnu/libc.so.6 ... Bits [12:14] are always 0, i.e. the address always ends in 0x8000 or 0x0000. 32-bit systems, as in the example above, are especially sensitive to this issue because 32-bit randomness for VA space is 8 bits (see mmap_rnd()). With the Bulldozer special case, this diminishes to only 32 different slots of mmap virtual addresses. This patch randomizes per boot the three affected bits rather than setting them to zero. Since all the shared pages have the same value at bits [12..14], there is no cache aliasing problems. This value gets generated during system boot and it is thus not known to a potential remote attacker. Therefore, the impact from the Bulldozer workaround gets diminished and ASLR randomness increased. More details at: http://hmarco.org/bugs/AMD-Bulldozer-linux-ASLR-weakness-reducing-mmaped-files-by-eight.html Original white paper by AMD dealing with the issue: http://developer.amd.com/wordpress/media/2012/10/SharedL1InstructionCacheonAMD15hCPU.pdf Mentored-by: Ismael Ripoll Signed-off-by: Hector Marco-Gisbert Signed-off-by: Borislav Petkov Acked-by: Kees Cook Cc: Alexander Viro Cc: Andrew Morton Cc: H. Peter Anvin Cc: Jan-Simon Cc: Thomas Gleixner Cc: linux-fsdevel@vger.kernel.org Link: http://lkml.kernel.org/r/1427456301-3764-1-git-send-email-hecmargi@upv.es Signed-off-by: Ingo Molnar