linux-stable.git/arch/x86/boot, branch linux-4.5.y

UBSAN: run-time undefined behavior sanity checker

2016-01-21T01:09:18+00:00

UBSAN uses compile-time instrumentation to catch undefined behavior
(UB).  Compiler inserts code that perform certain kinds of checks before
operations that could cause UB.  If check fails (i.e.  UB detected)
__ubsan_handle_* function called to print error message.

So the most of the work is done by compiler.  This patch just implements
ubsan handlers printing errors.

GCC has this capability since 4.9.x [1] (see -fsanitize=undefined
option and its suboptions).
However GCC 5.x has more checkers implemented [2].
Article [3] has a bit more details about UBSAN in the GCC.

[1] - https://gcc.gnu.org/onlinedocs/gcc-4.9.0/gcc/Debugging-Options.html
[2] - https://gcc.gnu.org/onlinedocs/gcc/Debugging-Options.html
[3] - http://developerblog.redhat.com/2014/10/16/gcc-undefined-behavior-sanitizer-ubsan/

Issues which UBSAN has found thus far are:

Found bugs:

 * out-of-bounds access - 97840cb67ff5 ("netfilter: nfnetlink: fix
   insufficient validation in nfnetlink_bind")

undefined shifts:

 * d48458d4a768 ("jbd2: use a better hash function for the revoke
   table")

 * 10632008b9e1 ("clockevents: Prevent shift out of bounds")

 * 'x << -1' shift in ext4 -
   http://lkml.kernel.org/r/<5444EF21.8020501@samsung.com>

 * undefined rol32(0) -
   http://lkml.kernel.org/r/<1449198241-20654-1-git-send-email-sasha.levin@oracle.com>

 * undefined dirty_ratelimit calculation -
   http://lkml.kernel.org/r/<566594E2.3050306@odin.com>

 * undefined roundown_pow_of_two(0) -
   http://lkml.kernel.org/r/<1449156616-11474-1-git-send-email-sasha.levin@oracle.com>

 * [WONTFIX] undefined shift in __bpf_prog_run -
   http://lkml.kernel.org/r/

   WONTFIX here because it should be fixed in bpf program, not in kernel.

signed overflows:

 * 32a8df4e0b33f ("sched: Fix odd values in effective_load()
   calculations")

 * mul overflow in ntp -
   http://lkml.kernel.org/r/<1449175608-1146-1-git-send-email-sasha.levin@oracle.com>

 * incorrect conversion into rtc_time in rtc_time64_to_tm() -
   http://lkml.kernel.org/r/<1449187944-11730-1-git-send-email-sasha.levin@oracle.com>

 * unvalidated timespec in io_getevents() -
   http://lkml.kernel.org/r/

 * [NOTABUG] signed overflow in ktime_add_safe() -
   http://lkml.kernel.org/r/

[akpm@linux-foundation.org: fix unused local warning]
[akpm@linux-foundation.org: fix __int128 build woes]
Signed-off-by: Andrey Ryabinin 
Cc: Peter Zijlstra 
Cc: Sasha Levin 
Cc: Randy Dunlap 
Cc: Rasmus Villemoes 
Cc: Jonathan Corbet 
Cc: Michal Marek 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: "H. Peter Anvin" 
Cc: Yury Gribov 
Cc: Dmitry Vyukov 
Cc: Konstantin Khlebnikov 
Cc: Kostya Serebryany 
Cc: Johannes Berg 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

x86/mm: Fix regression with huge pages on PAE

2015-12-04T08:14:27+00:00

Recent PAT patchset has caused issue on 32-bit PAE machines:

  page:eea45000 count:0 mapcount:-128 mapping:  (null) index:0x0 flags: 0x40000000()
  page dumped because: VM_BUG_ON_PAGE(page_mapcount(page) < 0)
  ------------[ cut here ]------------
  kernel BUG at /home/build/linux-boris/mm/huge_memory.c:1485!
  invalid opcode: 0000 [#1] SMP
  [...]
  Call Trace:
   unmap_single_vma
   ? __wake_up
   unmap_vmas
   unmap_region
   do_munmap
   vm_munmap
   SyS_munmap
   do_fast_syscall_32
   ? __do_page_fault
   sysenter_past_esp
  Code: ...
  EIP: [] zap_huge_pmd+0x240/0x260 SS:ESP 0068:f6459d98

The problem is in pmd_pfn_mask() and pmd_flags_mask(). These
helpers use PMD_PAGE_MASK to calculate resulting mask.
PMD_PAGE_MASK is 'unsigned long', not 'unsigned long long' as
phys_addr_t is on 32-bit PAE (ARCH_PHYS_ADDR_T_64BIT). As a
result, the upper bits of resulting mask get truncated.

pud_pfn_mask() and pud_flags_mask() aren't problematic since we
don't have PUD page table level on 32-bit systems, but it's
reasonable to keep them consistent with PMD counterpart.

Introduce PHYSICAL_PMD_PAGE_MASK and PHYSICAL_PUD_PAGE_MASK in
addition to existing PHYSICAL_PAGE_MASK and reworks helpers to
use them.

Reported-and-Tested-by: Boris Ostrovsky 
Signed-off-by: Kirill A. Shutemov 
[ Fix -Woverflow warnings from the realmode code. ]
Signed-off-by: Borislav Petkov 
Reviewed-by: Toshi Kani 
Cc: Andrew Morton 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Jürgen Gross 
Cc: Linus Torvalds 
Cc: Mel Gorman 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: elliott@hpe.com
Cc: konrad.wilk@oracle.com
Cc: linux-mm 
Fixes: f70abb0fc3da ("x86/asm: Fix pud/pmd interfaces to handle large PAT bit")
Link: http://lkml.kernel.org/r/1448878233-11390-2-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar 

Signed-off-by: Ingo Molnar

kasan: move KASAN_SANITIZE in arch/x86/boot/Makefile

2015-11-06T03:34:48+00:00

Move KASAN_SANITIZE in arch/x86/boot/Makefile above the comment
related to SVGA_MODE, since the comment refers to 'the next line'.

Signed-off-by: Andrey Konovalov 
Cc: Andrey Ryabinin 
Cc: Dmitry Vyukov 
Cc: Alexander Potapenko 
Cc: Konstantin Serebryany 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge tag 'efi-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into core/efi

2015-10-14T14:51:34+00:00

Pull v4.4 EFI updates from Matt Fleming:

  - Make the EFI System Resource Table (ESRT) driver explicitly
    non-modular by ripping out the module_* code since Kconfig doesn't
    allow it to be built as a module anyway. (Paul Gortmaker)

  - Make the x86 efi=debug kernel parameter, which enables EFI debug
    code and output, generic and usable by arm64. (Leif Lindholm)

  - Add support to the x86 EFI boot stub for 64-bit Graphics Output
    Protocol frame buffer addresses. (Matt Fleming)

  - Detect when the UEFI v2.5 EFI_PROPERTIES_TABLE feature is enabled
    in the firmware and set an efi.flags bit so the kernel knows when
    it can apply more strict runtime mapping attributes - Ard Biesheuvel

  - Auto-load the efi-pstore module on EFI systems, just like we
    currently do for the efivars module. (Ben Hutchings)

  - Add "efi_fake_mem" kernel parameter which allows the system's EFI
    memory map to be updated with additional attributes for specific
    memory ranges. This is useful for testing the kernel code that handles
    the EFI_MEMORY_MORE_RELIABLE memmap bit even if your firmware
    doesn't include support. (Taku Izumi)

Note: there is a semantic conflict between the following two commits:

  8a53554e12e9 ("x86/efi: Fix multiple GOP device support")
  ae2ee627dc87 ("efifb: Add support for 64-bit frame buffer addresses")

I fixed up the interaction in the merge commit, changing the type of
current_fb_base from u32 to u64.

Signed-off-by: Ingo Molnar

Merge branch 'x86/urgent' into core/efi, to pick up a pending EFI fix

2015-10-14T14:05:18+00:00

Signed-off-by: Ingo Molnar

x86/efi: Fix multiple GOP device support

2015-10-14T14:02:43+00:00

When multiple GOP devices exists, but none of them implements
ConOut, the code should just choose the first GOP (according to
the comments). But currently 'fb_base' will refer to the last GOP,
while other parameters to the first GOP, which will likely
result in a garbled display.

I can reliably reproduce this bug using my ASRock Z87M Extreme4
motherboard with CSM and integrated GPU disabled, and two PCIe
video cards (NVidia GT640 and GTX980), booting from efi-stub
(booting from grub works fine).  On the primary display the
ASRock logo remains and on the secondary screen it is garbled
up completely.

Signed-off-by: Kővágó, Zoltán 
Signed-off-by: Matt Fleming 
Cc: 
Cc: Linus Torvalds 
Cc: Matthew Garrett 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/1444659236-24837-2-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar

efifb: Add support for 64-bit frame buffer addresses

2015-10-12T13:20:06+00:00

The EFI Graphics Output Protocol uses 64-bit frame buffer addresses
but these get truncated to 32-bit by the EFI boot stub when storing
the address in the 'lfb_base' field of 'struct screen_info'.

Add a 'ext_lfb_base' field for the upper 32-bits of the frame buffer
address and set VIDEO_TYPE_CAPABILITY_64BIT_BASE when the field is
useable.

It turns out that the reason no one has required this support so far
is that there's actually code in tianocore to "downgrade" PCI
resources that have option ROMs and 64-bit BARS from 64-bit to 32-bit
to cope with legacy option ROMs that can't handle 64-bit addresses.
The upshot is that basically all GOP devices in the wild use a 32-bit
frame buffer address.

Still, it is possible to build firmware that uses a full 64-bit GOP
frame buffer address. Chad did, which led to him reporting this issue.

Add support in anticipation of GOP devices using 64-bit addresses more
widely, and so that efifb works out of the box when that happens.

Reported-by: Chad Page 
Cc: Pete Hawkins 
Acked-by: Peter Jones 
Cc: Matthew Garrett 
Cc: Geert Uytterhoeven 
Signed-off-by: Matt Fleming

lib/decompressors: use real out buf size for gunzip with kernel

2015-09-10T20:29:01+00:00

When loading x86 64bit kernel above 4GiB with patched grub2, got kernel
gunzip error.

| early console in decompress_kernel
| decompress_kernel:
|       input: [0x807f2143b4-0x807ff61aee]
|      output: [0x807cc00000-0x807f3ea29b] 0x027ea29c: output_len
| boot via startup_64
| KASLR using RDTSC...
|  new output: [0x46fe000000-0x470138cfff] 0x0338d000: output_run_size
|  decompress: [0x46fe000000-0x47007ea29b] <=== [0x807f2143b4-0x807ff61aee]
|
| Decompressing Linux... gz...
|
| uncompression error
|
| -- System halted

the new buffer is at 0x46fe000000ULL, decompressor_gzip is using
0xffffffb901ffffff as out_len.  gunzip in lib/zlib_inflate/inflate.c cap
that len to 0x01ffffff and decompress fails later.

We could hit this problem with crashkernel booting that uses kexec loading
kernel above 4GiB.

We have decompress_* support:
    1. inbuf[]/outbuf[] for kernel preboot.
    2. inbuf[]/flush() for initramfs
    3. fill()/flush() for initrd.
This bug only affect kernel preboot path that use outbuf[].

Add __decompress and take real out_buf_len for gunzip instead of guessing
wrong buf size.

Fixes: 1431574a1c4 (lib/decompressors: fix "no limit" output buffer length)
Signed-off-by: Yinghai Lu 
Cc: Alexandre Courbot 
Cc: Jon Medhurst 
Cc: Stephen Warren 
Cc: "H. Peter Anvin" 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kexec: split kexec_load syscall from kexec core code

2015-09-10T20:29:01+00:00

There are two kexec load syscalls, kexec_load another and kexec_file_load.
 kexec_file_load has been splited as kernel/kexec_file.c.  In this patch I
split kexec_load syscall code to kernel/kexec.c.

And add a new kconfig option KEXEC_CORE, so we can disable kexec_load and
use kexec_file_load only, or vice verse.

The original requirement is from Ted Ts'o, he want kexec kernel signature
being checked with CONFIG_KEXEC_VERIFY_SIG enabled.  But kexec-tools use
kexec_load syscall can bypass the checking.

Vivek Goyal proposed to create a common kconfig option so user can compile
in only one syscall for loading kexec kernel.  KEXEC/KEXEC_FILE selects
KEXEC_CORE so that old config files still work.

Because there's general code need CONFIG_KEXEC_CORE, so I updated all the
architecture Kconfig with a new option KEXEC_CORE, and let KEXEC selects
KEXEC_CORE in arch Kconfig.  Also updated general kernel code with to
kexec_load syscall.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Dave Young 
Cc: Eric W. Biederman 
Cc: Vivek Goyal 
Cc: Petr Tesarik 
Cc: Theodore Ts'o 
Cc: Josh Boyer 
Cc: David Howells 
Cc: Geert Uytterhoeven 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

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

2015-09-01T16:04:31+00:00

Pull x86 boot updates from Ingo Molnar:
 "The main x86 bootup related changes in this cycle were:

   - more boot time optimizations.  (Len Brown)

   - implement hex output to allow the debugging of early bootup
     parameters.  (Kees Cook)

   - remove obsolete MCA leftovers.  (Paolo Pisati)"

* 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/smpboot: Remove APIC.wait_for_init_deassert and atomic init_deasserted
  x86/smpboot: Remove SIPI delays from cpu_up()
  x86/smpboot: Remove udelay(100) when polling cpu_callin_map
  x86/smpboot: Remove udelay(100) when polling cpu_initialized_map
  x86/boot: Obsolete the MCA sys_desc_table
  x86/boot: Add hex output for debugging