linux-stable.git/arch/powerpc/lib, branch linux-5.0.y

powerpc/64: Fix memcmp reading past the end of src/dest

2019-04-03T04:27:38+00:00

commit d9470757398a700d9450a43508000bcfd010c7a4 upstream.

Chandan reported that fstests' generic/026 test hit a crash:

  BUG: Unable to handle kernel data access at 0xc00000062ac40000
  Faulting instruction address: 0xc000000000092240
  Oops: Kernel access of bad area, sig: 11 [#1]
  LE SMP NR_CPUS=2048 DEBUG_PAGEALLOC NUMA pSeries
  CPU: 0 PID: 27828 Comm: chacl Not tainted 5.0.0-rc2-next-20190115-00001-g6de6dba64dda #1
  NIP:  c000000000092240 LR: c00000000066a55c CTR: 0000000000000000
  REGS: c00000062c0c3430 TRAP: 0300   Not tainted  (5.0.0-rc2-next-20190115-00001-g6de6dba64dda)
  MSR:  8000000002009033   CR: 44000842  XER: 20000000
  CFAR: 00007fff7f3108ac DAR: c00000062ac40000 DSISR: 40000000 IRQMASK: 0
  GPR00: 0000000000000000 c00000062c0c36c0 c0000000017f4c00 c00000000121a660
  GPR04: c00000062ac3fff9 0000000000000004 0000000000000020 00000000275b19c4
  GPR08: 000000000000000c 46494c4500000000 5347495f41434c5f c0000000026073a0
  GPR12: 0000000000000000 c0000000027a0000 0000000000000000 0000000000000000
  GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  GPR20: c00000062ea70020 c00000062c0c38d0 0000000000000002 0000000000000002
  GPR24: c00000062ac3ffe8 00000000275b19c4 0000000000000001 c00000062ac30000
  GPR28: c00000062c0c38d0 c00000062ac30050 c00000062ac30058 0000000000000000
  NIP memcmp+0x120/0x690
  LR  xfs_attr3_leaf_lookup_int+0x53c/0x5b0
  Call Trace:
    xfs_attr3_leaf_lookup_int+0x78/0x5b0 (unreliable)
    xfs_da3_node_lookup_int+0x32c/0x5a0
    xfs_attr_node_addname+0x170/0x6b0
    xfs_attr_set+0x2ac/0x340
    __xfs_set_acl+0xf0/0x230
    xfs_set_acl+0xd0/0x160
    set_posix_acl+0xc0/0x130
    posix_acl_xattr_set+0x68/0x110
    __vfs_setxattr+0xa4/0x110
    __vfs_setxattr_noperm+0xac/0x240
    vfs_setxattr+0x128/0x130
    setxattr+0x248/0x600
    path_setxattr+0x108/0x120
    sys_setxattr+0x28/0x40
    system_call+0x5c/0x70
  Instruction dump:
  7d201c28 7d402428 7c295040 38630008 38840008 408201f0 4200ffe8 2c050000
  4182ff6c 20c50008 54c61838 7d201c28 <7d402428> 7d293436 7d4a3436 7c295040

The instruction dump decodes as:
  subfic  r6,r5,8
  rlwinm  r6,r6,3,0,28
  ldbrx   r9,0,r3
  ldbrx   r10,0,r4      <-

Which shows us doing an 8 byte load from c00000062ac3fff9, which
crosses the page boundary at c00000062ac40000 and faults.

It's not OK for memcmp to read past the end of the source or
destination buffers if that would cross a page boundary, because we
don't know that the next page is mapped.

As pointed out by Segher, we can read past the end of the source or
destination as long as we don't cross a 4K boundary, because that's
our minimum page size on all platforms.

The bug is in the code at the .Lcmp_rest_lt8bytes label. When we get
there we know that s1 is 8-byte aligned and we have at least 1 byte to
read, so a single 8-byte load won't read past the end of s1 and cross
a page boundary.

But we have to be more careful with s2. So check if it's within 8
bytes of a 4K boundary and if so go to the byte-by-byte loop.

Fixes: 2d9ee327adce ("powerpc/64: Align bytes before fall back to .Lshort in powerpc64 memcmp()")
Cc: stable@vger.kernel.org # v4.19+
Reported-by: Chandan Rajendra 
Signed-off-by: Michael Ellerman 
Reviewed-by: Segher Boessenkool 
Tested-by: Chandan Rajendra 
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

Remove 'type' argument from access_ok() function

2019-01-04T02:57:57+00:00

Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument
of the user address range verification function since we got rid of the
old racy i386-only code to walk page tables by hand.

It existed because the original 80386 would not honor the write protect
bit when in kernel mode, so you had to do COW by hand before doing any
user access.  But we haven't supported that in a long time, and these
days the 'type' argument is a purely historical artifact.

A discussion about extending 'user_access_begin()' to do the range
checking resulted this patch, because there is no way we're going to
move the old VERIFY_xyz interface to that model.  And it's best done at
the end of the merge window when I've done most of my merges, so let's
just get this done once and for all.

This patch was mostly done with a sed-script, with manual fix-ups for
the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form.

There were a couple of notable cases:

 - csky still had the old "verify_area()" name as an alias.

 - the iter_iov code had magical hardcoded knowledge of the actual
   values of VERIFY_{READ,WRITE} (not that they mattered, since nothing
   really used it)

 - microblaze used the type argument for a debug printout

but other than those oddities this should be a total no-op patch.

I tried to fix up all architectures, did fairly extensive grepping for
access_ok() uses, and the changes are trivial, but I may have missed
something.  Any missed conversion should be trivially fixable, though.

Signed-off-by: Linus Torvalds

powerpc/fsl: Add infrastructure to fixup branch predictor flush

2018-12-20T11:53:39+00:00

In order to protect against speculation attacks (Spectre
variant 2) on NXP PowerPC platforms, the branch predictor
should be flushed when the privillege level is changed.
This patch is adding the infrastructure to fixup at runtime
the code sections that are performing the branch predictor flush
depending on a boot arg parameter which is added later in a
separate patch.

Signed-off-by: Diana Craciun 
Signed-off-by: Michael Ellerman

powerpc: simplify patch_instruction_site() and patch_branch_site()

2018-12-19T07:56:32+00:00

Using patch_site_addr() helper, patch_instruction_site() and
patch_branch_site() can be simplified and inlined.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman

powerpc/lib: Declare static methods

2018-11-25T06:11:21+00:00

Functions do_stf_{entry,exit}_barrier_fixups are static but not declared as
such. This was detected by `sparse` tool with the following warning:

	arch/powerpc/lib/feature-fixups.c:121:6: warning: symbol 'do_stf_entry_barrier_fixups' was not declared. Should it be static?

	arch/powerpc/lib/feature-fixups.c:171:6: warning: symbol 'do_stf_exit_barrier_fixups' was not declared. Should it be static?

This patch declares both functions as static, as they are only called by
do_stf_barrier_fixups(), which is in the same source code file.

Signed-off-by: Breno Leitao 
Signed-off-by: Michael Ellerman

memblock: stop using implicit alignment to SMP_CACHE_BYTES

2018-10-31T15:54:16+00:00

When a memblock allocation APIs are called with align = 0, the alignment
is implicitly set to SMP_CACHE_BYTES.

Implicit alignment is done deep in the memblock allocator and it can
come as a surprise.  Not that such an alignment would be wrong even
when used incorrectly but it is better to be explicit for the sake of
clarity and the prinicple of the least surprise.

Replace all such uses of memblock APIs with the 'align' parameter
explicitly set to SMP_CACHE_BYTES and stop implicit alignment assignment
in the memblock internal allocation functions.

For the case when memblock APIs are used via helper functions, e.g.  like
iommu_arena_new_node() in Alpha, the helper functions were detected with
Coccinelle's help and then manually examined and updated where
appropriate.

The direct memblock APIs users were updated using the semantic patch below:

@@
expression size, min_addr, max_addr, nid;
@@
(
|
- memblock_alloc_try_nid_raw(size, 0, min_addr, max_addr, nid)
+ memblock_alloc_try_nid_raw(size, SMP_CACHE_BYTES, min_addr, max_addr,
nid)
|
- memblock_alloc_try_nid_nopanic(size, 0, min_addr, max_addr, nid)
+ memblock_alloc_try_nid_nopanic(size, SMP_CACHE_BYTES, min_addr, max_addr,
nid)
|
- memblock_alloc_try_nid(size, 0, min_addr, max_addr, nid)
+ memblock_alloc_try_nid(size, SMP_CACHE_BYTES, min_addr, max_addr, nid)
|
- memblock_alloc(size, 0)
+ memblock_alloc(size, SMP_CACHE_BYTES)
|
- memblock_alloc_raw(size, 0)
+ memblock_alloc_raw(size, SMP_CACHE_BYTES)
|
- memblock_alloc_from(size, 0, min_addr)
+ memblock_alloc_from(size, SMP_CACHE_BYTES, min_addr)
|
- memblock_alloc_nopanic(size, 0)
+ memblock_alloc_nopanic(size, SMP_CACHE_BYTES)
|
- memblock_alloc_low(size, 0)
+ memblock_alloc_low(size, SMP_CACHE_BYTES)
|
- memblock_alloc_low_nopanic(size, 0)
+ memblock_alloc_low_nopanic(size, SMP_CACHE_BYTES)
|
- memblock_alloc_from_nopanic(size, 0, min_addr)
+ memblock_alloc_from_nopanic(size, SMP_CACHE_BYTES, min_addr)
|
- memblock_alloc_node(size, 0, nid)
+ memblock_alloc_node(size, SMP_CACHE_BYTES, nid)
)

[mhocko@suse.com: changelog update]
[akpm@linux-foundation.org: coding-style fixes]
[rppt@linux.ibm.com: fix missed uses of implicit alignment]
  Link: http://lkml.kernel.org/r/20181016133656.GA10925@rapoport-lnx
Link: http://lkml.kernel.org/r/1538687224-17535-1-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport 
Suggested-by: Michal Hocko 
Acked-by: Paul Burton 	[MIPS]
Acked-by: Michael Ellerman 	[powerpc]
Acked-by: Michal Hocko 
Cc: Catalin Marinas 
Cc: Chris Zankel 
Cc: Geert Uytterhoeven 
Cc: Guan Xuetao 
Cc: Ingo Molnar 
Cc: Matt Turner 
Cc: Michal Simek 
Cc: Richard Weinberger 
Cc: Russell King 
Cc: Thomas Gleixner 
Cc: Tony Luck 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: remove include/linux/bootmem.h

2018-10-31T15:54:16+00:00

Move remaining definitions and declarations from include/linux/bootmem.h
into include/linux/memblock.h and remove the redundant header.

The includes were replaced with the semantic patch below and then
semi-automated removal of duplicated '#include 

@@
@@
- #include 
+ #include 

[sfr@canb.auug.org.au: dma-direct: fix up for the removal of linux/bootmem.h]
  Link: http://lkml.kernel.org/r/20181002185342.133d1680@canb.auug.org.au
[sfr@canb.auug.org.au: powerpc: fix up for removal of linux/bootmem.h]
  Link: http://lkml.kernel.org/r/20181005161406.73ef8727@canb.auug.org.au
[sfr@canb.auug.org.au: x86/kaslr, ACPI/NUMA: fix for linux/bootmem.h removal]
  Link: http://lkml.kernel.org/r/20181008190341.5e396491@canb.auug.org.au
Link: http://lkml.kernel.org/r/1536927045-23536-30-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport 
Signed-off-by: Stephen Rothwell 
Acked-by: Michal Hocko 
Cc: Catalin Marinas 
Cc: Chris Zankel 
Cc: "David S. Miller" 
Cc: Geert Uytterhoeven 
Cc: Greentime Hu 
Cc: Greg Kroah-Hartman 
Cc: Guan Xuetao 
Cc: Ingo Molnar 
Cc: "James E.J. Bottomley" 
Cc: Jonas Bonn 
Cc: Jonathan Corbet 
Cc: Ley Foon Tan 
Cc: Mark Salter 
Cc: Martin Schwidefsky 
Cc: Matt Turner 
Cc: Michael Ellerman 
Cc: Michal Simek 
Cc: Palmer Dabbelt 
Cc: Paul Burton 
Cc: Richard Kuo 
Cc: Richard Weinberger 
Cc: Rich Felker 
Cc: Russell King 
Cc: Serge Semin 
Cc: Thomas Gleixner 
Cc: Tony Luck 
Cc: Vineet Gupta 
Cc: Yoshinori Sato 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

memblock: remove _virt from APIs returning virtual address

2018-10-31T15:54:15+00:00

The conversion is done using

sed -i 's@memblock_virt_alloc@memblock_alloc@g' \
	$(git grep -l memblock_virt_alloc)

Link: http://lkml.kernel.org/r/1536927045-23536-8-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport 
Cc: Catalin Marinas 
Cc: Chris Zankel 
Cc: "David S. Miller" 
Cc: Geert Uytterhoeven 
Cc: Greentime Hu 
Cc: Greg Kroah-Hartman 
Cc: Guan Xuetao 
Cc: Ingo Molnar 
Cc: "James E.J. Bottomley" 
Cc: Jonas Bonn 
Cc: Jonathan Corbet 
Cc: Ley Foon Tan 
Cc: Mark Salter 
Cc: Martin Schwidefsky 
Cc: Matt Turner 
Cc: Michael Ellerman 
Cc: Michal Hocko 
Cc: Michal Simek 
Cc: Palmer Dabbelt 
Cc: Paul Burton 
Cc: Richard Kuo 
Cc: Richard Weinberger 
Cc: Rich Felker 
Cc: Russell King 
Cc: Serge Semin 
Cc: Thomas Gleixner 
Cc: Tony Luck 
Cc: Vineet Gupta 
Cc: Yoshinori Sato 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

powerpc: Add support for function error injection

2018-10-20T02:26:43+00:00

We implement regs_set_return_value() and override_function_with_return()
for this purpose.

On powerpc, a return from a function (blr) just branches to the location
contained in the link register. So, we can just update pt_regs rather
than redirecting execution to a dummy function that returns.

Signed-off-by: Naveen N. Rao 
Reviewed-by: Samuel Mendoza-Jonas 
Signed-off-by: Michael Ellerman

powerpc: Add -Werror at arch/powerpc level

2018-10-18T13:56:17+00:00

Back when I added -Werror in commit ba55bd74360e ("powerpc: Add
configurable -Werror for arch/powerpc") I did it by adding it to most
of the arch Makefiles.

At the time we excluded math-emu, because apparently it didn't build
cleanly. But that seems to have been fixed somewhere in the interim.

So move the -Werror addition to the top-level of the arch, this saves
us from repeating it in every Makefile and means we won't forget to
add it to any new sub-dirs.

Signed-off-by: Michael Ellerman