linux-stable.git/arch/arc/include, branch v4.9.321

arch: pgtable: define MAX_POSSIBLE_PHYSMEM_BITS where needed

2021-11-12T12:18:01+00:00

[ Upstream commit cef397038167ac15d085914493d6c86385773709 ]

Stefan Agner reported a bug when using zsram on 32-bit Arm machines
with RAM above the 4GB address boundary:

  Unable to handle kernel NULL pointer dereference at virtual address 00000000
  pgd = a27bd01c
  [00000000] *pgd=236a0003, *pmd=1ffa64003
  Internal error: Oops: 207 [#1] SMP ARM
  Modules linked in: mdio_bcm_unimac(+) brcmfmac cfg80211 brcmutil raspberrypi_hwmon hci_uart crc32_arm_ce bcm2711_thermal phy_generic genet
  CPU: 0 PID: 123 Comm: mkfs.ext4 Not tainted 5.9.6 #1
  Hardware name: BCM2711
  PC is at zs_map_object+0x94/0x338
  LR is at zram_bvec_rw.constprop.0+0x330/0xa64
  pc : []    lr : []    psr: 60000013
  sp : e376bbe0  ip : 00000000  fp : c1e2921c
  r10: 00000002  r9 : c1dda730  r8 : 00000000
  r7 : e8ff7a00  r6 : 00000000  r5 : 02f9ffa0  r4 : e3710000
  r3 : 000fdffe  r2 : c1e0ce80  r1 : ebf979a0  r0 : 00000000
  Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
  Control: 30c5383d  Table: 235c2a80  DAC: fffffffd
  Process mkfs.ext4 (pid: 123, stack limit = 0x495a22e6)
  Stack: (0xe376bbe0 to 0xe376c000)

As it turns out, zsram needs to know the maximum memory size, which
is defined in MAX_PHYSMEM_BITS when CONFIG_SPARSEMEM is set, or in
MAX_POSSIBLE_PHYSMEM_BITS on the x86 architecture.

The same problem will be hit on all 32-bit architectures that have a
physical address space larger than 4GB and happen to not enable sparsemem
and include asm/sparsemem.h from asm/pgtable.h.

After the initial discussion, I suggested just always defining
MAX_POSSIBLE_PHYSMEM_BITS whenever CONFIG_PHYS_ADDR_T_64BIT is
set, or provoking a build error otherwise. This addresses all
configurations that can currently have this runtime bug, but
leaves all other configurations unchanged.

I looked up the possible number of bits in source code and
datasheets, here is what I found:

 - on ARC, CONFIG_ARC_HAS_PAE40 controls whether 32 or 40 bits are used
 - on ARM, CONFIG_LPAE enables 40 bit addressing, without it we never
   support more than 32 bits, even though supersections in theory allow
   up to 40 bits as well.
 - on MIPS, some MIPS32r1 or later chips support 36 bits, and MIPS32r5
   XPA supports up to 60 bits in theory, but 40 bits are more than
   anyone will ever ship
 - On PowerPC, there are three different implementations of 36 bit
   addressing, but 32-bit is used without CONFIG_PTE_64BIT
 - On RISC-V, the normal page table format can support 34 bit
   addressing. There is no highmem support on RISC-V, so anything
   above 2GB is unused, but it might be useful to eventually support
   CONFIG_ZRAM for high pages.

Fixes: 61989a80fb3a ("staging: zsmalloc: zsmalloc memory allocation library")
Fixes: 02390b87a945 ("mm/zsmalloc: Prepare to variable MAX_PHYSMEM_BITS")
Acked-by: Thomas Bogendoerfer 
Reviewed-by: Stefan Agner 
Tested-by: Stefan Agner 
Acked-by: Mike Rapoport 
Link: https://lore.kernel.org/linux-mm/bdfa44bf1c570b05d6c70898e2bbb0acf234ecdf.1604762181.git.stefan@agner.ch/
Signed-off-by: Arnd Bergmann 
Signed-off-by: Sasha Levin 
[florian: patch arch/powerpc/include/asm/pte-common.h for 4.9.y
removed arch/riscv/include/asm/pgtable.h which does not exist]
Signed-off-by: Florian Fainelli 
Signed-off-by: Greg Kroah-Hartman

arch/arc: add copy_user_page() to to fix build error on ARC

2021-01-23T14:38:17+00:00

[ Upstream commit 8a48c0a3360bf2bf4f40c980d0ec216e770e58ee ]

fs/dax.c uses copy_user_page() but ARC does not provide that interface,
resulting in a build error.

Provide copy_user_page() in .

../fs/dax.c: In function 'copy_cow_page_dax':
../fs/dax.c:702:2: error: implicit declaration of function 'copy_user_page'; did you mean 'copy_to_user_page'? [-Werror=implicit-function-declaration]

Reported-by: kernel test robot 
Signed-off-by: Randy Dunlap 
Cc: Vineet Gupta 
Cc: linux-snps-arc@lists.infradead.org
Cc: Dan Williams 
#Acked-by: Vineet Gupta  # v1
Cc: Andrew Morton 
Cc: Matthew Wilcox 
Cc: Jan Kara 
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-nvdimm@lists.01.org
#Reviewed-by: Ira Weiny  # v2
Signed-off-by: Vineet Gupta 
Signed-off-by: Sasha Levin

ARC: elf: use right ELF_ARCH

2020-07-22T07:10:47+00:00

commit b7faf971081a4e56147f082234bfff55135305cb upstream.

Cc: 
Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman

ARC: define __ALIGN_STR and __ALIGN symbols for ARC

2020-03-20T08:07:44+00:00

commit 8d92e992a785f35d23f845206cf8c6cafbc264e0 upstream.

The default defintions use fill pattern 0x90 for padding which for ARC
generates unintended "ldh_s r12,[r0,0x20]" corresponding to opcode 0x9090

So use ".align 4" which insert a "nop_s" instruction instead.

Cc: stable@vger.kernel.org
Acked-by: Vineet Gupta 
Signed-off-by: Eugeniy Paltsev 
Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman

bug.h: work around GCC PR82365 in BUG()

2019-07-10T07:55:44+00:00

[ Upstream commit 173a3efd3edb2ef6ef07471397c5f542a360e9c1 ]

Looking at functions with large stack frames across all architectures
led me discovering that BUG() suffers from the same problem as
fortify_panic(), which I've added a workaround for already.

In short, variables that go out of scope by calling a noreturn function
or __builtin_unreachable() keep using stack space in functions
afterwards.

A workaround that was identified is to insert an empty assembler
statement just before calling the function that doesn't return.  I'm
adding a macro "barrier_before_unreachable()" to document this, and
insert calls to that in all instances of BUG() that currently suffer
from this problem.

The files that saw the largest change from this had these frame sizes
before, and much less with my patch:

  fs/ext4/inode.c:82:1: warning: the frame size of 1672 bytes is larger than 800 bytes [-Wframe-larger-than=]
  fs/ext4/namei.c:434:1: warning: the frame size of 904 bytes is larger than 800 bytes [-Wframe-larger-than=]
  fs/ext4/super.c:2279:1: warning: the frame size of 1160 bytes is larger than 800 bytes [-Wframe-larger-than=]
  fs/ext4/xattr.c:146:1: warning: the frame size of 1168 bytes is larger than 800 bytes [-Wframe-larger-than=]
  fs/f2fs/inode.c:152:1: warning: the frame size of 1424 bytes is larger than 800 bytes [-Wframe-larger-than=]
  net/netfilter/ipvs/ip_vs_core.c:1195:1: warning: the frame size of 1068 bytes is larger than 800 bytes [-Wframe-larger-than=]
  net/netfilter/ipvs/ip_vs_core.c:395:1: warning: the frame size of 1084 bytes is larger than 800 bytes [-Wframe-larger-than=]
  net/netfilter/ipvs/ip_vs_ftp.c:298:1: warning: the frame size of 928 bytes is larger than 800 bytes [-Wframe-larger-than=]
  net/netfilter/ipvs/ip_vs_ftp.c:418:1: warning: the frame size of 908 bytes is larger than 800 bytes [-Wframe-larger-than=]
  net/netfilter/ipvs/ip_vs_lblcr.c:718:1: warning: the frame size of 960 bytes is larger than 800 bytes [-Wframe-larger-than=]
  drivers/net/xen-netback/netback.c:1500:1: warning: the frame size of 1088 bytes is larger than 800 bytes [-Wframe-larger-than=]

In case of ARC and CRIS, it turns out that the BUG() implementation
actually does return (or at least the compiler thinks it does),
resulting in lots of warnings about uninitialized variable use and
leaving noreturn functions, such as:

  block/cfq-iosched.c: In function 'cfq_async_queue_prio':
  block/cfq-iosched.c:3804:1: error: control reaches end of non-void function [-Werror=return-type]
  include/linux/dmaengine.h: In function 'dma_maxpq':
  include/linux/dmaengine.h:1123:1: error: control reaches end of non-void function [-Werror=return-type]

This makes them call __builtin_trap() instead, which should normally
dump the stack and kill the current process, like some of the other
architectures already do.

I tried adding barrier_before_unreachable() to panic() and
fortify_panic() as well, but that had very little effect, so I'm not
submitting that patch.

Vineet said:

: For ARC, it is double win.
:
: 1. Fixes 3 -Wreturn-type warnings
:
: | ../net/core/ethtool.c:311:1: warning: control reaches end of non-void function
: [-Wreturn-type]
: | ../kernel/sched/core.c:3246:1: warning: control reaches end of non-void function
: [-Wreturn-type]
: | ../include/linux/sunrpc/svc_xprt.h:180:1: warning: control reaches end of
: non-void function [-Wreturn-type]
:
: 2.  bloat-o-meter reports code size improvements as gcc elides the
:    generated code for stack return.

Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82365
Link: http://lkml.kernel.org/r/20171219114112.939391-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann 
Acked-by: Vineet Gupta 	[arch/arc]
Tested-by: Vineet Gupta 	[arch/arc]
Cc: Mikael Starvik 
Cc: Jesper Nilsson 
Cc: Tony Luck 
Cc: Fenghua Yu 
Cc: Geert Uytterhoeven 
Cc: "David S. Miller" 
Cc: Christopher Li 
Cc: Thomas Gleixner 
Cc: Peter Zijlstra 
Cc: Kees Cook 
Cc: Ingo Molnar 
Cc: Josh Poimboeuf 
Cc: Will Deacon 
Cc: "Steven Rostedt (VMware)" 
Cc: Mark Rutland 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin 
[removed cris chunks - gregkh]
Signed-off-by: Greg Kroah-Hartman

ARC: fix build warnings with !CONFIG_KPROBES

2019-07-10T07:55:29+00:00

[ Upstream commit 4c6fabda1ad1dec6d274c098ef0a91809c74f2e3 ]

|   CC      lib/nmi_backtrace.o
| In file included from ../include/linux/kprobes.h:43:0,
|                  from ../lib/nmi_backtrace.c:17:
| ../arch/arc/include/asm/kprobes.h:57:13: warning: 'trap_is_kprobe' defined but not used [-Wunused-function]
|  static void trap_is_kprobe(unsigned long address, struct pt_regs *regs)
|              ^~~~~~~~~~~~~~

The warning started with 7d134b2ce6 ("kprobes: move kprobe declarations
to asm-generic/kprobes.h") which started including 
unconditionally into  exposing a stub function for
!CONFIG_KPROBES to rest of world. Fix that by making the stub a macro

Signed-off-by: Vineet Gupta 
Signed-off-by: Sasha Levin

ARC: uacces: remove lp_start, lp_end from clobber list

2019-03-23T12:19:44+00:00

[ Upstream commit d5e3c55e01d8b1774b37b4647c30fb22f1d39077 ]

Newer ARC gcc handles lp_start, lp_end in a different way and doesn't
like them in the clobber list.

Signed-off-by: Vineet Gupta 
Signed-off-by: Sasha Levin

ARC: fix __ffs return value to avoid build warnings

2019-03-05T16:57:05+00:00

[ Upstream commit 4e868f8419cb4cb558c5d428e7ab5629cef864c7 ]

|  CC      mm/nobootmem.o
|In file included from ./include/asm-generic/bug.h:18:0,
|                 from ./arch/arc/include/asm/bug.h:32,
|                 from ./include/linux/bug.h:5,
|                 from ./include/linux/mmdebug.h:5,
|                 from ./include/linux/gfp.h:5,
|                 from ./include/linux/slab.h:15,
|                 from mm/nobootmem.c:14:
|mm/nobootmem.c: In function '__free_pages_memory':
|./include/linux/kernel.h:845:29: warning: comparison of distinct pointer types lacks a cast
|   (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
|                             ^
|./include/linux/kernel.h:859:4: note: in expansion of macro '__typecheck'
|   (__typecheck(x, y) && __no_side_effects(x, y))
|    ^~~~~~~~~~~
|./include/linux/kernel.h:869:24: note: in expansion of macro '__safe_cmp'
|  __builtin_choose_expr(__safe_cmp(x, y), \
|                        ^~~~~~~~~~
|./include/linux/kernel.h:878:19: note: in expansion of macro '__careful_cmp'
| #define min(x, y) __careful_cmp(x, y, <)
|                   ^~~~~~~~~~~~~
|mm/nobootmem.c:104:11: note: in expansion of macro 'min'
|   order = min(MAX_ORDER - 1UL, __ffs(start));

Change __ffs return value from 'int' to 'unsigned long' as it
is done in other implementations (like asm-generic, x86, etc...)
to avoid build-time warnings in places where type is strictly
checked.

As __ffs may return values in [0-31] interval changing return
type to unsigned is valid.

Signed-off-by: Eugeniy Paltsev 
Signed-off-by: Vineet Gupta 
Signed-off-by: Sasha Levin

ARC: define ARCH_SLAB_MINALIGN = 8

2019-02-27T09:07:01+00:00

commit b6835ea77729e7faf4656ca637ba53f42b8ee3fd upstream.

The default value of ARCH_SLAB_MINALIGN in "include/linux/slab.h" is
"__alignof__(unsigned long long)" which for ARC unexpectedly turns out
to be 4. This is not a compiler bug, but as defined by ARC ABI [1]

Thus slab allocator would allocate a struct which is 32-bit aligned,
which is generally OK even if struct has long long members.
There was however potetial problem when it had any atomic64_t which
use LLOCKD/SCONDD instructions which are required by ISA to take
64-bit addresses. This is the problem we ran into

[    4.015732] EXT4-fs (mmcblk0p2): re-mounted. Opts: (null)
[    4.167881] Misaligned Access
[    4.172356] Path: /bin/busybox.nosuid
[    4.176004] CPU: 2 PID: 171 Comm: rm Not tainted 4.19.14-yocto-standard #1
[    4.182851]
[    4.182851] [ECR   ]: 0x000d0000 => Check Programmer's Manual
[    4.190061] [EFA   ]: 0xbeaec3fc
[    4.190061] [BLINK ]: ext4_delete_entry+0x210/0x234
[    4.190061] [ERET  ]: ext4_delete_entry+0x13e/0x234
[    4.202985] [STAT32]: 0x80080002 : IE K
[    4.207236] BTA: 0x9009329c   SP: 0xbe5b1ec4  FP: 0x00000000
[    4.212790] LPS: 0x9074b118  LPE: 0x9074b120 LPC: 0x00000000
[    4.218348] r00: 0x00000040  r01: 0x00000021 r02: 0x00000001
...
...
[    4.270510] Stack Trace:
[    4.274510]   ext4_delete_entry+0x13e/0x234
[    4.278695]   ext4_rmdir+0xe0/0x238
[    4.282187]   vfs_rmdir+0x50/0xf0
[    4.285492]   do_rmdir+0x9e/0x154
[    4.288802]   EV_Trap+0x110/0x114

The fix is to make sure slab allocations are 64-bit aligned.

Do note that atomic64_t is __attribute__((aligned(8)) which means gcc
does generate 64-bit aligned references, relative to beginning of
container struct. However the issue is if the container itself is not
64-bit aligned, atomic64_t ends up unaligned which is what this patch
ensures.

[1] https://github.com/foss-for-synopsys-dwc-arc-processors/toolchain/wiki/files/ARCv2_ABI.pdf

Signed-off-by: Alexey Brodkin 
Cc:  # 4.8+
Signed-off-by: Vineet Gupta 
[vgupta: reworked changelog, added dependency on LL64+LLSC]
Signed-off-by: Greg Kroah-Hartman

ARC: perf: map generic branches to correct hardware condition

2019-01-31T07:12:34+00:00

commit 3affbf0e154ee351add6fcc254c59c3f3947fa8f upstream.

So far we've mapped branches to "ijmp" which also counts conditional
branches NOT taken. This makes us different from other architectures
such as ARM which seem to be counting only taken branches.

So use "ijmptak" hardware condition which only counts (all jump
instructions that are taken)

'ijmptak' event is available on both ARCompact and ARCv2 ISA based
cores.

Signed-off-by: Eugeniy Paltsev 
Cc: stable@vger.kernel.org
Signed-off-by: Vineet Gupta 
[vgupta: reworked changelog]
Signed-off-by: Greg Kroah-Hartman