linux-stable.git/arch, branch v5.7.11

x86, vmlinux.lds: Page-align end of ..page_aligned sections

2020-07-29T08:19:59+00:00

commit de2b41be8fcccb2f5b6c480d35df590476344201 upstream.

On x86-32 the idt_table with 256 entries needs only 2048 bytes. It is
page-aligned, but the end of the .bss..page_aligned section is not
guaranteed to be page-aligned.

As a result, objects from other .bss sections may end up on the same 4k
page as the idt_table, and will accidentially get mapped read-only during
boot, causing unexpected page-faults when the kernel writes to them.

This could be worked around by making the objects in the page aligned
sections page sized, but that's wrong.

Explicit sections which store only page aligned objects have an implicit
guarantee that the object is alone in the page in which it is placed. That
works for all objects except the last one. That's inconsistent.

Enforcing page sized objects for these sections would wreckage memory
sanitizers, because the object becomes artificially larger than it should
be and out of bound access becomes legit.

Align the end of the .bss..page_aligned and .data..page_aligned section on
page-size so all objects places in these sections are guaranteed to have
their own page.

[ tglx: Amended changelog ]

Signed-off-by: Joerg Roedel 
Signed-off-by: Thomas Gleixner 
Reviewed-by: Kees Cook 
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20200721093448.10417-1-joro@8bytes.org
Signed-off-by: Greg Kroah-Hartman

parisc: Add atomic64_set_release() define to avoid CPU soft lockups

2020-07-29T08:19:59+00:00

commit be6577af0cef934ccb036445314072e8cb9217b9 upstream.

Stalls are quite frequent with recent kernels. I enabled
CONFIG_SOFTLOCKUP_DETECTOR and I caught the following stall:

watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [cc1:22803]
CPU: 0 PID: 22803 Comm: cc1 Not tainted 5.6.17+ #3
Hardware name: 9000/800/rp3440
 IAOQ[0]: d_alloc_parallel+0x384/0x688
 IAOQ[1]: d_alloc_parallel+0x388/0x688
 RP(r2): d_alloc_parallel+0x134/0x688
Backtrace:
 [<000000004036974c>] __lookup_slow+0xa4/0x200
 [<0000000040369fc8>] walk_component+0x288/0x458
 [<000000004036a9a0>] path_lookupat+0x88/0x198
 [<000000004036e748>] filename_lookup+0xa0/0x168
 [<000000004036e95c>] user_path_at_empty+0x64/0x80
 [<000000004035d93c>] vfs_statx+0x104/0x158
 [<000000004035dfcc>] __do_sys_lstat64+0x44/0x80
 [<000000004035e5a0>] sys_lstat64+0x20/0x38
 [<0000000040180054>] syscall_exit+0x0/0x14

The code was stuck in this loop in d_alloc_parallel:

    4037d414:   0e 00 10 dc     ldd 0(r16),ret0
    4037d418:   c7 fc 5f ed     bb,< ret0,1f,4037d414 
    4037d41c:   08 00 02 40     nop

This is the inner loop of bit_spin_lock which is called by hlist_bl_unlock in
d_alloc_parallel:

static inline void bit_spin_lock(int bitnum, unsigned long *addr)
{
        /*
         * Assuming the lock is uncontended, this never enters
         * the body of the outer loop. If it is contended, then
         * within the inner loop a non-atomic test is used to
         * busywait with less bus contention for a good time to
         * attempt to acquire the lock bit.
         */
        preempt_disable();
#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
        while (unlikely(test_and_set_bit_lock(bitnum, addr))) {
                preempt_enable();
                do {
                        cpu_relax();
                } while (test_bit(bitnum, addr));
                preempt_disable();
        }
#endif
        __acquire(bitlock);
}

After consideration, I realized that we must be losing bit unlocks.
Then, I noticed that we missed defining atomic64_set_release().
Adding this define fixes the stalls in bit operations.

Signed-off-by: Dave Anglin 
Cc: stable@vger.kernel.org
Signed-off-by: Helge Deller 
Signed-off-by: Greg Kroah-Hartman

arm64: vdso32: Fix '--prefix=' value for newer versions of clang

2020-07-29T08:19:59+00:00

commit 7b7891c7bdfd61fc9ed6747a0a05efe2394dddc6 upstream.

Newer versions of clang only look for $(COMPAT_GCC_TOOLCHAIN_DIR)as [1],
rather than $(COMPAT_GCC_TOOLCHAIN_DIR)$(CROSS_COMPILE_COMPAT)as,
resulting in the following build error:

$ make -skj"$(nproc)" ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- \
CROSS_COMPILE_COMPAT=arm-linux-gnueabi- LLVM=1 O=out/aarch64 distclean \
defconfig arch/arm64/kernel/vdso32/
...
/home/nathan/cbl/toolchains/llvm-binutils/bin/as: unrecognized option '-EL'
clang-12: error: assembler command failed with exit code 1 (use -v to see invocation)
make[3]: *** [arch/arm64/kernel/vdso32/Makefile:181: arch/arm64/kernel/vdso32/note.o] Error 1
...

Adding the value of CROSS_COMPILE_COMPAT (adding notdir to account for a
full path for CROSS_COMPILE_COMPAT) fixes this issue, which matches the
solution done for the main Makefile [2].

[1]: https://github.com/llvm/llvm-project/commit/3452a0d8c17f7166f479706b293caf6ac76ffd90
[2]: https://lore.kernel.org/lkml/20200721173125.1273884-1-maskray@google.com/

Signed-off-by: Nathan Chancellor 
Cc: stable@vger.kernel.org
Link: https://github.com/ClangBuiltLinux/linux/issues/1099
Link: https://lore.kernel.org/r/20200723041509.400450-1-natechancellor@gmail.com
Signed-off-by: Will Deacon 
Signed-off-by: Greg Kroah-Hartman

x86/boot: Don't add the EFI stub to targets

2020-07-29T08:19:54+00:00

[ Upstream commit da05b143a308bd6a7a444401f9732678ae63fc70 ]

vmlinux-objs-y is added to targets, which currently means that the EFI
stub gets added to the targets as well. It shouldn't be added since it
is built elsewhere.

This confuses Makefile.build which interprets the EFI stub as a target
	$(obj)/$(objtree)/drivers/firmware/efi/libstub/lib.a
and will create drivers/firmware/efi/libstub/ underneath
arch/x86/boot/compressed, to hold this supposed target, if building
out-of-tree. [0]

Fix this by pulling the stub out of vmlinux-objs-y into efi-obj-y.

[0] See scripts/Makefile.build near the end:
    # Create directories for object files if they do not exist

Signed-off-by: Arvind Sankar 
Signed-off-by: Thomas Gleixner 
Reviewed-by: Masahiro Yamada 
Acked-by: Ard Biesheuvel 
Link: https://lkml.kernel.org/r/20200715032631.1562882-1-nivedita@alum.mit.edu
Signed-off-by: Sasha Levin

RISC-V: Upgrade smp_mb__after_spinlock() to iorw,iorw

2020-07-29T08:19:54+00:00

[ Upstream commit 38b7c2a3ffb1fce8358ddc6006cfe5c038ff9963 ]

While digging through the recent mmiowb preemption issue it came up that
we aren't actually preventing IO from crossing a scheduling boundary.
While it's a bit ugly to overload smp_mb__after_spinlock() with this
behavior, it's what PowerPC is doing so there's some precedent.

Signed-off-by: Palmer Dabbelt 
Signed-off-by: Sasha Levin

x86: math-emu: Fix up 'cmp' insn for clang ias

2020-07-29T08:19:54+00:00

[ Upstream commit 81e96851ea32deb2c921c870eecabf335f598aeb ]

The clang integrated assembler requires the 'cmp' instruction to
have a length prefix here:

arch/x86/math-emu/wm_sqrt.S:212:2: error: ambiguous instructions require an explicit suffix (could be 'cmpb', 'cmpw', or 'cmpl')
 cmp $0xffffffff,-24(%ebp)
 ^

Make this a 32-bit comparison, which it was clearly meant to be.

Signed-off-by: Arnd Bergmann 
Signed-off-by: Thomas Gleixner 
Reviewed-by: Nick Desaulniers 
Link: https://lkml.kernel.org/r/20200527135352.1198078-1-arnd@arndb.de
Signed-off-by: Sasha Levin

arm64: Use test_tsk_thread_flag() for checking TIF_SINGLESTEP

2020-07-29T08:19:54+00:00

[ Upstream commit 5afc78551bf5d53279036e0bf63314e35631d79f ]

Rather than open-code test_tsk_thread_flag() at each callsite, simply
replace the couple of offenders with calls to test_tsk_thread_flag()
directly.

Signed-off-by: Will Deacon 
Signed-off-by: Sasha Levin

ARM: dts: n900: remove mmc1 card detect gpio

2020-07-29T08:19:51+00:00

[ Upstream commit ed3e98e919aaaa47e9d9f8a40c3f6f4a22577842 ]

Instead, expose the key via the input framework, as SW_MACHINE_COVER

The chip-detect GPIO is actually detecting if the cover is closed.
Technically it's possible to use the SD card with open cover. The
only downside is risk of battery falling out and user being able
to physically remove the card.

The behaviour of SD card not being available when the device is
open is unexpected and creates more problems than it solves. There
is a high chance, that more people accidentally break their rootfs
by opening the case without physically removing the card.

Reviewed-by: Sebastian Reichel 
Acked-by: Tony Lindgren 
Signed-off-by: Merlijn Wajer 
Link: https://lore.kernel.org/r/20200612125402.18393-3-merlijn@wizzup.org
Signed-off-by: Dmitry Torokhov 
Signed-off-by: Sasha Levin

RISC-V: Do not rely on initrd_start/end computed during early dt parsing

2020-07-29T08:19:49+00:00

[ Upstream commit 4400231c8acc7e513204c8470c6d796ba47dc169 ]

Currently, initrd_start/end are computed during early_init_dt_scan
but used during arch_setup. We will get the following panic if initrd is used
and CONFIG_DEBUG_VIRTUAL is turned on.

[    0.000000] ------------[ cut here ]------------
[    0.000000] kernel BUG at arch/riscv/mm/physaddr.c:33!
[    0.000000] Kernel BUG [#1]
[    0.000000] Modules linked in:
[    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 5.8.0-rc4-00015-ged0b226fed02 #886
[    0.000000] epc: ffffffe0002058d2 ra : ffffffe0000053f0 sp : ffffffe001001f40
[    0.000000]  gp : ffffffe00106e250 tp : ffffffe001009d40 t0 : ffffffe00107ee28
[    0.000000]  t1 : 0000000000000000 t2 : ffffffe000a2e880 s0 : ffffffe001001f50
[    0.000000]  s1 : ffffffe0001383e8 a0 : ffffffe00c087e00 a1 : 0000000080200000
[    0.000000]  a2 : 00000000010bf000 a3 : ffffffe00106f3c8 a4 : ffffffe0010bf000
[    0.000000]  a5 : ffffffe000000000 a6 : 0000000000000006 a7 : 0000000000000001
[    0.000000]  s2 : ffffffe00106f068 s3 : ffffffe00106f070 s4 : 0000000080200000
[    0.000000]  s5 : 0000000082200000 s6 : 0000000000000000 s7 : 0000000000000000
[    0.000000]  s8 : 0000000080011010 s9 : 0000000080012700 s10: 0000000000000000
[    0.000000]  s11: 0000000000000000 t3 : 000000000001fe30 t4 : 000000000001fe30
[    0.000000]  t5 : 0000000000000000 t6 : ffffffe00107c471
[    0.000000] status: 0000000000000100 badaddr: 0000000000000000 cause: 0000000000000003
[    0.000000] random: get_random_bytes called from print_oops_end_marker+0x22/0x46 with crng_init=0

To avoid the error, initrd_start/end can be computed from phys_initrd_start/size
in setup itself. It also improves the initrd placement by aligning the start
and size with the page size.

Fixes: 76d2a0493a17 ("RISC-V: Init and Halt Code")
Signed-off-by: Atish Patra 
Signed-off-by: Palmer Dabbelt 
Signed-off-by: Sasha Levin

arm64: dts: clearfog-gt-8k: fix switch link configuration

2020-07-29T08:19:43+00:00

[ Upstream commit 7c6719a1aaca51ffd7cdf3905e70aa8313f6ef26 ]

The commit below caused a regression for clearfog-gt-8k, where the link
between the switch and the host does not come up.

Investigation revealed two issues:
- MV88E6xxx DSA no longer allows an in-band link to come up as the link
  is programmed to be forced down. Commit "net: dsa: mv88e6xxx: fix
  in-band AN link establishment" addresses this.

- The dts configured dissimilar link modes at each end of the host to
  switch link; the host was configured using a fixed link (so has no
  in-band status) and the switch was configured to expect in-band
  status.

With both issues fixed, the regression is resolved.

Fixes: 34b5e6a33c1a ("net: dsa: mv88e6xxx: Configure MAC when using fixed link")
Reported-by: Martin Rowe 
Signed-off-by: Russell King 
Reviewed-by: Andrew Lunn 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin