130881 Commits

Author SHA1 Message Date
Chen Yu
bd9dc1ee61 x86/microcode/intel: Check patch signature before saving microcode for early loading
commit 1a371e67dc77125736cc56d3a0893f06b75855b6 upstream.

Currently, scan_microcode() leverages microcode_matches() to check
if the microcode matches the CPU by comparing the family and model.
However, the processor stepping and flags of the microcode signature
should also be considered when saving a microcode patch for early
update.

Use find_matching_signature() in scan_microcode() and get rid of the
now-unused microcode_matches() which is a good cleanup in itself.

Complete the verification of the patch being saved for early loading in
save_microcode_patch() directly. This needs to be done there too because
save_mc_for_early() will call save_microcode_patch() too.

The second reason why this needs to be done is because the loader still
tries to support, at least hypothetically, mixed-steppings systems and
thus adds all patches to the cache that belong to the same CPU model
albeit with different steppings.

For example:

  microcode: CPU: sig=0x906ec, pf=0x2, rev=0xd6
  microcode: mc_saved[0]: sig=0x906e9, pf=0x2a, rev=0xd6, total size=0x19400, date = 2020-04-23
  microcode: mc_saved[1]: sig=0x906ea, pf=0x22, rev=0xd6, total size=0x19000, date = 2020-04-27
  microcode: mc_saved[2]: sig=0x906eb, pf=0x2, rev=0xd6, total size=0x19400, date = 2020-04-23
  microcode: mc_saved[3]: sig=0x906ec, pf=0x22, rev=0xd6, total size=0x19000, date = 2020-04-27
  microcode: mc_saved[4]: sig=0x906ed, pf=0x22, rev=0xd6, total size=0x19400, date = 2020-04-23

The patch which is being saved for early loading, however, can only be
the one which fits the CPU this runs on so do the signature verification
before saving.

 [ bp: Do signature verification in save_microcode_patch()
       and rewrite commit message. ]

Fixes: ec400ddeff20 ("x86/microcode_intel_early.c: Early update ucode on Intel's CPU")
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: stable@vger.kernel.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=208535
Link: https://lkml.kernel.org/r/20201113015923.13960-1-yu.c.chen@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-24 13:03:10 +01:00
Thomas Richter
89c4735078 s390/cpum_sf.c: fix file permission for cpum_sfb_size
commit 78d732e1f326f74f240d416af9484928303d9951 upstream.

This file is installed by the s390 CPU Measurement sampling
facility device driver to export supported minimum and
maximum sample buffer sizes.
This file is read by lscpumf tool to display the details
of the device driver capabilities. The lscpumf tool might
be invoked by a non-root user. In this case it does not
print anything because the file contents can not be read.

Fix this by allowing read access for all users. Reading
the file contents is ok, changing the file contents is
left to the root user only.

For further reference and details see:
 [1] https://github.com/ibm-s390-tools/s390-tools/issues/97

Fixes: 69f239ed335a ("s390/cpum_sf: Dynamically extend the sampling buffer if overflows occur")
Cc: <stable@vger.kernel.org> # 3.14
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-24 13:03:10 +01:00
Max Filippov
b567396b24 xtensa: disable preemption around cache alias management calls
commit 3a860d165eb5f4d7cf0bf81ef6a5b5c5e1754422 upstream.

Although cache alias management calls set up and tear down TLB entries
and fast_second_level_miss is able to restore TLB entry should it be
evicted they absolutely cannot preempt each other because they use the
same TLBTEMP area for different purposes.
Disable preemption around all cache alias management calls to enforce
that.

Cc: stable@vger.kernel.org
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-24 13:03:08 +01:00
Daniel Axtens
71be97f561 powerpc/uaccess-flush: fix missing includes in kup-radix.h
Guenter reports a build failure on cell_defconfig and maple_defconfg:

In file included from arch/powerpc/include/asm/kup.h:10:0,
		 from arch/powerpc/include/asm/uaccess.h:12,
		 from arch/powerpc/lib/checksum_wrappers.c:24:
arch/powerpc/include/asm/book3s/64/kup-radix.h:5:1: error: data definition has no type or storage class [-Werror]
 DECLARE_STATIC_KEY_FALSE(uaccess_flush_key);
 ^~~~~~~~~~~~~~~~~~~~~~~~
arch/powerpc/include/asm/book3s/64/kup-radix.h:5:1: error: type defaults to ‘int’ in declaration of ‘DECLARE_STATIC_KEY_FALSE’ [-Werror=implicit-int]
arch/powerpc/include/asm/book3s/64/kup-radix.h:5:1: error: parameter names (without types) in function declaration [-Werror]
arch/powerpc/include/asm/book3s/64/kup-radix.h: In function ‘prevent_user_access’:
arch/powerpc/include/asm/book3s/64/kup-radix.h:18:6: error: implicit declaration of function ‘static_branch_unlikely’ [-Werror=implicit-function-declaration]
  if (static_branch_unlikely(&uaccess_flush_key))
      ^~~~~~~~~~~~~~~~~~~~~~
arch/powerpc/include/asm/book3s/64/kup-radix.h:18:30: error: ‘uaccess_flush_key’ undeclared (first use in this function); did you mean
‘do_uaccess_flush’?
  if (static_branch_unlikely(&uaccess_flush_key))
			      ^~~~~~~~~~~~~~~~~
			      do_uaccess_flush
arch/powerpc/include/asm/book3s/64/kup-radix.h:18:30: note: each undeclared identifier is reported only once for each function it appears in
cc1: all warnings being treated as errors

This is because I failed to include linux/jump_label.h in kup-radix.h. Include it.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-24 13:03:05 +01:00
Zhang Qilong
e8b3315007 MIPS: Alchemy: Fix memleak in alchemy_clk_setup_cpu
[ Upstream commit ac3b57adf87ad9bac7e33ca26bbbb13fae1ed62b ]

If the clk_register fails, we should free h before
function returns to prevent memleak.

Fixes: 474402291a0ad ("MIPS: Alchemy: clock framework integration of onchip clocks")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-24 13:03:04 +01:00
Fabio Estevam
3e25dfc5a5 ARM: dts: imx50-evk: Fix the chip select 1 IOMUX
[ Upstream commit 33d0d843872c5ddbe28457a92fc6f2487315fb9f ]

The SPI chip selects are represented as:

cs-gpios = <&gpio4 11 GPIO_ACTIVE_LOW>, <&gpio4 13 GPIO_ACTIVE_LOW>;

, which means that they are used in GPIO function instead of native
SPI mode.

Fix the IOMUX for the chip select 1 to use GPIO4_13 instead of
the native CSPI_SSI function.

Fixes: c605cbf5e135 ("ARM: dts: imx: add device tree support for Freescale imx50evk board")
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-24 13:03:02 +01:00
Sergey Matyukevich
2290f132c7 arm: dts: imx6qdl-udoo: fix rgmii phy-mode for ksz9031 phy
[ Upstream commit 7dd8f0ba88fce98e2953267a66af74c6f4792a56 ]

Commit bcf3440c6dd7 ("net: phy: micrel: add phy-mode support for the
KSZ9031 PHY") fixed micrel phy driver adding proper support for phy
modes. Adapt imx6q-udoo board phy settings : explicitly set required
delay configuration using "rgmii-id".

Fixes: cbd54fe0b2bc ("ARM: dts: imx6dl-udoo: Add board support based off imx6q-udoo")
Signed-off-by: Sergey Matyukevich <geomatsi@gmail.com>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-24 13:03:01 +01:00
Randy Dunlap
5f575c174b MIPS: export has_transparent_hugepage() for modules
[ Upstream commit 31b4d8e172f614adc53ddecb4b6b2f6411a49b84 ]

MIPS should export its local version of "has_transparent_hugepage"
so that loadable modules (dax) can use it.

Fixes this build error:
ERROR: modpost: "has_transparent_hugepage" [drivers/dax/dax.ko] undefined!

Fixes: fd8cfd300019 ("arch: fix has_transparent_hugepage()")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: linux-mips@vger.kernel.org
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: linux-nvdimm@lists.01.org
Cc: Hugh Dickins <hughd@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-24 13:03:01 +01:00
Will Deacon
e2ee9ea98d arm64: psci: Avoid printing in cpu_psci_cpu_die()
[ Upstream commit 891deb87585017d526b67b59c15d38755b900fea ]

cpu_psci_cpu_die() is called in the context of the dying CPU, which
will no longer be online or tracked by RCU. It is therefore not generally
safe to call printk() if the PSCI "cpu off" request fails, so remove the
pr_crit() invocation.

Cc: Qian Cai <cai@redhat.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20201106103602.9849-2-will@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-24 13:03:00 +01:00
David Edmondson
55f76704ec KVM: x86: clflushopt should be treated as a no-op by emulation
commit 51b958e5aeb1e18c00332e0b37c5d4e95a3eff84 upstream.

The instruction emulator ignores clflush instructions, yet fails to
support clflushopt. Treat both similarly.

Fixes: 13e457e0eebf ("KVM: x86: Emulator does not decode clflush well")
Signed-off-by: David Edmondson <david.edmondson@oracle.com>
Message-Id: <20201103120400.240882-1-david.edmondson@oracle.com>
Reviewed-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-22 09:58:14 +01:00
Christophe Leroy
4f268980d0 powerpc/8xx: Always fault when _PAGE_ACCESSED is not set
commit 29daf869cbab69088fe1755d9dd224e99ba78b56 upstream.

The kernel expects pte_young() to work regardless of CONFIG_SWAP.

Make sure a minor fault is taken to set _PAGE_ACCESSED when it
is not already set, regardless of the selection of CONFIG_SWAP.

This adds at least 3 instructions to the TLB miss exception
handlers fast path. Following patch will reduce this overhead.

Also update the rotation instruction to the correct number of bits
to reflect all changes done to _PAGE_ACCESSED over time.

Fixes: d069cb4373fe ("powerpc/8xx: Don't touch ACCESSED when no SWAP.")
Fixes: 5f356497c384 ("powerpc/8xx: remove unused _PAGE_WRITETHRU")
Fixes: e0a8e0d90a9f ("powerpc/8xx: Handle PAGE_USER via APG bits")
Fixes: 5b2753fc3e8a ("powerpc/8xx: Implementation of PAGE_EXEC")
Fixes: a891c43b97d3 ("powerpc/8xx: Prepare handlers for _PAGE_HUGE for 512k pages.")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/af834e8a0f1fa97bfae65664950f0984a70c4750.1602492856.git.christophe.leroy@csgroup.eu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-22 09:58:14 +01:00
Nicholas Piggin
d67c5c60a4 powerpc/64s: flush L1D after user accesses
commit 9a32a7e78bd0cd9a9b6332cbdc345ee5ffd0c5de upstream.

IBM Power9 processors can speculatively operate on data in the L1 cache before
it has been completely validated, via a way-prediction mechanism. It is not possible
for an attacker to determine the contents of impermissible memory using this method,
since these systems implement a combination of hardware and software security measures
to prevent scenarios where protected data could be leaked.

However these measures don't address the scenario where an attacker induces
the operating system to speculatively execute instructions using data that the
attacker controls. This can be used for example to speculatively bypass "kernel
user access prevention" techniques, as discovered by Anthony Steinhauser of
Google's Safeside Project. This is not an attack by itself, but there is a possibility
it could be used in conjunction with side-channels or other weaknesses in the
privileged code to construct an attack.

This issue can be mitigated by flushing the L1 cache between privilege boundaries
of concern. This patch flushes the L1 cache after user accesses.

This is part of the fix for CVE-2020-4788.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-22 09:58:14 +01:00
Nicholas Piggin
9fbcbd259c powerpc/uaccess: Evaluate macro arguments once, before user access is allowed
commit d02f6b7dab8228487268298ea1f21081c0b4b3eb upstream.

get/put_user() can be called with nontrivial arguments. fs/proc/page.c
has a good example:

    if (put_user(stable_page_flags(ppage), out)) {

stable_page_flags() is quite a lot of code, including spin locks in
the page allocator.

Ensure these arguments are evaluated before user access is allowed.

This improves security by reducing code with access to userspace, but
it also fixes a PREEMPT bug with KUAP on powerpc/64s:
stable_page_flags() is currently called with AMR set to allow writes,
it ends up calling spin_unlock(), which can call preempt_schedule. But
the task switch code can not be called with AMR set (it relies on
interrupts saving the register), so this blows up.

It's fine if the code inside allow_user_access() is preemptible,
because a timer or IPI will save the AMR, but it's not okay to
explicitly cause a reschedule.

Fixes: de78a9c42a79 ("powerpc: Add a framework for Kernel Userspace Access Protection")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200407041245.600651-1-npiggin@gmail.com
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-22 09:58:13 +01:00
Andrew Donnellan
d765c7b38b powerpc: Fix __clear_user() with KUAP enabled
commit 61e3acd8c693a14fc69b824cb5b08d02cb90a6e7 upstream.

The KUAP implementation adds calls in clear_user() to enable and
disable access to userspace memory. However, it doesn't add these to
__clear_user(), which is used in the ptrace regset code.

As there's only one direct user of __clear_user() (the regset code),
and the time taken to set the AMR for KUAP purposes is going to
dominate the cost of a quick access_ok(), there's not much point
having a separate path.

Rename __clear_user() to __arch_clear_user(), and make __clear_user()
just call clear_user().

Reported-by: syzbot+f25ecf4b2982d8c7a640@syzkaller-ppc64.appspotmail.com
Reported-by: Daniel Axtens <dja@axtens.net>
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Fixes: de78a9c42a79 ("powerpc: Add a framework for Kernel Userspace Access Protection")
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
[mpe: Use __arch_clear_user() for the asm version like arm64 & nds32]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191209132221.15328-1-ajd@linux.ibm.com
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-22 09:58:13 +01:00
Christophe Leroy
3853ff5774 powerpc: Implement user_access_begin and friends
commit 5cd623333e7cf4e3a334c70529268b65f2a6c2c7 upstream.

Today, when a function like strncpy_from_user() is called,
the userspace access protection is de-activated and re-activated
for every word read.

By implementing user_access_begin and friends, the protection
is de-activated at the beginning of the copy and re-activated at the
end.

Implement user_access_begin(), user_access_end() and
unsafe_get_user(), unsafe_put_user() and unsafe_copy_to_user()

For the time being, we keep user_access_save() and
user_access_restore() as nops.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/36d4fbf9e56a75994aca4ee2214c77b26a5a8d35.1579866752.git.christophe.leroy@c-s.fr
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-22 09:58:13 +01:00
Christophe Leroy
82973e9a1b powerpc: Add a framework for user access tracking
Backported from commit de78a9c42a79 ("powerpc: Add a framework
for Kernel Userspace Access Protection"). Here we don't try to
add the KUAP framework, we just want the helper functions
because we want to put uaccess flush helpers in them.

In terms of fixes, we don't need commit 1d8f739b07bd ("powerpc/kuap:
Fix set direction in allow/prevent_user_access()") as we don't have
real KUAP. Likewise as all our allows are noops and all our prevents
are just flushes, we don't need commit 9dc086f1e9ef ("powerpc/futex:
Fix incorrect user access blocking") The other 2 fixes we do need.

The original description is:

This patch implements a framework for Kernel Userspace Access
Protection.

Then subarches will have the possibility to provide their own
implementation by providing setup_kuap() and
allow/prevent_user_access().

Some platforms will need to know the area accessed and whether it is
accessed from read, write or both. Therefore source, destination and
size and handed over to the two functions.

mpe: Rename to allow/prevent rather than unlock/lock, and add
read/write wrappers. Drop the 32-bit code for now until we have an
implementation for it. Add kuap to pt_regs for 64-bit as well as
32-bit. Don't split strings, use pr_crit_ratelimited().

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-22 09:58:13 +01:00
Nicholas Piggin
fa4bf9f381 powerpc/64s: flush L1D on kernel entry
commit f79643787e0a0762d2409b7b8334e83f22d85695 upstream.

IBM Power9 processors can speculatively operate on data in the L1 cache before
it has been completely validated, via a way-prediction mechanism. It is not possible
for an attacker to determine the contents of impermissible memory using this method,
since these systems implement a combination of hardware and software security measures
to prevent scenarios where protected data could be leaked.

However these measures don't address the scenario where an attacker induces
the operating system to speculatively execute instructions using data that the
attacker controls. This can be used for example to speculatively bypass "kernel
user access prevention" techniques, as discovered by Anthony Steinhauser of
Google's Safeside Project. This is not an attack by itself, but there is a possibility
it could be used in conjunction with side-channels or other weaknesses in the
privileged code to construct an attack.

This issue can be mitigated by flushing the L1 cache between privilege boundaries
of concern. This patch flushes the L1 cache on kernel entry.

This is part of the fix for CVE-2020-4788.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-22 09:58:13 +01:00
Daniel Axtens
4eb53cb9f9 powerpc/64s: move some exception handlers out of line
(backport only)

We're about to grow the exception handlers, which will make a bunch of them
no longer fit within the space available. We move them out of line.

This is a fiddly and error-prone business, so in the interests of reviewability
I haven't merged this in with the addition of the entry flush.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-22 09:58:13 +01:00
Daniel Axtens
6672e0ba87 powerpc/64s: Define MASKABLE_RELON_EXCEPTION_PSERIES_OOL
Commit da2bc4644c75 ("powerpc/64s: Add new exception vector macros")
adds:

+#define __TRAMP_REAL_VIRT_OOL_MASKABLE(name, realvec)          \
+       TRAMP_REAL_BEGIN(tramp_virt_##name);                            \
+       MASKABLE_RELON_EXCEPTION_PSERIES_OOL(realvec, name##_common);   \

However there's no reference there or anywhere else to
MASKABLE_RELON_EXCEPTION_PSERIES_OOL and an attempt to use it
unsurprisingly doesn't work.

Add a definition provided by mpe.

Fixes: da2bc4644c75 ("powerpc/64s: Add new exception vector macros")
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-22 09:58:13 +01:00
Song Liu
51f0471b12 perf/core: Fix bad use of igrab()
commit 9511bce9fe8e5e6c0f923c09243a713eba560141 upstream

As Miklos reported and suggested:

 "This pattern repeats two times in trace_uprobe.c and in
  kernel/events/core.c as well:

      ret = kern_path(filename, LOOKUP_FOLLOW, &path);
      if (ret)
          goto fail_address_parse;

      inode = igrab(d_inode(path.dentry));
      path_put(&path);

  And it's wrong.  You can only hold a reference to the inode if you
  have an active ref to the superblock as well (which is normally
  through path.mnt) or holding s_umount.

  This way unmounting the containing filesystem while the tracepoint is
  active will give you the "VFS: Busy inodes after unmount..." message
  and a crash when the inode is finally put.

  Solution: store path instead of inode."

This patch fixes the issue in kernel/event/core.c.

Reviewed-and-tested-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reported-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <kernel-team@fb.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Fixes: 375637bc5249 ("perf/core: Introduce address range filtering")
Link: http://lkml.kernel.org/r/20180418062907.3210386-2-songliubraving@fb.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
[sudip: Backported to 4.9: use file_inode()]
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-18 18:26:29 +01:00
Anand K Mistry
27979f6087 x86/speculation: Allow IBPB to be conditionally enabled on CPUs with always-on STIBP
commit 1978b3a53a74e3230cd46932b149c6e62e832e9a upstream.

On AMD CPUs which have the feature X86_FEATURE_AMD_STIBP_ALWAYS_ON,
STIBP is set to on and

  spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT_PREFERRED

At the same time, IBPB can be set to conditional.

However, this leads to the case where it's impossible to turn on IBPB
for a process because in the PR_SPEC_DISABLE case in ib_prctl_set() the

  spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT_PREFERRED

condition leads to a return before the task flag is set. Similarly,
ib_prctl_get() will return PR_SPEC_DISABLE even though IBPB is set to
conditional.

More generally, the following cases are possible:

1. STIBP = conditional && IBPB = on for spectre_v2_user=seccomp,ibpb
2. STIBP = on && IBPB = conditional for AMD CPUs with
   X86_FEATURE_AMD_STIBP_ALWAYS_ON

The first case functions correctly today, but only because
spectre_v2_user_ibpb isn't updated to reflect the IBPB mode.

At a high level, this change does one thing. If either STIBP or IBPB
is set to conditional, allow the prctl to change the task flag.
Also, reflect that capability when querying the state. This isn't
perfect since it doesn't take into account if only STIBP or IBPB is
unconditionally on. But it allows the conditional feature to work as
expected, without affecting the unconditional one.

 [ bp: Massage commit message and comment; space out statements for
   better readability. ]

Fixes: 21998a351512 ("x86/speculation: Avoid force-disabling IBPB based on STIBP and enhanced IBRS.")
Signed-off-by: Anand K Mistry <amistry@google.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lkml.kernel.org/r/20201105163246.v2.1.Ifd7243cd3e2c2206a893ad0a5b9a4f19549e22c6@changeid
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-18 18:26:29 +01:00
Vineet Gupta
fc6220f23d Revert "ARC: entry: fix potential EFA clobber when TIF_SYSCALL_TRACE"
This reverts commit 00fdec98d9881bf5173af09aebd353ab3b9ac729.
(but only from 5.2 and prior kernels)

The original commit was a preventive fix based on code-review and was
auto-picked for stable back-port (for better or worse).
It was OK for v5.3+ kernels, but turned up needing an implicit change
68e5c6f073bcf70 "(ARC: entry: EV_Trap expects r10 (vs. r9) to have
 exception cause)" merged in v5.3 which itself was not backported.
So to summarize the stable backport of this patch for v5.2 and prior
kernels is busted and it won't boot.

The obvious solution is backport 68e5c6f073bcf70 but that is a pain as
it doesn't revert cleanly and each of affected kernels (so far v4.19,
v4.14, v4.9, v4.4) needs a slightly different massaged varaint.
So the easier fix is to simply revert the backport from 5.2 and prior.
The issue was not a big deal as it would cause strace to sporadically
not work correctly.

Waldemar Brodkorb first reported this when running ARC uClibc regressions
on latest stable kernels (with offending backport). Once he bisected it,
the analysis was trivial, so thx to him for this.

Reported-by: Waldemar Brodkorb <wbx@uclibc-ng.org>
Bisected-by: Waldemar Brodkorb <wbx@uclibc-ng.org>
Cc: stable <stable@vger.kernel.org> # 5.2 and prior
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-10 10:24:04 +01:00
Vineet Gupta
6ffed409b0 ARC: stack unwinding: avoid indefinite looping
commit 328d2168ca524d501fc4b133d6be076142bd305c upstream.

Currently stack unwinder is a while(1) loop which relies on the dwarf
unwinder to signal termination, which in turn relies on dwarf info to do
so. This in theory could cause an infinite loop if the dwarf info was
somehow messed up or the register contents were etc.

This fix thus detects the excessive looping and breaks the loop.

| Mem: 26184K used, 1009136K free, 0K shrd, 0K buff, 14416K cached
| CPU:  0.0% usr 72.8% sys  0.0% nic 27.1% idle  0.0% io  0.0% irq  0.0% sirq
| Load average: 4.33 2.60 1.11 2/74 139
|   PID  PPID USER     STAT   VSZ %VSZ CPU %CPU COMMAND
|   133     2 root     SWN      0  0.0   3 22.9 [rcu_torture_rea]
|   132     2 root     SWN      0  0.0   0 22.0 [rcu_torture_rea]
|   131     2 root     SWN      0  0.0   3 21.5 [rcu_torture_rea]
|   126     2 root     RW       0  0.0   2  5.4 [rcu_torture_wri]
|   129     2 root     SWN      0  0.0   0  0.2 [rcu_torture_fak]
|   137     2 root     SW       0  0.0   0  0.2 [rcu_torture_cbf]
|   127     2 root     SWN      0  0.0   0  0.1 [rcu_torture_fak]
|   138   115 root     R     1464  0.1   2  0.1 top
|   130     2 root     SWN      0  0.0   0  0.1 [rcu_torture_fak]
|   128     2 root     SWN      0  0.0   0  0.1 [rcu_torture_fak]
|   115     1 root     S     1472  0.1   1  0.0 -/bin/sh
|   104     1 root     S     1464  0.1   0  0.0 inetd
|     1     0 root     S     1456  0.1   2  0.0 init
|    78     1 root     S     1456  0.1   0  0.0 syslogd -O /var/log/messages
|   134     2 root     SW       0  0.0   2  0.0 [rcu_torture_sta]
|    10     2 root     IW       0  0.0   1  0.0 [rcu_preempt]
|    88     2 root     IW       0  0.0   1  0.0 [kworker/1:1-eve]
|    66     2 root     IW       0  0.0   2  0.0 [kworker/2:2-eve]
|    39     2 root     IW       0  0.0   2  0.0 [kworker/2:1-eve]
| unwinder looping too long, aborting !

Cc: <stable@vger.kernel.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-10 10:24:04 +01:00
Kairui Song
5eb9f353c2 x86/kexec: Use up-to-dated screen_info copy to fill boot params
[ Upstream commit afc18069a2cb7ead5f86623a5f3d4ad6e21f940d ]

kexec_file_load() currently reuses the old boot_params.screen_info,
but if drivers have change the hardware state, boot_param.screen_info
could contain invalid info.

For example, the video type might be no longer VGA, or the frame buffer
address might be changed. If the kexec kernel keeps using the old screen_info,
kexec'ed kernel may attempt to write to an invalid framebuffer
memory region.

There are two screen_info instances globally available, boot_params.screen_info
and screen_info. Later one is a copy, and is updated by drivers.

So let kexec_file_load use the updated copy.

[ mingo: Tidied up the changelog. ]

Signed-off-by: Kairui Song <kasong@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20201014092429.1415040-2-kasong@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-10 10:24:02 +01:00
Clément Péron
83f5b7bb79 ARM: dts: sun4i-a10: fix cpu_alert temperature
[ Upstream commit dea252fa41cd8ce332d148444e4799235a8a03ec ]

When running dtbs_check thermal_zone warn about the
temperature declared.

thermal-zones: cpu-thermal:trips:cpu-alert0:temperature:0:0: 850000 is greater than the maximum of 200000

It's indeed wrong the real value is 85°C and not 850°C.

Signed-off-by: Clément Péron <peron.clem@gmail.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20201003100332.431178-1-peron.clem@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-10 10:24:02 +01:00
Marc Zyngier
1ba973aafb KVM: arm64: Fix AArch32 handling of DBGD{CCINT,SCRext} and DBGVCR
commit 4a1c2c7f63c52ccb11770b5ae25920a6b79d3548 upstream.

The DBGD{CCINT,SCRext} and DBGVCR register entries in the cp14 array
are missing their target register, resulting in all accesses being
targetted at the guard sysreg (indexed by __INVALID_SYSREG__).

Point the emulation code at the actual register entries.

Fixes: bdfb4b389c8d ("arm64: KVM: add trap handlers for AArch32 debug registers")
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20201029172409.2768336-1-maz@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-10 10:24:01 +01:00
Krzysztof Kozlowski
1c71edbce5 ARM: s3c24xx: fix missing system reset
commit f6d7cde84f6c5551586c8b9b68d70f8e6dc9a000 upstream.

Commit f6361c6b3880 ("ARM: S3C24XX: remove separate restart code")
removed usage of the watchdog reset platform code in favor of the
Samsung SoC watchdog driver.  However the latter was not selected thus
S3C24xx platforms lost reset abilities.

Cc: <stable@vger.kernel.org>
Fixes: f6361c6b3880 ("ARM: S3C24XX: remove separate restart code")
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-10 10:24:00 +01:00
Krzysztof Kozlowski
2e76c253a0 ARM: samsung: fix PM debug build with DEBUG_LL but !MMU
commit 7be0d19c751b02db778ca95e3274d5ea7f31891c upstream.

Selecting CONFIG_SAMSUNG_PM_DEBUG (depending on CONFIG_DEBUG_LL) but
without CONFIG_MMU leads to build errors:

  arch/arm/plat-samsung/pm-debug.c: In function ‘s3c_pm_uart_base’:
  arch/arm/plat-samsung/pm-debug.c:57:2: error:
    implicit declaration of function ‘debug_ll_addr’ [-Werror=implicit-function-declaration]

Fixes: 99b2fc2b8b40 ("ARM: SAMSUNG: Use debug_ll_addr() to get UART base address")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200910154150.3318-1-krzk@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-10 10:24:00 +01:00
Jisheng Zhang
291f614da6 arm64: berlin: Select DW_APB_TIMER_OF
commit b0fc70ce1f028e14a37c186d9f7a55e51439b83a upstream.

Berlin SoCs always contain some DW APB timers which can be used as an
always-on broadcast timer.

Link: https://lore.kernel.org/r/20201009150536.214181fb@xhacker.debian
Cc: <stable@vger.kernel.org> # v3.14+
Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-10 10:24:00 +01:00
Krzysztof Kozlowski
1c01388c5e ia64: fix build error with !COREDUMP
commit 7404840d87557c4092bf0272bce5e0354c774bf9 upstream.

Fix linkage error when CONFIG_BINFMT_ELF is selected but CONFIG_COREDUMP
is not:

    ia64-linux-ld: arch/ia64/kernel/elfcore.o: in function `elf_core_write_extra_phdrs':
    elfcore.c:(.text+0x172): undefined reference to `dump_emit'
    ia64-linux-ld: arch/ia64/kernel/elfcore.o: in function `elf_core_write_extra_data':
    elfcore.c:(.text+0x2b2): undefined reference to `dump_emit'

Fixes: 1fcccbac89f5 ("elf coredump: replace ELF_CORE_EXTRA_* macros by functions")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20200819064146.12529-1-krzk@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-10 10:23:59 +01:00
Mahesh Salgaonkar
29b6e4eefe powerpc/powernv/elog: Fix race while processing OPAL error log event.
commit aea948bb80b478ddc2448f7359d574387521a52d upstream.

Every error log reported by OPAL is exported to userspace through a
sysfs interface and notified using kobject_uevent(). The userspace
daemon (opal_errd) then reads the error log and acknowledges the error
log is saved safely to disk. Once acknowledged the kernel removes the
respective sysfs file entry causing respective resources to be
released including kobject.

However it's possible the userspace daemon may already be scanning
elog entries when a new sysfs elog entry is created by the kernel.
User daemon may read this new entry and ack it even before kernel can
notify userspace about it through kobject_uevent() call. If that
happens then we have a potential race between
elog_ack_store->kobject_put() and kobject_uevent which can lead to
use-after-free of a kernfs object resulting in a kernel crash. eg:

  BUG: Unable to handle kernel data access on read at 0x6b6b6b6b6b6b6bfb
  Faulting instruction address: 0xc0000000008ff2a0
  Oops: Kernel access of bad area, sig: 11 [#1]
  LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA PowerNV
  CPU: 27 PID: 805 Comm: irq/29-opal-elo Not tainted 5.9.0-rc2-gcc-8.2.0-00214-g6f56a67bcbb5-dirty #363
  ...
  NIP kobject_uevent_env+0xa0/0x910
  LR  elog_event+0x1f4/0x2d0
  Call Trace:
    0x5deadbeef0000122 (unreliable)
    elog_event+0x1f4/0x2d0
    irq_thread_fn+0x4c/0xc0
    irq_thread+0x1c0/0x2b0
    kthread+0x1c4/0x1d0
    ret_from_kernel_thread+0x5c/0x6c

This patch fixes this race by protecting the sysfs file
creation/notification by holding a reference count on kobject until we
safely send kobject_uevent().

The function create_elog_obj() returns the elog object which if used
by caller function will end up in use-after-free problem again.
However, the return value of create_elog_obj() function isn't being
used today and there is no need as well. Hence change it to return
void to make this fix complete.

Fixes: 774fea1a38c6 ("powerpc/powernv: Read OPAL error log and export it through sysfs")
Cc: stable@vger.kernel.org # v3.15+
Reported-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reviewed-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
[mpe: Rework the logic to use a single return, reword comments, add oops]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201006122051.190176-1-mpe@ellerman.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-10 10:23:58 +01:00
Joel Stanley
45f0ea796c powerpc: Warn about use of smt_snooze_delay
commit a02f6d42357acf6e5de6ffc728e6e77faf3ad217 upstream.

It's not done anything for a long time. Save the percpu variable, and
emit a warning to remind users to not expect it to do anything.

This uses pr_warn_once instead of pr_warn_ratelimit as testing
'ppc64_cpu --smt=off' on a 24 core / 4 SMT system showed the warning
to be noisy, as the online/offline loop is slow.

Fixes: 3fa8cad82b94 ("powerpc/pseries/cpuidle: smt-snooze-delay cleanup.")
Cc: stable@vger.kernel.org # v3.14
Signed-off-by: Joel Stanley <joel@jms.id.au>
Acked-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200902000012.3440389-1-joel@jms.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-10 10:23:58 +01:00
Kim Phillips
66348e142d perf/x86/amd/ibs: Fix raw sample data accumulation
commit 36e1be8ada994d509538b3b1d0af8b63c351e729 upstream.

Neither IbsBrTarget nor OPDATA4 are populated in IBS Fetch mode.
Don't accumulate them into raw sample user data in that case.

Also, in Fetch mode, add saving the IBS Fetch Control Extended MSR.

Technically, there is an ABI change here with respect to the IBS raw
sample data format, but I don't see any perf driver version information
being included in perf.data file headers, but, existing users can detect
whether the size of the sample record has reduced by 8 bytes to
determine whether the IBS driver has this fix.

Fixes: 904cb3677f3a ("perf/x86/amd/ibs: Update IBS MSRs and feature definitions")
Reported-by: Stephane Eranian <stephane.eranian@google.com>
Signed-off-by: Kim Phillips <kim.phillips@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20200908214740.18097-6-kim.phillips@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-10 10:23:55 +01:00
Kim Phillips
df383f9814 perf/x86/amd/ibs: Don't include randomized bits in get_ibs_op_count()
commit 680d69635005ba0e58fe3f4c52fc162b8fc743b0 upstream.

get_ibs_op_count() adds hardware's current count (IbsOpCurCnt) bits
to its count regardless of hardware's valid status.

According to the PPR for AMD Family 17h Model 31h B0 55803 Rev 0.54,
if the counter rolls over, valid status is set, and the lower 7 bits
of IbsOpCurCnt are randomized by hardware.

Don't include those bits in the driver's event count.

Fixes: 8b1e13638d46 ("perf/x86-ibs: Fix usage of IBS op current count")
Signed-off-by: Kim Phillips <kim.phillips@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-10 10:23:55 +01:00
Krzysztof Kozlowski
dc984c639e ARM: dts: s5pv210: remove dedicated 'audio-subsystem' node
[ Upstream commit 6c17a2974abf68a58517f75741b15c4aba42b4b8 ]

The 'audio-subsystem' node is an artificial creation, not representing
real hardware.  The hardware is described by its nodes - AUDSS clock
controller and I2S0.

Remove the 'audio-subsystem' node along with its undocumented compatible
to fix dtbs_check warnings like:

  audio-subsystem: $nodename:0: 'audio-subsystem' does not match '^([a-z][a-z0-9\\-]+-bus|bus|soc|axi|ahb|apb)(@[0-9a-f]+)?$'

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Tested-by: Jonathan Bakker <xc-racer2@live.ca>
Link: https://lore.kernel.org/r/20200907161141.31034-9-krzk@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-10 10:23:55 +01:00
Krzysztof Kozlowski
61626b6477 ARM: dts: s5pv210: move PMU node out of clock controller
[ Upstream commit bb98fff84ad1ea321823759edaba573a16fa02bd ]

The Power Management Unit (PMU) is a separate device which has little
common with clock controller.  Moving it to one level up (from clock
controller child to SoC) allows to remove fake simple-bus compatible and
dtbs_check warnings like:

  clock-controller@e0100000: $nodename:0:
    'clock-controller@e0100000' does not match '^([a-z][a-z0-9\\-]+-bus|bus|soc|axi|ahb|apb)(@[0-9a-f]+)?$'

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Tested-by: Jonathan Bakker <xc-racer2@live.ca>
Link: https://lore.kernel.org/r/20200907161141.31034-8-krzk@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-10 10:23:55 +01:00
Krzysztof Kozlowski
35229d6865 ARM: dts: s5pv210: remove DMA controller bus node name to fix dtschema warnings
[ Upstream commit ea4e792f3c8931fffec4d700cf6197d84e9f35a6 ]

There is no need to keep DMA controller nodes under AMBA bus node.
Remove the "amba" node to fix dtschema warnings like:

  amba: $nodename:0: 'amba' does not match '^([a-z][a-z0-9\\-]+-bus|bus|soc|axi|ahb|apb)(@[0-9a-f]+)?$'

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Tested-by: Jonathan Bakker <xc-racer2@live.ca>
Link: https://lore.kernel.org/r/20200907161141.31034-6-krzk@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-10 10:23:55 +01:00
Zhengyuan Liu
ed121ea5a3 arm64/mm: return cpu_all_mask when node is NUMA_NO_NODE
[ Upstream commit a194c5f2d2b3a05428805146afcabe5140b5d378 ]

The @node passed to cpumask_of_node() can be NUMA_NO_NODE, in that
case it will trigger the following WARN_ON(node >= nr_node_ids) due to
mismatched data types of @node and @nr_node_ids. Actually we should
return cpu_all_mask just like most other architectures do if passed
NUMA_NO_NODE.

Also add a similar check to the inline cpumask_of_node() in numa.h.

Signed-off-by: Zhengyuan Liu <liuzhengyuan@tj.kylinos.cn>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Link: https://lore.kernel.org/r/20200921023936.21846-1-liuzhengyuan@tj.kylinos.cn
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-10 10:23:54 +01:00
Douglas Anderson
e8f7f0932b ARM: 8997/2: hw_breakpoint: Handle inexact watchpoint addresses
[ Upstream commit 22c9e58299e5f18274788ce54c03d4fb761e3c5d ]

This is commit fdfeff0f9e3d ("arm64: hw_breakpoint: Handle inexact
watchpoint addresses") but ported to arm32, which has the same
problem.

This problem was found by Android CTS tests, notably the
"watchpoint_imprecise" test [1].  I tested locally against a copycat
(simplified) version of the test though.

[1] https://android.googlesource.com/platform/bionic/+/master/tests/sys_ptrace_test.cpp

Link: https://lkml.kernel.org/r/20191019111216.1.I82eae759ca6dc28a245b043f485ca490e3015321@changeid

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-10 10:23:52 +01:00
Johannes Berg
529db6661c um: change sigio_spinlock to a mutex
[ Upstream commit f2d05059e15af3f70502074f4e3a504530af504a ]

Lockdep complains at boot:

=============================
[ BUG: Invalid wait context ]
5.7.0-05093-g46d91ecd597b #98 Not tainted
-----------------------------
swapper/1 is trying to lock:
0000000060931b98 (&desc[i].request_mutex){+.+.}-{3:3}, at: __setup_irq+0x11d/0x623
other info that might help us debug this:
context-{4:4}
1 lock held by swapper/1:
 #0: 000000006074fed8 (sigio_spinlock){+.+.}-{2:2}, at: sigio_lock+0x1a/0x1c
stack backtrace:
CPU: 0 PID: 1 Comm: swapper Not tainted 5.7.0-05093-g46d91ecd597b #98
Stack:
 7fa4fab0 6028dfd1 0000002a 6008bea5
 7fa50700 7fa50040 7fa4fac0 6028e016
 7fa4fb50 6007f6da 60959c18 00000000
Call Trace:
 [<60023a0e>] show_stack+0x13b/0x155
 [<6028e016>] dump_stack+0x2a/0x2c
 [<6007f6da>] __lock_acquire+0x515/0x15f2
 [<6007eb50>] lock_acquire+0x245/0x273
 [<6050d9f1>] __mutex_lock+0xbd/0x325
 [<6050dc76>] mutex_lock_nested+0x1d/0x1f
 [<6008e27e>] __setup_irq+0x11d/0x623
 [<6008e8ed>] request_threaded_irq+0x169/0x1a6
 [<60021eb0>] um_request_irq+0x1ee/0x24b
 [<600234ee>] write_sigio_irq+0x3b/0x76
 [<600383ca>] sigio_broken+0x146/0x2e4
 [<60020bd8>] do_one_initcall+0xde/0x281

Because we hold sigio_spinlock and then get into requesting
an interrupt with a mutex.

Change the spinlock to a mutex to avoid that.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-10 10:23:52 +01:00
Nicholas Piggin
0e6277eb59 sparc64: remove mm_cpumask clearing to fix kthread_use_mm race
[ Upstream commit bafb056ce27940c9994ea905336aa8f27b4f7275 ]

The de facto (and apparently uncommented) standard for using an mm had,
thanks to this code in sparc if nothing else, been that you must have a
reference on mm_users *and that reference must have been obtained with
mmget()*, i.e., from a thread with a reference to mm_users that had used
the mm.

The introduction of mmget_not_zero() in commit d2005e3f41d4
("userfaultfd: don't pin the user memory in userfaultfd_file_create()")
allowed mm_count holders to aoperate on user mappings asynchronously
from the actual threads using the mm, but they were not to load those
mappings into their TLB (i.e., walking vmas and page tables is okay,
kthread_use_mm() is not).

io_uring 2b188cc1bb857 ("Add io_uring IO interface") added code which
does a kthread_use_mm() from a mmget_not_zero() refcount.

The problem with this is code which previously assumed mm == current->mm
and mm->mm_users == 1 implies the mm will remain single-threaded at
least until this thread creates another mm_users reference, has now
broken.

arch/sparc/kernel/smp_64.c:

    if (atomic_read(&mm->mm_users) == 1) {
        cpumask_copy(mm_cpumask(mm), cpumask_of(cpu));
        goto local_flush_and_out;
    }

vs fs/io_uring.c

    if (unlikely(!(ctx->flags & IORING_SETUP_SQPOLL) ||
                 !mmget_not_zero(ctx->sqo_mm)))
        return -EFAULT;
    kthread_use_mm(ctx->sqo_mm);

mmget_not_zero() could come in right after the mm_users == 1 test, then
kthread_use_mm() which sets its CPU in the mm_cpumask. That update could
be lost if cpumask_copy() occurs afterward.

I propose we fix this by allowing mmget_not_zero() to be a first-class
reference, and not have this obscure undocumented and unchecked
restriction.

The basic fix for sparc64 is to remove its mm_cpumask clearing code. The
optimisation could be effectively restored by sending IPIs to mm_cpumask
members and having them remove themselves from mm_cpumask. This is more
tricky so I leave it as an exercise for someone with a sparc64 SMP.
powerpc has a (currently similarly broken) example.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200914045219.3736466-4-npiggin@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-10 10:23:52 +01:00
Oliver O'Halloran
726e1b2fc4 powerpc/powernv/smp: Fix spurious DBG() warning
[ Upstream commit f6bac19cf65c5be21d14a0c9684c8f560f2096dd ]

When building with W=1 we get the following warning:

 arch/powerpc/platforms/powernv/smp.c: In function ‘pnv_smp_cpu_kill_self’:
 arch/powerpc/platforms/powernv/smp.c:276:16: error: suggest braces around
 	empty body in an ‘if’ statement [-Werror=empty-body]
   276 |      cpu, srr1);
       |                ^
 cc1: all warnings being treated as errors

The full context is this block:

 if (srr1 && !generic_check_cpu_restart(cpu))
 	DBG("CPU%d Unexpected exit while offline srr1=%lx!\n",
 			cpu, srr1);

When building with DEBUG undefined DBG() expands to nothing and GCC emits
the warning due to the lack of braces around an empty statement.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200804005410.146094-2-oohall@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-10 10:23:52 +01:00
Kim Phillips
c54cd254fb arch/x86/amd/ibs: Fix re-arming IBS Fetch
commit 221bfce5ebbdf72ff08b3bf2510ae81058ee568b upstream.

Stephane Eranian found a bug in that IBS' current Fetch counter was not
being reset when the driver would write the new value to clear it along
with the enable bit set, and found that adding an MSR write that would
first disable IBS Fetch would make IBS Fetch reset its current count.

Indeed, the PPR for AMD Family 17h Model 31h B0 55803 Rev 0.54 - Sep 12,
2019 states "The periodic fetch counter is set to IbsFetchCnt [...] when
IbsFetchEn is changed from 0 to 1."

Explicitly set IbsFetchEn to 0 and then to 1 when re-enabling IBS Fetch,
so the driver properly resets the internal counter to 0 and IBS
Fetch starts counting again.

A family 15h machine tested does not have this problem, and the extra
wrmsr is also not needed on Family 19h, so only do the extra wrmsr on
families 16h through 18h.

Reported-by: Stephane Eranian <stephane.eranian@google.com>
Signed-off-by: Kim Phillips <kim.phillips@amd.com>
[peterz: optimized]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-10 10:23:50 +01:00
Mukesh Ojha
3657ef4774 powerpc/powernv/opal-dump : Use IRQ_HANDLED instead of numbers in interrupt handler
commit b29336c0e1785a28bc40a9fd47c2321671e9792e upstream.

Fixes: 8034f715f ("powernv/opal-dump: Convert to irq domain")

Converts all the return explicit number to a more proper IRQ_HANDLED,
which looks proper incase of interrupt handler returning case.

Here, It also removes error message like "nobody cared" which was
getting unveiled while returning -1 or 0 from handler.

Signed-off-by: Mukesh Ojha <mukesh02@linux.vnet.ibm.com>
Reviewed-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-10 10:23:50 +01:00
Vasant Hegde
aa3c87999c powerpc/powernv/dump: Fix race while processing OPAL dump
[ Upstream commit 0a43ae3e2beb77e3481d812834d33abe270768ab ]

Every dump reported by OPAL is exported to userspace through a sysfs
interface and notified using kobject_uevent(). The userspace daemon
(opal_errd) then reads the dump and acknowledges that the dump is
saved safely to disk. Once acknowledged the kernel removes the
respective sysfs file entry causing respective resources to be
released including kobject.

However it's possible the userspace daemon may already be scanning
dump entries when a new sysfs dump entry is created by the kernel.
User daemon may read this new entry and ack it even before kernel can
notify userspace about it through kobject_uevent() call. If that
happens then we have a potential race between
dump_ack_store->kobject_put() and kobject_uevent which can lead to
use-after-free of a kernfs object resulting in a kernel crash.

This patch fixes this race by protecting the sysfs file
creation/notification by holding a reference count on kobject until we
safely send kobject_uevent().

The function create_dump_obj() returns the dump object which if used
by caller function will end up in use-after-free problem again.
However, the return value of create_dump_obj() function isn't being
used today and there is no need as well. Hence change it to return
void to make this fix complete.

Fixes: c7e64b9ce04a ("powerpc/powernv Platform dump interface")
Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201017164210.264619-1-hegdevasant@linux.vnet.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-29 09:05:41 +01:00
Michal Simek
56da79528c arm64: dts: zynqmp: Remove additional compatible string for i2c IPs
[ Upstream commit 35292518cb0a626fcdcabf739aed75060a018ab5 ]

DT binding permits only one compatible string which was decribed in past by
commit 63cab195bf49 ("i2c: removed work arounds in i2c driver for Zynq
Ultrascale+ MPSoC").
The commit aea37006e183 ("dt-bindings: i2c: cadence: Migrate i2c-cadence
documentation to YAML") has converted binding to yaml and the following
issues is reported:
...: i2c@ff030000: compatible: Additional items are not allowed
('cdns,i2c-r1p10' was unexpected)
	From schema:
.../Documentation/devicetree/bindings/i2c/cdns,i2c-r1p10.yaml fds
...: i2c@ff030000: compatible: ['cdns,i2c-r1p14', 'cdns,i2c-r1p10'] is too
long

The commit c415f9e8304a ("ARM64: zynqmp: Fix i2c node's compatible string")
has added the second compatible string but without removing origin one.
The patch is only keeping one compatible string "cdns,i2c-r1p14".

Fixes: c415f9e8304a ("ARM64: zynqmp: Fix i2c node's compatible string")
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Link: https://lore.kernel.org/r/cc294ae1a79ef845af6809ddb4049f0c0f5bb87a.1598259551.git.michal.simek@xilinx.com
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-29 09:05:41 +01:00
Stephan Gerhold
886ce82a3b arm64: dts: qcom: msm8916: Fix MDP/DSI interrupts
[ Upstream commit 027cca9eb5b450c3f6bb916ba999144c2ec23cb7 ]

The mdss node sets #interrupt-cells = <1>, so its interrupts
should be referenced using a single cell (in this case: only the
interrupt number).

However, right now the mdp/dsi node both have two interrupt cells
set, e.g. interrupts = <4 0>. The 0 is probably meant to say
IRQ_TYPE_NONE (= 0), but with #interrupt-cells = <1> this is
actually interpreted as a second interrupt line.

Remove the IRQ flags from both interrupts to fix this.

Fixes: 305410ffd1b2 ("arm64: dts: msm8916: Add display support")
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Link: https://lore.kernel.org/r/20200915071221.72895-5-stephan@gerhold.net
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-29 09:05:41 +01:00
Robert Hoo
f90c8dd3a2 KVM: x86: emulating RDPID failure shall return #UD rather than #GP
[ Upstream commit a9e2e0ae686094571378c72d8146b5a1a92d0652 ]

Per Intel's SDM, RDPID takes a #UD if it is unsupported, which is more or
less what KVM is emulating when MSR_TSC_AUX is not available.  In fact,
there are no scenarios in which RDPID is supposed to #GP.

Fixes: fb6d4d340e ("KVM: x86: emulate RDPID")
Signed-off-by: Robert Hoo <robert.hu@linux.intel.com>
Message-Id: <1598581422-76264-1-git-send-email-robert.hu@linux.intel.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-29 09:05:40 +01:00
Kajol Jain
0fbdf9f706 powerpc/perf/hv-gpci: Fix starting index value
[ Upstream commit 0f9866f7e85765bbda86666df56c92f377c3bc10 ]

Commit 9e9f60108423f ("powerpc/perf/{hv-gpci, hv-common}: generate
requests with counters annotated") adds a framework for defining
gpci counters.
In this patch, they adds starting_index value as '0xffffffffffffffff'.
which is wrong as starting_index is of size 32 bits.

Because of this, incase we try to run hv-gpci event we get error.

In power9 machine:

command#: perf stat -e hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/
          -C 0 -I 1000
event syntax error: '..bie_count_and_time_tlbie_instructions_issued/'
                                  \___ value too big for format, maximum is 4294967295

This patch fix this issue and changes starting_index value to '0xffffffff'

After this patch:

command#: perf stat -e hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/ -C 0 -I 1000
     1.000085786              1,024      hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/
     2.000287818              1,024      hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/
     2.439113909             17,408      hv_gpci/system_tlbie_count_and_time_tlbie_instructions_issued/

Fixes: 9e9f60108423 ("powerpc/perf/{hv-gpci, hv-common}: generate requests with counters annotated")
Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201003074943.338618-1-kjain@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-29 09:05:39 +01:00
Athira Rajeev
471c2809a1 powerpc/perf: Exclude pmc5/6 from the irrelevant PMU group constraints
[ Upstream commit 3b6c3adbb2fa42749c3d38cfc4d4d0b7e096bb7b ]

PMU counter support functions enforces event constraints for group of
events to check if all events in a group can be monitored. Incase of
event codes using PMC5 and PMC6 ( 500fa and 600f4 respectively ), not
all constraints are applicable, say the threshold or sample bits. But
current code includes pmc5 and pmc6 in some group constraints (like
IC_DC Qualifier bits) which is actually not applicable and hence
results in those events not getting counted when scheduled along with
group of other events. Patch fixes this by excluding PMC5/6 from
constraints which are not relevant for it.

Fixes: 7ffd948 ("powerpc/perf: factor out power8 pmu functions")
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Reviewed-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1600672204-1610-1-git-send-email-atrajeev@linux.vnet.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-29 09:05:39 +01:00