<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/arch/powerpc/include, branch v5.4.44</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>powerpc/32s: Fix build failure with CONFIG_PPC_KUAP_DEBUG</title>
<updated>2020-05-20T06:20:33+00:00</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@c-s.fr</email>
</author>
<published>2020-04-20T07:47:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4e06196336a18263fe3b25bc9627cf9437d16acf'/>
<id>4e06196336a18263fe3b25bc9627cf9437d16acf</id>
<content type='text'>
commit 4833ce06e6855d526234618b746ffb71d6612c9a upstream.

gpr2 is not a parametre of kuap_check(), it doesn't exist.

Use gpr instead.

Fixes: a68c31fc01ef ("powerpc/32s: Implement Kernel Userspace Access Protection")
Signed-off-by: Christophe Leroy &lt;christophe.leroy@c-s.fr&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/ea599546f2a7771bde551393889e44e6b2632332.1587368807.git.christophe.leroy@c-s.fr
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 4833ce06e6855d526234618b746ffb71d6612c9a upstream.

gpr2 is not a parametre of kuap_check(), it doesn't exist.

Use gpr instead.

Fixes: a68c31fc01ef ("powerpc/32s: Implement Kernel Userspace Access Protection")
Signed-off-by: Christophe Leroy &lt;christophe.leroy@c-s.fr&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/ea599546f2a7771bde551393889e44e6b2632332.1587368807.git.christophe.leroy@c-s.fr
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Make setjmp/longjmp signature standard</title>
<updated>2020-04-17T08:50:23+00:00</updated>
<author>
<name>Clement Courbet</name>
<email>courbet@google.com</email>
</author>
<published>2020-03-30T08:03:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ba7581be850be4f031d20796045e49b63b43010e'/>
<id>ba7581be850be4f031d20796045e49b63b43010e</id>
<content type='text'>
commit c17eb4dca5a353a9dbbb8ad6934fe57af7165e91 upstream.

Declaring setjmp()/longjmp() as taking longs makes the signature
non-standard, and makes clang complain. In the past, this has been
worked around by adding -ffreestanding to the compile flags.

The implementation looks like it only ever propagates the value
(in longjmp) or sets it to 1 (in setjmp), and we only call longjmp
with integer parameters.

This allows removing -ffreestanding from the compilation flags.

Fixes: c9029ef9c957 ("powerpc: Avoid clang warnings around setjmp and longjmp")
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: Clement Courbet &lt;courbet@google.com&gt;
Reviewed-by: Nathan Chancellor &lt;natechancellor@gmail.com&gt;
Tested-by: Nathan Chancellor &lt;natechancellor@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20200330080400.124803-1-courbet@google.com
Signed-off-by: Nathan Chancellor &lt;natechancellor@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit c17eb4dca5a353a9dbbb8ad6934fe57af7165e91 upstream.

Declaring setjmp()/longjmp() as taking longs makes the signature
non-standard, and makes clang complain. In the past, this has been
worked around by adding -ffreestanding to the compile flags.

The implementation looks like it only ever propagates the value
(in longjmp) or sets it to 1 (in setjmp), and we only call longjmp
with integer parameters.

This allows removing -ffreestanding from the compilation flags.

Fixes: c9029ef9c957 ("powerpc: Avoid clang warnings around setjmp and longjmp")
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: Clement Courbet &lt;courbet@google.com&gt;
Reviewed-by: Nathan Chancellor &lt;natechancellor@gmail.com&gt;
Tested-by: Nathan Chancellor &lt;natechancellor@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20200330080400.124803-1-courbet@google.com
Signed-off-by: Nathan Chancellor &lt;natechancellor@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/hash64/devmap: Use H_PAGE_THP_HUGE when setting up huge devmap PTE entries</title>
<updated>2020-04-17T08:50:22+00:00</updated>
<author>
<name>Aneesh Kumar K.V</name>
<email>aneesh.kumar@linux.ibm.com</email>
</author>
<published>2020-03-13T09:48:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=bd0fa144737c6bc333c2d605bd615a8a4d58ca05'/>
<id>bd0fa144737c6bc333c2d605bd615a8a4d58ca05</id>
<content type='text'>
commit 36b78402d97a3b9aeab136feb9b00d8647ec2c20 upstream.

H_PAGE_THP_HUGE is used to differentiate between a THP hugepage and
hugetlb hugepage entries. The difference is WRT how we handle hash
fault on these address. THP address enables MPSS in segments. We want
to manage devmap hugepage entries similar to THP pt entries. Hence use
H_PAGE_THP_HUGE for devmap huge PTE entries.

With current code while handling hash PTE fault, we do set is_thp =
true when finding devmap PTE huge PTE entries.

Current code also does the below sequence we setting up huge devmap
entries.

	entry = pmd_mkhuge(pfn_t_pmd(pfn, prot));
	if (pfn_t_devmap(pfn))
		entry = pmd_mkdevmap(entry);

In that case we would find both H_PAGE_THP_HUGE and PAGE_DEVMAP set
for huge devmap PTE entries. This results in false positive error like
below.

  kernel BUG at /home/kvaneesh/src/linux/mm/memory.c:4321!
  Oops: Exception in kernel mode, sig: 5 [#1]
  LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
  Modules linked in:
  CPU: 56 PID: 67996 Comm: t_mmap_dio Not tainted 5.6.0-rc4-59640-g371c804dedbc #128
  ....
  NIP [c00000000044c9e4] __follow_pte_pmd+0x264/0x900
  LR [c0000000005d45f8] dax_writeback_one+0x1a8/0x740
  Call Trace:
    str_spec.74809+0x22ffb4/0x2d116c (unreliable)
    dax_writeback_one+0x1a8/0x740
    dax_writeback_mapping_range+0x26c/0x700
    ext4_dax_writepages+0x150/0x5a0
    do_writepages+0x68/0x180
    __filemap_fdatawrite_range+0x138/0x180
    file_write_and_wait_range+0xa4/0x110
    ext4_sync_file+0x370/0x6e0
    vfs_fsync_range+0x70/0xf0
    sys_msync+0x220/0x2e0
    system_call+0x5c/0x68

This is because our pmd_trans_huge check doesn't exclude _PAGE_DEVMAP.

To make this all consistent, update pmd_mkdevmap to set
H_PAGE_THP_HUGE and pmd_trans_huge check now excludes _PAGE_DEVMAP
correctly.

Fixes: ebd31197931d ("powerpc/mm: Add devmap support for ppc64")
Cc: stable@vger.kernel.org # v4.13+
Signed-off-by: Aneesh Kumar K.V &lt;aneesh.kumar@linux.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20200313094842.351830-1-aneesh.kumar@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 36b78402d97a3b9aeab136feb9b00d8647ec2c20 upstream.

H_PAGE_THP_HUGE is used to differentiate between a THP hugepage and
hugetlb hugepage entries. The difference is WRT how we handle hash
fault on these address. THP address enables MPSS in segments. We want
to manage devmap hugepage entries similar to THP pt entries. Hence use
H_PAGE_THP_HUGE for devmap huge PTE entries.

With current code while handling hash PTE fault, we do set is_thp =
true when finding devmap PTE huge PTE entries.

Current code also does the below sequence we setting up huge devmap
entries.

	entry = pmd_mkhuge(pfn_t_pmd(pfn, prot));
	if (pfn_t_devmap(pfn))
		entry = pmd_mkdevmap(entry);

In that case we would find both H_PAGE_THP_HUGE and PAGE_DEVMAP set
for huge devmap PTE entries. This results in false positive error like
below.

  kernel BUG at /home/kvaneesh/src/linux/mm/memory.c:4321!
  Oops: Exception in kernel mode, sig: 5 [#1]
  LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
  Modules linked in:
  CPU: 56 PID: 67996 Comm: t_mmap_dio Not tainted 5.6.0-rc4-59640-g371c804dedbc #128
  ....
  NIP [c00000000044c9e4] __follow_pte_pmd+0x264/0x900
  LR [c0000000005d45f8] dax_writeback_one+0x1a8/0x740
  Call Trace:
    str_spec.74809+0x22ffb4/0x2d116c (unreliable)
    dax_writeback_one+0x1a8/0x740
    dax_writeback_mapping_range+0x26c/0x700
    ext4_dax_writepages+0x150/0x5a0
    do_writepages+0x68/0x180
    __filemap_fdatawrite_range+0x138/0x180
    file_write_and_wait_range+0xa4/0x110
    ext4_sync_file+0x370/0x6e0
    vfs_fsync_range+0x70/0xf0
    sys_msync+0x220/0x2e0
    system_call+0x5c/0x68

This is because our pmd_trans_huge check doesn't exclude _PAGE_DEVMAP.

To make this all consistent, update pmd_mkdevmap to set
H_PAGE_THP_HUGE and pmd_trans_huge check now excludes _PAGE_DEVMAP
correctly.

Fixes: ebd31197931d ("powerpc/mm: Add devmap support for ppc64")
Cc: stable@vger.kernel.org # v4.13+
Signed-off-by: Aneesh Kumar K.V &lt;aneesh.kumar@linux.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20200313094842.351830-1-aneesh.kumar@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/pseries: Avoid NULL pointer dereference when drmem is unavailable</title>
<updated>2020-04-17T08:50:20+00:00</updated>
<author>
<name>Libor Pechacek</name>
<email>lpechacek@suse.cz</email>
</author>
<published>2020-01-31T13:28:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=27993365c009e2e96ff55a648bf0b12c7744c92b'/>
<id>27993365c009e2e96ff55a648bf0b12c7744c92b</id>
<content type='text'>
commit a83836dbc53e96f13fec248ecc201d18e1e3111d upstream.

In guests without hotplugagble memory drmem structure is only zero
initialized. Trying to manipulate DLPAR parameters results in a crash.

  $ echo "memory add count 1" &gt; /sys/kernel/dlpar
  Oops: Kernel access of bad area, sig: 11 [#1]
  LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
  ...
  NIP:  c0000000000ff294 LR: c0000000000ff248 CTR: 0000000000000000
  REGS: c0000000fb9d3880 TRAP: 0300   Tainted: G            E      (5.5.0-rc6-2-default)
  MSR:  8000000000009033 &lt;SF,EE,ME,IR,DR,RI,LE&gt;  CR: 28242428  XER: 20000000
  CFAR: c0000000009a6c10 DAR: 0000000000000010 DSISR: 40000000 IRQMASK: 0
  ...
  NIP dlpar_memory+0x6e4/0xd00
  LR  dlpar_memory+0x698/0xd00
  Call Trace:
    dlpar_memory+0x698/0xd00 (unreliable)
    handle_dlpar_errorlog+0xc0/0x190
    dlpar_store+0x198/0x4a0
    kobj_attr_store+0x30/0x50
    sysfs_kf_write+0x64/0x90
    kernfs_fop_write+0x1b0/0x290
    __vfs_write+0x3c/0x70
    vfs_write+0xd0/0x260
    ksys_write+0xdc/0x130
    system_call+0x5c/0x68

Taking closer look at the code, I can see that for_each_drmem_lmb is a
macro expanding into `for (lmb = &amp;drmem_info-&gt;lmbs[0]; lmb &lt;=
&amp;drmem_info-&gt;lmbs[drmem_info-&gt;n_lmbs - 1]; lmb++)`. When drmem_info-&gt;lmbs
is NULL, the loop would iterate through the whole address range if it
weren't stopped by the NULL pointer dereference on the next line.

This patch aligns for_each_drmem_lmb and for_each_drmem_lmb_in_range
macro behavior with the common C semantics, where the end marker does
not belong to the scanned range, and alters get_lmb_range() semantics.
As a side effect, the wraparound observed in the crash is prevented.

Fixes: 6c6ea53725b3 ("powerpc/mm: Separate ibm, dynamic-memory data from DT format")
Cc: stable@vger.kernel.org # v4.16+
Signed-off-by: Libor Pechacek &lt;lpechacek@suse.cz&gt;
Signed-off-by: Michal Suchanek &lt;msuchanek@suse.de&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20200131132829.10281-1-msuchanek@suse.de
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit a83836dbc53e96f13fec248ecc201d18e1e3111d upstream.

In guests without hotplugagble memory drmem structure is only zero
initialized. Trying to manipulate DLPAR parameters results in a crash.

  $ echo "memory add count 1" &gt; /sys/kernel/dlpar
  Oops: Kernel access of bad area, sig: 11 [#1]
  LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
  ...
  NIP:  c0000000000ff294 LR: c0000000000ff248 CTR: 0000000000000000
  REGS: c0000000fb9d3880 TRAP: 0300   Tainted: G            E      (5.5.0-rc6-2-default)
  MSR:  8000000000009033 &lt;SF,EE,ME,IR,DR,RI,LE&gt;  CR: 28242428  XER: 20000000
  CFAR: c0000000009a6c10 DAR: 0000000000000010 DSISR: 40000000 IRQMASK: 0
  ...
  NIP dlpar_memory+0x6e4/0xd00
  LR  dlpar_memory+0x698/0xd00
  Call Trace:
    dlpar_memory+0x698/0xd00 (unreliable)
    handle_dlpar_errorlog+0xc0/0x190
    dlpar_store+0x198/0x4a0
    kobj_attr_store+0x30/0x50
    sysfs_kf_write+0x64/0x90
    kernfs_fop_write+0x1b0/0x290
    __vfs_write+0x3c/0x70
    vfs_write+0xd0/0x260
    ksys_write+0xdc/0x130
    system_call+0x5c/0x68

Taking closer look at the code, I can see that for_each_drmem_lmb is a
macro expanding into `for (lmb = &amp;drmem_info-&gt;lmbs[0]; lmb &lt;=
&amp;drmem_info-&gt;lmbs[drmem_info-&gt;n_lmbs - 1]; lmb++)`. When drmem_info-&gt;lmbs
is NULL, the loop would iterate through the whole address range if it
weren't stopped by the NULL pointer dereference on the next line.

This patch aligns for_each_drmem_lmb and for_each_drmem_lmb_in_range
macro behavior with the common C semantics, where the end marker does
not belong to the scanned range, and alters get_lmb_range() semantics.
As a side effect, the wraparound observed in the crash is prevented.

Fixes: 6c6ea53725b3 ("powerpc/mm: Separate ibm, dynamic-memory data from DT format")
Cc: stable@vger.kernel.org # v4.16+
Signed-off-by: Libor Pechacek &lt;lpechacek@suse.cz&gt;
Signed-off-by: Michal Suchanek &lt;msuchanek@suse.de&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20200131132829.10281-1-msuchanek@suse.de
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Convert flush_icache_range &amp; friends to C</title>
<updated>2020-03-12T12:00:25+00:00</updated>
<author>
<name>Alastair D'Silva</name>
<email>alastair@d-silva.org</email>
</author>
<published>2019-11-04T02:32:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=42dac16dc4b09bbd70f041842a134e403a980753'/>
<id>42dac16dc4b09bbd70f041842a134e403a980753</id>
<content type='text'>
[ Upstream commit 23eb7f560a2a6a1b0dbaaaae8685da75314347e4 ]

Similar to commit 22e9c88d486a
("powerpc/64: reuse PPC32 static inline flush_dcache_range()")
this patch converts the following ASM symbols to C:
    flush_icache_range()
    __flush_dcache_icache()
    __flush_dcache_icache_phys()

This was done as we discovered a long-standing bug where the length of the
range was truncated due to using a 32 bit shift instead of a 64 bit one.

By converting these functions to C, it becomes easier to maintain.

flush_dcache_icache_phys() retains a critical assembler section as we must
ensure there are no memory accesses while the data MMU is disabled
(authored by Christophe Leroy). Since this has no external callers, it has
also been made static, allowing the compiler to inline it within
flush_dcache_icache_page().

Signed-off-by: Alastair D'Silva &lt;alastair@d-silva.org&gt;
Signed-off-by: Christophe Leroy &lt;christophe.leroy@c-s.fr&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
[mpe: Minor fixups, don't export __flush_dcache_icache()]
Link: https://lore.kernel.org/r/20191104023305.9581-5-alastair@au1.ibm.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 23eb7f560a2a6a1b0dbaaaae8685da75314347e4 ]

Similar to commit 22e9c88d486a
("powerpc/64: reuse PPC32 static inline flush_dcache_range()")
this patch converts the following ASM symbols to C:
    flush_icache_range()
    __flush_dcache_icache()
    __flush_dcache_icache_phys()

This was done as we discovered a long-standing bug where the length of the
range was truncated due to using a 32 bit shift instead of a 64 bit one.

By converting these functions to C, it becomes easier to maintain.

flush_dcache_icache_phys() retains a critical assembler section as we must
ensure there are no memory accesses while the data MMU is disabled
(authored by Christophe Leroy). Since this has no external callers, it has
also been made static, allowing the compiler to inline it within
flush_dcache_icache_page().

Signed-off-by: Alastair D'Silva &lt;alastair@d-silva.org&gt;
Signed-off-by: Christophe Leroy &lt;christophe.leroy@c-s.fr&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
[mpe: Minor fixups, don't export __flush_dcache_icache()]
Link: https://lore.kernel.org/r/20191104023305.9581-5-alastair@au1.ibm.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: define helpers to get L1 icache sizes</title>
<updated>2020-03-12T12:00:25+00:00</updated>
<author>
<name>Alastair D'Silva</name>
<email>alastair@d-silva.org</email>
</author>
<published>2019-11-04T02:32:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ec21f6d52bd435662cc06d89a12d3bd0c3eaafc3'/>
<id>ec21f6d52bd435662cc06d89a12d3bd0c3eaafc3</id>
<content type='text'>
[ Upstream commit 7a0745c5e03ff1129864bc6d80f5c4417e8d7893 ]

This patch adds helpers to retrieve icache sizes, and renames the existing
helpers to make it clear that they are for dcache.

Signed-off-by: Alastair D'Silva &lt;alastair@d-silva.org&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20191104023305.9581-4-alastair@au1.ibm.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 7a0745c5e03ff1129864bc6d80f5c4417e8d7893 ]

This patch adds helpers to retrieve icache sizes, and renames the existing
helpers to make it clear that they are for dcache.

Signed-off-by: Alastair D'Silva &lt;alastair@d-silva.org&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20191104023305.9581-4-alastair@au1.ibm.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/hugetlb: Fix 8M hugepages on 8xx</title>
<updated>2020-02-28T16:22:18+00:00</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@c-s.fr</email>
</author>
<published>2020-02-09T16:02:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9b9374cf1ea7ff2a899ae6f7557a64458d3b23b3'/>
<id>9b9374cf1ea7ff2a899ae6f7557a64458d3b23b3</id>
<content type='text'>
commit 50a175dd18de7a647e72aca7daf4744e3a5a81e3 upstream.

With HW assistance all page tables must be 4k aligned, the 8xx drops
the last 12 bits during the walk.

Redefine HUGEPD_SHIFT_MASK to mask last 12 bits out. HUGEPD_SHIFT_MASK
is used to for alignment of page table cache.

Fixes: 22569b881d37 ("powerpc/8xx: Enable 8M hugepage support with HW assistance")
Cc: stable@vger.kernel.org # v5.0+
Signed-off-by: Christophe Leroy &lt;christophe.leroy@c-s.fr&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/778b1a248c4c7ca79640eeff7740044da6a220a0.1581264115.git.christophe.leroy@c-s.fr
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 50a175dd18de7a647e72aca7daf4744e3a5a81e3 upstream.

With HW assistance all page tables must be 4k aligned, the 8xx drops
the last 12 bits during the walk.

Redefine HUGEPD_SHIFT_MASK to mask last 12 bits out. HUGEPD_SHIFT_MASK
is used to for alignment of page table cache.

Fixes: 22569b881d37 ("powerpc/8xx: Enable 8M hugepage support with HW assistance")
Cc: stable@vger.kernel.org # v5.0+
Signed-off-by: Christophe Leroy &lt;christophe.leroy@c-s.fr&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/778b1a248c4c7ca79640eeff7740044da6a220a0.1581264115.git.christophe.leroy@c-s.fr
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/kuap: Fix set direction in allow/prevent_user_access()</title>
<updated>2020-02-11T12:35:55+00:00</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@c-s.fr</email>
</author>
<published>2020-01-24T11:54:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=866323ccc1388f68b866396dc06991b83c2ec2a3'/>
<id>866323ccc1388f68b866396dc06991b83c2ec2a3</id>
<content type='text'>
[ Upstream commit 1d8f739b07bd538f272f60bf53f10e7e6248d295 ]

__builtin_constant_p() always return 0 for pointers, so on RADIX
we always end up opening both direction (by writing 0 in SPR29):

  0000000000000170 &lt;._copy_to_user&gt;:
  ...
   1b0:	4c 00 01 2c 	isync
   1b4:	39 20 00 00 	li      r9,0
   1b8:	7d 3d 03 a6 	mtspr   29,r9
   1bc:	4c 00 01 2c 	isync
   1c0:	48 00 00 01 	bl      1c0 &lt;._copy_to_user+0x50&gt;
  			1c0: R_PPC64_REL24	.__copy_tofrom_user
  ...
  0000000000000220 &lt;._copy_from_user&gt;:
  ...
   2ac:	4c 00 01 2c 	isync
   2b0:	39 20 00 00 	li      r9,0
   2b4:	7d 3d 03 a6 	mtspr   29,r9
   2b8:	4c 00 01 2c 	isync
   2bc:	7f c5 f3 78 	mr      r5,r30
   2c0:	7f 83 e3 78 	mr      r3,r28
   2c4:	48 00 00 01 	bl      2c4 &lt;._copy_from_user+0xa4&gt;
  			2c4: R_PPC64_REL24	.__copy_tofrom_user
  ...

Use an explicit parameter for direction selection, so that GCC
is able to see it is a constant:

  00000000000001b0 &lt;._copy_to_user&gt;:
  ...
   1f0:	4c 00 01 2c 	isync
   1f4:	3d 20 40 00 	lis     r9,16384
   1f8:	79 29 07 c6 	rldicr  r9,r9,32,31
   1fc:	7d 3d 03 a6 	mtspr   29,r9
   200:	4c 00 01 2c 	isync
   204:	48 00 00 01 	bl      204 &lt;._copy_to_user+0x54&gt;
  			204: R_PPC64_REL24	.__copy_tofrom_user
  ...
  0000000000000260 &lt;._copy_from_user&gt;:
  ...
   2ec:	4c 00 01 2c 	isync
   2f0:	39 20 ff ff 	li      r9,-1
   2f4:	79 29 00 04 	rldicr  r9,r9,0,0
   2f8:	7d 3d 03 a6 	mtspr   29,r9
   2fc:	4c 00 01 2c 	isync
   300:	7f c5 f3 78 	mr      r5,r30
   304:	7f 83 e3 78 	mr      r3,r28
   308:	48 00 00 01 	bl      308 &lt;._copy_from_user+0xa8&gt;
  			308: R_PPC64_REL24	.__copy_tofrom_user
  ...

Signed-off-by: Christophe Leroy &lt;christophe.leroy@c-s.fr&gt;
[mpe: Spell out the directions, s/KUAP_R/KUAP_READ/ etc.]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/f4e88ec4941d5facb35ce75026b0112f980086c3.1579866752.git.christophe.leroy@c-s.fr
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 1d8f739b07bd538f272f60bf53f10e7e6248d295 ]

__builtin_constant_p() always return 0 for pointers, so on RADIX
we always end up opening both direction (by writing 0 in SPR29):

  0000000000000170 &lt;._copy_to_user&gt;:
  ...
   1b0:	4c 00 01 2c 	isync
   1b4:	39 20 00 00 	li      r9,0
   1b8:	7d 3d 03 a6 	mtspr   29,r9
   1bc:	4c 00 01 2c 	isync
   1c0:	48 00 00 01 	bl      1c0 &lt;._copy_to_user+0x50&gt;
  			1c0: R_PPC64_REL24	.__copy_tofrom_user
  ...
  0000000000000220 &lt;._copy_from_user&gt;:
  ...
   2ac:	4c 00 01 2c 	isync
   2b0:	39 20 00 00 	li      r9,0
   2b4:	7d 3d 03 a6 	mtspr   29,r9
   2b8:	4c 00 01 2c 	isync
   2bc:	7f c5 f3 78 	mr      r5,r30
   2c0:	7f 83 e3 78 	mr      r3,r28
   2c4:	48 00 00 01 	bl      2c4 &lt;._copy_from_user+0xa4&gt;
  			2c4: R_PPC64_REL24	.__copy_tofrom_user
  ...

Use an explicit parameter for direction selection, so that GCC
is able to see it is a constant:

  00000000000001b0 &lt;._copy_to_user&gt;:
  ...
   1f0:	4c 00 01 2c 	isync
   1f4:	3d 20 40 00 	lis     r9,16384
   1f8:	79 29 07 c6 	rldicr  r9,r9,32,31
   1fc:	7d 3d 03 a6 	mtspr   29,r9
   200:	4c 00 01 2c 	isync
   204:	48 00 00 01 	bl      204 &lt;._copy_to_user+0x54&gt;
  			204: R_PPC64_REL24	.__copy_tofrom_user
  ...
  0000000000000260 &lt;._copy_from_user&gt;:
  ...
   2ec:	4c 00 01 2c 	isync
   2f0:	39 20 ff ff 	li      r9,-1
   2f4:	79 29 00 04 	rldicr  r9,r9,0,0
   2f8:	7d 3d 03 a6 	mtspr   29,r9
   2fc:	4c 00 01 2c 	isync
   300:	7f c5 f3 78 	mr      r5,r30
   304:	7f 83 e3 78 	mr      r3,r28
   308:	48 00 00 01 	bl      308 &lt;._copy_from_user+0xa8&gt;
  			308: R_PPC64_REL24	.__copy_tofrom_user
  ...

Signed-off-by: Christophe Leroy &lt;christophe.leroy@c-s.fr&gt;
[mpe: Spell out the directions, s/KUAP_R/KUAP_READ/ etc.]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/f4e88ec4941d5facb35ce75026b0112f980086c3.1579866752.git.christophe.leroy@c-s.fr
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm/mmu_gather: invalidate TLB correctly on batch allocation failure and flush</title>
<updated>2020-02-11T12:35:42+00:00</updated>
<author>
<name>Peter Zijlstra</name>
<email>peterz@infradead.org</email>
</author>
<published>2020-02-04T01:36:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=806cabd3117f46b505d7a7fdb33d3ce1db99e77a'/>
<id>806cabd3117f46b505d7a7fdb33d3ce1db99e77a</id>
<content type='text'>
commit 0ed1325967ab5f7a4549a2641c6ebe115f76e228 upstream.

Architectures for which we have hardware walkers of Linux page table
should flush TLB on mmu gather batch allocation failures and batch flush.
Some architectures like POWER supports multiple translation modes (hash
and radix) and in the case of POWER only radix translation mode needs the
above TLBI.  This is because for hash translation mode kernel wants to
avoid this extra flush since there are no hardware walkers of linux page
table.  With radix translation, the hardware also walks linux page table
and with that, kernel needs to make sure to TLB invalidate page walk cache
before page table pages are freed.

More details in commit d86564a2f085 ("mm/tlb, x86/mm: Support invalidating
TLB caches for RCU_TABLE_FREE")

The changes to sparc are to make sure we keep the old behavior since we
are now removing HAVE_RCU_TABLE_NO_INVALIDATE.  The default value for
tlb_needs_table_invalidate is to always force an invalidate and sparc can
avoid the table invalidate.  Hence we define tlb_needs_table_invalidate to
false for sparc architecture.

Link: http://lkml.kernel.org/r/20200116064531.483522-3-aneesh.kumar@linux.ibm.com
Fixes: a46cc7a90fd8 ("powerpc/mm/radix: Improve TLB/PWC flushes")
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org
Signed-off-by: Aneesh Kumar K.V &lt;aneesh.kumar@linux.ibm.com&gt;
Acked-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;	[powerpc]
Cc: &lt;stable@vger.kernel.org&gt;	[4.14+]
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 0ed1325967ab5f7a4549a2641c6ebe115f76e228 upstream.

Architectures for which we have hardware walkers of Linux page table
should flush TLB on mmu gather batch allocation failures and batch flush.
Some architectures like POWER supports multiple translation modes (hash
and radix) and in the case of POWER only radix translation mode needs the
above TLBI.  This is because for hash translation mode kernel wants to
avoid this extra flush since there are no hardware walkers of linux page
table.  With radix translation, the hardware also walks linux page table
and with that, kernel needs to make sure to TLB invalidate page walk cache
before page table pages are freed.

More details in commit d86564a2f085 ("mm/tlb, x86/mm: Support invalidating
TLB caches for RCU_TABLE_FREE")

The changes to sparc are to make sure we keep the old behavior since we
are now removing HAVE_RCU_TABLE_NO_INVALIDATE.  The default value for
tlb_needs_table_invalidate is to always force an invalidate and sparc can
avoid the table invalidate.  Hence we define tlb_needs_table_invalidate to
false for sparc architecture.

Link: http://lkml.kernel.org/r/20200116064531.483522-3-aneesh.kumar@linux.ibm.com
Fixes: a46cc7a90fd8 ("powerpc/mm/radix: Improve TLB/PWC flushes")
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org
Signed-off-by: Aneesh Kumar K.V &lt;aneesh.kumar@linux.ibm.com&gt;
Acked-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;	[powerpc]
Cc: &lt;stable@vger.kernel.org&gt;	[4.14+]
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/futex: Fix incorrect user access blocking</title>
<updated>2020-02-11T12:35:31+00:00</updated>
<author>
<name>Michael Ellerman</name>
<email>mpe@ellerman.id.au</email>
</author>
<published>2020-02-07T11:15:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=246a54895ac6cc117b064c5f65648076b9f2a5fc'/>
<id>246a54895ac6cc117b064c5f65648076b9f2a5fc</id>
<content type='text'>
commit 9dc086f1e9ef39dd823bd27954b884b2062f9e70 upstream.

The early versions of our kernel user access prevention (KUAP) were
written by Russell and Christophe, and didn't have separate
read/write access.

At some point I picked up the series and added the read/write access,
but I failed to update the usages in futex.h to correctly allow read
and write.

However we didn't notice because of another bug which was causing the
low-level code to always enable read and write. That bug was fixed
recently in commit 1d8f739b07bd ("powerpc/kuap: Fix set direction in
allow/prevent_user_access()").

futex_atomic_cmpxchg_inatomic() is passed the user address as %3 and
does:

  1:     lwarx   %1,  0, %3
         cmpw    0,  %1, %4
         bne-    3f
  2:     stwcx.  %5,  0, %3

Which clearly loads and stores from/to %3. The logic in
arch_futex_atomic_op_inuser() is similar, so fix both of them to use
allow_read_write_user().

Without this fix, and with PPC_KUAP_DEBUG=y, we see eg:

  Bug: Read fault blocked by AMR!
  WARNING: CPU: 94 PID: 149215 at arch/powerpc/include/asm/book3s/64/kup-radix.h:126 __do_page_fault+0x600/0xf30
  CPU: 94 PID: 149215 Comm: futex_requeue_p Tainted: G        W         5.5.0-rc7-gcc9x-g4c25df5640ae #1
  ...
  NIP [c000000000070680] __do_page_fault+0x600/0xf30
  LR [c00000000007067c] __do_page_fault+0x5fc/0xf30
  Call Trace:
  [c00020138e5637e0] [c00000000007067c] __do_page_fault+0x5fc/0xf30 (unreliable)
  [c00020138e5638c0] [c00000000000ada8] handle_page_fault+0x10/0x30
  --- interrupt: 301 at cmpxchg_futex_value_locked+0x68/0xd0
      LR = futex_lock_pi_atomic+0xe0/0x1f0
  [c00020138e563bc0] [c000000000217b50] futex_lock_pi_atomic+0x80/0x1f0 (unreliable)
  [c00020138e563c30] [c00000000021b668] futex_requeue+0x438/0xb60
  [c00020138e563d60] [c00000000021c6cc] do_futex+0x1ec/0x2b0
  [c00020138e563d90] [c00000000021c8b8] sys_futex+0x128/0x200
  [c00020138e563e20] [c00000000000b7ac] system_call+0x5c/0x68

Fixes: de78a9c42a79 ("powerpc: Add a framework for Kernel Userspace Access Protection")
Cc: stable@vger.kernel.org # v5.2+
Reported-by: syzbot+e808452bad7c375cbee6@syzkaller-ppc64.appspotmail.com
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Reviewed-by: Christophe Leroy &lt;christophe.leroy@c-s.fr&gt;
Link: https://lore.kernel.org/r/20200207122145.11928-1-mpe@ellerman.id.au
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 9dc086f1e9ef39dd823bd27954b884b2062f9e70 upstream.

The early versions of our kernel user access prevention (KUAP) were
written by Russell and Christophe, and didn't have separate
read/write access.

At some point I picked up the series and added the read/write access,
but I failed to update the usages in futex.h to correctly allow read
and write.

However we didn't notice because of another bug which was causing the
low-level code to always enable read and write. That bug was fixed
recently in commit 1d8f739b07bd ("powerpc/kuap: Fix set direction in
allow/prevent_user_access()").

futex_atomic_cmpxchg_inatomic() is passed the user address as %3 and
does:

  1:     lwarx   %1,  0, %3
         cmpw    0,  %1, %4
         bne-    3f
  2:     stwcx.  %5,  0, %3

Which clearly loads and stores from/to %3. The logic in
arch_futex_atomic_op_inuser() is similar, so fix both of them to use
allow_read_write_user().

Without this fix, and with PPC_KUAP_DEBUG=y, we see eg:

  Bug: Read fault blocked by AMR!
  WARNING: CPU: 94 PID: 149215 at arch/powerpc/include/asm/book3s/64/kup-radix.h:126 __do_page_fault+0x600/0xf30
  CPU: 94 PID: 149215 Comm: futex_requeue_p Tainted: G        W         5.5.0-rc7-gcc9x-g4c25df5640ae #1
  ...
  NIP [c000000000070680] __do_page_fault+0x600/0xf30
  LR [c00000000007067c] __do_page_fault+0x5fc/0xf30
  Call Trace:
  [c00020138e5637e0] [c00000000007067c] __do_page_fault+0x5fc/0xf30 (unreliable)
  [c00020138e5638c0] [c00000000000ada8] handle_page_fault+0x10/0x30
  --- interrupt: 301 at cmpxchg_futex_value_locked+0x68/0xd0
      LR = futex_lock_pi_atomic+0xe0/0x1f0
  [c00020138e563bc0] [c000000000217b50] futex_lock_pi_atomic+0x80/0x1f0 (unreliable)
  [c00020138e563c30] [c00000000021b668] futex_requeue+0x438/0xb60
  [c00020138e563d60] [c00000000021c6cc] do_futex+0x1ec/0x2b0
  [c00020138e563d90] [c00000000021c8b8] sys_futex+0x128/0x200
  [c00020138e563e20] [c00000000000b7ac] system_call+0x5c/0x68

Fixes: de78a9c42a79 ("powerpc: Add a framework for Kernel Userspace Access Protection")
Cc: stable@vger.kernel.org # v5.2+
Reported-by: syzbot+e808452bad7c375cbee6@syzkaller-ppc64.appspotmail.com
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Reviewed-by: Christophe Leroy &lt;christophe.leroy@c-s.fr&gt;
Link: https://lore.kernel.org/r/20200207122145.11928-1-mpe@ellerman.id.au
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
</feed>
