<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/linux.git/arch/powerpc/include, branch v5.10.257</title>
<subtitle>Linux kernel stable tree (mirror)</subtitle>
<id>https://git.radix-linux.su/kernel/linux.git/atom?h=v5.10.257</id>
<link rel='self' href='https://git.radix-linux.su/kernel/linux.git/atom?h=v5.10.257'/>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/'/>
<updated>2026-04-18T08:30:52+00:00</updated>
<entry>
<title>powerpc/uaccess: Fix inline assembly for clang build on PPC32</title>
<updated>2026-04-18T08:30:52+00:00</updated>
<author>
<name>Christophe Leroy (CS GROUP)</name>
<email>chleroy@kernel.org</email>
</author>
<published>2026-02-03T07:30:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=588101fe60ed2b2e9fa179522e9d12b5dd65f0f5'/>
<id>urn:sha1:588101fe60ed2b2e9fa179522e9d12b5dd65f0f5</id>
<content type='text'>
[ Upstream commit 0ee95a1d458630272d0415d0ffa9424fcb606c90 ]

Test robot reports the following error with clang-16.0.6:

   In file included from kernel/rseq.c:75:
   include/linux/rseq_entry.h:141:3: error: invalid operand for instruction
                   unsafe_get_user(offset, &amp;ucs-&gt;post_commit_offset, efault);
                   ^
   include/linux/uaccess.h:608:2: note: expanded from macro 'unsafe_get_user'
           arch_unsafe_get_user(x, ptr, local_label);      \
           ^
   arch/powerpc/include/asm/uaccess.h:518:2: note: expanded from macro 'arch_unsafe_get_user'
           __get_user_size_goto(__gu_val, __gu_addr, sizeof(*(p)), e); \
           ^
   arch/powerpc/include/asm/uaccess.h:284:2: note: expanded from macro '__get_user_size_goto'
           __get_user_size_allowed(x, ptr, size, __gus_retval);    \
           ^
   arch/powerpc/include/asm/uaccess.h:275:10: note: expanded from macro '__get_user_size_allowed'
           case 8: __get_user_asm2(x, (u64 __user *)ptr, retval);  break;  \
                   ^
   arch/powerpc/include/asm/uaccess.h:258:4: note: expanded from macro '__get_user_asm2'
                   "       li %1+1,0\n"                    \
                    ^
   &lt;inline asm&gt;:7:5: note: instantiated into assembly here
           li 31+1,0
              ^
   1 error generated.

On PPC32, for 64 bits vars a pair of registers is used. Usually the
lower register in the pair is the high part and the higher register is
the low part. GCC uses r3/r4 ... r11/r12 ... r14/r15 ... r30/r31

In older kernel code inline assembly was using %1 and %1+1 to represent
64 bits values. However here it looks like clang uses r31 as high part,
allthough r32 doesn't exist hence the error.

Allthoug %1+1 should work, most places now use %L1 instead of %1+1, so
let's do the same here.

With that change, the build doesn't fail anymore and a disassembly shows
clang uses r17/r18 and r31/r14 pair when GCC would have used r16/r17 and
r30/r31:

	Disassembly of section .fixup:

	00000000 &lt;.fixup&gt;:
	   0:	38 a0 ff f2 	li      r5,-14
	   4:	3a 20 00 00 	li      r17,0
	   8:	3a 40 00 00 	li      r18,0
	   c:	48 00 00 00 	b       c &lt;.fixup+0xc&gt;
				c: R_PPC_REL24	.text+0xbc
	  10:	38 a0 ff f2 	li      r5,-14
	  14:	3b e0 00 00 	li      r31,0
	  18:	39 c0 00 00 	li      r14,0
	  1c:	48 00 00 00 	b       1c &lt;.fixup+0x1c&gt;
				1c: R_PPC_REL24	.text+0x144

Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Closes: https://lore.kernel.org/oe-kbuild-all/202602021825.otcItxGi-lkp@intel.com/
Fixes: c20beffeec3c ("powerpc/uaccess: Use flexible addressing with __put_user()/__get_user()")
Signed-off-by: Christophe Leroy (CS GROUP) &lt;chleroy@kernel.org&gt;
Acked-by: Nathan Chancellor &lt;nathan@kernel.org&gt;
Signed-off-by: Madhavan Srinivasan &lt;maddy@linux.ibm.com&gt;
Link: https://patch.msgid.link/8ca3a657a650e497a96bfe7acde2f637dadab344.1770103646.git.chleroy@kernel.org
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>powerpc/eeh: fix recursive pci_lock_rescan_remove locking in EEH event handling</title>
<updated>2026-03-04T12:19:27+00:00</updated>
<author>
<name>Narayana Murty N</name>
<email>nnmlinux@linux.ibm.com</email>
</author>
<published>2025-12-10T14:25:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=89810e2d80281d42f855fac813786758ee16e323'/>
<id>urn:sha1:89810e2d80281d42f855fac813786758ee16e323</id>
<content type='text'>
[ Upstream commit 815a8d2feb5615ae7f0b5befd206af0b0160614c ]

The recent commit 1010b4c012b0 ("powerpc/eeh: Make EEH driver device
hotplug safe") restructured the EEH driver to improve synchronization
with the PCI hotplug layer.

However, it inadvertently moved pci_lock_rescan_remove() outside its
intended scope in eeh_handle_normal_event(), leading to broken PCI
error reporting and improper EEH event triggering. Specifically,
eeh_handle_normal_event() acquired pci_lock_rescan_remove() before
calling eeh_pe_bus_get(), but eeh_pe_bus_get() itself attempts to
acquire the same lock internally, causing nested locking and disrupting
normal EEH event handling paths.

This patch adds a boolean parameter do_lock to _eeh_pe_bus_get(),
with two public wrappers:
    eeh_pe_bus_get() with locking enabled.
    eeh_pe_bus_get_nolock() that skips locking.

Callers that already hold pci_lock_rescan_remove() now use
eeh_pe_bus_get_nolock() to avoid recursive lock acquisition.

Additionally, pci_lock_rescan_remove() calls are restored to the correct
position—after eeh_pe_bus_get() and immediately before iterating affected
PEs and devices. This ensures EEH-triggered PCI removes occur under proper
bus rescan locking without recursive lock contention.

The eeh_pe_loc_get() function has been split into two functions:
    eeh_pe_loc_get(struct eeh_pe *pe) which retrieves the loc for given PE.
    eeh_pe_loc_get_bus(struct pci_bus *bus) which retrieves the location
    code for given bus.

This resolves lockdep warnings such as:
&lt;snip&gt;
[   84.964298] [    T928] ============================================
[   84.964304] [    T928] WARNING: possible recursive locking detected
[   84.964311] [    T928] 6.18.0-rc3 #51 Not tainted
[   84.964315] [    T928] --------------------------------------------
[   84.964320] [    T928] eehd/928 is trying to acquire lock:
[   84.964324] [    T928] c000000003b29d58 (pci_rescan_remove_lock){+.+.}-{3:3}, at: pci_lock_rescan_remove+0x28/0x40
[   84.964342] [    T928]
                       but task is already holding lock:
[   84.964347] [    T928] c000000003b29d58 (pci_rescan_remove_lock){+.+.}-{3:3}, at: pci_lock_rescan_remove+0x28/0x40
[   84.964357] [    T928]
                       other info that might help us debug this:
[   84.964363] [    T928]  Possible unsafe locking scenario:

[   84.964367] [    T928]        CPU0
[   84.964370] [    T928]        ----
[   84.964373] [    T928]   lock(pci_rescan_remove_lock);
[   84.964378] [    T928]   lock(pci_rescan_remove_lock);
[   84.964383] [    T928]
                       *** DEADLOCK ***

[   84.964388] [    T928]  May be due to missing lock nesting notation

[   84.964393] [    T928] 1 lock held by eehd/928:
[   84.964397] [    T928]  #0: c000000003b29d58 (pci_rescan_remove_lock){+.+.}-{3:3}, at: pci_lock_rescan_remove+0x28/0x40
[   84.964408] [    T928]
                       stack backtrace:
[   84.964414] [    T928] CPU: 2 UID: 0 PID: 928 Comm: eehd Not tainted 6.18.0-rc3 #51 VOLUNTARY
[   84.964417] [    T928] Hardware name: IBM,9080-HEX POWER10 (architected) 0x800200 0xf000006 of:IBM,FW1060.00 (NH1060_022) hv:phyp pSeries
[   84.964419] [    T928] Call Trace:
[   84.964420] [    T928] [c0000011a7157990] [c000000001705de4] dump_stack_lvl+0xc8/0x130 (unreliable)
[   84.964424] [    T928] [c0000011a71579d0] [c0000000002f66e0] print_deadlock_bug+0x430/0x440
[   84.964428] [    T928] [c0000011a7157a70] [c0000000002fd0c0] __lock_acquire+0x1530/0x2d80
[   84.964431] [    T928] [c0000011a7157ba0] [c0000000002fea54] lock_acquire+0x144/0x410
[   84.964433] [    T928] [c0000011a7157cb0] [c0000011a7157cb0] __mutex_lock+0xf4/0x1050
[   84.964436] [    T928] [c0000011a7157e00] [c000000000de21d8] pci_lock_rescan_remove+0x28/0x40
[   84.964439] [    T928] [c0000011a7157e20] [c00000000004ed98] eeh_pe_bus_get+0x48/0xc0
[   84.964442] [    T928] [c0000011a7157e50] [c000000000050434] eeh_handle_normal_event+0x64/0xa60
[   84.964446] [    T928] [c0000011a7157f30] [c000000000051de8] eeh_event_handler+0xf8/0x190
[   84.964450] [    T928] [c0000011a7157f90] [c0000000002747ac] kthread+0x16c/0x180
[   84.964453] [    T928] [c0000011a7157fe0] [c00000000000ded8] start_kernel_thread+0x14/0x18
&lt;/snip&gt;

Fixes: 1010b4c012b0 ("powerpc/eeh: Make EEH driver device hotplug safe")
Signed-off-by: Narayana Murty N &lt;nnmlinux@linux.ibm.com&gt;
Reviewed-by: Sourabh Jain &lt;sourabhjain@linux.ibm.com&gt;
Reviewed-by: Mahesh Salgaonkar &lt;mahesh@linux.ibm.com&gt;
Signed-off-by: Madhavan Srinivasan &lt;maddy@linux.ibm.com&gt;
Link: https://patch.msgid.link/20251210142559.8874-1-nnmlinux@linux.ibm.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>powerpc: Fix struct termio related ioctl macros</title>
<updated>2025-07-17T16:27:48+00:00</updated>
<author>
<name>Madhavan Srinivasan</name>
<email>maddy@linux.ibm.com</email>
</author>
<published>2025-05-17T14:22:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=d50e80f6f992d32a7413ec1ef9619261a88bc50a'/>
<id>urn:sha1:d50e80f6f992d32a7413ec1ef9619261a88bc50a</id>
<content type='text'>
[ Upstream commit ab107276607af90b13a5994997e19b7b9731e251 ]

Since termio interface is now obsolete, include/uapi/asm/ioctls.h
has some constant macros referring to "struct termio", this caused
build failure at userspace.

In file included from /usr/include/asm/ioctl.h:12,
                 from /usr/include/asm/ioctls.h:5,
                 from tst-ioctls.c:3:
tst-ioctls.c: In function 'get_TCGETA':
tst-ioctls.c:12:10: error: invalid application of 'sizeof' to incomplete type 'struct termio'
   12 |   return TCGETA;
      |          ^~~~~~

Even though termios.h provides "struct termio", trying to juggle definitions around to
make it compile could introduce regressions. So better to open code it.

Reported-by: Tulio Magno &lt;tuliom@ascii.art.br&gt;
Suggested-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Tested-by: Justin M. Forbes &lt;jforbes@fedoraproject.org&gt;
Reviewed-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Closes: https://lore.kernel.org/linuxppc-dev/8734dji5wl.fsf@ascii.art.br/
Signed-off-by: Madhavan Srinivasan &lt;maddy@linux.ibm.com&gt;
Link: https://patch.msgid.link/20250517142237.156665-1-maddy@linux.ibm.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>powerpc/vas: Move VAS API to book3s common platform</title>
<updated>2025-06-27T10:04:08+00:00</updated>
<author>
<name>Haren Myneni</name>
<email>haren@linux.ibm.com</email>
</author>
<published>2021-06-17T20:29:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=bd53773795a9c51449ed491a2bc171cfea275b15'/>
<id>urn:sha1:bd53773795a9c51449ed491a2bc171cfea275b15</id>
<content type='text'>
[ Upstream commit 413d6ed3eac387a2876893c337174f0c5b99d01d ]

The pseries platform will share vas and nx code and interfaces
with the PowerNV platform, so create the
arch/powerpc/platforms/book3s/ directory and move VAS API code
there. Functionality is not changed.

Signed-off-by: Haren Myneni &lt;haren@linux.ibm.com&gt;
Reviewed-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/e05c8db17b9eabe3545b902d034238e4c6c08180.camel@linux.ibm.com
Stable-dep-of: 0d67f0dee6c9 ("powerpc/vas: Return -EINVAL if the offset is non-zero in mmap()")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>powerpc/64s: Rewrite __real_pte() and __rpte_to_hidx() as static inline</title>
<updated>2025-03-13T11:47:28+00:00</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@csgroup.eu</email>
</author>
<published>2025-01-12T18:24:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=138cbc307ff70fdf85a4374d2ccfb8bcb600c4f1'/>
<id>urn:sha1:138cbc307ff70fdf85a4374d2ccfb8bcb600c4f1</id>
<content type='text'>
[ Upstream commit 61bcc752d1b81fde3cae454ff20c1d3c359df500 ]

Rewrite __real_pte() and __rpte_to_hidx() as static inline in order to
avoid following warnings/errors when building with 4k page size:

	  CC      arch/powerpc/mm/book3s64/hash_tlb.o
	arch/powerpc/mm/book3s64/hash_tlb.c: In function 'hpte_need_flush':
	arch/powerpc/mm/book3s64/hash_tlb.c:49:16: error: variable 'offset' set but not used [-Werror=unused-but-set-variable]
	   49 |         int i, offset;
	      |                ^~~~~~

	  CC      arch/powerpc/mm/book3s64/hash_native.o
	arch/powerpc/mm/book3s64/hash_native.c: In function 'native_flush_hash_range':
	arch/powerpc/mm/book3s64/hash_native.c:782:29: error: variable 'index' set but not used [-Werror=unused-but-set-variable]
	  782 |         unsigned long hash, index, hidx, shift, slot;
	      |                             ^~~~~

Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Closes: https://lore.kernel.org/oe-kbuild-all/202501081741.AYFwybsq-lkp@intel.com/
Fixes: ff31e105464d ("powerpc/mm/hash64: Store the slot information at the right offset for hugetlb")
Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Reviewed-by: Ritesh Harjani (IBM) &lt;ritesh.list@gmail.com&gt;
Signed-off-by: Madhavan Srinivasan &lt;maddy@linux.ibm.com&gt;
Link: https://patch.msgid.link/e0d340a5b7bd478ecbf245d826e6ab2778b74e06.1736706263.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>powerpc/64s/mm: Move __real_pte stubs into hash-4k.h</title>
<updated>2025-03-13T11:47:28+00:00</updated>
<author>
<name>Michael Ellerman</name>
<email>mpe@ellerman.id.au</email>
</author>
<published>2024-08-21T08:07:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=91550c6dc4f8cd0077ba8e45e4e499b6584fbf67'/>
<id>urn:sha1:91550c6dc4f8cd0077ba8e45e4e499b6584fbf67</id>
<content type='text'>
[ Upstream commit 8ae4f16f7d7b59cca55aeca6db7c9636ffe7fbaa ]

The stub versions of __real_pte() etc are only used with HPT &amp; 4K pages,
so move them into the hash-4k.h header.

Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://msgid.link/20240821080729.872034-1-mpe@ellerman.id.au
Stable-dep-of: 61bcc752d1b8 ("powerpc/64s: Rewrite __real_pte() and __rpte_to_hidx() as static inline")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>powerpc/sstep: make emulate_vsx_load and emulate_vsx_store static</title>
<updated>2024-12-14T18:47:59+00:00</updated>
<author>
<name>Michal Suchanek</name>
<email>msuchanek@suse.de</email>
</author>
<published>2024-10-01T13:03:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=fd57d992f371584f4891c1b935cb68552ab7da5d'/>
<id>urn:sha1:fd57d992f371584f4891c1b935cb68552ab7da5d</id>
<content type='text'>
[ Upstream commit a26c4dbb3d9c1821cb0fc11cb2dbc32d5bf3463b ]

These functions are not used outside of sstep.c

Fixes: 350779a29f11 ("powerpc: Handle most loads and stores in instruction emulation code")
Signed-off-by: Michal Suchanek &lt;msuchanek@suse.de&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://patch.msgid.link/20241001130356.14664-1-msuchanek@suse.de
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>powerpc/pseries: Fix dtl_access_lock to be a rw_semaphore</title>
<updated>2024-12-14T18:47:58+00:00</updated>
<author>
<name>Michael Ellerman</name>
<email>mpe@ellerman.id.au</email>
</author>
<published>2024-08-19T12:24:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=6956c0e7346ce1bbfc726755aa8da10d26e84276'/>
<id>urn:sha1:6956c0e7346ce1bbfc726755aa8da10d26e84276</id>
<content type='text'>
[ Upstream commit cadae3a45d23aa4f6485938a67cbc47aaaa25e38 ]

The dtl_access_lock needs to be a rw_sempahore, a sleeping lock, because
the code calls kmalloc() while holding it, which can sleep:

  # echo 1 &gt; /proc/powerpc/vcpudispatch_stats
  BUG: sleeping function called from invalid context at include/linux/sched/mm.h:337
  in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 199, name: sh
  preempt_count: 1, expected: 0
  3 locks held by sh/199:
   #0: c00000000a0743f8 (sb_writers#3){.+.+}-{0:0}, at: vfs_write+0x324/0x438
   #1: c0000000028c7058 (dtl_enable_mutex){+.+.}-{3:3}, at: vcpudispatch_stats_write+0xd4/0x5f4
   #2: c0000000028c70b8 (dtl_access_lock){+.+.}-{2:2}, at: vcpudispatch_stats_write+0x220/0x5f4
  CPU: 0 PID: 199 Comm: sh Not tainted 6.10.0-rc4 #152
  Hardware name: IBM pSeries (emulated by qemu) POWER9 (raw) 0x4e1202 0xf000005 of:SLOF,HEAD hv:linux,kvm pSeries
  Call Trace:
    dump_stack_lvl+0x130/0x148 (unreliable)
    __might_resched+0x174/0x410
    kmem_cache_alloc_noprof+0x340/0x3d0
    alloc_dtl_buffers+0x124/0x1ac
    vcpudispatch_stats_write+0x2a8/0x5f4
    proc_reg_write+0xf4/0x150
    vfs_write+0xfc/0x438
    ksys_write+0x88/0x148
    system_call_exception+0x1c4/0x5a0
    system_call_common+0xf4/0x258

Fixes: 06220d78f24a ("powerpc/pseries: Introduce rwlock to gatekeep DTLB usage")
Tested-by: Kajol Jain &lt;kjain@linux.ibm.com&gt;
Reviewed-by: Nysal Jan K.A &lt;nysal@linux.ibm.com&gt;
Reviewed-by: Kajol Jain &lt;kjain@linux.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://patch.msgid.link/20240819122401.513203-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>powerpc/vdso: Flag VDSO64 entry points as functions</title>
<updated>2024-12-14T18:47:57+00:00</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@csgroup.eu</email>
</author>
<published>2024-10-09T22:17:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=a85e5215609d39cce5a4d5e059c949ed3dc9610a'/>
<id>urn:sha1:a85e5215609d39cce5a4d5e059c949ed3dc9610a</id>
<content type='text'>
[ Upstream commit 0161bd38c24312853ed5ae9a425a1c41c4ac674a ]

On powerpc64 as shown below by readelf, vDSO functions symbols have
type NOTYPE.

$ powerpc64-linux-gnu-readelf -a arch/powerpc/kernel/vdso/vdso64.so.dbg
ELF Header:
  Magic:   7f 45 4c 46 02 02 01 00 00 00 00 00 00 00 00 00
  Class:                             ELF64
  Data:                              2's complement, big endian
  Version:                           1 (current)
  OS/ABI:                            UNIX - System V
  ABI Version:                       0
  Type:                              DYN (Shared object file)
  Machine:                           PowerPC64
  Version:                           0x1
...

Symbol table '.dynsym' contains 12 entries:
   Num:    Value          Size Type    Bind   Vis      Ndx Name
...
     1: 0000000000000524    84 NOTYPE  GLOBAL DEFAULT    8 __[...]@@LINUX_2.6.15
...
     4: 0000000000000000     0 OBJECT  GLOBAL DEFAULT  ABS LINUX_2.6.15
     5: 00000000000006c0    48 NOTYPE  GLOBAL DEFAULT    8 __[...]@@LINUX_2.6.15

Symbol table '.symtab' contains 56 entries:
   Num:    Value          Size Type    Bind   Vis      Ndx Name
...
    45: 0000000000000000     0 OBJECT  GLOBAL DEFAULT  ABS LINUX_2.6.15
    46: 00000000000006c0    48 NOTYPE  GLOBAL DEFAULT    8 __kernel_getcpu
    47: 0000000000000524    84 NOTYPE  GLOBAL DEFAULT    8 __kernel_clock_getres

To overcome that, commit ba83b3239e65 ("selftests: vDSO: fix vDSO
symbols lookup for powerpc64") was applied to have selftests also
look for NOTYPE symbols, but the correct fix should be to flag VDSO
entry points as functions.

The original commit that brought VDSO support into powerpc/64 has the
following explanation:

    Note that the symbols exposed by the vDSO aren't "normal" function symbols, apps
    can't be expected to link against them directly, the vDSO's are both seen
    as if they were linked at 0 and the symbols just contain offsets to the
    various functions.  This is done on purpose to avoid a relocation step
    (ppc64 functions normally have descriptors with abs addresses in them).
    When glibc uses those functions, it's expected to use it's own trampolines
    that know how to reach them.

The descriptors it's talking about are the OPD function descriptors
used on ABI v1 (big endian). But it would be more correct for a text
symbol to have type function, even if there's no function descriptor
for it.

glibc has a special case already for handling the VDSO symbols which
creates a fake opd pointing at the kernel symbol. So changing the VDSO
symbol type to function shouldn't affect that.

For ABI v2, there is no function descriptors and VDSO functions can
safely have function type.

So lets flag VDSO entry points as functions and revert the
selftest change.

Link: https://github.com/mpe/linux-fullhistory/commit/5f2dd691b62da9d9cc54b938f8b29c22c93cb805
Fixes: ba83b3239e65 ("selftests: vDSO: fix vDSO symbols lookup for powerpc64")
Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Reviewed-By: Segher Boessenkool &lt;segher@kernel.crashing.org&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://patch.msgid.link/b6ad2f1ee9887af3ca5ecade2a56f4acda517a85.1728512263.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>powerpc: Avoid nmi_enter/nmi_exit in real mode interrupt.</title>
<updated>2024-08-19T03:41:22+00:00</updated>
<author>
<name>Mahesh Salgaonkar</name>
<email>mahesh@linux.ibm.com</email>
</author>
<published>2024-04-10T04:30:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=fb6675db04c4b79883373edc578d5df7bbc84848'/>
<id>urn:sha1:fb6675db04c4b79883373edc578d5df7bbc84848</id>
<content type='text'>
commit 0db880fc865ffb522141ced4bfa66c12ab1fbb70 upstream.

nmi_enter()/nmi_exit() touches per cpu variables which can lead to kernel
crash when invoked during real mode interrupt handling (e.g. early HMI/MCE
interrupt handler) if percpu allocation comes from vmalloc area.

Early HMI/MCE handlers are called through DEFINE_INTERRUPT_HANDLER_NMI()
wrapper which invokes nmi_enter/nmi_exit calls. We don't see any issue when
percpu allocation is from the embedded first chunk. However with
CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK enabled there are chances where percpu
allocation can come from the vmalloc area.

With kernel command line "percpu_alloc=page" we can force percpu allocation
to come from vmalloc area and can see kernel crash in machine_check_early:

[    1.215714] NIP [c000000000e49eb4] rcu_nmi_enter+0x24/0x110
[    1.215717] LR [c0000000000461a0] machine_check_early+0xf0/0x2c0
[    1.215719] --- interrupt: 200
[    1.215720] [c000000fffd73180] [0000000000000000] 0x0 (unreliable)
[    1.215722] [c000000fffd731b0] [0000000000000000] 0x0
[    1.215724] [c000000fffd73210] [c000000000008364] machine_check_early_common+0x134/0x1f8

Fix this by avoiding use of nmi_enter()/nmi_exit() in real mode if percpu
first chunk is not embedded.

Reviewed-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Tested-by: Shirisha Ganta &lt;shirisha@linux.ibm.com&gt;
Signed-off-by: Mahesh Salgaonkar &lt;mahesh@linux.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://msgid.link/20240410043006.81577-1-mahesh@linux.ibm.com
[ Conflicts in arch/powerpc/include/asm/interrupt.h
  because machine_check_early() and machine_check_exception()
  has been refactored. ]
Signed-off-by: Jinjie Ruan &lt;ruanjinjie@huawei.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
</feed>
