linux-stable.git/arch/powerpc/kernel, branch v6.12.2 Linux kernel stable tree powerpc/pseries: Fix KVM guest detection for disabling hardlockup detector 2024-12-05T13:02:43+00:00 Gautam Menghani gautam@linux.ibm.com 2024-11-08T09:48:37+00:00 58d6473042e8ef117ad0d339bd782ed6854d3bf1 commit 44e5d21e6d3fd2a1fed7f0327cf72e99397e2eaf upstream. As per the kernel documentation[1], hardlockup detector should be disabled in KVM guests as it may give false positives. On PPC, hardlockup detector is enabled inside KVM guests because disable_hardlockup_detector() is marked as early_initcall and it relies on kvm_guest static key (is_kvm_guest()) which is initialized later during boot by check_kvm_guest(), which is a core_initcall. check_kvm_guest() is also called in pSeries_smp_probe(), which is called before initcalls, but it is skipped if KVM guest does not have doorbell support or if the guest is launched with SMT=1. Call check_kvm_guest() in disable_hardlockup_detector() so that is_kvm_guest() check goes through fine and hardlockup detector can be disabled inside the KVM guest. [1]: Documentation/admin-guide/sysctl/kernel.rst Fixes: 633c8e9800f3 ("powerpc/pseries: Enable hardlockup watchdog for PowerVM partitions") Cc: stable@vger.kernel.org # v5.14+ Signed-off-by: Gautam Menghani <gautam@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://patch.msgid.link/20241108094839.33084-1-gautam@linux.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 44e5d21e6d3fd2a1fed7f0327cf72e99397e2eaf upstream.

As per the kernel documentation[1], hardlockup detector should
be disabled in KVM guests as it may give false positives. On
PPC, hardlockup detector is enabled inside KVM guests because
disable_hardlockup_detector() is marked as early_initcall and it
relies on kvm_guest static key (is_kvm_guest()) which is initialized
later during boot by check_kvm_guest(), which is a core_initcall.
check_kvm_guest() is also called in pSeries_smp_probe(), which is called
before initcalls, but it is skipped if KVM guest does not have doorbell
support or if the guest is launched with SMT=1.

Call check_kvm_guest() in disable_hardlockup_detector() so that
is_kvm_guest() check goes through fine and hardlockup detector can be
disabled inside the KVM guest.

[1]: Documentation/admin-guide/sysctl/kernel.rst

Fixes: 633c8e9800f3 ("powerpc/pseries: Enable hardlockup watchdog for PowerVM partitions")
Cc: stable@vger.kernel.org # v5.14+
Signed-off-by: Gautam Menghani <gautam@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://patch.msgid.link/20241108094839.33084-1-gautam@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fadump: reserve param area if below boot_mem_top 2024-12-05T13:02:12+00:00 Sourabh Jain sourabhjain@linux.ibm.com 2024-11-07T05:58:17+00:00 361a7f8e019943c9bc4f9a255f3b92fb48c99169 [ Upstream commit fb90dca828b6070709093934c6dec56489a2d91d ] The param area is a memory region where the kernel places additional command-line arguments for fadump kernel. Currently, the param memory area is reserved in fadump kernel if it is above boot_mem_top. However, it should be reserved if it is below boot_mem_top because the fadump kernel already reserves memory from boot_mem_top to the end of DRAM. Currently, there is no impact from not reserving param memory if it is below boot_mem_top, as it is not used after the early boot phase of the fadump kernel. However, if this changes in the future, it could lead to issues in the fadump kernel. Fixes: 3416c9daa6b1 ("powerpc/fadump: pass additional parameters when fadump is active") Acked-by: Hari Bathini <hbathini@linux.ibm.com> Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://patch.msgid.link/20241107055817.489795-2-sourabhjain@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit fb90dca828b6070709093934c6dec56489a2d91d ]

The param area is a memory region where the kernel places additional
command-line arguments for fadump kernel. Currently, the param memory
area is reserved in fadump kernel if it is above boot_mem_top. However,
it should be reserved if it is below boot_mem_top because the fadump
kernel already reserves memory from boot_mem_top to the end of DRAM.

Currently, there is no impact from not reserving param memory if it is
below boot_mem_top, as it is not used after the early boot phase of the
fadump kernel. However, if this changes in the future, it could lead to
issues in the fadump kernel.

Fixes: 3416c9daa6b1 ("powerpc/fadump: pass additional parameters when fadump is active")
Acked-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://patch.msgid.link/20241107055817.489795-2-sourabhjain@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
powerpc/fadump: allocate memory for additional parameters early 2024-12-05T13:02:11+00:00 Hari Bathini hbathini@linux.ibm.com 2024-11-07T05:58:16+00:00 561482826a7af22e569920fbe69b8519da9f3302 [ Upstream commit f4892c68ecc1cf45e41a78820dd2eebccc945b66 ] Memory for passing additional parameters to fadump capture kernel is allocated during subsys_initcall level, using memblock. But as slab is already available by this time, allocation happens via the buddy allocator. This may work for radix MMU but is likely to fail in most cases for hash MMU as hash MMU needs this memory in the first memory block for it to be accessible in real mode in the capture kernel (second boot). So, allocate memory for additional parameters area as soon as MMU mode is obvious. Fixes: 683eab94da75 ("powerpc/fadump: setup additional parameters for dump capture kernel") Reported-by: Venkat Rao Bagalkote <venkat88@linux.vnet.ibm.com> Closes: https://lore.kernel.org/lkml/a70e4064-a040-447b-8556-1fd02f19383d@linux.vnet.ibm.com/T/#u Signed-off-by: Hari Bathini <hbathini@linux.ibm.com> Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com> Tested-by: Venkat Rao Bagalkote <venkat88@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://patch.msgid.link/20241107055817.489795-1-sourabhjain@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit f4892c68ecc1cf45e41a78820dd2eebccc945b66 ]

Memory for passing additional parameters to fadump capture kernel
is allocated during subsys_initcall level, using memblock. But
as slab is already available by this time, allocation happens via
the buddy allocator. This may work for radix MMU but is likely to
fail in most cases for hash MMU as hash MMU needs this memory in
the first memory block for it to be accessible in real mode in the
capture kernel (second boot). So, allocate memory for additional
parameters area as soon as MMU mode is obvious.

Fixes: 683eab94da75 ("powerpc/fadump: setup additional parameters for dump capture kernel")
Reported-by: Venkat Rao Bagalkote <venkat88@linux.vnet.ibm.com>
Closes: https://lore.kernel.org/lkml/a70e4064-a040-447b-8556-1fd02f19383d@linux.vnet.ibm.com/T/#u
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://patch.msgid.link/20241107055817.489795-1-sourabhjain@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
powerpc/fadump: Move fadump_cma_init to setup_arch() after initmem_init() 2024-12-05T13:02:04+00:00 Ritesh Harjani (IBM) ritesh.list@gmail.com 2024-10-18T16:17:57+00:00 7351c5a6507b4401aeecadb5959131410a339520 [ Upstream commit 05b94cae1c47f94588c3e7096963c1007c4d9c1d ] During early init CMA_MIN_ALIGNMENT_BYTES can be PAGE_SIZE, since pageblock_order is still zero and it gets initialized later during initmem_init() e.g. setup_arch() -> initmem_init() -> sparse_init() -> set_pageblock_order() One such use case where this causes issue is - early_setup() -> early_init_devtree() -> fadump_reserve_mem() -> fadump_cma_init() This causes CMA memory alignment check to be bypassed in cma_init_reserved_mem(). Then later cma_activate_area() can hit a VM_BUG_ON_PAGE(pfn & ((1 << order) - 1)) if the reserved memory area was not pageblock_order aligned. Fix it by moving the fadump_cma_init() after initmem_init(), where other such cma reservations also gets called. <stack trace> ============== page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10010 flags: 0x13ffff800000000(node=1|zone=0|lastcpupid=0x7ffff) CMA raw: 013ffff800000000 5deadbeef0000100 5deadbeef0000122 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: VM_BUG_ON_PAGE(pfn & ((1 << order) - 1)) ------------[ cut here ]------------ kernel BUG at mm/page_alloc.c:778! Call Trace: __free_one_page+0x57c/0x7b0 (unreliable) free_pcppages_bulk+0x1a8/0x2c8 free_unref_page_commit+0x3d4/0x4e4 free_unref_page+0x458/0x6d0 init_cma_reserved_pageblock+0x114/0x198 cma_init_reserved_areas+0x270/0x3e0 do_one_initcall+0x80/0x2f8 kernel_init_freeable+0x33c/0x530 kernel_init+0x34/0x26c ret_from_kernel_user_thread+0x14/0x1c Fixes: 11ac3e87ce09 ("mm: cma: use pageblock_order as the single alignment") Suggested-by: David Hildenbrand <david@redhat.com> Reported-by: Sachin P Bappalige <sachinpb@linux.ibm.com> Acked-by: Hari Bathini <hbathini@linux.ibm.com> Reviewed-by: Madhavan Srinivasan <maddy@linux.ibm.com> Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://patch.msgid.link/3ae208e48c0d9cefe53d2dc4f593388067405b7d.1729146153.git.ritesh.list@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 05b94cae1c47f94588c3e7096963c1007c4d9c1d ]

During early init CMA_MIN_ALIGNMENT_BYTES can be PAGE_SIZE,
since pageblock_order is still zero and it gets initialized
later during initmem_init() e.g.
setup_arch() -> initmem_init() -> sparse_init() -> set_pageblock_order()

One such use case where this causes issue is -
early_setup() -> early_init_devtree() -> fadump_reserve_mem() -> fadump_cma_init()

This causes CMA memory alignment check to be bypassed in
cma_init_reserved_mem(). Then later cma_activate_area() can hit
a VM_BUG_ON_PAGE(pfn & ((1 << order) - 1)) if the reserved memory
area was not pageblock_order aligned.

Fix it by moving the fadump_cma_init() after initmem_init(),
where other such cma reservations also gets called.

<stack trace>
==============
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10010
flags: 0x13ffff800000000(node=1|zone=0|lastcpupid=0x7ffff) CMA
raw: 013ffff800000000 5deadbeef0000100 5deadbeef0000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: VM_BUG_ON_PAGE(pfn & ((1 << order) - 1))
------------[ cut here ]------------
kernel BUG at mm/page_alloc.c:778!

Call Trace:
__free_one_page+0x57c/0x7b0 (unreliable)
free_pcppages_bulk+0x1a8/0x2c8
free_unref_page_commit+0x3d4/0x4e4
free_unref_page+0x458/0x6d0
init_cma_reserved_pageblock+0x114/0x198
cma_init_reserved_areas+0x270/0x3e0
do_one_initcall+0x80/0x2f8
kernel_init_freeable+0x33c/0x530
kernel_init+0x34/0x26c
ret_from_kernel_user_thread+0x14/0x1c

Fixes: 11ac3e87ce09 ("mm: cma: use pageblock_order as the single alignment")
Suggested-by: David Hildenbrand <david@redhat.com>
Reported-by: Sachin P Bappalige <sachinpb@linux.ibm.com>
Acked-by: Hari Bathini <hbathini@linux.ibm.com>
Reviewed-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://patch.msgid.link/3ae208e48c0d9cefe53d2dc4f593388067405b7d.1729146153.git.ritesh.list@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
powerpc/fadump: Refactor and prepare fadump_cma_init for late init 2024-12-05T13:02:04+00:00 Ritesh Harjani (IBM) ritesh.list@gmail.com 2024-10-18T16:17:55+00:00 7528e270fa9973f597b65b4d3681c77eb71847fe [ Upstream commit adfaec30ffaceecd565e06adae367aa944acc3c9 ] We anyway don't use any return values from fadump_cma_init(). Since fadump_reserve_mem() from where fadump_cma_init() gets called today, already has the required checks. This patch makes this function return type as void. Let's also handle extra cases like return if fadump_supported is false or dump_active, so that in later patches we can call fadump_cma_init() separately from setup_arch(). Acked-by: Hari Bathini <hbathini@linux.ibm.com> Reviewed-by: Madhavan Srinivasan <maddy@linux.ibm.com> Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://patch.msgid.link/a2afc3d6481a87a305e89cfc4a3f3d2a0b8ceab3.1729146153.git.ritesh.list@gmail.com Stable-dep-of: 05b94cae1c47 ("powerpc/fadump: Move fadump_cma_init to setup_arch() after initmem_init()") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit adfaec30ffaceecd565e06adae367aa944acc3c9 ]

We anyway don't use any return values from fadump_cma_init(). Since
fadump_reserve_mem() from where fadump_cma_init() gets called today,
already has the required checks.
This patch makes this function return type as void. Let's also handle
extra cases like return if fadump_supported is false or dump_active, so
that in later patches we can call fadump_cma_init() separately from
setup_arch().

Acked-by: Hari Bathini <hbathini@linux.ibm.com>
Reviewed-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://patch.msgid.link/a2afc3d6481a87a305e89cfc4a3f3d2a0b8ceab3.1729146153.git.ritesh.list@gmail.com
Stable-dep-of: 05b94cae1c47 ("powerpc/fadump: Move fadump_cma_init to setup_arch() after initmem_init()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
of/fdt: add dt_phys arg to early_init_dt_scan and early_init_dt_verify 2024-12-05T13:01:32+00:00 Usama Arif usamaarif642@gmail.com 2024-10-23T17:14:26+00:00 b5f599af75a50aa80d82f772d65889050375ab32 [ Upstream commit b2473a359763e27567993e7d8f37de82f57a0829 ] __pa() is only intended to be used for linear map addresses and using it for initial_boot_params which is in fixmap for arm64 will give an incorrect value. Hence save the physical address when it is known at boot time when calling early_init_dt_scan for arm64 and use it at kexec time instead of converting the virtual address using __pa(). Note that arm64 doesn't need the FDT region reserved in the DT as the kernel explicitly reserves the passed in FDT. Therefore, only a debug warning is fixed with this change. Reported-by: Breno Leitao <leitao@debian.org> Suggested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Usama Arif <usamaarif642@gmail.com> Fixes: ac10be5cdbfa ("arm64: Use common of_kexec_alloc_and_setup_fdt()") Link: https://lore.kernel.org/r/20241023171426.452688-1-usamaarif642@gmail.com Signed-off-by: Rob Herring (Arm) <robh@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit b2473a359763e27567993e7d8f37de82f57a0829 ]

 __pa() is only intended to be used for linear map addresses and using
it for initial_boot_params which is in fixmap for arm64 will give an
incorrect value. Hence save the physical address when it is known at
boot time when calling early_init_dt_scan for arm64 and use it at kexec
time instead of converting the virtual address using __pa().

Note that arm64 doesn't need the FDT region reserved in the DT as the
kernel explicitly reserves the passed in FDT. Therefore, only a debug
warning is fixed with this change.

Reported-by: Breno Leitao <leitao@debian.org>
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Usama Arif <usamaarif642@gmail.com>
Fixes: ac10be5cdbfa ("arm64: Use common of_kexec_alloc_and_setup_fdt()")
Link: https://lore.kernel.org/r/20241023171426.452688-1-usamaarif642@gmail.com
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
powerpc/8xx: Fix kernel DTLB miss on dcbz 2024-10-11T04:53:06+00:00 Christophe Leroy christophe.leroy@csgroup.eu 2024-10-05T08:53:29+00:00 8956c582ac6b1693a351230179f898979dd00bdf Following OOPS is encountered while loading test_bpf module on powerpc 8xx: [ 218.835567] BUG: Unable to handle kernel data access on write at 0xcb000000 [ 218.842473] Faulting instruction address: 0xc0017a80 [ 218.847451] Oops: Kernel access of bad area, sig: 11 [#1] [ 218.852854] BE PAGE_SIZE=16K PREEMPT CMPC885 [ 218.857207] SAF3000 DIE NOTIFICATION [ 218.860713] Modules linked in: test_bpf(+) test_module [ 218.865867] CPU: 0 UID: 0 PID: 527 Comm: insmod Not tainted 6.11.0-s3k-dev-09856-g3de3d71ae2e6-dirty #1280 [ 218.875546] Hardware name: MIAE 8xx 0x500000 CMPC885 [ 218.880521] NIP: c0017a80 LR: beab859c CTR: 000101d4 [ 218.885584] REGS: cac2bc90 TRAP: 0300 Not tainted (6.11.0-s3k-dev-09856-g3de3d71ae2e6-dirty) [ 218.894308] MSR: 00009032 <EE,ME,IR,DR,RI> CR: 55005555 XER: a0007100 [ 218.901290] DAR: cb000000 DSISR: c2000000 [ 218.901290] GPR00: 000185d1 cac2bd50 c21b9580 caf7c030 c3883fcc 00000008 cafffffc 00000000 [ 218.901290] GPR08: 00040000 18300000 20000000 00000004 99005555 100d815e ca669d08 00000369 [ 218.901290] GPR16: ca730000 00000000 ca2c004c 00000000 00000000 0000035d 00000311 00000369 [ 218.901290] GPR24: ca732240 00000001 00030ba3 c3800000 00000000 00185d48 caf7c000 ca2c004c [ 218.941087] NIP [c0017a80] memcpy+0x88/0xec [ 218.945277] LR [beab859c] test_bpf_init+0x22c/0x3c90 [test_bpf] [ 218.951476] Call Trace: [ 218.953916] [cac2bd50] [beab8570] test_bpf_init+0x200/0x3c90 [test_bpf] (unreliable) [ 218.962034] [cac2bde0] [c0004c04] do_one_initcall+0x4c/0x1fc [ 218.967706] [cac2be40] [c00a2ec4] do_init_module+0x68/0x360 [ 218.973292] [cac2be60] [c00a5194] init_module_from_file+0x8c/0xc0 [ 218.979401] [cac2bed0] [c00a5568] sys_finit_module+0x250/0x3f0 [ 218.985248] [cac2bf20] [c000e390] system_call_exception+0x8c/0x15c [ 218.991444] [cac2bf30] [c00120a8] ret_from_syscall+0x0/0x28 This happens in the main loop of memcpy() ==> c0017a80: 7c 0b 37 ec dcbz r11,r6 c0017a84: 80 e4 00 04 lwz r7,4(r4) c0017a88: 81 04 00 08 lwz r8,8(r4) c0017a8c: 81 24 00 0c lwz r9,12(r4) c0017a90: 85 44 00 10 lwzu r10,16(r4) c0017a94: 90 e6 00 04 stw r7,4(r6) c0017a98: 91 06 00 08 stw r8,8(r6) c0017a9c: 91 26 00 0c stw r9,12(r6) c0017aa0: 95 46 00 10 stwu r10,16(r6) c0017aa4: 42 00 ff dc bdnz c0017a80 <memcpy+0x88> Commit ac9f97ff8b32 ("powerpc/8xx: Inconditionally use task PGDIR in DTLB misses") relies on re-reading DAR register to know if an error is due to a missing copy of a PMD entry in task's PGDIR, allthough DAR was already read in the exception prolog and copied into thread struct. This is because is it done very early in the exception and there are not enough registers available to keep a pointer to thread struct. However, dcbz instruction is buggy and doesn't update DAR register on fault. That is detected and generates a call to FixupDAR workaround which updates DAR copy in thread struct but doesn't fix DAR register. Let's fix DAR in addition to the update of DAR copy in thread struct. Fixes: ac9f97ff8b32 ("powerpc/8xx: Inconditionally use task PGDIR in DTLB misses") Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/2b851399bd87e81c6ccb87ea3a7a6b32c7aa04d7.1728118396.git.christophe.leroy@csgroup.eu 
Following OOPS is encountered while loading test_bpf module
on powerpc 8xx:

[  218.835567] BUG: Unable to handle kernel data access on write at 0xcb000000
[  218.842473] Faulting instruction address: 0xc0017a80
[  218.847451] Oops: Kernel access of bad area, sig: 11 [#1]
[  218.852854] BE PAGE_SIZE=16K PREEMPT CMPC885
[  218.857207] SAF3000 DIE NOTIFICATION
[  218.860713] Modules linked in: test_bpf(+) test_module
[  218.865867] CPU: 0 UID: 0 PID: 527 Comm: insmod Not tainted 6.11.0-s3k-dev-09856-g3de3d71ae2e6-dirty #1280
[  218.875546] Hardware name: MIAE 8xx 0x500000 CMPC885
[  218.880521] NIP:  c0017a80 LR: beab859c CTR: 000101d4
[  218.885584] REGS: cac2bc90 TRAP: 0300   Not tainted  (6.11.0-s3k-dev-09856-g3de3d71ae2e6-dirty)
[  218.894308] MSR:  00009032 <EE,ME,IR,DR,RI>  CR: 55005555  XER: a0007100
[  218.901290] DAR: cb000000 DSISR: c2000000
[  218.901290] GPR00: 000185d1 cac2bd50 c21b9580 caf7c030 c3883fcc 00000008 cafffffc 00000000
[  218.901290] GPR08: 00040000 18300000 20000000 00000004 99005555 100d815e ca669d08 00000369
[  218.901290] GPR16: ca730000 00000000 ca2c004c 00000000 00000000 0000035d 00000311 00000369
[  218.901290] GPR24: ca732240 00000001 00030ba3 c3800000 00000000 00185d48 caf7c000 ca2c004c
[  218.941087] NIP [c0017a80] memcpy+0x88/0xec
[  218.945277] LR [beab859c] test_bpf_init+0x22c/0x3c90 [test_bpf]
[  218.951476] Call Trace:
[  218.953916] [cac2bd50] [beab8570] test_bpf_init+0x200/0x3c90 [test_bpf] (unreliable)
[  218.962034] [cac2bde0] [c0004c04] do_one_initcall+0x4c/0x1fc
[  218.967706] [cac2be40] [c00a2ec4] do_init_module+0x68/0x360
[  218.973292] [cac2be60] [c00a5194] init_module_from_file+0x8c/0xc0
[  218.979401] [cac2bed0] [c00a5568] sys_finit_module+0x250/0x3f0
[  218.985248] [cac2bf20] [c000e390] system_call_exception+0x8c/0x15c
[  218.991444] [cac2bf30] [c00120a8] ret_from_syscall+0x0/0x28

This happens in the main loop of memcpy()

  ==>	c0017a80:	7c 0b 37 ec 	dcbz    r11,r6
	c0017a84:	80 e4 00 04 	lwz     r7,4(r4)
	c0017a88:	81 04 00 08 	lwz     r8,8(r4)
	c0017a8c:	81 24 00 0c 	lwz     r9,12(r4)
	c0017a90:	85 44 00 10 	lwzu    r10,16(r4)
	c0017a94:	90 e6 00 04 	stw     r7,4(r6)
	c0017a98:	91 06 00 08 	stw     r8,8(r6)
	c0017a9c:	91 26 00 0c 	stw     r9,12(r6)
	c0017aa0:	95 46 00 10 	stwu    r10,16(r6)
	c0017aa4:	42 00 ff dc 	bdnz    c0017a80 <memcpy+0x88>

Commit ac9f97ff8b32 ("powerpc/8xx: Inconditionally use task PGDIR in
DTLB misses") relies on re-reading DAR register to know if an error is
due to a missing copy of a PMD entry in task's PGDIR, allthough DAR
was already read in the exception prolog and copied into thread
struct. This is because is it done very early in the exception and
there are not enough registers available to keep a pointer to thread
struct.

However, dcbz instruction is buggy and doesn't update DAR register on
fault. That is detected and generates a call to FixupDAR workaround
which updates DAR copy in thread struct but doesn't fix DAR register.

Let's fix DAR in addition to the update of DAR copy in thread struct.

Fixes: ac9f97ff8b32 ("powerpc/8xx: Inconditionally use task PGDIR in DTLB misses")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/2b851399bd87e81c6ccb87ea3a7a6b32c7aa04d7.1728118396.git.christophe.leroy@csgroup.eu
powerpc/vdso: allow r30 in vDSO code generation of getrandom 2024-09-30T09:19:43+00:00 Jason A. Donenfeld Jason@zx2c4.com 2024-09-25T17:50:22+00:00 4b058c9f281f5b100efbf665dd5a1a05e1654d6d For gettimeofday, -ffixed-r30 was passed to work around a bug in Go code, where the vDSO trampoline forgot to save and restore this register across function calls. But Go requires a different trampoline for every call, and there's no reason that new Go code needs to be broken and add more bugs. So remove -ffixed-r30 for getrandom. Fixes: 8072b39c3a75 ("powerpc/vdso: Wire up getrandom() vDSO implementation on VDSO64") Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20240925175021.1526936-2-Jason@zx2c4.com 
For gettimeofday, -ffixed-r30 was passed to work around a bug in Go
code, where the vDSO trampoline forgot to save and restore this register
across function calls. But Go requires a different trampoline for every
call, and there's no reason that new Go code needs to be broken and add
more bugs. So remove -ffixed-r30 for getrandom.

Fixes: 8072b39c3a75 ("powerpc/vdso: Wire up getrandom() vDSO implementation on VDSO64")
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240925175021.1526936-2-Jason@zx2c4.com
Merge tag 'powerpc-6.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux 2024-09-25T18:17:25+00:00 Linus Torvalds torvalds@linux-foundation.org 2024-09-25T18:17:25+00:00 4ffc45808373e32112500756d6f02fe56c42f371 Pull powerpc fixes from Michael Ellerman: - Fix build error in vdso32 when building 64-bit with COMPAT=y and -Os - Fix build error in pseries EEH when CONFIG_DEBUG_FS is not set Thanks to Christophe Leroy, Narayana Murty N, Christian Zigotzky, and Ritesh Harjani. * tag 'powerpc-6.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/pseries/eeh: move pseries_eeh_err_inject() outside CONFIG_DEBUG_FS block powerpc/vdso32: Fix use of crtsavres for PPC64 
Pull powerpc fixes from Michael Ellerman:

 - Fix build error in vdso32 when building 64-bit with COMPAT=y and -Os

 - Fix build error in pseries EEH when CONFIG_DEBUG_FS is not set

Thanks to Christophe Leroy, Narayana Murty N, Christian Zigotzky, and
Ritesh Harjani.

* tag 'powerpc-6.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/pseries/eeh: move pseries_eeh_err_inject() outside CONFIG_DEBUG_FS block
  powerpc/vdso32: Fix use of crtsavres for PPC64
Merge tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm 2024-09-21T14:29:05+00:00 Linus Torvalds torvalds@linux-foundation.org 2024-09-21T14:29:05+00:00 617a814f14b8914271f7a70366d72c6196d17663 Pull MM updates from Andrew Morton: "Along with the usual shower of singleton patches, notable patch series in this pull request are: - "Align kvrealloc() with krealloc()" from Danilo Krummrich. Adds consistency to the APIs and behaviour of these two core allocation functions. This also simplifies/enables Rustification. - "Some cleanups for shmem" from Baolin Wang. No functional changes - mode code reuse, better function naming, logic simplifications. - "mm: some small page fault cleanups" from Josef Bacik. No functional changes - code cleanups only. - "Various memory tiering fixes" from Zi Yan. A small fix and a little cleanup. - "mm/swap: remove boilerplate" from Yu Zhao. Code cleanups and simplifications and .text shrinkage. - "Kernel stack usage histogram" from Pasha Tatashin and Shakeel Butt. This is a feature, it adds new feilds to /proc/vmstat such as $ grep kstack /proc/vmstat kstack_1k 3 kstack_2k 188 kstack_4k 11391 kstack_8k 243 kstack_16k 0 which tells us that 11391 processes used 4k of stack while none at all used 16k. Useful for some system tuning things, but partivularly useful for "the dynamic kernel stack project". - "kmemleak: support for percpu memory leak detect" from Pavel Tikhomirov. Teaches kmemleak to detect leaksage of percpu memory. - "mm: memcg: page counters optimizations" from Roman Gushchin. "3 independent small optimizations of page counters". - "mm: split PTE/PMD PT table Kconfig cleanups+clarifications" from David Hildenbrand. Improves PTE/PMD splitlock detection, makes powerpc/8xx work correctly by design rather than by accident. - "mm: remove arch_make_page_accessible()" from David Hildenbrand. Some folio conversions which make arch_make_page_accessible() unneeded. - "mm, memcg: cg2 memory{.swap,}.peak write handlers" fro David Finkel. Cleans up and fixes our handling of the resetting of the cgroup/process peak-memory-use detector. - "Make core VMA operations internal and testable" from Lorenzo Stoakes. Rationalizaion and encapsulation of the VMA manipulation APIs. With a view to better enable testing of the VMA functions, even from a userspace-only harness. - "mm: zswap: fixes for global shrinker" from Takero Funaki. Fix issues in the zswap global shrinker, resulting in improved performance. - "mm: print the promo watermark in zoneinfo" from Kaiyang Zhao. Fill in some missing info in /proc/zoneinfo. - "mm: replace follow_page() by folio_walk" from David Hildenbrand. Code cleanups and rationalizations (conversion to folio_walk()) resulting in the removal of follow_page(). - "improving dynamic zswap shrinker protection scheme" from Nhat Pham. Some tuning to improve zswap's dynamic shrinker. Significant reductions in swapin and improvements in performance are shown. - "mm: Fix several issues with unaccepted memory" from Kirill Shutemov. Improvements to the new unaccepted memory feature, - "mm/mprotect: Fix dax puds" from Peter Xu. Implements mprotect on DAX PUDs. This was missing, although nobody seems to have notied yet. - "Introduce a store type enum for the Maple tree" from Sidhartha Kumar. Cleanups and modest performance improvements for the maple tree library code. - "memcg: further decouple v1 code from v2" from Shakeel Butt. Move more cgroup v1 remnants away from the v2 memcg code. - "memcg: initiate deprecation of v1 features" from Shakeel Butt. Adds various warnings telling users that memcg v1 features are deprecated. - "mm: swap: mTHP swap allocator base on swap cluster order" from Chris Li. Greatly improves the success rate of the mTHP swap allocation. - "mm: introduce numa_memblks" from Mike Rapoport. Moves various disparate per-arch implementations of numa_memblk code into generic code. - "mm: batch free swaps for zap_pte_range()" from Barry Song. Greatly improves the performance of munmap() of swap-filled ptes. - "support large folio swap-out and swap-in for shmem" from Baolin Wang. With this series we no longer split shmem large folios into simgle-page folios when swapping out shmem. - "mm/hugetlb: alloc/free gigantic folios" from Yu Zhao. Nice performance improvements and code reductions for gigantic folios. - "support shmem mTHP collapse" from Baolin Wang. Adds support for khugepaged's collapsing of shmem mTHP folios. - "mm: Optimize mseal checks" from Pedro Falcato. Fixes an mprotect() performance regression due to the addition of mseal(). - "Increase the number of bits available in page_type" from Matthew Wilcox. Increases the number of bits available in page_type! - "Simplify the page flags a little" from Matthew Wilcox. Many legacy page flags are now folio flags, so the page-based flags and their accessors/mutators can be removed. - "mm: store zero pages to be swapped out in a bitmap" from Usama Arif. An optimization which permits us to avoid writing/reading zero-filled zswap pages to backing store. - "Avoid MAP_FIXED gap exposure" from Liam Howlett. Fixes a race window which occurs when a MAP_FIXED operqtion is occurring during an unrelated vma tree walk. - "mm: remove vma_merge()" from Lorenzo Stoakes. Major rotorooting of the vma_merge() functionality, making ot cleaner, more testable and better tested. - "misc fixups for DAMON {self,kunit} tests" from SeongJae Park. Minor fixups of DAMON selftests and kunit tests. - "mm: memory_hotplug: improve do_migrate_range()" from Kefeng Wang. Code cleanups and folio conversions. - "Shmem mTHP controls and stats improvements" from Ryan Roberts. Cleanups for shmem controls and stats. - "mm: count the number of anonymous THPs per size" from Barry Song. Expose additional anon THP stats to userspace for improved tuning. - "mm: finish isolate/putback_lru_page()" from Kefeng Wang: more folio conversions and removal of now-unused page-based APIs. - "replace per-quota region priorities histogram buffer with per-context one" from SeongJae Park. DAMON histogram rationalization. - "Docs/damon: update GitHub repo URLs and maintainer-profile" from SeongJae Park. DAMON documentation updates. - "mm/vdpa: correct misuse of non-direct-reclaim __GFP_NOFAIL and improve related doc and warn" from Jason Wang: fixes usage of page allocator __GFP_NOFAIL and GFP_ATOMIC flags. - "mm: split underused THPs" from Yu Zhao. Improve THP=always policy. This was overprovisioning THPs in sparsely accessed memory areas. - "zram: introduce custom comp backends API" frm Sergey Senozhatsky. Add support for zram run-time compression algorithm tuning. - "mm: Care about shadow stack guard gap when getting an unmapped area" from Mark Brown. Fix up the various arch_get_unmapped_area() implementations to better respect guard areas. - "Improve mem_cgroup_iter()" from Kinsey Ho. Improve the reliability of mem_cgroup_iter() and various code cleanups. - "mm: Support huge pfnmaps" from Peter Xu. Extends the usage of huge pfnmap support. - "resource: Fix region_intersects() vs add_memory_driver_managed()" from Huang Ying. Fix a bug in region_intersects() for systems with CXL memory. - "mm: hwpoison: two more poison recovery" from Kefeng Wang. Teaches a couple more code paths to correctly recover from the encountering of poisoned memry. - "mm: enable large folios swap-in support" from Barry Song. Support the swapin of mTHP memory into appropriately-sized folios, rather than into single-page folios" * tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (416 commits) zram: free secondary algorithms names uprobes: turn xol_area->pages[2] into xol_area->page uprobes: introduce the global struct vm_special_mapping xol_mapping Revert "uprobes: use vm_special_mapping close() functionality" mm: support large folios swap-in for sync io devices mm: add nr argument in mem_cgroup_swapin_uncharge_swap() helper to support large folios mm: fix swap_read_folio_zeromap() for large folios with partial zeromap mm/debug_vm_pgtable: Use pxdp_get() for accessing page table entries set_memory: add __must_check to generic stubs mm/vma: return the exact errno in vms_gather_munmap_vmas() memcg: cleanup with !CONFIG_MEMCG_V1 mm/show_mem.c: report alloc tags in human readable units mm: support poison recovery from copy_present_page() mm: support poison recovery from do_cow_fault() resource, kunit: add test case for region_intersects() resource: make alloc_free_mem_region() works for iomem_resource mm: z3fold: deprecate CONFIG_Z3FOLD vfio/pci: implement huge_fault support mm/arm64: support large pfn mappings mm/x86: support large pfn mappings ... 
Pull MM updates from Andrew Morton:
 "Along with the usual shower of singleton patches, notable patch series
  in this pull request are:

   - "Align kvrealloc() with krealloc()" from Danilo Krummrich. Adds
     consistency to the APIs and behaviour of these two core allocation
     functions. This also simplifies/enables Rustification.

   - "Some cleanups for shmem" from Baolin Wang. No functional changes -
     mode code reuse, better function naming, logic simplifications.

   - "mm: some small page fault cleanups" from Josef Bacik. No
     functional changes - code cleanups only.

   - "Various memory tiering fixes" from Zi Yan. A small fix and a
     little cleanup.

   - "mm/swap: remove boilerplate" from Yu Zhao. Code cleanups and
     simplifications and .text shrinkage.

   - "Kernel stack usage histogram" from Pasha Tatashin and Shakeel
     Butt. This is a feature, it adds new feilds to /proc/vmstat such as

       $ grep kstack /proc/vmstat
       kstack_1k 3
       kstack_2k 188
       kstack_4k 11391
       kstack_8k 243
       kstack_16k 0

     which tells us that 11391 processes used 4k of stack while none at
     all used 16k. Useful for some system tuning things, but
     partivularly useful for "the dynamic kernel stack project".

   - "kmemleak: support for percpu memory leak detect" from Pavel
     Tikhomirov. Teaches kmemleak to detect leaksage of percpu memory.

   - "mm: memcg: page counters optimizations" from Roman Gushchin. "3
     independent small optimizations of page counters".

   - "mm: split PTE/PMD PT table Kconfig cleanups+clarifications" from
     David Hildenbrand. Improves PTE/PMD splitlock detection, makes
     powerpc/8xx work correctly by design rather than by accident.

   - "mm: remove arch_make_page_accessible()" from David Hildenbrand.
     Some folio conversions which make arch_make_page_accessible()
     unneeded.

   - "mm, memcg: cg2 memory{.swap,}.peak write handlers" fro David
     Finkel. Cleans up and fixes our handling of the resetting of the
     cgroup/process peak-memory-use detector.

   - "Make core VMA operations internal and testable" from Lorenzo
     Stoakes. Rationalizaion and encapsulation of the VMA manipulation
     APIs. With a view to better enable testing of the VMA functions,
     even from a userspace-only harness.

   - "mm: zswap: fixes for global shrinker" from Takero Funaki. Fix
     issues in the zswap global shrinker, resulting in improved
     performance.

   - "mm: print the promo watermark in zoneinfo" from Kaiyang Zhao. Fill
     in some missing info in /proc/zoneinfo.

   - "mm: replace follow_page() by folio_walk" from David Hildenbrand.
     Code cleanups and rationalizations (conversion to folio_walk())
     resulting in the removal of follow_page().

   - "improving dynamic zswap shrinker protection scheme" from Nhat
     Pham. Some tuning to improve zswap's dynamic shrinker. Significant
     reductions in swapin and improvements in performance are shown.

   - "mm: Fix several issues with unaccepted memory" from Kirill
     Shutemov. Improvements to the new unaccepted memory feature,

   - "mm/mprotect: Fix dax puds" from Peter Xu. Implements mprotect on
     DAX PUDs. This was missing, although nobody seems to have notied
     yet.

   - "Introduce a store type enum for the Maple tree" from Sidhartha
     Kumar. Cleanups and modest performance improvements for the maple
     tree library code.

   - "memcg: further decouple v1 code from v2" from Shakeel Butt. Move
     more cgroup v1 remnants away from the v2 memcg code.

   - "memcg: initiate deprecation of v1 features" from Shakeel Butt.
     Adds various warnings telling users that memcg v1 features are
     deprecated.

   - "mm: swap: mTHP swap allocator base on swap cluster order" from
     Chris Li. Greatly improves the success rate of the mTHP swap
     allocation.

   - "mm: introduce numa_memblks" from Mike Rapoport. Moves various
     disparate per-arch implementations of numa_memblk code into generic
     code.

   - "mm: batch free swaps for zap_pte_range()" from Barry Song. Greatly
     improves the performance of munmap() of swap-filled ptes.

   - "support large folio swap-out and swap-in for shmem" from Baolin
     Wang. With this series we no longer split shmem large folios into
     simgle-page folios when swapping out shmem.

   - "mm/hugetlb: alloc/free gigantic folios" from Yu Zhao. Nice
     performance improvements and code reductions for gigantic folios.

   - "support shmem mTHP collapse" from Baolin Wang. Adds support for
     khugepaged's collapsing of shmem mTHP folios.

   - "mm: Optimize mseal checks" from Pedro Falcato. Fixes an mprotect()
     performance regression due to the addition of mseal().

   - "Increase the number of bits available in page_type" from Matthew
     Wilcox. Increases the number of bits available in page_type!

   - "Simplify the page flags a little" from Matthew Wilcox. Many legacy
     page flags are now folio flags, so the page-based flags and their
     accessors/mutators can be removed.

   - "mm: store zero pages to be swapped out in a bitmap" from Usama
     Arif. An optimization which permits us to avoid writing/reading
     zero-filled zswap pages to backing store.

   - "Avoid MAP_FIXED gap exposure" from Liam Howlett. Fixes a race
     window which occurs when a MAP_FIXED operqtion is occurring during
     an unrelated vma tree walk.

   - "mm: remove vma_merge()" from Lorenzo Stoakes. Major rotorooting of
     the vma_merge() functionality, making ot cleaner, more testable and
     better tested.

   - "misc fixups for DAMON {self,kunit} tests" from SeongJae Park.
     Minor fixups of DAMON selftests and kunit tests.

   - "mm: memory_hotplug: improve do_migrate_range()" from Kefeng Wang.
     Code cleanups and folio conversions.

   - "Shmem mTHP controls and stats improvements" from Ryan Roberts.
     Cleanups for shmem controls and stats.

   - "mm: count the number of anonymous THPs per size" from Barry Song.
     Expose additional anon THP stats to userspace for improved tuning.

   - "mm: finish isolate/putback_lru_page()" from Kefeng Wang: more
     folio conversions and removal of now-unused page-based APIs.

   - "replace per-quota region priorities histogram buffer with
     per-context one" from SeongJae Park. DAMON histogram
     rationalization.

   - "Docs/damon: update GitHub repo URLs and maintainer-profile" from
     SeongJae Park. DAMON documentation updates.

   - "mm/vdpa: correct misuse of non-direct-reclaim __GFP_NOFAIL and
     improve related doc and warn" from Jason Wang: fixes usage of page
     allocator __GFP_NOFAIL and GFP_ATOMIC flags.

   - "mm: split underused THPs" from Yu Zhao. Improve THP=always policy.
     This was overprovisioning THPs in sparsely accessed memory areas.

   - "zram: introduce custom comp backends API" frm Sergey Senozhatsky.
     Add support for zram run-time compression algorithm tuning.

   - "mm: Care about shadow stack guard gap when getting an unmapped
     area" from Mark Brown. Fix up the various arch_get_unmapped_area()
     implementations to better respect guard areas.

   - "Improve mem_cgroup_iter()" from Kinsey Ho. Improve the reliability
     of mem_cgroup_iter() and various code cleanups.

   - "mm: Support huge pfnmaps" from Peter Xu. Extends the usage of huge
     pfnmap support.

   - "resource: Fix region_intersects() vs add_memory_driver_managed()"
     from Huang Ying. Fix a bug in region_intersects() for systems with
     CXL memory.

   - "mm: hwpoison: two more poison recovery" from Kefeng Wang. Teaches
     a couple more code paths to correctly recover from the encountering
     of poisoned memry.

   - "mm: enable large folios swap-in support" from Barry Song. Support
     the swapin of mTHP memory into appropriately-sized folios, rather
     than into single-page folios"

* tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (416 commits)
  zram: free secondary algorithms names
  uprobes: turn xol_area->pages[2] into xol_area->page
  uprobes: introduce the global struct vm_special_mapping xol_mapping
  Revert "uprobes: use vm_special_mapping close() functionality"
  mm: support large folios swap-in for sync io devices
  mm: add nr argument in mem_cgroup_swapin_uncharge_swap() helper to support large folios
  mm: fix swap_read_folio_zeromap() for large folios with partial zeromap
  mm/debug_vm_pgtable: Use pxdp_get() for accessing page table entries
  set_memory: add __must_check to generic stubs
  mm/vma: return the exact errno in vms_gather_munmap_vmas()
  memcg: cleanup with !CONFIG_MEMCG_V1
  mm/show_mem.c: report alloc tags in human readable units
  mm: support poison recovery from copy_present_page()
  mm: support poison recovery from do_cow_fault()
  resource, kunit: add test case for region_intersects()
  resource: make alloc_free_mem_region() works for iomem_resource
  mm: z3fold: deprecate CONFIG_Z3FOLD
  vfio/pci: implement huge_fault support
  mm/arm64: support large pfn mappings
  mm/x86: support large pfn mappings
  ...