linux.git/arch/powerpc, branch v5.19 Linux kernel source tree Merge tag 'powerpc-5.19-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux 2022-07-29T16:57:07+00:00 Linus Torvalds torvalds@linux-foundation.org 2022-07-29T16:57:07+00:00 9d928d9b78beec5d4b8afde9c144919b979685f2 Pull powerpc fixes from Michael Ellerman: - Re-enable the new amdgpu display engine for powerpc, as long as the compiler is correctly configured. - Disable stack variable initialisation in prom_init to fix GCC 12 allmodconfig. Thanks to Dan Horák and Sudip Mukherjee. * tag 'powerpc-5.19-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: drm/amdgpu: Re-enable DCN for 64-bit powerpc powerpc/64s: Disable stack variable initialisation for prom_init 
Pull powerpc fixes from Michael Ellerman:

 - Re-enable the new amdgpu display engine for powerpc, as long as the
   compiler is correctly configured.

 - Disable stack variable initialisation in prom_init to fix GCC 12
   allmodconfig.

Thanks to Dan Horák and Sudip Mukherjee.

* tag 'powerpc-5.19-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  drm/amdgpu: Re-enable DCN for 64-bit powerpc
  powerpc/64s: Disable stack variable initialisation for prom_init
drm/amdgpu: Re-enable DCN for 64-bit powerpc 2022-07-25T22:25:38+00:00 Michael Ellerman mpe@ellerman.id.au 2022-07-25T04:37:29+00:00 c653c591789b3acfa4bf6ae45d5af4f330e50a91 Commit d11219ad53dc ("amdgpu: disable powerpc support for the newer display engine") disabled the DCN driver for all of powerpc due to unresolved build failures with some compilers. Further digging shows that the build failures only occur with compilers that default to 64-bit long double. Both the ppc64 and ppc64le ABIs define long double to be 128-bits, but there are compilers in the wild that default to 64-bits. The compilers provided by the major distros (Fedora, Ubuntu) default to 128-bits and are not affected by the build failure. There is a compiler flag to force 128-bit long double, which may be the correct long term fix, but as an interim fix only allow building the DCN driver if long double is 128-bits by default. The bisection in commit d11219ad53dc must have gone off the rails at some point, the build failure occurs all the way back to the original commit that enabled DCN support on powerpc, at least with some toolchains. Depends-on: d11219ad53dc ("amdgpu: disable powerpc support for the newer display engine") Fixes: 16a9dea110a6 ("amdgpu: Enable initial DCN support on POWER") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Alex Deucher <alexander.deucher@amd.com> Reviewed-by: Dan Horák <dan@danny.cz> Link: https://gitlab.freedesktop.org/drm/amd/-/issues/2100 Link: https://lore.kernel.org/r/20220725123918.1903255-1-mpe@ellerman.id.au 
Commit d11219ad53dc ("amdgpu: disable powerpc support for the newer
display engine") disabled the DCN driver for all of powerpc due to
unresolved build failures with some compilers.

Further digging shows that the build failures only occur with compilers
that default to 64-bit long double.

Both the ppc64 and ppc64le ABIs define long double to be 128-bits, but
there are compilers in the wild that default to 64-bits. The compilers
provided by the major distros (Fedora, Ubuntu) default to 128-bits and
are not affected by the build failure.

There is a compiler flag to force 128-bit long double, which may be the
correct long term fix, but as an interim fix only allow building the DCN
driver if long double is 128-bits by default.

The bisection in commit d11219ad53dc must have gone off the rails at
some point, the build failure occurs all the way back to the original
commit that enabled DCN support on powerpc, at least with some
toolchains.

Depends-on: d11219ad53dc ("amdgpu: disable powerpc support for the newer display engine")
Fixes: 16a9dea110a6 ("amdgpu: Enable initial DCN support on POWER")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Dan Horák <dan@danny.cz>
Link: https://gitlab.freedesktop.org/drm/amd/-/issues/2100
Link: https://lore.kernel.org/r/20220725123918.1903255-1-mpe@ellerman.id.au
mmu_gather: Remove per arch tlb_{start,end}_vma() 2022-07-21T17:50:13+00:00 Peter Zijlstra peterz@infradead.org 2022-07-08T07:18:03+00:00 1e9fdf21a4339b102539f476a9842e7526c01939 Scattered across the archs are 3 basic forms of tlb_{start,end}_vma(). Provide two new MMU_GATHER_knobs to enumerate them and remove the per arch tlb_{start,end}_vma() implementations. - MMU_GATHER_NO_FLUSH_CACHE indicates the arch has flush_cache_range() but does *NOT* want to call it for each VMA. - MMU_GATHER_MERGE_VMAS indicates the arch wants to merge the invalidate across multiple VMAs if possible. With these it is possible to capture the three forms: 1) empty stubs; select MMU_GATHER_NO_FLUSH_CACHE and MMU_GATHER_MERGE_VMAS 2) start: flush_cache_range(), end: empty; select MMU_GATHER_MERGE_VMAS 3) start: flush_cache_range(), end: flush_tlb_range(); default Obviously, if the architecture does not have flush_cache_range() then it also doesn't need to select MMU_GATHER_NO_FLUSH_CACHE. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Will Deacon <will@kernel.org> Cc: David Miller <davem@davemloft.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
Scattered across the archs are 3 basic forms of tlb_{start,end}_vma().
Provide two new MMU_GATHER_knobs to enumerate them and remove the per
arch tlb_{start,end}_vma() implementations.

 - MMU_GATHER_NO_FLUSH_CACHE indicates the arch has flush_cache_range()
   but does *NOT* want to call it for each VMA.

 - MMU_GATHER_MERGE_VMAS indicates the arch wants to merge the
   invalidate across multiple VMAs if possible.

With these it is possible to capture the three forms:

  1) empty stubs;
     select MMU_GATHER_NO_FLUSH_CACHE and MMU_GATHER_MERGE_VMAS

  2) start: flush_cache_range(), end: empty;
     select MMU_GATHER_MERGE_VMAS

  3) start: flush_cache_range(), end: flush_tlb_range();
     default

Obviously, if the architecture does not have flush_cache_range() then
it also doesn't need to select MMU_GATHER_NO_FLUSH_CACHE.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will@kernel.org>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
powerpc/64s: Disable stack variable initialisation for prom_init 2022-07-20T05:13:02+00:00 Michael Ellerman mpe@ellerman.id.au 2022-07-18T13:44:18+00:00 be640317a1d0b9cf42fedb2debc2887a7cfa38de With GCC 12 allmodconfig prom_init fails to build: Error: External symbol 'memset' referenced from prom_init.c make[2]: *** [arch/powerpc/kernel/Makefile:204: arch/powerpc/kernel/prom_init_check] Error 1 The allmodconfig build enables KASAN, so all calls to memset in prom_init should be converted to __memset by the #ifdefs in asm/string.h, because prom_init must use the non-KASAN instrumented versions. The build failure happens because there's a call to memset that hasn't been caught by the pre-processor and converted to __memset. Typically that's because it's a memset generated by the compiler itself, and that is the case here. With GCC 12, allmodconfig enables CONFIG_INIT_STACK_ALL_PATTERN, which causes the compiler to emit memset calls to initialise on-stack variables with a pattern. Because prom_init is non-user-facing boot-time only code, as a workaround just disable stack variable initialisation to unbreak the build. Reported-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220718134418.354114-1-mpe@ellerman.id.au 
With GCC 12 allmodconfig prom_init fails to build:

  Error: External symbol 'memset' referenced from prom_init.c
  make[2]: *** [arch/powerpc/kernel/Makefile:204: arch/powerpc/kernel/prom_init_check] Error 1

The allmodconfig build enables KASAN, so all calls to memset in
prom_init should be converted to __memset by the #ifdefs in
asm/string.h, because prom_init must use the non-KASAN instrumented
versions.

The build failure happens because there's a call to memset that hasn't
been caught by the pre-processor and converted to __memset. Typically
that's because it's a memset generated by the compiler itself, and that
is the case here.

With GCC 12, allmodconfig enables CONFIG_INIT_STACK_ALL_PATTERN, which
causes the compiler to emit memset calls to initialise on-stack
variables with a pattern.

Because prom_init is non-user-facing boot-time only code, as a
workaround just disable stack variable initialisation to unbreak the
build.

Reported-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220718134418.354114-1-mpe@ellerman.id.au
powerpc/powernv: delay rng platform device creation until later in boot 2022-07-04T11:11:47+00:00 Jason A. Donenfeld Jason@zx2c4.com 2022-06-30T12:16:54+00:00 887502826549caa7e4215fd9e628f48f14c0825a The platform device for the rng must be created much later in boot. Otherwise it tries to connect to a parent that doesn't yet exist, resulting in this splat: [ 0.000478] kobject: '(null)' ((____ptrval____)): is not initialized, yet kobject_get() is being called. [ 0.002925] [c000000002a0fb30] [c00000000073b0bc] kobject_get+0x8c/0x100 (unreliable) [ 0.003071] [c000000002a0fba0] [c00000000087e464] device_add+0xf4/0xb00 [ 0.003194] [c000000002a0fc80] [c000000000a7f6e4] of_device_add+0x64/0x80 [ 0.003321] [c000000002a0fcb0] [c000000000a800d0] of_platform_device_create_pdata+0xd0/0x1b0 [ 0.003476] [c000000002a0fd00] [c00000000201fa44] pnv_get_random_long_early+0x240/0x2e4 [ 0.003623] [c000000002a0fe20] [c000000002060c38] random_init+0xc0/0x214 This patch fixes the issue by doing the platform device creation inside of machine_subsys_initcall. Fixes: f3eac426657d ("powerpc/powernv: wire up rng during setup_arch") Cc: stable@vger.kernel.org Reported-by: Sachin Sant <sachinp@linux.ibm.com> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Tested-by: Sachin Sant <sachinp@linux.ibm.com> [mpe: Change "of node" to "platform device" in change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220630121654.1939181-1-Jason@zx2c4.com 
The platform device for the rng must be created much later in boot.
Otherwise it tries to connect to a parent that doesn't yet exist,
resulting in this splat:

  [    0.000478] kobject: '(null)' ((____ptrval____)): is not initialized, yet kobject_get() is being called.
  [    0.002925] [c000000002a0fb30] [c00000000073b0bc] kobject_get+0x8c/0x100 (unreliable)
  [    0.003071] [c000000002a0fba0] [c00000000087e464] device_add+0xf4/0xb00
  [    0.003194] [c000000002a0fc80] [c000000000a7f6e4] of_device_add+0x64/0x80
  [    0.003321] [c000000002a0fcb0] [c000000000a800d0] of_platform_device_create_pdata+0xd0/0x1b0
  [    0.003476] [c000000002a0fd00] [c00000000201fa44] pnv_get_random_long_early+0x240/0x2e4
  [    0.003623] [c000000002a0fe20] [c000000002060c38] random_init+0xc0/0x214

This patch fixes the issue by doing the platform device creation inside
of machine_subsys_initcall.

Fixes: f3eac426657d ("powerpc/powernv: wire up rng during setup_arch")
Cc: stable@vger.kernel.org
Reported-by: Sachin Sant <sachinp@linux.ibm.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Tested-by: Sachin Sant <sachinp@linux.ibm.com>
[mpe: Change "of node" to "platform device" in change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220630121654.1939181-1-Jason@zx2c4.com
powerpc/memhotplug: Add add_pages override for PPC 2022-06-29T10:43:16+00:00 Aneesh Kumar K.V aneesh.kumar@linux.ibm.com 2022-06-29T05:09:25+00:00 ac790d09885d36143076e7e02825c541e8eee899 With commit ffa0b64e3be5 ("powerpc: Fix virt_addr_valid() for 64-bit Book3E & 32-bit") the kernel now validate the addr against high_memory value. This results in the below BUG_ON with dax pfns. [ 635.798741][T26531] kernel BUG at mm/page_alloc.c:5521! 1:mon> e cpu 0x1: Vector: 700 (Program Check) at [c000000007287630] pc: c00000000055ed48: free_pages.part.0+0x48/0x110 lr: c00000000053ca70: tlb_finish_mmu+0x80/0xd0 sp: c0000000072878d0 msr: 800000000282b033 current = 0xc00000000afabe00 paca = 0xc00000037ffff300 irqmask: 0x03 irq_happened: 0x05 pid = 26531, comm = 50-landscape-sy kernel BUG at :5521! Linux version 5.19.0-rc3-14659-g4ec05be7c2e1 (kvaneesh@ltc-boston8) (gcc (Ubuntu 9.4.0-1ubuntu1~20.04.1) 9.4.0, GNU ld (GNU Binutils for Ubuntu) 2.34) #625 SMP Thu Jun 23 00:35:43 CDT 2022 1:mon> t [link register ] c00000000053ca70 tlb_finish_mmu+0x80/0xd0 [c0000000072878d0] c00000000053ca54 tlb_finish_mmu+0x64/0xd0 (unreliable) [c000000007287900] c000000000539424 exit_mmap+0xe4/0x2a0 [c0000000072879e0] c00000000019fc1c mmput+0xcc/0x210 [c000000007287a20] c000000000629230 begin_new_exec+0x5e0/0xf40 [c000000007287ae0] c00000000070b3cc load_elf_binary+0x3ac/0x1e00 [c000000007287c10] c000000000627af0 bprm_execve+0x3b0/0xaf0 [c000000007287cd0] c000000000628414 do_execveat_common.isra.0+0x1e4/0x310 [c000000007287d80] c00000000062858c sys_execve+0x4c/0x60 [c000000007287db0] c00000000002c1b0 system_call_exception+0x160/0x2c0 [c000000007287e10] c00000000000c53c system_call_common+0xec/0x250 The fix is to make sure we update high_memory on memory hotplug. This is similar to what x86 does in commit 3072e413e305 ("mm/memory_hotplug: introduce add_pages") Fixes: ffa0b64e3be5 ("powerpc: Fix virt_addr_valid() for 64-bit Book3E & 32-bit") Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220629050925.31447-1-aneesh.kumar@linux.ibm.com 
With commit ffa0b64e3be5 ("powerpc: Fix virt_addr_valid() for 64-bit Book3E & 32-bit")
the kernel now validate the addr against high_memory value. This results
in the below BUG_ON with dax pfns.

[  635.798741][T26531] kernel BUG at mm/page_alloc.c:5521!
1:mon> e
cpu 0x1: Vector: 700 (Program Check) at [c000000007287630]
    pc: c00000000055ed48: free_pages.part.0+0x48/0x110
    lr: c00000000053ca70: tlb_finish_mmu+0x80/0xd0
    sp: c0000000072878d0
   msr: 800000000282b033
  current = 0xc00000000afabe00
  paca    = 0xc00000037ffff300   irqmask: 0x03   irq_happened: 0x05
    pid   = 26531, comm = 50-landscape-sy
kernel BUG at :5521!
Linux version 5.19.0-rc3-14659-g4ec05be7c2e1 (kvaneesh@ltc-boston8) (gcc (Ubuntu 9.4.0-1ubuntu1~20.04.1) 9.4.0, GNU ld (GNU Binutils for Ubuntu) 2.34) #625 SMP Thu Jun 23 00:35:43 CDT 2022
1:mon> t
[link register   ] c00000000053ca70 tlb_finish_mmu+0x80/0xd0
[c0000000072878d0] c00000000053ca54 tlb_finish_mmu+0x64/0xd0 (unreliable)
[c000000007287900] c000000000539424 exit_mmap+0xe4/0x2a0
[c0000000072879e0] c00000000019fc1c mmput+0xcc/0x210
[c000000007287a20] c000000000629230 begin_new_exec+0x5e0/0xf40
[c000000007287ae0] c00000000070b3cc load_elf_binary+0x3ac/0x1e00
[c000000007287c10] c000000000627af0 bprm_execve+0x3b0/0xaf0
[c000000007287cd0] c000000000628414 do_execveat_common.isra.0+0x1e4/0x310
[c000000007287d80] c00000000062858c sys_execve+0x4c/0x60
[c000000007287db0] c00000000002c1b0 system_call_exception+0x160/0x2c0
[c000000007287e10] c00000000000c53c system_call_common+0xec/0x250

The fix is to make sure we update high_memory on memory hotplug.
This is similar to what x86 does in commit 3072e413e305 ("mm/memory_hotplug: introduce add_pages")

Fixes: ffa0b64e3be5 ("powerpc: Fix virt_addr_valid() for 64-bit Book3E & 32-bit")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220629050925.31447-1-aneesh.kumar@linux.ibm.com
powerpc/bpf: Fix use of user_pt_regs in uapi 2022-06-29T10:43:04+00:00 Naveen N. Rao naveen.n.rao@linux.vnet.ibm.com 2022-06-27T19:11:19+00:00 b21bd5a4b130f8370861478d2880985daace5913 Trying to build a .c file that includes <linux/bpf_perf_event.h>: $ cat test_bpf_headers.c #include <linux/bpf_perf_event.h> throws the below error: /usr/include/linux/bpf_perf_event.h:14:28: error: field ‘regs’ has incomplete type 14 | bpf_user_pt_regs_t regs; | ^~~~ This is because we typedef bpf_user_pt_regs_t to 'struct user_pt_regs' in arch/powerpc/include/uaps/asm/bpf_perf_event.h, but 'struct user_pt_regs' is not exposed to userspace. Powerpc has both pt_regs and user_pt_regs structures. However, unlike arm64 and s390, we expose user_pt_regs to userspace as just 'pt_regs'. As such, we should typedef bpf_user_pt_regs_t to 'struct pt_regs' for userspace. Within the kernel though, we want to typedef bpf_user_pt_regs_t to 'struct user_pt_regs'. Remove arch/powerpc/include/uapi/asm/bpf_perf_event.h so that the uapi/asm-generic version of the header is exposed to userspace. Introduce arch/powerpc/include/asm/bpf_perf_event.h so that we can typedef bpf_user_pt_regs_t to 'struct user_pt_regs' for use within the kernel. Note that this was not showing up with the bpf selftest build since tools/include/uapi/asm/bpf_perf_event.h didn't include the powerpc variant. Fixes: a6460b03f945ee ("powerpc/bpf: Fix broken uapi for BPF_PROG_TYPE_PERF_EVENT") Cc: stable@vger.kernel.org # v4.20+ Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> [mpe: Use typical naming for header include guard] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220627191119.142867-1-naveen.n.rao@linux.vnet.ibm.com 
Trying to build a .c file that includes <linux/bpf_perf_event.h>:
  $ cat test_bpf_headers.c
  #include <linux/bpf_perf_event.h>

throws the below error:
  /usr/include/linux/bpf_perf_event.h:14:28: error: field ‘regs’ has incomplete type
     14 |         bpf_user_pt_regs_t regs;
	|                            ^~~~

This is because we typedef bpf_user_pt_regs_t to 'struct user_pt_regs'
in arch/powerpc/include/uaps/asm/bpf_perf_event.h, but 'struct
user_pt_regs' is not exposed to userspace.

Powerpc has both pt_regs and user_pt_regs structures. However, unlike
arm64 and s390, we expose user_pt_regs to userspace as just 'pt_regs'.
As such, we should typedef bpf_user_pt_regs_t to 'struct pt_regs' for
userspace.

Within the kernel though, we want to typedef bpf_user_pt_regs_t to
'struct user_pt_regs'.

Remove arch/powerpc/include/uapi/asm/bpf_perf_event.h so that the
uapi/asm-generic version of the header is exposed to userspace.
Introduce arch/powerpc/include/asm/bpf_perf_event.h so that we can
typedef bpf_user_pt_regs_t to 'struct user_pt_regs' for use within the
kernel.

Note that this was not showing up with the bpf selftest build since
tools/include/uapi/asm/bpf_perf_event.h didn't include the powerpc
variant.

Fixes: a6460b03f945ee ("powerpc/bpf: Fix broken uapi for BPF_PROG_TYPE_PERF_EVENT")
Cc: stable@vger.kernel.org # v4.20+
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
[mpe: Use typical naming for header include guard]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220627191119.142867-1-naveen.n.rao@linux.vnet.ibm.com
powerpc/prom_init: Fix kernel config grep 2022-06-24T03:47:26+00:00 Liam Howlett liam.howlett@oracle.com 2022-06-24T01:17:58+00:00 6886da5f49e6d86aad76807a93f3eef5e4f01b10 When searching for config options, use the KCONFIG_CONFIG shell variable so that builds using non-standard config locations work. Fixes: 26deb04342e3 ("powerpc: prepare string/mem functions for KASAN") Cc: stable@vger.kernel.org # v5.2+ Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220624011745.4060795-1-Liam.Howlett@oracle.com 
When searching for config options, use the KCONFIG_CONFIG shell variable
so that builds using non-standard config locations work.

Fixes: 26deb04342e3 ("powerpc: prepare string/mem functions for KASAN")
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220624011745.4060795-1-Liam.Howlett@oracle.com
powerpc/book3e: Fix PUD allocation size in map_kernel_page() 2022-06-24T02:42:45+00:00 Christophe Leroy christophe.leroy@csgroup.eu 2022-06-23T08:56:17+00:00 986481618023e18e187646b0fff05a3c337531cb Commit 2fb4706057bc ("powerpc: add support for folded p4d page tables") erroneously changed PUD setup to a mix of PMD and PUD. Fix it. While at it, use PTE_TABLE_SIZE instead of PAGE_SIZE for PTE tables in order to avoid any confusion. Fixes: 2fb4706057bc ("powerpc: add support for folded p4d page tables") Cc: stable@vger.kernel.org # v5.8+ Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Acked-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/95ddfd6176d53e6c85e13bd1c358359daa56775f.1655974558.git.christophe.leroy@csgroup.eu 
Commit 2fb4706057bc ("powerpc: add support for folded p4d page tables")
erroneously changed PUD setup to a mix of PMD and PUD. Fix it.

While at it, use PTE_TABLE_SIZE instead of PAGE_SIZE for PTE tables
in order to avoid any confusion.

Fixes: 2fb4706057bc ("powerpc: add support for folded p4d page tables")
Cc: stable@vger.kernel.org # v5.8+
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/95ddfd6176d53e6c85e13bd1c358359daa56775f.1655974558.git.christophe.leroy@csgroup.eu
powerpc/xive/spapr: correct bitmap allocation size 2022-06-24T02:40:38+00:00 Nathan Lynch nathanl@linux.ibm.com 2022-06-23T18:25:09+00:00 19fc5bb93c6bbdce8292b4d7eed04e2fa118d2fe kasan detects access beyond the end of the xibm->bitmap allocation: BUG: KASAN: slab-out-of-bounds in _find_first_zero_bit+0x40/0x140 Read of size 8 at addr c00000001d1d0118 by task swapper/0/1 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.19.0-rc2-00001-g90df023b36dd #28 Call Trace: [c00000001d98f770] [c0000000012baab8] dump_stack_lvl+0xac/0x108 (unreliable) [c00000001d98f7b0] [c00000000068faac] print_report+0x37c/0x710 [c00000001d98f880] [c0000000006902c0] kasan_report+0x110/0x354 [c00000001d98f950] [c000000000692324] __asan_load8+0xa4/0xe0 [c00000001d98f970] [c0000000011c6ed0] _find_first_zero_bit+0x40/0x140 [c00000001d98f9b0] [c0000000000dbfbc] xive_spapr_get_ipi+0xcc/0x260 [c00000001d98fa70] [c0000000000d6d28] xive_setup_cpu_ipi+0x1e8/0x450 [c00000001d98fb30] [c000000004032a20] pSeries_smp_probe+0x5c/0x118 [c00000001d98fb60] [c000000004018b44] smp_prepare_cpus+0x944/0x9ac [c00000001d98fc90] [c000000004009f9c] kernel_init_freeable+0x2d4/0x640 [c00000001d98fd90] [c0000000000131e8] kernel_init+0x28/0x1d0 [c00000001d98fe10] [c00000000000cd54] ret_from_kernel_thread+0x5c/0x64 Allocated by task 0: kasan_save_stack+0x34/0x70 __kasan_kmalloc+0xb4/0xf0 __kmalloc+0x268/0x540 xive_spapr_init+0x4d0/0x77c pseries_init_irq+0x40/0x27c init_IRQ+0x44/0x84 start_kernel+0x2a4/0x538 start_here_common+0x1c/0x20 The buggy address belongs to the object at c00000001d1d0118 which belongs to the cache kmalloc-8 of size 8 The buggy address is located 0 bytes inside of 8-byte region [c00000001d1d0118, c00000001d1d0120) The buggy address belongs to the physical page: page:c00c000000074740 refcount:1 mapcount:0 mapping:0000000000000000 index:0xc00000001d1d0558 pfn:0x1d1d flags: 0x7ffff000000200(slab|node=0|zone=0|lastcpupid=0x7ffff) raw: 007ffff000000200 c00000001d0003c8 c00000001d0003c8 c00000001d010480 raw: c00000001d1d0558 0000000001e1000a 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: c00000001d1d0000: fc 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc c00000001d1d0080: fc fc 00 fc fc fc fc fc fc fc fc fc fc fc fc fc >c00000001d1d0100: fc fc fc 02 fc fc fc fc fc fc fc fc fc fc fc fc ^ c00000001d1d0180: fc fc fc fc 04 fc fc fc fc fc fc fc fc fc fc fc c00000001d1d0200: fc fc fc fc fc 04 fc fc fc fc fc fc fc fc fc fc This happens because the allocation uses the wrong unit (bits) when it should pass (BITS_TO_LONGS(count) * sizeof(long)) or equivalent. With small numbers of bits, the allocated object can be smaller than sizeof(long), which results in invalid accesses. Use bitmap_zalloc() to allocate and initialize the irq bitmap, paired with bitmap_free() for consistency. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220623182509.3985625-1-nathanl@linux.ibm.com 
kasan detects access beyond the end of the xibm->bitmap allocation:

BUG: KASAN: slab-out-of-bounds in _find_first_zero_bit+0x40/0x140
Read of size 8 at addr c00000001d1d0118 by task swapper/0/1

CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.19.0-rc2-00001-g90df023b36dd #28
Call Trace:
[c00000001d98f770] [c0000000012baab8] dump_stack_lvl+0xac/0x108 (unreliable)
[c00000001d98f7b0] [c00000000068faac] print_report+0x37c/0x710
[c00000001d98f880] [c0000000006902c0] kasan_report+0x110/0x354
[c00000001d98f950] [c000000000692324] __asan_load8+0xa4/0xe0
[c00000001d98f970] [c0000000011c6ed0] _find_first_zero_bit+0x40/0x140
[c00000001d98f9b0] [c0000000000dbfbc] xive_spapr_get_ipi+0xcc/0x260
[c00000001d98fa70] [c0000000000d6d28] xive_setup_cpu_ipi+0x1e8/0x450
[c00000001d98fb30] [c000000004032a20] pSeries_smp_probe+0x5c/0x118
[c00000001d98fb60] [c000000004018b44] smp_prepare_cpus+0x944/0x9ac
[c00000001d98fc90] [c000000004009f9c] kernel_init_freeable+0x2d4/0x640
[c00000001d98fd90] [c0000000000131e8] kernel_init+0x28/0x1d0
[c00000001d98fe10] [c00000000000cd54] ret_from_kernel_thread+0x5c/0x64

Allocated by task 0:
 kasan_save_stack+0x34/0x70
 __kasan_kmalloc+0xb4/0xf0
 __kmalloc+0x268/0x540
 xive_spapr_init+0x4d0/0x77c
 pseries_init_irq+0x40/0x27c
 init_IRQ+0x44/0x84
 start_kernel+0x2a4/0x538
 start_here_common+0x1c/0x20

The buggy address belongs to the object at c00000001d1d0118
 which belongs to the cache kmalloc-8 of size 8
The buggy address is located 0 bytes inside of
 8-byte region [c00000001d1d0118, c00000001d1d0120)

The buggy address belongs to the physical page:
page:c00c000000074740 refcount:1 mapcount:0 mapping:0000000000000000 index:0xc00000001d1d0558 pfn:0x1d1d
flags: 0x7ffff000000200(slab|node=0|zone=0|lastcpupid=0x7ffff)
raw: 007ffff000000200 c00000001d0003c8 c00000001d0003c8 c00000001d010480
raw: c00000001d1d0558 0000000001e1000a 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 c00000001d1d0000: fc 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 c00000001d1d0080: fc fc 00 fc fc fc fc fc fc fc fc fc fc fc fc fc
>c00000001d1d0100: fc fc fc 02 fc fc fc fc fc fc fc fc fc fc fc fc
                            ^
 c00000001d1d0180: fc fc fc fc 04 fc fc fc fc fc fc fc fc fc fc fc
 c00000001d1d0200: fc fc fc fc fc 04 fc fc fc fc fc fc fc fc fc fc

This happens because the allocation uses the wrong unit (bits) when it
should pass (BITS_TO_LONGS(count) * sizeof(long)) or equivalent. With small
numbers of bits, the allocated object can be smaller than sizeof(long),
which results in invalid accesses.

Use bitmap_zalloc() to allocate and initialize the irq bitmap, paired with
bitmap_free() for consistency.

Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220623182509.3985625-1-nathanl@linux.ibm.com