linux.git/arch/powerpc, branch v5.17 Linux kernel source tree powerpc: Fix STACKTRACE=n build 2022-03-06T23:26:20+00:00 Michael Ellerman mpe@ellerman.id.au 2022-02-11T06:32:37+00:00 48015b632f770c401f3816f144499a39f2884677 Our skiroot_defconfig doesn't enable FTRACE, and so doesn't get STACKTRACE enabled either. That leads to a build failure since commit 1614b2b11fab ("arch: Make ARCH_STACKWALK independent of STACKTRACE") made stacktrace.c build even when STACKTRACE=n. arch/powerpc/kernel/stacktrace.c: In function ‘handle_backtrace_ipi’: arch/powerpc/kernel/stacktrace.c:171:2: error: implicit declaration of function ‘nmi_cpu_backtrace’ 171 | nmi_cpu_backtrace(regs); | ^~~~~~~~~~~~~~~~~ arch/powerpc/kernel/stacktrace.c: In function ‘arch_trigger_cpumask_backtrace’: arch/powerpc/kernel/stacktrace.c:226:2: error: implicit declaration of function ‘nmi_trigger_cpumask_backtrace’ 226 | nmi_trigger_cpumask_backtrace(mask, exclude_self, raise_backtrace_ipi); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ This happens because our headers haven't defined arch_trigger_cpumask_backtrace, which causes lib/nmi_backtrace.c not to build nmi_cpu_backtrace(). The code in question doesn't actually depend on STACKTRACE=y, that was just added because arch_trigger_cpumask_backtrace() lived in stacktrace.c for convenience. So drop the dependency on CONFIG_STACKTRACE, that causes lib/nmi_backtrace.c to build nmi_cpu_backtrace() etc. and fixes the build. Fixes: 1614b2b11fab ("arch: Make ARCH_STACKWALK independent of STACKTRACE") [mpe: Cherry pick of 5a72345e6a78 from next into fixes] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220212111349.2806972-1-mpe@ellerman.id.au 
Our skiroot_defconfig doesn't enable FTRACE, and so doesn't get
STACKTRACE enabled either. That leads to a build failure since commit
1614b2b11fab ("arch: Make ARCH_STACKWALK independent of STACKTRACE")
made stacktrace.c build even when STACKTRACE=n.

  arch/powerpc/kernel/stacktrace.c: In function ‘handle_backtrace_ipi’:
  arch/powerpc/kernel/stacktrace.c:171:2: error: implicit declaration of function ‘nmi_cpu_backtrace’
    171 |  nmi_cpu_backtrace(regs);
        |  ^~~~~~~~~~~~~~~~~
  arch/powerpc/kernel/stacktrace.c: In function ‘arch_trigger_cpumask_backtrace’:
  arch/powerpc/kernel/stacktrace.c:226:2: error: implicit declaration of function ‘nmi_trigger_cpumask_backtrace’
    226 |  nmi_trigger_cpumask_backtrace(mask, exclude_self, raise_backtrace_ipi);
        |  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This happens because our headers haven't defined
arch_trigger_cpumask_backtrace, which causes lib/nmi_backtrace.c not to
build nmi_cpu_backtrace().

The code in question doesn't actually depend on STACKTRACE=y, that was
just added because arch_trigger_cpumask_backtrace() lived in
stacktrace.c for convenience. So drop the dependency on
CONFIG_STACKTRACE, that causes lib/nmi_backtrace.c to build
nmi_cpu_backtrace() etc. and fixes the build.

Fixes: 1614b2b11fab ("arch: Make ARCH_STACKWALK independent of STACKTRACE")
[mpe: Cherry pick of 5a72345e6a78 from next into fixes]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220212111349.2806972-1-mpe@ellerman.id.au
powerpc/64s: Fix build failure when CONFIG_PPC_64S_HASH_MMU is not set 2022-03-05T09:42:21+00:00 Murilo Opsfelder Araujo muriloo@linux.ibm.com 2022-03-01T20:47:43+00:00 58dbe9b373df2828d873b1c0e5afc77485b2f376 The following build failure occurs when CONFIG_PPC_64S_HASH_MMU is not set: arch/powerpc/kernel/setup_64.c: In function ‘setup_per_cpu_areas’: arch/powerpc/kernel/setup_64.c:811:21: error: ‘mmu_linear_psize’ undeclared (first use in this function); did you mean ‘mmu_virtual_psize’? 811 | if (mmu_linear_psize == MMU_PAGE_4K) | ^~~~~~~~~~~~~~~~ | mmu_virtual_psize arch/powerpc/kernel/setup_64.c:811:21: note: each undeclared identifier is reported only once for each function it appears in Move the declaration of mmu_linear_psize outside of CONFIG_PPC_64S_HASH_MMU ifdef. After the above is fixed, it fails later with the following error: ld: arch/powerpc/kexec/file_load_64.o: in function `.arch_kexec_kernel_image_probe': file_load_64.c:(.text+0x1c1c): undefined reference to `.add_htab_mem_range' Fix that, too, by conditioning add_htab_mem_range() symbol to CONFIG_PPC_64S_HASH_MMU. Fixes: 387e220a2e5e ("powerpc/64s: Move hash MMU support code under CONFIG_PPC_64S_HASH_MMU") Reported-by: Erhard F. <erhard_f@mailbox.org> Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=215567 Link: https://lore.kernel.org/r/20220301204743.45133-1-muriloo@linux.ibm.com 
The following build failure occurs when CONFIG_PPC_64S_HASH_MMU is not
set:

    arch/powerpc/kernel/setup_64.c: In function ‘setup_per_cpu_areas’:
    arch/powerpc/kernel/setup_64.c:811:21: error: ‘mmu_linear_psize’ undeclared (first use in this function); did you mean ‘mmu_virtual_psize’?
      811 |                 if (mmu_linear_psize == MMU_PAGE_4K)
          |                     ^~~~~~~~~~~~~~~~
          |                     mmu_virtual_psize
    arch/powerpc/kernel/setup_64.c:811:21: note: each undeclared identifier is reported only once for each function it appears in

Move the declaration of mmu_linear_psize outside of
CONFIG_PPC_64S_HASH_MMU ifdef.

After the above is fixed, it fails later with the following error:

    ld: arch/powerpc/kexec/file_load_64.o: in function `.arch_kexec_kernel_image_probe':
    file_load_64.c:(.text+0x1c1c): undefined reference to `.add_htab_mem_range'

Fix that, too, by conditioning add_htab_mem_range() symbol to
CONFIG_PPC_64S_HASH_MMU.

Fixes: 387e220a2e5e ("powerpc/64s: Move hash MMU support code under CONFIG_PPC_64S_HASH_MMU")
Reported-by: Erhard F. <erhard_f@mailbox.org>
Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=215567
Link: https://lore.kernel.org/r/20220301204743.45133-1-muriloo@linux.ibm.com
powerpc/lib/sstep: fix 'ptesync' build error 2022-02-15T11:31:35+00:00 Anders Roxell anders.roxell@linaro.org 2022-02-11T00:51:13+00:00 fe663df7825811358531dc2e8a52d9eaa5e3515e Building tinyconfig with gcc (Debian 11.2.0-16) and assembler (Debian 2.37.90.20220207) the following build error shows up: {standard input}: Assembler messages: {standard input}:2088: Error: unrecognized opcode: `ptesync' make[3]: *** [/builds/linux/scripts/Makefile.build:287: arch/powerpc/lib/sstep.o] Error 1 Add the 'ifdef CONFIG_PPC64' around the 'ptesync' in function 'emulate_update_regs()' to like it is in 'analyse_instr()'. Since it looks like it got dropped inadvertently by commit 3cdfcbfd32b9 ("powerpc: Change analyse_instr so it doesn't modify *regs"). A key detail is that analyse_instr() will never recognise lwsync or ptesync on 32-bit (because of the existing ifdef), and as a result emulate_update_regs() should never be called with an op specifying either of those on 32-bit. So removing them from emulate_update_regs() should be a nop in terms of runtime behaviour. Fixes: 3cdfcbfd32b9 ("powerpc: Change analyse_instr so it doesn't modify *regs") Cc: stable@vger.kernel.org # v4.14+ Suggested-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Anders Roxell <anders.roxell@linaro.org> [mpe: Add last paragraph of change log mentioning analyse_instr() details] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220211005113.1361436-1-anders.roxell@linaro.org 
Building tinyconfig with gcc (Debian 11.2.0-16) and assembler (Debian
2.37.90.20220207) the following build error shows up:

  {standard input}: Assembler messages:
  {standard input}:2088: Error: unrecognized opcode: `ptesync'
  make[3]: *** [/builds/linux/scripts/Makefile.build:287: arch/powerpc/lib/sstep.o] Error 1

Add the 'ifdef CONFIG_PPC64' around the 'ptesync' in function
'emulate_update_regs()' to like it is in 'analyse_instr()'. Since it looks like
it got dropped inadvertently by commit 3cdfcbfd32b9 ("powerpc: Change
analyse_instr so it doesn't modify *regs").

A key detail is that analyse_instr() will never recognise lwsync or
ptesync on 32-bit (because of the existing ifdef), and as a result
emulate_update_regs() should never be called with an op specifying
either of those on 32-bit. So removing them from emulate_update_regs()
should be a nop in terms of runtime behaviour.

Fixes: 3cdfcbfd32b9 ("powerpc: Change analyse_instr so it doesn't modify *regs")
Cc: stable@vger.kernel.org # v4.14+
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
[mpe: Add last paragraph of change log mentioning analyse_instr() details]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220211005113.1361436-1-anders.roxell@linaro.org
powerpc/603: Fix boot failure with DEBUG_PAGEALLOC and KFENCE 2022-02-07T06:18:47+00:00 Christophe Leroy christophe.leroy@csgroup.eu 2021-12-07T06:10:05+00:00 9bb162fa26ed76031ed0e7dbc77ccea0bf977758 Allthough kernel text is always mapped with BATs, we still have inittext mapped with pages, so TLB miss handling is required when CONFIG_DEBUG_PAGEALLOC or CONFIG_KFENCE is set. The final solution should be to set a BAT that also maps inittext but that BAT then needs to be cleared at end of init, and it will require more changes to be able to do it properly. As DEBUG_PAGEALLOC or KFENCE are debugging, performance is not a big deal so let's fix it simply for now to enable easy stable application. Fixes: 035b19a15a98 ("powerpc/32s: Always map kernel text and rodata with BATs") Cc: stable@vger.kernel.org # v5.11+ Reported-by: Maxime Bizon <mbizon@freebox.fr> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/aea33b4813a26bdb9378b5f273f00bd5d4abe240.1638857364.git.christophe.leroy@csgroup.eu 
Allthough kernel text is always mapped with BATs, we still have
inittext mapped with pages, so TLB miss handling is required
when CONFIG_DEBUG_PAGEALLOC or CONFIG_KFENCE is set.

The final solution should be to set a BAT that also maps inittext
but that BAT then needs to be cleared at end of init, and it will
require more changes to be able to do it properly.

As DEBUG_PAGEALLOC or KFENCE are debugging, performance is not a big
deal so let's fix it simply for now to enable easy stable application.

Fixes: 035b19a15a98 ("powerpc/32s: Always map kernel text and rodata with BATs")
Cc: stable@vger.kernel.org # v5.11+
Reported-by: Maxime Bizon <mbizon@freebox.fr>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/aea33b4813a26bdb9378b5f273f00bd5d4abe240.1638857364.git.christophe.leroy@csgroup.eu
powerpc/64s/interrupt: Fix decrementer storm 2022-01-25T05:50:10+00:00 Nicholas Piggin npiggin@gmail.com 2022-01-24T14:39:28+00:00 8defc2a5dd8f4c0cb19ecbaca8d3e89ab98524da The decrementer exception can fail to be cleared when the interrupt returns in the case where the decrementer wraps with the next timer still beyond decrementer_max. This results in a decrementer interrupt storm. This is triggerable with small decrementer system with hard and soft watchdogs disabled. Fix this by always programming the decrementer if there was no timer. Fixes: 0faf20a1ad16 ("powerpc/64s/interrupt: Don't enable MSR[EE] in irq handlers unless perf is in use") Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220124143930.3923442-1-npiggin@gmail.com 
The decrementer exception can fail to be cleared when the interrupt
returns in the case where the decrementer wraps with the next timer
still beyond decrementer_max. This results in a decrementer interrupt
storm. This is triggerable with small decrementer system with hard
and soft watchdogs disabled.

Fix this by always programming the decrementer if there was no timer.

Fixes: 0faf20a1ad16 ("powerpc/64s/interrupt: Don't enable MSR[EE] in irq handlers unless perf is in use")
Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220124143930.3923442-1-npiggin@gmail.com
KVM: PPC: Book3S HV Nested: Fix nested HFSCR being clobbered with multiple vCPUs 2022-01-25T05:39:41+00:00 Nicholas Piggin npiggin@gmail.com 2022-01-22T10:55:30+00:00 22f7ff0dea9491e90b6fe808ed40c30bd791e5c2 The L0 is storing HFSCR requested by the L1 for the L2 in struct kvm_nested_guest when the L1 requests a vCPU enter L2. kvm_nested_guest is not a per-vCPU structure. Hilarity ensues. Fix it by moving the nested hfscr into the vCPU structure together with the other per-vCPU nested fields. Fixes: 8b210a880b35 ("KVM: PPC: Book3S HV Nested: Make nested HFSCR state accessible") Cc: stable@vger.kernel.org # v5.15+ Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220122105530.3477250-1-npiggin@gmail.com 
The L0 is storing HFSCR requested by the L1 for the L2 in struct
kvm_nested_guest when the L1 requests a vCPU enter L2. kvm_nested_guest
is not a per-vCPU structure. Hilarity ensues.

Fix it by moving the nested hfscr into the vCPU structure together with
the other per-vCPU nested fields.

Fixes: 8b210a880b35 ("KVM: PPC: Book3S HV Nested: Make nested HFSCR state accessible")
Cc: stable@vger.kernel.org # v5.15+
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220122105530.3477250-1-npiggin@gmail.com
powerpc/perf: Fix power_pmu_disable to call clear_pmi_irq_pending only if PMI is pending 2022-01-24T06:31:15+00:00 Athira Rajeev atrajeev@linux.vnet.ibm.com 2022-01-22T03:34:29+00:00 fb6433b48a178d4672cb26632454ee0b21056eaa Running selftest with CONFIG_PPC_IRQ_SOFT_MASK_DEBUG enabled in kernel triggered below warning: [ 172.851380] ------------[ cut here ]------------ [ 172.851391] WARNING: CPU: 8 PID: 2901 at arch/powerpc/include/asm/hw_irq.h:246 power_pmu_disable+0x270/0x280 [ 172.851402] Modules linked in: dm_mod bonding nft_ct nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ip_set nf_tables rfkill nfnetlink sunrpc xfs libcrc32c pseries_rng xts vmx_crypto uio_pdrv_genirq uio sch_fq_codel ip_tables ext4 mbcache jbd2 sd_mod t10_pi sg ibmvscsi ibmveth scsi_transport_srp fuse [ 172.851442] CPU: 8 PID: 2901 Comm: lost_exception_ Not tainted 5.16.0-rc5-03218-g798527287598 #2 [ 172.851451] NIP: c00000000013d600 LR: c00000000013d5a4 CTR: c00000000013b180 [ 172.851458] REGS: c000000017687860 TRAP: 0700 Not tainted (5.16.0-rc5-03218-g798527287598) [ 172.851465] MSR: 8000000000029033 <SF,EE,ME,IR,DR,RI,LE> CR: 48004884 XER: 20040000 [ 172.851482] CFAR: c00000000013d5b4 IRQMASK: 1 [ 172.851482] GPR00: c00000000013d5a4 c000000017687b00 c000000002a10600 0000000000000004 [ 172.851482] GPR04: 0000000082004000 c0000008ba08f0a8 0000000000000000 00000008b7ed0000 [ 172.851482] GPR08: 00000000446194f6 0000000000008000 c00000000013b118 c000000000d58e68 [ 172.851482] GPR12: c00000000013d390 c00000001ec54a80 0000000000000000 0000000000000000 [ 172.851482] GPR16: 0000000000000000 0000000000000000 c000000015d5c708 c0000000025396d0 [ 172.851482] GPR20: 0000000000000000 0000000000000000 c00000000a3bbf40 0000000000000003 [ 172.851482] GPR24: 0000000000000000 c0000008ba097400 c0000000161e0d00 c00000000a3bb600 [ 172.851482] GPR28: c000000015d5c700 0000000000000001 0000000082384090 c0000008ba0020d8 [ 172.851549] NIP [c00000000013d600] power_pmu_disable+0x270/0x280 [ 172.851557] LR [c00000000013d5a4] power_pmu_disable+0x214/0x280 [ 172.851565] Call Trace: [ 172.851568] [c000000017687b00] [c00000000013d5a4] power_pmu_disable+0x214/0x280 (unreliable) [ 172.851579] [c000000017687b40] [c0000000003403ac] perf_pmu_disable+0x4c/0x60 [ 172.851588] [c000000017687b60] [c0000000003445e4] __perf_event_task_sched_out+0x1d4/0x660 [ 172.851596] [c000000017687c50] [c000000000d1175c] __schedule+0xbcc/0x12a0 [ 172.851602] [c000000017687d60] [c000000000d11ea8] schedule+0x78/0x140 [ 172.851608] [c000000017687d90] [c0000000001a8080] sys_sched_yield+0x20/0x40 [ 172.851615] [c000000017687db0] [c0000000000334dc] system_call_exception+0x18c/0x380 [ 172.851622] [c000000017687e10] [c00000000000c74c] system_call_common+0xec/0x268 The warning indicates that MSR_EE being set(interrupt enabled) when there was an overflown PMC detected. This could happen in power_pmu_disable since it runs under interrupt soft disable condition ( local_irq_save ) and not with interrupts hard disabled. commit 2c9ac51b850d ("powerpc/perf: Fix PMU callbacks to clear pending PMI before resetting an overflown PMC") intended to clear PMI pending bit in Paca when disabling the PMU. It could happen that PMC gets overflown while code is in power_pmu_disable callback function. Hence add a check to see if PMI pending bit is set in Paca before clearing it via clear_pmi_pending. Fixes: 2c9ac51b850d ("powerpc/perf: Fix PMU callbacks to clear pending PMI before resetting an overflown PMC") Reported-by: Sachin Sant <sachinp@linux.ibm.com> Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com> Tested-by: Sachin Sant <sachinp@linux.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220122033429.25395-1-atrajeev@linux.vnet.ibm.com 
Running selftest with CONFIG_PPC_IRQ_SOFT_MASK_DEBUG enabled in kernel
triggered below warning:

[  172.851380] ------------[ cut here ]------------
[  172.851391] WARNING: CPU: 8 PID: 2901 at arch/powerpc/include/asm/hw_irq.h:246 power_pmu_disable+0x270/0x280
[  172.851402] Modules linked in: dm_mod bonding nft_ct nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ip_set nf_tables rfkill nfnetlink sunrpc xfs libcrc32c pseries_rng xts vmx_crypto uio_pdrv_genirq uio sch_fq_codel ip_tables ext4 mbcache jbd2 sd_mod t10_pi sg ibmvscsi ibmveth scsi_transport_srp fuse
[  172.851442] CPU: 8 PID: 2901 Comm: lost_exception_ Not tainted 5.16.0-rc5-03218-g798527287598 #2
[  172.851451] NIP:  c00000000013d600 LR: c00000000013d5a4 CTR: c00000000013b180
[  172.851458] REGS: c000000017687860 TRAP: 0700   Not tainted  (5.16.0-rc5-03218-g798527287598)
[  172.851465] MSR:  8000000000029033 <SF,EE,ME,IR,DR,RI,LE>  CR: 48004884  XER: 20040000
[  172.851482] CFAR: c00000000013d5b4 IRQMASK: 1
[  172.851482] GPR00: c00000000013d5a4 c000000017687b00 c000000002a10600 0000000000000004
[  172.851482] GPR04: 0000000082004000 c0000008ba08f0a8 0000000000000000 00000008b7ed0000
[  172.851482] GPR08: 00000000446194f6 0000000000008000 c00000000013b118 c000000000d58e68
[  172.851482] GPR12: c00000000013d390 c00000001ec54a80 0000000000000000 0000000000000000
[  172.851482] GPR16: 0000000000000000 0000000000000000 c000000015d5c708 c0000000025396d0
[  172.851482] GPR20: 0000000000000000 0000000000000000 c00000000a3bbf40 0000000000000003
[  172.851482] GPR24: 0000000000000000 c0000008ba097400 c0000000161e0d00 c00000000a3bb600
[  172.851482] GPR28: c000000015d5c700 0000000000000001 0000000082384090 c0000008ba0020d8
[  172.851549] NIP [c00000000013d600] power_pmu_disable+0x270/0x280
[  172.851557] LR [c00000000013d5a4] power_pmu_disable+0x214/0x280
[  172.851565] Call Trace:
[  172.851568] [c000000017687b00] [c00000000013d5a4] power_pmu_disable+0x214/0x280 (unreliable)
[  172.851579] [c000000017687b40] [c0000000003403ac] perf_pmu_disable+0x4c/0x60
[  172.851588] [c000000017687b60] [c0000000003445e4] __perf_event_task_sched_out+0x1d4/0x660
[  172.851596] [c000000017687c50] [c000000000d1175c] __schedule+0xbcc/0x12a0
[  172.851602] [c000000017687d60] [c000000000d11ea8] schedule+0x78/0x140
[  172.851608] [c000000017687d90] [c0000000001a8080] sys_sched_yield+0x20/0x40
[  172.851615] [c000000017687db0] [c0000000000334dc] system_call_exception+0x18c/0x380
[  172.851622] [c000000017687e10] [c00000000000c74c] system_call_common+0xec/0x268

The warning indicates that MSR_EE being set(interrupt enabled) when
there was an overflown PMC detected. This could happen in
power_pmu_disable since it runs under interrupt soft disable
condition ( local_irq_save ) and not with interrupts hard disabled.
commit 2c9ac51b850d ("powerpc/perf: Fix PMU callbacks to clear
pending PMI before resetting an overflown PMC") intended to clear
PMI pending bit in Paca when disabling the PMU. It could happen
that PMC gets overflown while code is in power_pmu_disable
callback function. Hence add a check to see if PMI pending bit
is set in Paca before clearing it via clear_pmi_pending.

Fixes: 2c9ac51b850d ("powerpc/perf: Fix PMU callbacks to clear pending PMI before resetting an overflown PMC")
Reported-by: Sachin Sant <sachinp@linux.ibm.com>
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Tested-by: Sachin Sant <sachinp@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220122033429.25395-1-atrajeev@linux.vnet.ibm.com
powerpc/fixmap: Fix VM debug warning on unmap 2022-01-24T06:29:05+00:00 Christophe Leroy christophe.leroy@csgroup.eu 2021-12-06T11:11:51+00:00 aec982603aa8cc0a21143681feb5f60ecc69d718 Unmapping a fixmap entry is done by calling __set_fixmap() with FIXMAP_PAGE_CLEAR as flags. Today, powerpc __set_fixmap() calls map_kernel_page(). map_kernel_page() is not happy when called a second time for the same page. WARNING: CPU: 0 PID: 1 at arch/powerpc/mm/pgtable.c:194 set_pte_at+0xc/0x1e8 CPU: 0 PID: 1 Comm: swapper Not tainted 5.16.0-rc3-s3k-dev-01993-g350ff07feb7d-dirty #682 NIP: c0017cd4 LR: c00187f0 CTR: 00000010 REGS: e1011d50 TRAP: 0700 Not tainted (5.16.0-rc3-s3k-dev-01993-g350ff07feb7d-dirty) MSR: 00029032 <EE,ME,IR,DR,RI> CR: 42000208 XER: 00000000 GPR00: c0165fec e1011e10 c14c0000 c0ee2550 ff800000 c0f3d000 00000000 c001686c GPR08: 00001000 b00045a9 00000001 c0f58460 c0f50000 00000000 c0007e10 00000000 GPR16: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 GPR24: 00000000 00000000 c0ee2550 00000000 c0f57000 00000ff8 00000000 ff800000 NIP [c0017cd4] set_pte_at+0xc/0x1e8 LR [c00187f0] map_kernel_page+0x9c/0x100 Call Trace: [e1011e10] [c0736c68] vsnprintf+0x358/0x6c8 (unreliable) [e1011e30] [c0165fec] __set_fixmap+0x30/0x44 [e1011e40] [c0c13bdc] early_iounmap+0x11c/0x170 [e1011e70] [c0c06cb0] ioremap_legacy_serial_console+0x88/0xc0 [e1011e90] [c0c03634] do_one_initcall+0x80/0x178 [e1011ef0] [c0c0385c] kernel_init_freeable+0xb4/0x250 [e1011f20] [c0007e34] kernel_init+0x24/0x140 [e1011f30] [c0016268] ret_from_kernel_thread+0x5c/0x64 Instruction dump: 7fe3fb78 48019689 80010014 7c630034 83e1000c 5463d97e 7c0803a6 38210010 4e800020 81250000 712a0001 41820008 <0fe00000> 9421ffe0 93e1001c 48000030 Implement unmap_kernel_page() which clears an existing pte. Reported-by: Maxime Bizon <mbizon@freebox.fr> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Tested-by: Maxime Bizon <mbizon@freebox.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/b0b752f6f6ecc60653e873f385c6f0dce4e9ab6a.1638789098.git.christophe.leroy@csgroup.eu 
Unmapping a fixmap entry is done by calling __set_fixmap()
with FIXMAP_PAGE_CLEAR as flags.

Today, powerpc __set_fixmap() calls map_kernel_page().

map_kernel_page() is not happy when called a second time
for the same page.

	WARNING: CPU: 0 PID: 1 at arch/powerpc/mm/pgtable.c:194 set_pte_at+0xc/0x1e8
	CPU: 0 PID: 1 Comm: swapper Not tainted 5.16.0-rc3-s3k-dev-01993-g350ff07feb7d-dirty #682
	NIP:  c0017cd4 LR: c00187f0 CTR: 00000010
	REGS: e1011d50 TRAP: 0700   Not tainted  (5.16.0-rc3-s3k-dev-01993-g350ff07feb7d-dirty)
	MSR:  00029032 <EE,ME,IR,DR,RI>  CR: 42000208  XER: 00000000

	GPR00: c0165fec e1011e10 c14c0000 c0ee2550 ff800000 c0f3d000 00000000 c001686c
	GPR08: 00001000 b00045a9 00000001 c0f58460 c0f50000 00000000 c0007e10 00000000
	GPR16: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
	GPR24: 00000000 00000000 c0ee2550 00000000 c0f57000 00000ff8 00000000 ff800000
	NIP [c0017cd4] set_pte_at+0xc/0x1e8
	LR [c00187f0] map_kernel_page+0x9c/0x100
	Call Trace:
	[e1011e10] [c0736c68] vsnprintf+0x358/0x6c8 (unreliable)
	[e1011e30] [c0165fec] __set_fixmap+0x30/0x44
	[e1011e40] [c0c13bdc] early_iounmap+0x11c/0x170
	[e1011e70] [c0c06cb0] ioremap_legacy_serial_console+0x88/0xc0
	[e1011e90] [c0c03634] do_one_initcall+0x80/0x178
	[e1011ef0] [c0c0385c] kernel_init_freeable+0xb4/0x250
	[e1011f20] [c0007e34] kernel_init+0x24/0x140
	[e1011f30] [c0016268] ret_from_kernel_thread+0x5c/0x64
	Instruction dump:
	7fe3fb78 48019689 80010014 7c630034 83e1000c 5463d97e 7c0803a6 38210010
	4e800020 81250000 712a0001 41820008 <0fe00000> 9421ffe0 93e1001c 48000030

Implement unmap_kernel_page() which clears an existing pte.

Reported-by: Maxime Bizon <mbizon@freebox.fr>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Tested-by: Maxime Bizon <mbizon@freebox.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b0b752f6f6ecc60653e873f385c6f0dce4e9ab6a.1638789098.git.christophe.leroy@csgroup.eu
Merge tag 'powerpc-5.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux 2022-01-23T15:52:42+00:00 Linus Torvalds torvalds@linux-foundation.org 2022-01-23T15:52:42+00:00 dd81e1c7d5fb126e5fbc5c9e334d7b3ec29a16a0 Pull powerpc fixes from Michael Ellerman: - A series of bpf fixes, including an oops fix and some codegen fixes. - Fix a regression in syscall_get_arch() for compat processes. - Fix boot failure on some 32-bit systems with KASAN enabled. - A couple of other build/minor fixes. Thanks to Athira Rajeev, Christophe Leroy, Dmitry V. Levin, Jiri Olsa, Johan Almbladh, Maxime Bizon, Naveen N. Rao, and Nicholas Piggin. * tag 'powerpc-5.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/64s: Mask SRR0 before checking against the masked NIP powerpc/perf: Only define power_pmu_wants_prompt_pmi() for CONFIG_PPC64 powerpc/32s: Fix kasan_init_region() for KASAN powerpc/time: Fix build failure due to do_hard_irq_enable() on PPC32 powerpc/audit: Fix syscall_get_arch() powerpc64/bpf: Limit 'ldbrx' to processors compliant with ISA v2.06 tools/bpf: Rename 'struct event' to avoid naming conflict powerpc/bpf: Update ldimm64 instructions during extra pass powerpc32/bpf: Fix codegen for bpf-to-bpf calls bpf: Guard against accessing NULL pt_regs in bpf_get_task_stack() 
Pull powerpc fixes from Michael Ellerman:

 - A series of bpf fixes, including an oops fix and some codegen fixes.

 - Fix a regression in syscall_get_arch() for compat processes.

 - Fix boot failure on some 32-bit systems with KASAN enabled.

 - A couple of other build/minor fixes.

Thanks to Athira Rajeev, Christophe Leroy, Dmitry V. Levin, Jiri Olsa,
Johan Almbladh, Maxime Bizon, Naveen N. Rao, and Nicholas Piggin.

* tag 'powerpc-5.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/64s: Mask SRR0 before checking against the masked NIP
  powerpc/perf: Only define power_pmu_wants_prompt_pmi() for CONFIG_PPC64
  powerpc/32s: Fix kasan_init_region() for KASAN
  powerpc/time: Fix build failure due to do_hard_irq_enable() on PPC32
  powerpc/audit: Fix syscall_get_arch()
  powerpc64/bpf: Limit 'ldbrx' to processors compliant with ISA v2.06
  tools/bpf: Rename 'struct event' to avoid naming conflict
  powerpc/bpf: Update ldimm64 instructions during extra pass
  powerpc32/bpf: Fix codegen for bpf-to-bpf calls
  bpf: Guard against accessing NULL pt_regs in bpf_get_task_stack()
Merge tag 'bitmap-5.17-rc1' of git://github.com/norov/linux 2022-01-23T04:20:44+00:00 Linus Torvalds torvalds@linux-foundation.org 2022-01-23T04:20:44+00:00 3689f9f8b0c52dfd8f5995e4b58917f8f3ac3ee3 Pull bitmap updates from Yury Norov: - introduce for_each_set_bitrange() - use find_first_*_bit() instead of find_next_*_bit() where possible - unify for_each_bit() macros * tag 'bitmap-5.17-rc1' of git://github.com/norov/linux: vsprintf: rework bitmap_list_string lib: bitmap: add performance test for bitmap_print_to_pagebuf bitmap: unify find_bit operations mm/percpu: micro-optimize pcpu_is_populated() Replace for_each_*_bit_from() with for_each_*_bit() where appropriate find: micro-optimize for_each_{set,clear}_bit() include/linux: move for_each_bit() macros from bitops.h to find.h cpumask: replace cpumask_next_* with cpumask_first_* where appropriate tools: sync tools/bitmap with mother linux all: replace find_next{,_zero}_bit with find_first{,_zero}_bit where appropriate cpumask: use find_first_and_bit() lib: add find_first_and_bit() arch: remove GENERIC_FIND_FIRST_BIT entirely include: move find.h from asm_generic to linux bitops: move find_bit_*_le functions from le.h to find.h bitops: protect find_first_{,zero}_bit properly 
Pull bitmap updates from Yury Norov:

 - introduce for_each_set_bitrange()

 - use find_first_*_bit() instead of find_next_*_bit() where possible

 - unify for_each_bit() macros

* tag 'bitmap-5.17-rc1' of git://github.com/norov/linux:
  vsprintf: rework bitmap_list_string
  lib: bitmap: add performance test for bitmap_print_to_pagebuf
  bitmap: unify find_bit operations
  mm/percpu: micro-optimize pcpu_is_populated()
  Replace for_each_*_bit_from() with for_each_*_bit() where appropriate
  find: micro-optimize for_each_{set,clear}_bit()
  include/linux: move for_each_bit() macros from bitops.h to find.h
  cpumask: replace cpumask_next_* with cpumask_first_* where appropriate
  tools: sync tools/bitmap with mother linux
  all: replace find_next{,_zero}_bit with find_first{,_zero}_bit where appropriate
  cpumask: use find_first_and_bit()
  lib: add find_first_and_bit()
  arch: remove GENERIC_FIND_FIRST_BIT entirely
  include: move find.h from asm_generic to linux
  bitops: move find_bit_*_le functions from le.h to find.h
  bitops: protect find_first_{,zero}_bit properly