ioremap_page_range() should be used for ranges within vmalloc range only.
The vmalloc ranges are allocated by get_vm_area(). PCI has "resource"
allocator that manages PCI_IOBASE, IO_SPACE_LIMIT address range, hence
introduce vmap_page_range() to be used exclusively to map pages
in PCI address space.
Fixes: 3e49a866c9 ("mm: Enforce VM_IOREMAP flag and range in ioremap_page_range.")
Reported-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://lore.kernel.org/bpf/CANiq72ka4rir+RTN2FQoT=Vvprp_Ao-CvoYEkSNqtSY+RZj+AA@mail.gmail.com
- Fix IOMMU table initialisation when doing kdump over SR-IOV.
- Fix incorrect RTAS function name for resetting TCE tables.
- Fix fpu_signal selftest failures since a recent change.
Thanks to: Gaurav Batra, Nathan Lynch.
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Merge tag 'powerpc-6.8-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
- Fix IOMMU table initialisation when doing kdump over SR-IOV
- Fix incorrect RTAS function name for resetting TCE tables
- Fix fpu_signal selftest failures since a recent change
Thanks to Gaurav Batra and Nathan Lynch.
* tag 'powerpc-6.8-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
selftests/powerpc: Fix fpu_signal failures
powerpc/rtas: use correct function name for resetting TCE tables
powerpc/pseries/iommu: IOMMU table is not initialized for kdump over SR-IOV
Allow a transition from the softirq stack to the hardirq stack when
handling a hardirq. Doing so means a hardirq received while deep in
softirq processing is less likely to cause a stack overflow of the
softirq stack.
Previously it wasn't safe to do so because irq_exit() (which initiates
softirq processing) was called on the hardirq stack.
That was changed in commit 1b1b6a6f4c ("powerpc: handle irq_enter/
irq_exit in interrupt handler wrappers") and 1346d00e1b ("powerpc:
Don't select HAVE_IRQ_EXIT_ON_IRQ_STACK").
The allowed transitions are now:
- process stack -> hardirq stack
- process stack -> softirq stack
- process stack -> softirq stack -> hardirq stack
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231130125045.3080961-1-mpe@ellerman.id.au
Replace all usages of of_root by of_find_node_by_path("/")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231214103152.12269-5-mpe@ellerman.id.au
Most probe functions that do not use the 'compatible' string do
nothing else than checking whether the machine is compatible with
one of the strings in a NULL terminated table of strings.
Define that table of strings in ppc_md structure and check it directly
from probe_machine() instead of using ppc_md.probe() for that.
Keep checking in ppc_md.probe() only for more complex probing.
All .compatible could be replaced with a single element NULL
terminated list but that's not worth the churn. Can be do incrementaly
in follow-up patches.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231214103152.12269-4-mpe@ellerman.id.au
SD_SHARE_PKG_RESOURCES is a bit of a misnomer: its naming suggests that
it's sharing all 'package resources' - while in reality it's specifically
for sharing the LLC only.
Rename it to SD_SHARE_LLC to reduce confusion.
[ mingo: Rewrote the confusing changelog as well. ]
Suggested-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Alex Shi <alexs@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Reviewed-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Reviewed-by: Barry Song <baohua@kernel.org>
Link: https://lore.kernel.org/r/20240210113924.1130448-5-alexs@kernel.org
- Fix a crash when hot adding a PCI device to an LPAR since recent changes.
- Fix nested KVM level-2 guest reboot failure due to empty 'arch_compat'.
Thanks to: Amit Machhiwal, Aneesh Kumar K.V (IBM), Brian King, Gaurav Batra,
Vaibhav Jain.
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Merge tag 'powerpc-6.8-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
- Fix a crash when hot adding a PCI device to an LPAR since
recent changes
- Fix nested KVM level-2 guest reboot failure due to empty
'arch_compat'
Thanks to Amit Machhiwal, Aneesh Kumar K.V (IBM), Brian King, Gaurav
Batra, and Vaibhav Jain.
* tag 'powerpc-6.8-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
KVM: PPC: Book3S HV: Fix L2 guest reboot failure due to empty 'arch_compat'
powerpc/pseries/iommu: DLPAR add doesn't completely initialize pci_controller
Now move the relevant codes into separate files:
kernel/crash_reserve.c, include/linux/crash_reserve.h.
And add config item CRASH_RESERVE to control its enabling.
And also update the old ifdeffery of CONFIG_CRASH_CORE, including of
<linux/crash_core.h> and config item dependency on CRASH_CORE
accordingly.
And also do renaming as follows:
- arch/xxx/kernel/{crash_core.c => vmcore_info.c}
because they are only related to vmcoreinfo exporting on x86, arm64,
riscv.
And also Remove config item CRASH_CORE, and rely on CONFIG_KEXEC_CORE to
decide if build in crash_core.c.
[yang.lee@linux.alibaba.com: remove duplicated include in vmcore_info.c]
Link: https://lkml.kernel.org/r/20240126005744.16561-1-yang.lee@linux.alibaba.com
Link: https://lkml.kernel.org/r/20240124051254.67105-3-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Acked-by: Hari Bathini <hbathini@linux.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Pingfan Liu <piliu@redhat.com>
Cc: Klara Modin <klarasmodin@gmail.com>
Cc: Michael Kelley <mhklinux@outlook.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The PAPR spec spells the function name as
"ibm,reset-pe-dma-windows"
but in practice firmware uses the singular form:
"ibm,reset-pe-dma-window"
in the device tree. Since we have the wrong spelling in the RTAS
function table, reverse lookups (token -> name) fail and warn:
unexpected failed lookup for token 86
WARNING: CPU: 1 PID: 545 at arch/powerpc/kernel/rtas.c:659 __do_enter_rtas_trace+0x2a4/0x2b4
CPU: 1 PID: 545 Comm: systemd-udevd Not tainted 6.8.0-rc4 #30
Hardware name: IBM,9105-22A POWER10 (raw) 0x800200 0xf000006 of:IBM,FW1060.00 (NL1060_028) hv:phyp pSeries
NIP [c0000000000417f0] __do_enter_rtas_trace+0x2a4/0x2b4
LR [c0000000000417ec] __do_enter_rtas_trace+0x2a0/0x2b4
Call Trace:
__do_enter_rtas_trace+0x2a0/0x2b4 (unreliable)
rtas_call+0x1f8/0x3e0
enable_ddw.constprop.0+0x4d0/0xc84
dma_iommu_dma_supported+0xe8/0x24c
dma_set_mask+0x5c/0xd8
mlx5_pci_init.constprop.0+0xf0/0x46c [mlx5_core]
probe_one+0xfc/0x32c [mlx5_core]
local_pci_probe+0x68/0x12c
pci_call_probe+0x68/0x1ec
pci_device_probe+0xbc/0x1a8
really_probe+0x104/0x570
__driver_probe_device+0xb8/0x224
driver_probe_device+0x54/0x130
__driver_attach+0x158/0x2b0
bus_for_each_dev+0xa8/0x120
driver_attach+0x34/0x48
bus_add_driver+0x174/0x304
driver_register+0x8c/0x1c4
__pci_register_driver+0x68/0x7c
mlx5_init+0xb8/0x118 [mlx5_core]
do_one_initcall+0x60/0x388
do_init_module+0x7c/0x2a4
init_module_from_file+0xb4/0x108
idempotent_init_module+0x184/0x34c
sys_finit_module+0x90/0x114
And oopses are possible when lockdep is enabled or the RTAS
tracepoints are active, since those paths dereference the result of
the lookup.
Use the correct spelling to match firmware's behavior, adjusting the
related constants to match.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Fixes: 8252b88294 ("powerpc/rtas: improve function information lookups")
Reported-by: Gaurav Batra <gbatra@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240222-rtas-fix-ibm-reset-pe-dma-window-v1-1-7aaf235ac63c@linux.ibm.com
PAPR will define a new ibm,pi-features bit which says that doorbells
should not be used even on architectures where they exist. This could be
because they are emulated and slower than using the interrupt controller
directly for IPIs.
Wire this bit into the pi-features parser to clear CPU_FTR_DBELL, and
ensure CPU_FTR_DBELL is not in CPU_FTRS_ALWAYS.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Tested-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240207035220.339726-2-npiggin@gmail.com
When a new ibm,pa/pi-features bit is introduced that is intended to
apply to existing systems and features, it may have an "inverted"
meaning (i.e., bit clear => feature available; bit set => unavailable).
Depending on the nature of the feature, this may give the best
backward compatibility result where old firmware will continue to
have that bit clear and therefore the feature available.
The 'invert' modifier presumably was introduced for this type of
feature bit. However it invert will set the feature if the bit is
clear, which prevents it being used in the situation where an old
CPU lacks a feature that a new CPU has, then a new firmware comes
out to disable that feature on the new CPU if the bit is set.
Adding an 'invert' entry for that feature would incorrectly enable
it for the old CPU.
So add a 'clear' modifier that clears the feature if the bit is set,
but it does not set the feature if the bit is clear. The feature
is expected to be set in the cpu table.
This replaces the 'invert' modifier, which is unused since commit
7d47034551 ("powerpc/feature: Remove CPU_FTR_NODSISRALIGN").
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Tested-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240207035220.339726-1-npiggin@gmail.com
Add CPU table entries for raw and architected mode. Most fields are
copied from the Power10 table entries.
CPU, MMU and user (ELF_HWCAP) features are unchanged vs P10. However
userspace can detect P11 because the AT_PLATFORM value changes to
"power11".
The logical PVR value of 0x0F000007, passed to firmware via the
ibm_arch_vec, indicates the kernel can support a P11 compatible CPU,
which means at least ISA v3.1 compliant.
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240221044623.1598642-1-mpe@ellerman.id.au
When an ifdef is used in the below manner, second one could be considered
as duplicate.
ifdef DEFINE_A
...code block...
ifdef DEFINE_A <-- This is a duplicate.
...code block...
endif
else
ifndef DEFINE_A <-- This is also duplicate.
...code block...
endif
endif
More details about the script and methods used to find these code
patterns are in cover letter of [1].
Few places in arch/powerpc where this pattern was seen:
paca.h:
Hunk1: Code is under check of CONFIG_PPC64 from line 13, hence the
second CONFIG_PPC64 at line 166 is a duplicate.
Hunk2: CONFIG_PPC_BOOK3S_64 was defined back to back. Merged the two
ifdefs.
asm-offsets.c:
Code is under check of CONFIG_PPC64 from line 176 hence second
CONFIG_PPC64 at line 249 is a duplicate.
powermac/feature.c:
#ifndef CONFIG_PPC64 is used at line 2066. And then in #else again
#ifdef CONFIG_PPC64 is used. Which is a duplicate since in #else means
CONFIG_PPC64 is defined.
xmon.c:
Code is under the check of CONFIG_SMP from line 521 hence the same
check of CONFIG_SMP at line 646 is a duplicate.
No functional change is intended here. It only aims to improve code
readability.
[1] https://lore.kernel.org/all/20240118080326.13137-1-sshegde@linux.ibm.com/
Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240216053016.528906-1-sshegde@linux.ibm.com
Commit 2fb857bc9f ("powerpc/kcsan: Add exclusions from instrumentation")
added KCSAN_SANITIZE_early_64.o to arch/powerpc/kernel/Makefile, while
it does not compile early_64.o.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240216135817.2003106-1-masahiroy@kernel.org
- Fix ftrace bug on boot caused by exit text sections with -fpatchable-function-entry.
- Fix accuracy of stolen time on pseries since the switch to VIRT_CPU_ACCOUNTING_GEN.
- Fix a crash in the IOMMU code when doing DLPAR remove.
- Set pt_regs->link on scv entry to fix BPF stack unwinding.
- Add missing PPC_FEATURE_BOOKE on 64-bit e5500/e6500, which broke gdb.
- Fix boot on some 6xx platforms with STRICT_KERNEL_RWX enabled.
- Fix build failures with KASAN enabled and 32KB stack size.
- Some other minor fixes.
Thanks to: Arnd Bergmann, Benjamin Gray, Christophe Leroy, David Engraf, Gaurav
Batra, Jason Gunthorpe, Jiangfeng Xiao, Matthias Schiffer, Nathan Lynch, Naveen
N Rao, Nicholas Piggin, Nysal Jan K.A, R Nageswara Sastry, Shivaprasad G Bhat,
Shrikanth Hegde, Spoorthy, Srikar Dronamraju, Venkat Rao Bagalkote.
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Merge tag 'powerpc-6.8-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
"This is a bit of a big batch for rc4, but just due to holiday hangover
and because I didn't send any fixes last week due to a late revert
request. I think next week should be back to normal.
- Fix ftrace bug on boot caused by exit text sections with
'-fpatchable-function-entry'
- Fix accuracy of stolen time on pseries since the switch to
VIRT_CPU_ACCOUNTING_GEN
- Fix a crash in the IOMMU code when doing DLPAR remove
- Set pt_regs->link on scv entry to fix BPF stack unwinding
- Add missing PPC_FEATURE_BOOKE on 64-bit e5500/e6500, which broke
gdb
- Fix boot on some 6xx platforms with STRICT_KERNEL_RWX enabled
- Fix build failures with KASAN enabled and 32KB stack size
- Some other minor fixes
Thanks to Arnd Bergmann, Benjamin Gray, Christophe Leroy, David
Engraf, Gaurav Batra, Jason Gunthorpe, Jiangfeng Xiao, Matthias
Schiffer, Nathan Lynch, Naveen N Rao, Nicholas Piggin, Nysal Jan K.A,
R Nageswara Sastry, Shivaprasad G Bhat, Shrikanth Hegde, Spoorthy,
Srikar Dronamraju, and Venkat Rao Bagalkote"
* tag 'powerpc-6.8-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/iommu: Fix the missing iommu_group_put() during platform domain attach
powerpc/pseries: fix accuracy of stolen time
powerpc/ftrace: Ignore ftrace locations in exit text sections
powerpc/cputable: Add missing PPC_FEATURE_BOOKE on PPC64 Book-E
powerpc/kasan: Limit KASAN thread size increase to 32KB
Revert "powerpc/pseries/iommu: Fix iommu initialisation during DLPAR add"
powerpc: 85xx: mark local functions static
powerpc: udbg_memcons: mark functions static
powerpc/kasan: Fix addr error caused by page alignment
powerpc/6xx: set High BAT Enable flag on G2_LE cores
selftests/powerpc/papr_vpd: Check devfd before get_system_loc_code()
powerpc/64: Set task pt_regs->link to the LR value on scv entry
powerpc/pseries/iommu: Fix iommu initialisation during DLPAR add
powerpc/pseries/papr-sysparm: use u8 arrays for payloads
If nr_cpu_ids is too low to include the boot CPU, remap the boot CPU
onto logical core 0.
This is achieved in two stages. In early_init_dt_scan_cpus() the boot
CPU is renumbered to be on logical core 0, and the original boot core's
hardware ID is recorded.
Later in smp_setup_cpu_maps(), if the original boot core ID is set, the
logical CPU numbers on the 0th core are skipped in the normal device
tree search over CPU device tree nodes. Then the search is continued
until the device tree node matching the boot core is found, and those
CPUs are assigned the CPU numbers starting at 0.
This allows kdump kernels to be booted with low values for nr_cpu_ids
to conserve memory, while also allowing the crashing/boot CPU to be
any CPU.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Tested-by: Wen Xiong <wenxiong@us.ibm.com>
Link: https://msgid.link/20231229120107.2281153-5-mpe@ellerman.id.au
Factor out the for loop that assigns CPU numbers to threads of a core.
The function takes the next CPU number to use as input, and returns the
next available CPU number after the threads has been assigned.
This will allow a subsequent change to assign threads out of order.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231229120107.2281153-4-mpe@ellerman.id.au
The of_device_is_available() check only needs to be done once per device
node, there's no need to repeat it for each thread. Move it out of the
loop.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231229120107.2281153-3-mpe@ellerman.id.au
If nr_cpu_ids is too low to include at least all the threads of a single
core adjust nr_cpu_ids upwards. This avoids triggering odd bugs in code
that assumes all threads of a core are available.
Cc: stable@vger.kernel.org
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231229120107.2281153-1-mpe@ellerman.id.au
Michael reported that we are seeing an ftrace bug on bootup when KASAN
is enabled and we are using -fpatchable-function-entry:
ftrace: allocating 47780 entries in 18 pages
ftrace-powerpc: 0xc0000000020b3d5c: No module provided for non-kernel address
------------[ ftrace bug ]------------
ftrace faulted on modifying
[<c0000000020b3d5c>] 0xc0000000020b3d5c
Initializing ftrace call sites
ftrace record flags: 0
(0)
expected tramp: c00000000008cef4
------------[ cut here ]------------
WARNING: CPU: 0 PID: 0 at kernel/trace/ftrace.c:2180 ftrace_bug+0x3c0/0x424
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0-rc3-00120-g0f71dcfb4aef #860
Hardware name: IBM pSeries (emulated by qemu) POWER9 (raw) 0x4e1202 0xf000005 of:SLOF,HEAD hv:linux,kvm pSeries
NIP: c0000000003aa81c LR: c0000000003aa818 CTR: 0000000000000000
REGS: c0000000033cfab0 TRAP: 0700 Not tainted (6.5.0-rc3-00120-g0f71dcfb4aef)
MSR: 8000000002021033 <SF,VEC,ME,IR,DR,RI,LE> CR: 28028240 XER: 00000000
CFAR: c0000000002781a8 IRQMASK: 3
...
NIP [c0000000003aa81c] ftrace_bug+0x3c0/0x424
LR [c0000000003aa818] ftrace_bug+0x3bc/0x424
Call Trace:
ftrace_bug+0x3bc/0x424 (unreliable)
ftrace_process_locs+0x5f4/0x8a0
ftrace_init+0xc0/0x1d0
start_kernel+0x1d8/0x484
With CONFIG_FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY=y and
CONFIG_KASAN=y, compiler emits nops in functions that it generates for
registering and unregistering global variables (unlike with -pg and
-mprofile-kernel where calls to _mcount() are not generated in those
functions). Those functions then end up in INIT_TEXT and EXIT_TEXT
respectively. We don't expect to see any profiled functions in
EXIT_TEXT, so ftrace_init_nop() assumes that all addresses that aren't
in the core kernel text belongs to a module. Since these functions do
not match that criteria, we see the above bug.
Address this by having ftrace ignore all locations in the text exit
sections of vmlinux.
Fixes: 0f71dcfb4a ("powerpc/ftrace: Add support for -fpatchable-function-entry")
Cc: stable@vger.kernel.org # v6.6+
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Naveen N Rao <naveen@kernel.org>
Reviewed-by: Benjamin Gray <bgray@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240213175410.1091313-1-naveen@kernel.org
Commit e320a76db4 ("powerpc/cputable: Split cpu_specs[] out of
cputable.h") moved the cpu_specs to separate header files. Previously
PPC_FEATURE_BOOKE was enabled by CONFIG_PPC_BOOK3E_64. The definition in
cpu_specs_e500mc.h for PPC64 no longer enables PPC_FEATURE_BOOKE.
This breaks user space reading the ELF hwcaps and expect
PPC_FEATURE_BOOKE. Debugging an application with gdb is no longer
working on e5500/e6500 because the 64-bit detection relies on
PPC_FEATURE_BOOKE for Book-E.
Fixes: e320a76db4 ("powerpc/cputable: Split cpu_specs[] out of cputable.h")
Cc: stable@vger.kernel.org # v6.1+
Signed-off-by: David Engraf <david.engraf@sysgo.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240207092758.1058893-1-david.engraf@sysgo.com
We've had issues with gcc and 'asm goto' before, and we created a
'asm_volatile_goto()' macro for that in the past: see commits
3f0116c323 ("compiler/gcc4: Add quirk for 'asm goto' miscompilation
bug") and a9f180345f ("compiler/gcc4: Make quirk for
asm_volatile_goto() unconditional").
Then, much later, we ended up removing the workaround in commit
43c249ea0b ("compiler-gcc.h: remove ancient workaround for gcc PR
58670") because we no longer supported building the kernel with the
affected gcc versions, but we left the macro uses around.
Now, Sean Christopherson reports a new version of a very similar
problem, which is fixed by re-applying that ancient workaround. But the
problem in question is limited to only the 'asm goto with outputs'
cases, so instead of re-introducing the old workaround as-is, let's
rename and limit the workaround to just that much less common case.
It looks like there are at least two separate issues that all hit in
this area:
(a) some versions of gcc don't mark the asm goto as 'volatile' when it
has outputs:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98619https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110420
which is easy to work around by just adding the 'volatile' by hand.
(b) Internal compiler errors:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110422
which are worked around by adding the extra empty 'asm' as a
barrier, as in the original workaround.
but the problem Sean sees may be a third thing since it involves bad
code generation (not an ICE) even with the manually added 'volatile'.
but the same old workaround works for this case, even if this feels a
bit like voodoo programming and may only be hiding the issue.
Reported-and-tested-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/all/20240208220604.140859-1-seanjc@google.com/
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Uros Bizjak <ubizjak@gmail.com>
Cc: Jakub Jelinek <jakub@redhat.com>
Cc: Andrew Pinski <quic_apinski@quicinc.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
MMU_FTR_USE_HIGH_BATS is set for G2_LE cores and derivatives like e300cX,
but the high BATs need to be enabled in HID2 to work. Add register
definitions and add the needed setup to __setup_cpu_603.
This fixes boot on CPUs like the MPC5200B with STRICT_KERNEL_RWX enabled
on systems where the flag has not been set by the bootloader already.
Fixes: e4d6654ebe ("powerpc/mm/32s: rework mmu_mapin_ram()")
Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240124103838.43675-1-matthias.schiffer@ew.tq-group.com
Nysal reported that userspace backtraces are missing in offcputime bcc
tool. As an example:
$ sudo ./bcc/tools/offcputime.py -uU
Tracing off-CPU time (us) of user threads by user stack... Hit Ctrl-C to end.
^C
write
- python (9107)
8
write
- sudo (9105)
9
mmap
- python (9107)
16
clock_nanosleep
- multipathd (697)
3001604
The offcputime bcc tool attaches a bpf program to a kprobe on
finish_task_switch(), which is usually hit on a syscall from userspace.
With the switch to system call vectored, we started setting
pt_regs->link to zero. This is because system call vectored behaves like
a function call with LR pointing to the system call return address, and
with no modification to SRR0/SRR1. The LR value does indicate our next
instruction, so it is being saved as pt_regs->nip, and pt_regs->link is
being set to zero. This is not a problem by itself, but BPF uses perf
callchain infrastructure for capturing stack traces, and that stores LR
as the second entry in the stack trace. perf has code to cope with the
second entry being zero, and skips over it. However, generic userspace
unwinders assume that a zero entry indicates end of the stack trace,
resulting in a truncated userspace stack trace.
Rather than fixing all userspace unwinders to ignore/skip past the
second entry, store the real LR value in pt_regs->link so that there
continues to be a valid, though duplicate entry in the stack trace.
With this change:
$ sudo ./bcc/tools/offcputime.py -uU
Tracing off-CPU time (us) of user threads by user stack... Hit Ctrl-C to end.
^C
write
write
[unknown]
[unknown]
[unknown]
[unknown]
[unknown]
PyObject_VectorcallMethod
[unknown]
[unknown]
PyObject_CallOneArg
PyFile_WriteObject
PyFile_WriteString
[unknown]
[unknown]
PyObject_Vectorcall
_PyEval_EvalFrameDefault
PyEval_EvalCode
[unknown]
[unknown]
[unknown]
_PyRun_SimpleFileObject
_PyRun_AnyFileObject
Py_RunMain
[unknown]
Py_BytesMain
[unknown]
__libc_start_main
- python (1293)
7
write
write
[unknown]
sudo_ev_loop_v1
sudo_ev_dispatch_v1
[unknown]
[unknown]
[unknown]
[unknown]
__libc_start_main
- sudo (1291)
7
syscall
syscall
bpf_open_perf_buffer_opts
[unknown]
[unknown]
[unknown]
[unknown]
_PyObject_MakeTpCall
PyObject_Vectorcall
_PyEval_EvalFrameDefault
PyEval_EvalCode
[unknown]
[unknown]
[unknown]
_PyRun_SimpleFileObject
_PyRun_AnyFileObject
Py_RunMain
[unknown]
Py_BytesMain
[unknown]
__libc_start_main
- python (1293)
11
clock_nanosleep
clock_nanosleep
nanosleep
sleep
[unknown]
[unknown]
__clone
- multipathd (698)
3001661
Fixes: 7fa95f9ada ("powerpc/64s: system call support for scv/rfscv instructions")
Cc: stable@vger.kernel.org
Reported-by: "Nysal Jan K.A" <nysal@linux.ibm.com>
Signed-off-by: Naveen N Rao <naveen@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240202154316.395276-1-naveen@kernel.org
The commit 2ad56efa80 ("powerpc/iommu: Setup a default domain and
remove set_platform_dma_ops") refactored the code removing the
set_platform_dma_ops(). It missed out the table group
release_ownership() call which would have got called otherwise
during the guest shutdown via vfio_group_detach_container(). On
PPC64, this particular call actually sets up the 32-bit TCE table,
and enables the 64-bit DMA bypass etc. Now after guest shutdown,
the subsequent host driver (e.g megaraid-sas) probe post unbind
from vfio-pci fails like,
megaraid_sas 0031:01:00.0: Warning: IOMMU dma not supported: mask 0x7fffffffffffffff, table unavailable
megaraid_sas 0031:01:00.0: Warning: IOMMU dma not supported: mask 0xffffffff, table unavailable
megaraid_sas 0031:01:00.0: Failed to set DMA mask
megaraid_sas 0031:01:00.0: Failed from megasas_init_fw 6539
The patch brings back the call to table_group release_ownership()
call when switching back to PLATFORM domain from BLOCKED, while
also separates the domain_ops for both.
Fixes: 2ad56efa80 ("powerpc/iommu: Setup a default domain and remove set_platform_dma_ops")
Signed-off-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/170628173462.3742.18330000394415935845.stgit@ltcd48-lp2.aus.stglab.ibm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
The goal is to get sched.h down to a type only header, so the main thing
happening in this patchset is splitting out various _types.h headers and
dependency fixups, as well as moving some things out of sched.h to
better locations.
This is prep work for the memory allocation profiling patchset which
adds new sched.h interdepencencies.
Testing - it's been in -next, and fixes from pretty much all
architectures have percolated in - nothing major.
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Merge tag 'header_cleanup-2024-01-10' of https://evilpiepirate.org/git/bcachefs
Pull header cleanups from Kent Overstreet:
"The goal is to get sched.h down to a type only header, so the main
thing happening in this patchset is splitting out various _types.h
headers and dependency fixups, as well as moving some things out of
sched.h to better locations.
This is prep work for the memory allocation profiling patchset which
adds new sched.h interdepencencies"
* tag 'header_cleanup-2024-01-10' of https://evilpiepirate.org/git/bcachefs: (51 commits)
Kill sched.h dependency on rcupdate.h
kill unnecessary thread_info.h include
Kill unnecessary kernel.h include
preempt.h: Kill dependency on list.h
rseq: Split out rseq.h from sched.h
LoongArch: signal.c: add header file to fix build error
restart_block: Trim includes
lockdep: move held_lock to lockdep_types.h
sem: Split out sem_types.h
uidgid: Split out uidgid_types.h
seccomp: Split out seccomp_types.h
refcount: Split out refcount_types.h
uapi/linux/resource.h: fix include
x86/signal: kill dependency on time.h
syscall_user_dispatch.h: split out *_types.h
mm_types_task.h: Trim dependencies
Split out irqflags_types.h
ipc: Kill bogus dependency on spinlock.h
shm: Slim down dependencies
workqueue: Split out workqueue_types.h
...
- btree write buffer rewrite: instead of adding keys to the btree write
buffer at transaction commit time, we know journal them with a
different journal entry type and copy them from the journal to the
write buffer just prior to journal write.
This reduces the number of atomic operations on shared cachelines
in the transaction commit path and is a signicant performance
improvement on some workloads: multithreaded 4k random writes went
from ~650k iops to ~850k iops.
- Bring back optimistic spinning for six locks: the new implementation
doesn't use osq locks; instead we add to the lock waitlist as normal,
and then spin on the lock_acquired bit in the waitlist entry, _not_
the lock itself.
- BCH_IOCTL_DEV_USAGE_V2, which allows for new data types
- BCH_IOCTL_OFFLINE_FSCK, which runs the kernel implementation of fsck
but without mounting: useful for transparently using the kernel
version of fsck from 'bcachefs fsck' when the kernel version is a
better match for the on disk filesystem.
- BCH_IOCTL_ONLINE_FSCK: online fsck. Not all passes are supported yet,
but the passes that are supported are fully featured - errors may be
corrected as normal.
The new ioctls use the new 'thread_with_file' abstraction for kicking
off a kthread that's tied to a file descriptor returned to userspace
via the ioctl.
- btree_paths within a btree_trans are now dynamically growable,
instead of being limited to 64. This is important for the
check_directory_structure phase of fsck, and also fixes some issues
we were having with btree path overflow in the reflink btree.
- Trigger refactoring; prep work for the upcoming disk space accounting
rewrite
- Numerous bugfixes :)
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Merge tag 'bcachefs-2024-01-10' of https://evilpiepirate.org/git/bcachefs
Pull bcachefs updates from Kent Overstreet:
- btree write buffer rewrite: instead of adding keys to the btree write
buffer at transaction commit time, we now journal them with a
different journal entry type and copy them from the journal to the
write buffer just prior to journal write.
This reduces the number of atomic operations on shared cachelines in
the transaction commit path and is a signicant performance
improvement on some workloads: multithreaded 4k random writes went
from ~650k iops to ~850k iops.
- Bring back optimistic spinning for six locks: the new implementation
doesn't use osq locks; instead we add to the lock waitlist as normal,
and then spin on the lock_acquired bit in the waitlist entry, _not_
the lock itself.
- New ioctls:
- BCH_IOCTL_DEV_USAGE_V2, which allows for new data types
- BCH_IOCTL_OFFLINE_FSCK, which runs the kernel implementation of
fsck but without mounting: useful for transparently using the
kernel version of fsck from 'bcachefs fsck' when the kernel
version is a better match for the on disk filesystem.
- BCH_IOCTL_ONLINE_FSCK: online fsck. Not all passes are supported
yet, but the passes that are supported are fully featured - errors
may be corrected as normal.
The new ioctls use the new 'thread_with_file' abstraction for kicking
off a kthread that's tied to a file descriptor returned to userspace
via the ioctl.
- btree_paths within a btree_trans are now dynamically growable,
instead of being limited to 64. This is important for the
check_directory_structure phase of fsck, and also fixes some issues
we were having with btree path overflow in the reflink btree.
- Trigger refactoring; prep work for the upcoming disk space accounting
rewrite
- Numerous bugfixes :)
* tag 'bcachefs-2024-01-10' of https://evilpiepirate.org/git/bcachefs: (226 commits)
bcachefs: eytzinger0_find() search should be const
bcachefs: move "ptrs not changing" optimization to bch2_trigger_extent()
bcachefs: fix simulateously upgrading & downgrading
bcachefs: Restart recovery passes more reliably
bcachefs: bch2_dump_bset() doesn't choke on u64s == 0
bcachefs: improve checksum error messages
bcachefs: improve validate_bset_keys()
bcachefs: print sb magic when relevant
bcachefs: __bch2_sb_field_to_text()
bcachefs: %pg is banished
bcachefs: Improve would_deadlock trace event
bcachefs: fsck_err()s don't need to manually check c->sb.version anymore
bcachefs: Upgrades now specify errors to fix, like downgrades
bcachefs: no thread_with_file in userspace
bcachefs: Don't autofix errors we can't fix
bcachefs: add missing bch2_latency_acct() call
bcachefs: increase max_active on io_complete_wq
bcachefs: add time_stats for btree_node_read_done()
bcachefs: don't clear accessed bit in btree node fill
bcachefs: Add an option to control btree node prefetching
...
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Merge tag 'lsm-pr-20240105' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm
Pull security module updates from Paul Moore:
- Add three new syscalls: lsm_list_modules(), lsm_get_self_attr(), and
lsm_set_self_attr().
The first syscall simply lists the LSMs enabled, while the second and
third get and set the current process' LSM attributes. Yes, these
syscalls may provide similar functionality to what can be found under
/proc or /sys, but they were designed to support multiple,
simultaneaous (stacked) LSMs from the start as opposed to the current
/proc based solutions which were created at a time when only one LSM
was allowed to be active at a given time.
We have spent considerable time discussing ways to extend the
existing /proc interfaces to support multiple, simultaneaous LSMs and
even our best ideas have been far too ugly to support as a kernel
API; after +20 years in the kernel, I felt the LSM layer had
established itself enough to justify a handful of syscalls.
Support amongst the individual LSM developers has been nearly
unanimous, with a single objection coming from Tetsuo (TOMOYO) as he
is worried that the LSM_ID_XXX token concept will make it more
difficult for out-of-tree LSMs to survive. Several members of the LSM
community have demonstrated the ability for out-of-tree LSMs to
continue to exist by picking high/unused LSM_ID values as well as
pointing out that many kernel APIs rely on integer identifiers, e.g.
syscalls (!), but unfortunately Tetsuo's objections remain.
My personal opinion is that while I have no interest in penalizing
out-of-tree LSMs, I'm not going to penalize in-tree development to
support out-of-tree development, and I view this as a necessary step
forward to support the push for expanded LSM stacking and reduce our
reliance on /proc and /sys which has occassionally been problematic
for some container users. Finally, we have included the linux-api
folks on (all?) recent revisions of the patchset and addressed all of
their concerns.
- Add a new security_file_ioctl_compat() LSM hook to handle the 32-bit
ioctls on 64-bit systems problem.
This patch includes support for all of the existing LSMs which
provide ioctl hooks, although it turns out only SELinux actually
cares about the individual ioctls. It is worth noting that while
Casey (Smack) and Tetsuo (TOMOYO) did not give explicit ACKs to this
patch, they did both indicate they are okay with the changes.
- Fix a potential memory leak in the CALIPSO code when IPv6 is disabled
at boot.
While it's good that we are fixing this, I doubt this is something
users are seeing in the wild as you need to both disable IPv6 and
then attempt to configure IPv6 labeled networking via
NetLabel/CALIPSO; that just doesn't make much sense.
Normally this would go through netdev, but Jakub asked me to take
this patch and of all the trees I maintain, the LSM tree seemed like
the best fit.
- Update the LSM MAINTAINERS entry with additional information about
our process docs, patchwork, bug reporting, etc.
I also noticed that the Lockdown LSM is missing a dedicated
MAINTAINERS entry so I've added that to the pull request. I've been
working with one of the major Lockdown authors/contributors to see if
they are willing to step up and assume a Lockdown maintainer role;
hopefully that will happen soon, but in the meantime I'll continue to
look after it.
- Add a handful of mailmap entries for Serge Hallyn and myself.
* tag 'lsm-pr-20240105' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm: (27 commits)
lsm: new security_file_ioctl_compat() hook
lsm: Add a __counted_by() annotation to lsm_ctx.ctx
calipso: fix memory leak in netlbl_calipso_add_pass()
selftests: remove the LSM_ID_IMA check in lsm/lsm_list_modules_test
MAINTAINERS: add an entry for the lockdown LSM
MAINTAINERS: update the LSM entry
mailmap: add entries for Serge Hallyn's dead accounts
mailmap: update/replace my old email addresses
lsm: mark the lsm_id variables are marked as static
lsm: convert security_setselfattr() to use memdup_user()
lsm: align based on pointer length in lsm_fill_user_ctx()
lsm: consolidate buffer size handling into lsm_fill_user_ctx()
lsm: correct error codes in security_getselfattr()
lsm: cleanup the size counters in security_getselfattr()
lsm: don't yet account for IMA in LSM_CONFIG_COUNT calculation
lsm: drop LSM_ID_IMA
LSM: selftests for Linux Security Module syscalls
SELinux: Add selfattr hooks
AppArmor: Add selfattr hooks
Smack: implement setselfattr and getselfattr hooks
...
- Add initial support to recognise the HeXin C2000 processor.
- Add papr-vpd and papr-sysparm character device drivers for VPD & sysparm
retrieval, so userspace tools can be adapted to avoid doing raw firmware
calls from userspace.
- Sched domains optimisations for shared processor partitions on P9/P10.
- A series of optimisations for KVM running as a nested HV under PowerVM.
- Other small features and fixes.
Thanks to: Aditya Gupta, Aneesh Kumar K.V, Arnd Bergmann, Christophe Leroy,
Colin Ian King, Dario Binacchi, David Heidelberg, Geoff Levand, Gustavo A.
R. Silva, Haoran Liu, Jordan Niethe, Kajol Jain, Kevin Hao, Kunwu Chan, Li
kunyu, Li zeming, Masahiro Yamada, Michal Suchánek, Nathan Lynch, Naveen N Rao,
Nicholas Piggin, Randy Dunlap, Sathvika Vasireddy, Srikar Dronamraju, Stephen
Rothwell, Vaibhav Jain, Zhao Ke.
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Merge tag 'powerpc-6.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:
- Add initial support to recognise the HeXin C2000 processor.
- Add papr-vpd and papr-sysparm character device drivers for VPD &
sysparm retrieval, so userspace tools can be adapted to avoid doing
raw firmware calls from userspace.
- Sched domains optimisations for shared processor partitions on
P9/P10.
- A series of optimisations for KVM running as a nested HV under
PowerVM.
- Other small features and fixes.
Thanks to Aditya Gupta, Aneesh Kumar K.V, Arnd Bergmann, Christophe
Leroy, Colin Ian King, Dario Binacchi, David Heidelberg, Geoff Levand,
Gustavo A. R. Silva, Haoran Liu, Jordan Niethe, Kajol Jain, Kevin Hao,
Kunwu Chan, Li kunyu, Li zeming, Masahiro Yamada, Michal Suchánek,
Nathan Lynch, Naveen N Rao, Nicholas Piggin, Randy Dunlap, Sathvika
Vasireddy, Srikar Dronamraju, Stephen Rothwell, Vaibhav Jain, and
Zhao Ke.
* tag 'powerpc-6.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (96 commits)
powerpc/ps3_defconfig: Disable PPC64_BIG_ENDIAN_ELF_ABI_V2
powerpc/86xx: Drop unused CONFIG_MPC8610
powerpc/powernv: Add error handling to opal_prd_range_is_valid
selftests/powerpc: Fix spelling mistake "EACCESS" -> "EACCES"
powerpc/hvcall: Reorder Nestedv2 hcall opcodes
powerpc/ps3: Add missing set_freezable() for ps3_probe_thread()
powerpc/mpc83xx: Use wait_event_freezable() for freezable kthread
powerpc/mpc83xx: Add the missing set_freezable() for agent_thread_fn()
powerpc/fsl: Fix fsl,tmu-calibration to match the schema
powerpc/smp: Dynamically build Powerpc topology
powerpc/smp: Avoid asym packing within thread_group of a core
powerpc/smp: Add __ro_after_init attribute
powerpc/smp: Disable MC domain for shared processor
powerpc/smp: Enable Asym packing for cores on shared processor
powerpc/sched: Cleanup vcpu_is_preempted()
powerpc: add cpu_spec.cpu_features to vmcoreinfo
powerpc/imc-pmu: Add a null pointer check in update_events_in_group()
powerpc/powernv: Add a null pointer check in opal_powercap_init()
powerpc/powernv: Add a null pointer check in opal_event_init()
powerpc/powernv: Add a null pointer check to scom_debug_init_one()
...
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Merge tag 'vfs-6.8.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs mount updates from Christian Brauner:
"This contains the work to retrieve detailed information about mounts
via two new system calls. This is hopefully the beginning of the end
of the saga that started with fsinfo() years ago.
The LWN articles in [1] and [2] can serve as a summary so we can avoid
rehashing everything here.
At LSFMM in May 2022 we got into a room and agreed on what we want to
do about fsinfo(). Basically, split it into pieces. This is the first
part of that agreement. Specifically, it is concerned with retrieving
information about mounts. So this only concerns the mount information
retrieval, not the mount table change notification, or the extended
filesystem specific mount option work. That is separate work.
Currently mounts have a 32bit id. Mount ids are already in heavy use
by libmount and other low-level userspace but they can't be relied
upon because they're recycled very quickly. We agreed that mounts
should carry a unique 64bit id by which they can be referenced
directly. This is now implemented as part of this work.
The new 64bit mount id is exposed in statx() through the new
STATX_MNT_ID_UNIQUE flag. If the flag isn't raised the old mount id is
returned. If it is raised and the kernel supports the new 64bit mount
id the flag is raised in the result mask and the new 64bit mount id is
returned. New and old mount ids do not overlap so they cannot be
conflated.
Two new system calls are introduced that operate on the 64bit mount
id: statmount() and listmount(). A summary of the api and usage can be
found on LWN as well (cf. [3]) but of course, I'll provide a summary
here as well.
Both system calls rely on struct mnt_id_req. Which is the request
struct used to pass the 64bit mount id identifying the mount to
operate on. It is extensible to allow for the addition of new
parameters and for future use in other apis that make use of mount
ids.
statmount() mimicks the semantics of statx() and exposes a set flags
that userspace may raise in mnt_id_req to request specific information
to be retrieved. A statmount() call returns a struct statmount filled
in with information about the requested mount. Supported requests are
indicated by raising the request flag passed in struct mnt_id_req in
the @mask argument in struct statmount.
Currently we do support:
- STATMOUNT_SB_BASIC:
Basic filesystem info
- STATMOUNT_MNT_BASIC
Mount information (mount id, parent mount id, mount attributes etc)
- STATMOUNT_PROPAGATE_FROM
Propagation from what mount in current namespace
- STATMOUNT_MNT_ROOT
Path of the root of the mount (e.g., mount --bind /bla /mnt returns /bla)
- STATMOUNT_MNT_POINT
Path of the mount point (e.g., mount --bind /bla /mnt returns /mnt)
- STATMOUNT_FS_TYPE
Name of the filesystem type as the magic number isn't enough due to submounts
The string options STATMOUNT_MNT_{ROOT,POINT} and STATMOUNT_FS_TYPE
are appended to the end of the struct. Userspace can use the offsets
in @fs_type, @mnt_root, and @mnt_point to reference those strings
easily.
The struct statmount reserves quite a bit of space currently for
future extensibility. This isn't really a problem and if this bothers
us we can just send a follow-up pull request during this cycle.
listmount() is given a 64bit mount id via mnt_id_req just as
statmount(). It takes a buffer and a size to return an array of the
64bit ids of the child mounts of the requested mount. Userspace can
thus choose to either retrieve child mounts for a mount in batches or
iterate through the child mounts. For most use-cases it will be
sufficient to just leave space for a few child mounts. But for big
mount tables having an iterator is really helpful. Iterating through a
mount table works by setting @param in mnt_id_req to the mount id of
the last child mount retrieved in the previous listmount() call"
Link: https://lwn.net/Articles/934469 [1]
Link: https://lwn.net/Articles/829212 [2]
Link: https://lwn.net/Articles/950569 [3]
* tag 'vfs-6.8.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
add selftest for statmount/listmount
fs: keep struct mnt_id_req extensible
wire up syscalls for statmount/listmount
add listmount(2) syscall
statmount: simplify string option retrieval
statmount: simplify numeric option retrieval
add statmount(2) syscall
namespace: extract show_path() helper
mounts: keep list of mounts in an rbtree
add unique mount ID
bcachefs's six locks need kvm_guest, via
ower_on_cpu() -> vcpu_is_preempted() -> is_kvm_guest()
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Cc: linuxppc-dev@lists.ozlabs.org
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
We're trying to get sched.h down to more or less just types only, not
code - rseq can live in its own header.
This helps us kill the dependency on preempt.h in sched.h.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Merge a branch containing SMP topology updates from Srikar, purely so we can
include the cover letter which has a lot of good detail here:
PowerVM systems configured in shared processors mode have some unique
challenges. Some device-tree properties will be missing on a shared
processor. Hence some sched domains may not make sense for shared processor
systems.
Most shared processor systems are over-provisioned. Underlying PowerVM
Hypervisor would schedule at a Big Core (SMT8) granularity. The most recent
power processors support two almost independent cores. In a lightly loaded
condition, it helps the overall system performance if we pack to lesser number
of Big Cores.
Since each thread-group is independent, running threads on both the
thread-groups of a SMT8 core, should have a minimal adverse impact in
non over provisioned scenarios. These changes in this patchset will not
affect in the over provisioned scenario. If there are more threads than
SMT domains, then asym_packing will not kick-in.
System Configuration
type=Shared mode=Uncapped smt=8 lcpu=96 mem=1066409344 kB cpus=96 ent=64.00
So *64 Entitled cores/ 96 Virtual processor* Scenario
lscpu
Architecture: ppc64le
Byte Order: Little Endian
CPU(s): 768
On-line CPU(s) list: 0-767
Model name: POWER10 (architected), altivec supported
Model: 2.0 (pvr 0080 0200)
Thread(s) per core: 8
Core(s) per socket: 16
Socket(s): 6
Hypervisor vendor: pHyp
Virtualization type: para
L1d cache: 6 MiB (192 instances)
L1i cache: 9 MiB (192 instances)
NUMA node(s): 6
NUMA node0 CPU(s): 0-7,32-39,80-87,128-135,176-183,224-231,272-279,320-327,368-375,416-423,464-471,512-519,560-567,608-615,656-663,704-711,752-759
NUMA node1 CPU(s): 8-15,40-47,88-95,136-143,184-191,232-239,280-287,328-335,376-383,424-431,472-479,520-527,568-575,616-623,664-671,712-719,760-767
NUMA node4 CPU(s): 64-71,112-119,160-167,208-215,256-263,304-311,352-359,400-407,448-455,496-503,544-551,592-599,640-647,688-695,736-743
NUMA node5 CPU(s): 16-23,48-55,96-103,144-151,192-199,240-247,288-295,336-343,384-391,432-439,480-487,528-535,576-583,624-631,672-679,720-727
NUMA node6 CPU(s): 72-79,120-127,168-175,216-223,264-271,312-319,360-367,408-415,456-463,504-511,552-559,600-607,648-655,696-703,744-751
NUMA node7 CPU(s): 24-31,56-63,104-111,152-159,200-207,248-255,296-303,344-351,392-399,440-447,488-495,536-543,584-591,632-639,680-687,728-735
ebizzy -t 32 -S 200 (5 iterations) Records per second. (Higher is better)
Kernel N Min Max Median Avg Stddev %Change
6.6.0-rc3 5 3840178 4059268 3978042 3973936.6 84264.456
+patch 5 3768393 3927901 3874994 3854046 71532.926 -3.01692
>From lparstat (when the workload stabilized)
Kernel %user %sys %wait %idle physc %entc lbusy app vcsw phint
6.6.0-rc3 4.16 0.00 0.00 95.84 26.06 40.72 4.16 69.88 276906989 578
+patch 4.16 0.00 0.00 95.83 17.70 27.66 4.17 78.26 70436663 119
ebizzy -t 128 -S 200 (5 iterations) Records per second. (Higher is better)
Kernel N Min Max Median Avg Stddev %Change
6.6.0-rc3 5 5520692 5981856 5717709 5727053.2 176093.2
+patch 5 5305888 6259610 5854590 5843311 375917.03 2.02998
>From lparstat (when the workload stabilized)
Kernel %user %sys %wait %idle physc %entc lbusy app vcsw phint
6.6.0-rc3 16.66 0.00 0.00 83.33 45.49 71.08 16.67 50.50 288778533 581
+patch 16.65 0.00 0.00 83.35 30.15 47.11 16.65 65.76 85196150 133
ebizzy -t 512 -S 200 (5 iterations) Records per second. (Higher is better)
Kernel N Min Max Median Avg Stddev %Change
6.6.0-rc3 5 19563921 20049955 19701510 19728733 198295.18
+patch 5 19455992 20176445 19718427 19832017 304094.05 0.523521
>From lparstat (when the workload stabilized)
%Kernel user %sys %wait %idle physc %entc lbusy app vcsw phint
66.6.0-rc3 6.44 0.01 0.00 33.55 94.14 147.09 66.45 1.33 313345175 621
6+patch 6.44 0.01 0.00 33.55 94.15 147.11 66.45 1.33 109193889 309
System Configuration
type=Shared mode=Uncapped smt=8 lcpu=40 mem=1067539392 kB cpus=96 ent=40.00
So *40 Entitled cores/ 40 Virtual processor* Scenario
lscpu
Architecture: ppc64le
Byte Order: Little Endian
CPU(s): 320
On-line CPU(s) list: 0-319
Model name: POWER10 (architected), altivec supported
Model: 2.0 (pvr 0080 0200)
Thread(s) per core: 8
Core(s) per socket: 10
Socket(s): 4
Hypervisor vendor: pHyp
Virtualization type: para
L1d cache: 2.5 MiB (80 instances)
L1i cache: 3.8 MiB (80 instances)
NUMA node(s): 4
NUMA node0 CPU(s): 0-7,32-39,64-71,96-103,128-135,160-167,192-199,224-231,256-263,288-295
NUMA node1 CPU(s): 8-15,40-47,72-79,104-111,136-143,168-175,200-207,232-239,264-271,296-303
NUMA node4 CPU(s): 16-23,48-55,80-87,112-119,144-151,176-183,208-215,240-247,272-279,304-311
NUMA node5 CPU(s): 24-31,56-63,88-95,120-127,152-159,184-191,216-223,248-255,280-287,312-319
ebizzy -t 32 -S 200 (5 iterations) Records per second. (Higher is better)
Kernel N Min Max Median Avg Stddev %Change
6.6.0-rc3 5 3535518 3864532 3745967 3704233.2 130216.76
+patch 5 3608385 3708026 3649379 3651596.6 37862.163 -1.42099
%Kernel user %sys %wait %idle physc %entc lbusy app vcsw phint
6.6.0-rc3 10.00 0.01 0.00 89.99 22.98 57.45 10.01 41.01 1135139 262
+patch 10.00 0.00 0.00 90.00 16.95 42.37 10.00 47.05 925561 19
ebizzy -t 64 -S 200 (5 iterations) Records per second. (Higher is better)
Kernel N Min Max Median Avg Stddev %Change
6.6.0-rc3 5 4434984 4957281 4548786 4591298.2 211770.2
+patch 5 4461115 4835167 4544716 4607795.8 151474.85 0.359323
%Kernel user %sys %wait %idle physc %entc lbusy app vcsw phint
6.6.0-rc3 20.01 0.00 0.00 79.99 38.22 95.55 20.01 25.77 1287553 265
+patch 19.99 0.00 0.00 80.01 25.55 63.88 19.99 38.44 1077341 20
ebizzy -t 256 -S 200 (5 iterations) Records per second. (Higher is better)
Kernel N Min Max Median Avg Stddev %Change
6.6.0-rc3 5 8850648 8982659 8951911 8936869.2 52278.031
+patch 5 8751038 9060510 8981409 8942268.4 117070.6 0.0604149
%Kernel user %sys %wait %idle physc %entc lbusy app vcsw phint
6.6.0-rc3 80.02 0.01 0.01 19.96 40.00 100.00 80.03 24.00 1597665 276
+patch 80.02 0.01 0.01 19.96 40.00 100.00 80.03 23.99 1383921 63
Observation:
We are able to see Improvement in ebizzy throughput even with lesser
core utilization (almost half the core utilization) in low utilization
scenarios while still retaining throughput in mid and higher utilization
scenarios.
Note: The numbers are with Uncapped + no-noise case. In the Capped and/or
noise case, due to contention on the Cores, the numbers are expected to
further improve.
Note: The numbers included (sched/fair: Enable group_asym_packing in find_idlest_group)
https://lore.kernel.org/all/20231018155036.2314342-1-srikar@linux.vnet.ibm.com/
Currently there are four Powerpc specific sched topologies. These are
all statically defined. However not all these topologies are used by
all Powerpc systems.
To avoid unnecessary degenerations by the scheduler, masks and flags
are compared. However if the sched topologies are build dynamically then
the code is simpler and there are greater chances of avoiding
degenerations.
Note:
Even X86 builds its sched topologies dynamically and proposed changes
are very similar to the way X86 is building its topologies.
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231214180720.310852-6-srikar@linux.vnet.ibm.com
PowerVM Hypervisor will schedule at a core granularity. However each
core can have more than one thread_groups. For better utilization in
case of a shared processor, its preferable for the scheduler to pack to
the lowest core. However there is no benefit of moving a thread between
two thread groups of the same core.
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231214180720.310852-5-srikar@linux.vnet.ibm.com
There are some variables that are only updated at boot time.
So add __ro_after_init attribute to such variables
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231214180720.310852-4-srikar@linux.vnet.ibm.com
Like L2-cache info, coregroup information which is used to determine MC
sched domains is only present on dedicated LPARs. i.e PowerVM doesn't
export coregroup information for shared processor LPARs. Hence disable
creating MC domains on shared LPAR Systems.
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231214180720.310852-3-srikar@linux.vnet.ibm.com
If there are shared processor LPARs, underlying Hypervisor can have more
virtual cores to handle than actual physical cores.
Starting with Power 9, a big core (aka SMT8 core) has 2 nearly
independent thread groups. On a shared processors LPARs, it helps to
pack threads to lesser number of cores so that the overall system
performance and utilization improves. PowerVM schedules at a big core
level. Hence packing to fewer cores helps.
Since each thread-group is independent, running threads on both the
thread-groups of a SMT8 core, should have a minimal adverse impact in
non over provisioned scenarios. These changes in this patchset will not
affect in the over provisioned scenario. If there are more threads than
SMT domains, then asym_packing will not kick-in
For example: Lets says there are two 8-core Shared LPARs that are
actually sharing a 8 Core shared physical pool, each running 8 threads
each. Then Consolidating 8 threads to 4 cores on each LPAR would help
them to perform better. This is because each of the LPAR will get
100% time to run applications and there will no switching required by
the Hypervisor.
To achieve this, enable SD_ASYM_PACKING flag at CACHE, MC and DIE level
when the system is running in shared processor mode and has big cores.
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231214180720.310852-2-srikar@linux.vnet.ibm.com
If the function descriptor has a populated lock member, then callers
are required to hold it across calls. Now that the firmware activation
sequence is appropriately guarded, we can warn when the requirement
isn't satisfied.
__do_enter_rtas_trace() gets reorganized a bit as a result of
performing the function descriptor lookup unconditionally now.
Reviewed-by: "Aneesh Kumar K.V (IBM)" <aneesh.kumar@kernel.org>
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231212-papr-sys_rtas-vs-lockdown-v6-8-e9eafd0c8c6c@linux.ibm.com
Use rtas_ibm_activate_firmware_lock to prevent interleaving call
sequences of the ibm,activate-firmware RTAS function, which typically
requires multiple calls to complete the update. While the spec does
not specifically prohibit interleaved sequences, there's almost
certainly no advantage to allowing them.
Reviewed-by: "Aneesh Kumar K.V (IBM)" <aneesh.kumar@kernel.org>
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231212-papr-sys_rtas-vs-lockdown-v6-7-e9eafd0c8c6c@linux.ibm.com
On RTAS platforms there is a general restriction that the OS must not
enter RTAS on more than one CPU at a time. This low-level
serialization requirement is satisfied by holding a spin
lock (rtas_lock) across most RTAS function invocations.
However, some pseries RTAS functions require multiple successive calls
to complete a logical operation. Beginning a new call sequence for such a
function may disrupt any other sequences of that function already in
progress. Safe and reliable use of these functions effectively
requires higher-level serialization beyond what is already done at the
level of RTAS entry and exit.
Where a sequence-based RTAS function is invoked only through
sys_rtas(), with no in-kernel users, there is no issue as far as the
kernel is concerned. User space is responsible for appropriately
serializing its call sequences. (Whether user space code actually
takes measures to prevent sequence interleaving is another matter.)
Examples of such functions currently include ibm,platform-dump and
ibm,get-vpd.
But where a sequence-based RTAS function has both user space and
in-kernel uesrs, there is a hazard. Even if the in-kernel call sites
of such a function serialize their sequences correctly, a user of
sys_rtas() can invoke the same function at any time, potentially
disrupting a sequence in progress.
So in order to prevent disruption of kernel-based RTAS call sequences,
they must serialize not only with themselves but also with sys_rtas()
users, somehow. Preferably without adding more function-specific hacks
to sys_rtas(). This is a prerequisite for adding an in-kernel call
sequence of ibm,get-vpd, which is in a change to follow.
Note that it has never been feasible for the kernel to prevent
sys_rtas()-based sequences from being disrupted because control
returns to user space on every call. sys_rtas()-based users of these
functions have always been, and continue to be, responsible for
coordinating their call sequences with other users, even those which
may invoke the RTAS functions through less direct means than
sys_rtas(). This is an unavoidable consequence of exposing
sequence-based RTAS functions through sys_rtas().
* Add an optional mutex member to struct rtas_function.
* Statically define a mutex for each RTAS function with known call
sequence serialization requirements, and assign its address to the
.lock member of the corresponding function table entry, along with
justifying commentary.
* In sys_rtas(), if the table entry for the RTAS function being
called has a populated lock member, acquire it before taking
rtas_lock and entering RTAS.
* Kernel-based RTAS call sequences are expected to access the
appropriate mutex explicitly by name. For example, a user of the
ibm,activate-firmware RTAS function would do:
int token = rtas_function_token(RTAS_FN_IBM_ACTIVATE_FIRMWARE);
int fwrc;
mutex_lock(&rtas_ibm_activate_firmware_lock);
do {
fwrc = rtas_call(token, 0, 1, NULL);
} while (rtas_busy_delay(fwrc));
mutex_unlock(&rtas_ibm_activate_firmware_lock);
There should be no perceivable change introduced here except that
concurrent callers of the same RTAS function via sys_rtas() may block
on a mutex instead of spinning on rtas_lock.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231212-papr-sys_rtas-vs-lockdown-v6-6-e9eafd0c8c6c@linux.ibm.com
