- 11 Oct, 2016 4 commits
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Paul Mackerras authored
Debugging a data corruption issue with virtio-net/vhost-net led to the observation that __copy_tofrom_user was occasionally returning a value 16 larger than it should. Since the return value from __copy_tofrom_user is the number of bytes not copied, this means that __copy_tofrom_user can occasionally return a value larger than the number of bytes it was asked to copy. In turn this can cause higher-level copy functions such as copy_page_to_iter_iovec to corrupt memory by copying data into the wrong memory locations. It turns out that the failing case involves a fault on the store at label 79, and at that point the first unmodified byte of the destination is at R3 + 16. Consequently the exception handler for that store needs to add 16 to R3 before using it to work out how many bytes were not copied, but in this one case it was not adding the offset to R3. To fix it, this moves the label 179 to the point where we add 16 to R3. I have checked manually all the exception handlers for the loads and stores in this code and the rest of them are correct (it would be excellent to have an automated test of all the exception cases). This bug has been present since this code was initially committed in May 2002 to Linux version 2.5.20. Cc: stable@vger.kernel.org Signed-off-by:
Paul Mackerras <paulus@ozlabs.org> Signed-off-by:
Michael Ellerman <mpe@ellerman.id.au>
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Nicholas Piggin authored
power4_fixup_nap is called from the "common" handlers, not the virt/real handlers, therefore it should itself be a common handler. Placing it down in the trampoline space caused it to go out of reach of its callers, requiring a trampoline inserted at the start of the text section, which breaks the fixed section address calculations. Fixes: da2bc464 ("powerpc/64s: Add new exception vector macros") Reported-by:
Guenter Roeck <linux@roeck-us.net> Signed-off-by:
Nicholas Piggin <npiggin@gmail.com> Signed-off-by:
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Laurent Dufour authored
This commit fixes a stack corruption in the pseries specific code dealing with the huge pages. In __pSeries_lpar_hugepage_invalidate() the buffer used to pass arguments to the hypervisor is not large enough. This leads to a stack corruption where a previously saved register could be corrupted leading to unexpected result in the caller, like the following panic: Oops: Kernel access of bad area, sig: 11 [#1] SMP NR_CPUS=2048 NUMA pSeries Modules linked in: virtio_balloon ip_tables x_tables autofs4 virtio_blk 8139too virtio_pci virtio_ring 8139cp virtio CPU: 11 PID: 1916 Comm: mmstress Not tainted 4.8.0 #76 task: c000000005394880 task.stack: c000000005570000 NIP: c00000000027bf6c LR: c00000000027bf64 CTR: 0000000000000000 REGS: c000000005573820 TRAP: 0300 Not tainted (4.8.0) MSR: 8000000000009033 <SF,EE,ME,IR,DR,RI,LE> CR: 84822884 XER: 20000000 CFAR: c00000000010a924 DAR: 420000000014e5e0 DSISR: 40000000 SOFTE: 1 GPR00: c00000000027bf64 c000000005573aa0 c000000000e02800 c000000004447964 GPR04: c00000000404de18 c000000004d38810 00000000042100f5 00000000f5002104 GPR08: e0000000f5002104 0000000000000001 042100f5000000e0 00000000042100f5 GPR12: 0000000000002200 c00000000fe02c00 c00000000404de18 0000000000000000 GPR16: c1ffffffffffe7ff 00003fff62000000 420000000014e5e0 00003fff63000000 GPR20: 0008000000000000 c0000000f7014800 0405e600000000e0 0000000000010000 GPR24: c000000004d38810 c000000004447c10 c00000000404de18 c000000004447964 GPR28: c000000005573b10 c000000004d38810 00003fff62000000 420000000014e5e0 NIP [c00000000027bf6c] zap_huge_pmd+0x4c/0x470 LR [c00000000027bf64] zap_huge_pmd+0x44/0x470 Call Trace: [c000000005573aa0] [c00000000027bf64] zap_huge_pmd+0x44/0x470 (unreliable) [c000000005573af0] [c00000000022bbd8] unmap_page_range+0xcf8/0xed0 [c000000005573c30] [c00000000022c2d4] unmap_vmas+0x84/0x120 [c000000005573c80] [c000000000235448] unmap_region+0xd8/0x1b0 [c000000005573d80] [c0000000002378f0] do_munmap+0x2d0/0x4c0 [c000000005573df0] [c000000000237be4] SyS_munmap+0x64/0xb0 [c000000005573e30] [c000000000009560] system_call+0x38/0x108 Instruction dump: fbe1fff8 fb81ffe0 7c7f1b78 7ca32b78 7cbd2b78 f8010010 7c9a2378 f821ffb1 7cde3378 4bfffea9 7c7b1b79 41820298 <e87f0000> 48000130 7fa5eb78 7fc4f378 Most of the time, the bug is surfacing in a caller up in the stack from __pSeries_lpar_hugepage_invalidate() which is quite confusing. This bug is pending since v3.11 but was hidden if a caller of the caller of __pSeries_lpar_hugepage_invalidate() has pushed the corruped register (r18 in this case) in the stack and is not using it until restoring it. GCC 6.2.0 seems to raise it more frequently. This commit also change the definition of the parameter buffer in pSeries_lpar_flush_hash_range() to rely on the global define PLPAR_HCALL9_BUFSIZE (no functional change here). Fixes: 1a527286 ("powerpc: Optimize hugepage invalidate") Cc: stable@vger.kernel.org # v3.11+ Signed-off-by:
Laurent Dufour <ldufour@linux.vnet.ibm.com> Reviewed-by:
Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by:
Balbir Singh <bsingharora@gmail.com> Signed-off-by:
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git://git.kernel.org/pub/scm/linux/kernel/git/scottwood/linuxMichael Ellerman authored
Freescale updates from Scott: "Highlights include qbman support (a prerequisite for datapath drivers such as ethernet), a PCI DMA fix+improvement, reset handler changes, more 8xx optimizations, and some cleanups and fixes."
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- 06 Oct, 2016 5 commits
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Michael Ellerman authored
The changes to make EXPORT_SYMBOL work in asm, specifically commit 9445aa1a ("ppc: move exports to definitions"), in the kbuild tree, breaks some of our selftests. That is because we symlink the kernel code into the selftest, and shim the required headers, and we are now missing asm/export.h So create a minimal export.h to keep the tests building once powerpc and the kbuild trees are merged. Signed-off-by:
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Michael Ellerman authored
The selftests under tools/testing/selftests/powerpc are maintained by us, so add a file pattern for them. Also drop the www.penguinppc.org link, it's not dead, but the site is dead (database error). Instead link to the wiki attached to our github, there is some info there which may be useful, which is better than none. Signed-off-by: -
Michael Ellerman authored
Paul is no longer acting as a separate maintainer for pseries, it is handled along with the rest of powerpc. The URL no longer links anywhere meaningful, so drop it also. Signed-off-by:
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Olof Johansson authored
The platform is old, very few users and I lack bandwidth to keep after it these days. Mark the base platform as well as the drivers as orphans, patches have been flowing through the fallback maintainers for a while already. Signed-off-by:
Olof Johansson <olof@lixom.net> Acked-by:
Wolfram Sang <wsa@the-dreams.de> Signed-off-by:
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Michael Ellerman authored
Some of the recent new selftests were missing additions to .gitignore, add them now. Signed-off-by:
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- 04 Oct, 2016 31 commits
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Naveen N. Rao authored
In line with similar support for other architectures by Daniel Borkmann. 'MOD Default X' from test_bpf without constant blinding: 84 bytes emitted from JIT compiler (pass:3, flen:7) d0000000058a4688 + <x>: 0: nop 4: nop 8: std r27,-40(r1) c: std r28,-32(r1) 10: xor r8,r8,r8 14: xor r28,r28,r28 18: mr r27,r3 1c: li r8,66 20: cmpwi r28,0 24: bne 0x0000000000000030 28: li r8,0 2c: b 0x0000000000000044 30: divwu r9,r8,r28 34: mullw r9,r28,r9 38: subf r8,r9,r8 3c: rotlwi r8,r8,0 40: li r8,66 44: ld r27,-40(r1) 48: ld r28,-32(r1) 4c: mr r3,r8 50: blr ... and with constant blinding: 140 bytes emitted from JIT compiler (pass:3, flen:11) d00000000bd6ab24 + <x>: 0: nop 4: nop 8: std r27,-40(r1) c: std r28,-32(r1) 10: xor r8,r8,r8 14: xor r28,r28,r28 18: mr r27,r3 1c: lis r2,-22834 20: ori r2,r2,36083 24: rotlwi r2,r2,0 28: xori r2,r2,36017 2c: xoris r2,r2,42702 30: rotlwi r2,r2,0 34: mr r8,r2 38: rotlwi r8,r8,0 3c: cmpwi r28,0 40: bne 0x000000000000004c 44: li r8,0 48: b 0x000000000000007c 4c: divwu r9,r8,r28 50: mullw r9,r28,r9 54: subf r8,r9,r8 58: rotlwi r8,r8,0 5c: lis r2,-17137 60: ori r2,r2,39065 64: rotlwi r2,r2,0 68: xori r2,r2,39131 6c: xoris r2,r2,48399 70: rotlwi r2,r2,0 74: mr r8,r2 78: rotlwi r8,r8,0 7c: ld r27,-40(r1) 80: ld r28,-32(r1) 84: mr r3,r8 88: blr Signed-off-by:
Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Acked-by:
Daniel Borkmann <daniel@iogearbox.net> Signed-off-by:
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Naveen N. Rao authored
Tail calls allow JIT'ed eBPF programs to call into other JIT'ed eBPF programs. This can be achieved either by: (1) retaining the stack setup by the first eBPF program and having all subsequent eBPF programs re-using it, or, (2) by unwinding/tearing down the stack and having each eBPF program deal with its own stack as it sees fit. To ensure that this does not create loops, there is a limit to how many tail calls can be done (currently 32). This requires the JIT'ed code to maintain a count of the number of tail calls done so far. Approach (1) is simple, but requires every eBPF program to have (almost) the same prologue/epilogue, regardless of whether they need it. This is inefficient for small eBPF programs which may not sometimes need a prologue at all. As such, to minimize impact of tail call implementation, we use approach (2) here which needs each eBPF program in the chain to use its own prologue/epilogue. This is not ideal when many tail calls are involved and when all the eBPF programs in the chain have similar prologue/epilogue. However, the impact is restricted to programs that do tail calls. Individual eBPF programs are not affected. We maintain the tail call count in a fixed location on the stack and updated tail call count values are passed in through this. The very first eBPF program in a chain sets this up to 0 (the first 2 instructions). Subsequent tail calls skip the first two eBPF JIT instructions to maintain the count. For programs that don't do tail calls themselves, the first two instructions are NOPs. Signed-off-by:
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Naveen N. Rao authored
While at it, ensure that the location of the local save area is consistent whether or not we setup our own stackframe. This property is utilised in the next patch that adds support for tail calls. Signed-off-by:
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Michael Ellerman authored
The fadump code calls vmcore_cleanup() which only exists if CONFIG_PROC_VMCORE=y. We don't want to depend on CONFIG_PROC_VMCORE, because it's user selectable, so just wrap the call in an #ifdef. Signed-off-by: -
Cyril Bur authored
Currently the MSR TM bit is always set if the hardware is TM capable. This adds extra overhead as it means the TM SPRS (TFHAR, TEXASR and TFAIR) must be swapped for each process regardless of if they use TM. For processes that don't use TM the TM MSR bit can be turned off allowing the kernel to avoid the expensive swap of the TM registers. A TM unavailable exception will occur if a thread does use TM and the kernel will enable MSR_TM and leave it so for some time afterwards. Signed-off-by:
Cyril Bur <cyrilbur@gmail.com> Signed-off-by:
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Cyril Bur authored
If the kernel disables transactional memory (TM) and userspace still tries TM related actions (TM instructions or TM SPR accesses) TM aware hardware will cause the kernel to take a facility unavailable exception. Add checks for the exception being caused by illegal TM access in userspace. Signed-off-by:
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Cyril Bur authored
Previous rework of TM code leaves these functions unused Signed-off-by:
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Cyril Bur authored
Make the structures being used for checkpointed state named consistently with the pt_regs/ckpt_regs. Signed-off-by:
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Cyril Bur authored
There is currently an inconsistency as to how the entire CPU register state is saved and restored when a thread uses transactional memory (TM). Using transactional memory results in the CPU having duplicated (almost) all of its register state. This duplication results in a set of registers which can be considered 'live', those being currently modified by the instructions being executed and another set that is frozen at a point in time. On context switch, both sets of state have to be saved and (later) restored. These two states are often called a variety of different things. Common terms for the state which only exists after the CPU has entered a transaction (performed a TBEGIN instruction) in hardware are 'transactional' or 'speculative'. Between a TBEGIN and a TEND or TABORT (or an event that causes the hardware to abort), regardless of the use of TSUSPEND the transactional state can be referred to as the live state. The second state is often to referred to as the 'checkpointed' state and is a duplication of the live state when the TBEGIN instruction is executed. This state is kept in the hardware and will be rolled back to on transaction failure. Currently all the registers stored in pt_regs are ALWAYS the live registers, that is, when a thread has transactional registers their values are stored in pt_regs and the checkpointed state is in ckpt_regs. A strange opposite is true for fp_state/vr_state. When a thread is non transactional fp_state/vr_state holds the live registers. When a thread has initiated a transaction fp_state/vr_state holds the checkpointed state and transact_fp/transact_vr become the structure which holds the live state (at this point it is a transactional state). This method creates confusion as to where the live state is, in some circumstances it requires extra work to determine where to put the live state and prevents the use of common functions designed (probably before TM) to save the live state. With this patch pt_regs, fp_state and vr_state all represent the same thing and the other structures [pending rename] are for checkpointed state. Acked-by:
Simon Guo <wei.guo.simon@gmail.com> Signed-off-by:
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Cyril Bur authored
If a thread receives a signal while transactional the kernel creates a second context to show the transactional state of the process. This test loads some known values and waits for a signal and confirms that the expected values are in the signal context. Signed-off-by:
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Cyril Bur authored
If a thread receives a signal while transactional the kernel creates a second context to show the transactional state of the process. This test loads some known values and waits for a signal and confirms that the expected values are in the signal context. Signed-off-by:
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Cyril Bur authored
If a thread receives a signal while transactional the kernel creates a second context to show the transactional state of the process. This test loads some known values and waits for a signal and confirms that the expected values are in the signal context. Signed-off-by:
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Cyril Bur authored
If a thread receives a signal while transactional the kernel creates a second context to show the transactional state of the process. This test loads some known values and waits for a signal and confirms that the expected values are in the signal context. Signed-off-by:
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Cyril Bur authored
Signed-off-by:
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Cyril Bur authored
Signed-off-by:
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Cyril Bur authored
Signed-off-by:
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Cyril Bur authored
Signed-off-by:
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Cyril Bur authored
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Cyril Bur authored
The FPU regs are placed at the top of the stack frame. Currently the position expected to be passed to the macro. The macros now should be passed the stack frame size and from there they can calculate where to put the regs, this makes the use simpler. Also move them to a header file to be used in an different area of the powerpc selftests Signed-off-by:
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Cyril Bur authored
Ensure the kernel correctly switches VSX registers correctly. VSX registers are all volatile, and despite the kernel preserving VSX across syscalls, it doesn't have to. Test that during interrupts and timeslices ending the VSX regs remain the same. Signed-off-by:
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Cyril Bur authored
Much of the signal code takes a pt_regs on which it operates. Over time the signal code has needed to know more about the thread than what pt_regs can supply, this information is obtained as needed by using 'current'. This approach is not strictly incorrect however it does mean that there is now a hard requirement that the pt_regs being passed around does belong to current, this is never checked. A safer approach is for the majority of the signal functions to take a task_struct from which they can obtain pt_regs and any other information they need. The caveat that the task_struct they are passed must be current doesn't go away but can more easily be checked for. Functions called from outside powerpc signal code are passed a pt_regs and they can confirm that the pt_regs is that of current and pass current to other functions, furthurmore, powerpc signal functions can check that the task_struct they are passed is the same as current avoiding possible corruption of current (or the task they are passed) if this assertion ever fails. CC: paulus@samba.org Signed-off-by:
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Cyril Bur authored
After a thread is reclaimed from its active or suspended transactional state the checkpointed state exists on CPU, this state (along with the live/transactional state) has been saved in its entirety by the reclaiming process. There exists a sequence of events that would cause the kernel to call one of enable_kernel_fp(), enable_kernel_altivec() or enable_kernel_vsx() after a thread has been reclaimed. These functions save away any user state on the CPU so that the kernel can use the registers. Not only is this saving away unnecessary at this point, it is actually incorrect. It causes a save of the checkpointed state to the live structures within the thread struct thus destroying the true live state for that thread. Signed-off-by:
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Cyril Bur authored
msr_check_and_set() always performs a mfmsr() to determine if it needs to perform an mtmsr(), as mfmsr() can be a costly operation msr_check_and_set() could return the MSR now on the CPU to avoid callers of msr_check_and_set having to make their own mfmsr() call. Signed-off-by:
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Cyril Bur authored
giveup_all() causes FPU/VMX/VSX facilities to be disabled in a threads MSR. If the thread performing the giveup was transactional, the kernel must record which facilities were in use before the giveup as the thread must have these facilities re-enabled on return to userspace. >From process.c: /* * This is called if we are on the way out to userspace and the * TIF_RESTORE_TM flag is set. It checks if we need to reload * FP and/or vector state and does so if necessary. * If userspace is inside a transaction (whether active or * suspended) and FP/VMX/VSX instructions have ever been enabled * inside that transaction, then we have to keep them enabled * and keep the FP/VMX/VSX state loaded while ever the transaction * continues. The reason is that if we didn't, and subsequently * got a FP/VMX/VSX unavailable interrupt inside a transaction, * we don't know whether it's the same transaction, and thus we * don't know which of the checkpointed state and the transactional * state to use. */ Calling check_if_tm_restore_required() will set TIF_RESTORE_TM and save the MSR if needed. Fixes: c2085059 ("powerpc: create giveup_all()") Signed-off-by:
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Cyril Bur authored
Comment from arch/powerpc/kernel/process.c:967: If userspace is inside a transaction (whether active or suspended) and FP/VMX/VSX instructions have ever been enabled inside that transaction, then we have to keep them enabled and keep the FP/VMX/VSX state loaded while ever the transaction continues. The reason is that if we didn't, and subsequently got a FP/VMX/VSX unavailable interrupt inside a transaction, we don't know whether it's the same transaction, and thus we don't know which of the checkpointed state and the ransactional state to use. restore_math() restore_fp() and restore_altivec() currently may not restore the registers. It doesn't appear that this is more serious than a performance penalty. If the math registers aren't restored the userspace thread will still be run with the facility disabled. Userspace will not be able to read invalid values. On the first access it will take an facility unavailable exception and the kernel will detected an active transaction, at which point it will abort the transaction. There is the possibility for a pathological case preventing any progress by transactions, however, transactions are never guaranteed to make progress. Fixes: 70fe3d98 ("powerpc: Restore FPU/VEC/VSX if previously used") Signed-off-by:
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Gavin Shan authored
This fixes warning reported from sparse: pci-ioda.c:451:49: warning: incorrect type in argument 2 (different base types) Fixes: 262af557 ("powerpc/powernv: Enable M64 aperatus for PHB3") Signed-off-by:
Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by:
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Gavin Shan authored
This fixes the warnings reported from sparse: pci.c:312:33: warning: restricted __be64 degrades to integer pci.c:313:33: warning: restricted __be64 degrades to integer Fixes: cee72d5b ("powerpc/powernv: Display diag data on p7ioc EEH errors") Cc: stable@vger.kernel.org # v3.3+ Signed-off-by:
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Gavin Shan authored
This fixes the warning reported from sparse: eeh-powernv.c:875:23: warning: constant 0x8000000000000000 is so big it is unsigned long Fixes: ebe22531 ("powerpc/powernv: Support PCI slot ID") Suggested-by:
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Gavin Shan authored
The hub diag-data type is filled with big-endian data by OPAL call opal_pci_get_hub_diag_data(). We need convert it to CPU-endian value before using it. The issue is reported by sparse as pointed by Michael Ellerman: eeh-powernv.c:1309:21: warning: restricted __be16 degrades to integer This converts hub diag-data type to CPU-endian before using it in pnv_eeh_get_and_dump_hub_diag(). Fixes: 2a485ad7 ("powerpc/powernv: Drop PHB operation next_error()") Cc: stable@vger.kernel.org # v4.1+ Suggested-by:
Russell Currey <ruscur@russell.cc> Signed-off-by:
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Gavin Shan authored
The PE number (@frozen_pe_no), filled by opal_pci_next_error() is in big-endian format. It should be converted to CPU-endian before it is passed to opal_pci_eeh_freeze_clear() when clearing the frozen state if the PE is invalid one. As Michael Ellerman pointed out, the issue is also detected by sparse: eeh-powernv.c:1541:41: warning: incorrect type in argument 2 (different base types) This passes CPU-endian PE number to opal_pci_eeh_freeze_clear() and it should be part of commit <0f36db77> ("powerpc/eeh: Fix wrong printed PE number"), which was merged to 4.3 kernel. Fixes: 71b540ad ("powerpc/powernv: Don't escalate non-existing frozen PE") Cc: stable@vger.kernel.org # v4.3+ Suggested-by:
Paul Mackerras <paulus@samba.org> Signed-off-by:
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Gavin Shan authored
This replaces of_get_property() with of_property_read_u32() or of_property_read_string() so that we needn't consider the endian issue, the returned value always is in CPU-endian. Signed-off-by:
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