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2019-02-18swiotlb: remove swiotlb_dma_supportedChristoph Hellwig
The only user left is powerpc, but even there the generic dma-direct version works just as well, given that we guarantee that the swiotlb buffer must always be addressable. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Christian Zigotzky <chzigotzky@xenosoft.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-18powerpc/dma: remove dma_nommu_dma_supportedChristoph Hellwig
This function is largely identical to the generic version used everywhere else. Replace it with the generic version. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Christian Zigotzky <chzigotzky@xenosoft.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-18powerpc/dma: remove dma_nommu_get_required_maskChristoph Hellwig
This function is identical to the generic dma_direct_get_required_mask, except that the generic version also takes the bus_dma_mask account, which could lead to incorrect results in the powerpc version. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Christian Zigotzky <chzigotzky@xenosoft.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-18powerpc/dma: remove dma_nommu_mmap_coherentChristoph Hellwig
The coherent cache version of this function already is functionally identicall to the default version, and by defining the arch_dma_coherent_to_pfn hook the same is ture for the noncoherent version as well. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Christian Zigotzky <chzigotzky@xenosoft.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-18powerpc/dma: use phys_to_dma instead of get_dma_offsetChristoph Hellwig
Use the standard portable helper instead of the powerpc specific one, which is about to go away. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Christian Zigotzky <chzigotzky@xenosoft.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-18dma-mapping, powerpc: simplify the arch dma_set_mask overrideChristoph Hellwig
Instead of letting the architecture supply all of dma_set_mask just give it an additional hook selected by Kconfig. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Christian Zigotzky <chzigotzky@xenosoft.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-18powerpc/dma: fix an off-by-one in dma_capableChristoph Hellwig
We need to compare the last byte in the dma range and not the one after it for the bus_dma_mask, just like we do for the regular dma_mask. Fix this cleanly by merging the two comparisms into one. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Christian Zigotzky <chzigotzky@xenosoft.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-18powerpc/dma: remove max_direct_dma_addrChristoph Hellwig
The max_direct_dma_addr duplicates the bus_dma_mask field in struct device. Use the generic field instead. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Christian Zigotzky <chzigotzky@xenosoft.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-18powerpc/dma: move pci_dma_dev_setup_swiotlb to fsl_pci.cChristoph Hellwig
pci_dma_dev_setup_swiotlb is only used by the fsl_pci code, and closely related to it, so fsl_pci.c seems like a better place for it. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Christian Zigotzky <chzigotzky@xenosoft.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-18powerpc/dma: remove get_pci_dma_opsChristoph Hellwig
This function is only used by the Cell iommu code, which can keep track if it is using the iommu internally just as good. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Christian Zigotzky <chzigotzky@xenosoft.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-18powerpc/dma: remove the iommu fallback for coherent allocationsChristoph Hellwig
All iommu capable platforms now always use the iommu code with the internal bypass, so there is not need for this magic anymore. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Christian Zigotzky <chzigotzky@xenosoft.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-18powerpc/pci: remove the dma_set_mask pci_controller ops methodsChristoph Hellwig
Unused now. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-18powerpc/dma: stop overriding dma_get_required_maskChristoph Hellwig
The ppc_md and pci_controller_ops methods are unused now and can be removed. The dma_nommu implementation is generic to the generic one except for using max_pfn instead of calling into the memblock API, and all other dma_map_ops instances implement a method of their own. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Christian Zigotzky <chzigotzky@xenosoft.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-18powerpc/powernv: use the generic iommu bypass codeChristoph Hellwig
Use the generic iommu bypass code instead of overriding set_dma_mask. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-18powerpc/powernv: remove pnv_npu_dma_set_maskChristoph Hellwig
These devices are not PCIe devices and do not have associated dma map ops, so this is just dead code. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-18powerpc/powernv: remove pnv_pci_ioda_pe_single_vendorChristoph Hellwig
This function is completely bogus - the fact that two PCIe devices come from the same vendor has absolutely nothing to say about the DMA capabilities and characteristics. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-18powerpc/dart: use the generic iommu bypass codeChristoph Hellwig
Use the generic iommu bypass code instead of overriding set_dma_mask. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-18powerpc/dart: remove dead cleanup code in iommu_init_early_dartChristoph Hellwig
If dart_init failed we didn't have a chance to setup dma or controller ops yet, so there is no point in resetting them. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-18powerpc/cell: use the generic iommu bypass codeChristoph Hellwig
This gets rid of a lot of clumsy code and finally allows us to mark dma_iommu_ops const. Includes fixes from Michael Ellerman. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-18powerpc/cell: move dma direct window setup out of dma_configureChristoph Hellwig
Configure the dma settings at device setup time, and stop playing games with get_pci_dma_ops. This prepares for using the common dma_configure code later on. Includes fixes from Michael Ellerman. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-18powerpc/pseries: use the generic iommu bypass codeChristoph Hellwig
Use the generic iommu bypass code instead of overriding set_dma_mask. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-18powerpc/pseries: unwind dma_get_required_mask_pSeriesLP a bitChristoph Hellwig
Call dma_get_required_mask_pSeriesLP directly instead of dma_iommu_ops to simply the code a bit. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-18powerpc/dma: handle iommu bypass in dma_iommu_opsChristoph Hellwig
Add a new iommu_bypass flag to struct dev_archdata so that the dma_iommu implementation can handle the direct mapping transparently instead of switiching ops around. Setting of this flag is controlled by new pci_controller_ops method. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Christian Zigotzky <chzigotzky@xenosoft.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-18powerpc/dma: untangle vio_dma_mapping_ops from dma_iommu_opsChristoph Hellwig
vio_dma_mapping_ops currently does a lot of indirect calls through dma_iommu_ops, which not only make the code harder to follow but are also expensive in the post-spectre world. Unwind the indirect calls by calling the ppc_iommu_* or iommu_* APIs directly applicable, or just use the dma_iommu_* methods directly where we can. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-18dma-direct: we might need GFP_DMA for 32-bit dma masksChristoph Hellwig
If there is no ZONE_DMA32 we might need GFP_DMA to be able to allocate memory that satisfies a 32-bit DMA mask. Reported-by: Christian Zigotzky <chzigotzky@xenosoft.de> Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Christian Zigotzky <chzigotzky@xenosoft.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-18net: pasemi: set a 64-bit DMA mask on the DMA deviceChristoph Hellwig
The pasemi driver never set a DMA mask, and given that the powerpc DMA mapping routines never check it this worked ok so far. But the generic dma-direct code which I plan to switch on for powerpc checks the DMA mask and fails unsupported mapping requests, so we need to make sure the proper 64-bit mask is set. Reported-by: Christian Zigotzky <chzigotzky@xenosoft.de> Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Christian Zigotzky <chzigotzky@xenosoft.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-17powerpc/64s: Fix possible corruption on big endian due to pgd/pud_present()Michael Ellerman
In v4.20 we changed our pgd/pud_present() to check for _PAGE_PRESENT rather than just checking that the value is non-zero, e.g.: static inline int pgd_present(pgd_t pgd) { - return !pgd_none(pgd); + return (pgd_raw(pgd) & cpu_to_be64(_PAGE_PRESENT)); } Unfortunately this is broken on big endian, as the result of the bitwise & is truncated to int, which is always zero because _PAGE_PRESENT is 0x8000000000000000ul. This means pgd_present() and pud_present() are always false at compile time, and the compiler elides the subsequent code. Remarkably with that bug present we are still able to boot and run with few noticeable effects. However under some work loads we are able to trigger a warning in the ext4 code: WARNING: CPU: 11 PID: 29593 at fs/ext4/inode.c:3927 .ext4_set_page_dirty+0x70/0xb0 CPU: 11 PID: 29593 Comm: debugedit Not tainted 4.20.0-rc1 #1 ... NIP .ext4_set_page_dirty+0x70/0xb0 LR .set_page_dirty+0xa0/0x150 Call Trace: .set_page_dirty+0xa0/0x150 .unmap_page_range+0xbf0/0xe10 .unmap_vmas+0x84/0x130 .unmap_region+0xe8/0x190 .__do_munmap+0x2f0/0x510 .__vm_munmap+0x80/0x110 .__se_sys_munmap+0x14/0x30 system_call+0x5c/0x70 The fix is simple, we need to convert the result of the bitwise & to an int before returning it. Thanks to Erhard, Jan Kara and Aneesh for help with debugging. Fixes: da7ad366b497 ("powerpc/mm/book3s: Update pmd_present to look at _PAGE_PRESENT bit") Cc: stable@vger.kernel.org # v4.20+ Reported-by: Erhard F. <erhard_f@mailbox.org> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-07powerpc/powernv: Escalate reset when IODA reset failsOliver O'Halloran
The IODA reset is used to flush out any OS controlled state from the PHB. This reset can fail if a PHB fatal error has occurred in early boot, probably due to a because of a bad device. We already do a fundemental reset of the device in some cases, so this patch just adds a test to force a full reset if firmware reports an error when performing the IODA reset. Signed-off-by: Oliver O'Halloran <oohall@gmail.com> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-07powerpc/ptrace: Mitigate potential Spectre v1Breno Leitao
'regno' is directly controlled by user space, hence leading to a potential exploitation of the Spectre variant 1 vulnerability. On PTRACE_SETREGS and PTRACE_GETREGS requests, user space passes the register number that would be read or written. This register number is called 'regno' which is part of the 'addr' syscall parameter. This 'regno' value is checked against the maximum pt_regs structure size, and then used to dereference it, which matches the initial part of a Spectre v1 (and Spectre v1.1) attack. The dereferenced value, then, is returned to userspace in the GETREGS case. This patch sanitizes 'regno' before using it to dereference pt_reg. Notice that given that speculation windows are large, the policy is to kill the speculation on the first load and not worry if it can be completed with a dependent load/store [1]. [1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2 Signed-off-by: Breno Leitao <leitao@debian.org> Acked-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-05powerpc/32: Include .branch_lt in data sectionJoel Stanley
When building a 32 bit powerpc kernel with Binutils 2.31.1 this warning is emitted: powerpc-linux-gnu-ld: warning: orphan section `.branch_lt' from `arch/powerpc/kernel/head_44x.o' being placed in section `.branch_lt' As of binutils commit 2d7ad24e8726 ("Support PLT16 relocs against local symbols")[1], 32 bit targets can produce .branch_lt sections in their output. Include these symbols in the .data section as the ppc64 kernel does. [1] https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=commitdiff;h=2d7ad24e8726ba4c45c9e67be08223a146a837ce Signed-off-by: Joel Stanley <joel@jms.id.au> Reviewed-by: Alan Modra <amodra@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-05powerpc/eeh: Correct retries in eeh_pe_reset_full()Sam Bobroff
Currently, eeh_pe_reset_full() will only attempt to reset a PE more than once if activating the reset state and deactivating it both succeed, but later polling shows that it hasn't become active. Change this so that it will try up to three times for any reason other than an unrecoverable slot error and adjust the message generation so that it's clear weather the reset has ultimately succeeded or failed. This allows the reset to succeed in some situations where it would currently fail. Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-05powerpc/eeh: Improve recovery of passed-through devicesSam Bobroff
Currently, the EEH recovery process considers passed-through devices as if they were not EEH-aware, which can cause them to be removed as part of recovery. Because device removal requires cooperation from the guest, this may lead to the process stalling or deadlocking. Also, if devices are removed on the host side, they will be removed from their IOMMU group, making recovery in the guest impossible. Therefore, alter the recovery process so that passed-through devices are not removed but are instead left frozen (and marked isolated) until the guest performs it's own recovery. If firmware thaws a passed-through PE because it's parent PE has been thawed (because it was not passed through), re-freeze it. Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-05powerpc/eeh: Add include_passed to eeh_clear_pe_frozen_state()Sam Bobroff
Add a parameter to eeh_clear_pe_frozen_state() that allows passed-through PEs to be excluded. Update callers to always pass true so that there is no change in behaviour. This is to prepare for follow-up work for passed-through devices. Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-05powerpc/eeh: Add include_passed to eeh_pe_state_clear()Sam Bobroff
Add a parameter to eeh_pe_state_clear() that allows passed-through PEs to be excluded. Update callers to always pass true so that there is no change in behaviour. Also refactor to use direct traversal, to allow the removal of some boilerplate. This is to prepare for follow-up work for passed-through devices. Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-05powerpc/eeh: remove sw_state from eeh_unfreeze_pe()Sam Bobroff
eeh_unfreeze_pe() performs two operations: unfreezing a PE (which may cause firmware to unfreeze child PEs as well) and de-isolating the PE and it's children. To simplify this and support future work, separate out the de-isolation and perform it at the call sites (when necessary). There should be no change in behaviour. Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-05powerpc/eeh: Cleanup eeh_pe_clear_frozen_state()Sam Bobroff
The 'clear_sw_state' parameter for eeh_pe_clear_frozen_state() is redundant because it has no effect (except in the rare case of a hardware error part way through unfreezing a tree of PEs, where it would dangerously allow partial de-isolation before returning failure). It is passed down to __eeh_pe_clear_frozen_state(), and from there to eeh_unfreeze_pe(), where it causes EEH_PE_ISOLATED to be removed from the state of each PE during the traversal. However, when the traversal finishes, EEH_PE_ISOLATED is unconditionally removed by a call to eeh_pe_state_clear() regardless of the parameter's value. So remove the flag and pass false to eeh_unfreeze_pe() (to avoid the rare case described above, as it was before the flag was introduced). Also, perform the recursion directly in the function and eliminate a bit of boilerplate. There should be no change in functionality, except as mentioned above. Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-04powerpc: Drop page_is_ram() and walk_system_ram_range()Christophe Leroy
Since commit c40dd2f76644 ("powerpc: Add System RAM to /proc/iomem") it is possible to use the generic walk_system_ram_range() and the generic page_is_ram(). To enable the use of walk_system_ram_range() by the IBM EHEA ethernet driver, we still need an export of the generic function. As powerpc was the only user of CONFIG_ARCH_HAS_WALK_MEMORY, the ifdef around the generic walk_system_ram_range() has become useless and can be dropped. Fixes: c40dd2f76644 ("powerpc: Add System RAM to /proc/iomem") Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> [mpe: Keep the EXPORT_SYMBOL_GPL in powerpc code] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-03Move static keyword at beginning of declarationMathieu Malaterre
Move the static keyword around to remove the following warnings (W=1): arch/powerpc/platforms/ps3/os-area.c:212:1: error: 'static' is not at beginning of declaration [-Werror=old-style-declaration] arch/powerpc/platforms/ps3/system-bus.c:45:1: error: 'static' is not at beginning of declaration [-Werror=old-style-declaration] Signed-off-by: Mathieu Malaterre <malat@debian.org> Acked-by: Geoff Levand <geoff@infradead.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-03powerpc: Remove trailing semicolon after curly braceMathieu Malaterre
There is not point in having a trailing semicolon after a closing curly brace. Remove it. Signed-off-by: Mathieu Malaterre <malat@debian.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-01powerpc: Enable kernel XZ compression option on 44xChristian Lamparter
Enable kernel XZ compression option on 44x. Tested on a Western Digital - MyBook Live NAS. It takes 22 seconds for the 800 MHz CPU to decompress and boot a 2.63 MiB XZ-compressed kernel simpleImage. Signed-off-by: Christian Lamparter <chunkeey@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-01powerpc/papr_scm: Use the correct bind addressOliver O'Halloran
When binding an SCM volume to a physical address the hypervisor has the option to return early with a continue token with the expectation that the guest will resume the bind operation until it completes. A quirk of this interface is that the bind address will only be returned by the first bind h-call and the subsequent calls will return 0xFFFF_FFFF_FFFF_FFFF for the bind address. We currently do not save the address returned by the first h-call. As a result we will use the junk address as the base of the bound region if the hypervisor decides to split the bind across multiple h-calls. This bug was found when testing with very large SCM volumes where the bind process would take more time than they hypervisor's internal h-call time limit would allow. This patch fixes the issue by saving the bind address from the first call. Cc: stable@vger.kernel.org Fixes: b5beae5e224f ("powerpc/pseries: Add driver for PAPR SCM regions") Signed-off-by: Oliver O'Halloran <oohall@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-01-31powerpc/radix: Fix kernel crash with mremap()Aneesh Kumar K.V
With support for split pmd lock, we use pmd page pmd_huge_pte pointer to store the deposited page table. In those config when we move page tables we need to make sure we move the deposited page table to the correct pmd page. Otherwise this can result in crash when we withdraw of deposited page table because we can find the pmd_huge_pte NULL. eg: __split_huge_pmd+0x1070/0x1940 __split_huge_pmd+0xe34/0x1940 (unreliable) vma_adjust_trans_huge+0x110/0x1c0 __vma_adjust+0x2b4/0x9b0 __split_vma+0x1b8/0x280 __do_munmap+0x13c/0x550 sys_mremap+0x220/0x7e0 system_call+0x5c/0x70 Fixes: 675d995297d4 ("powerpc/book3s64: Enable split pmd ptlock.") Cc: stable@vger.kernel.org # v4.18+ Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-01-31powerpc/livepatch: return -ERRNO values in save_stack_trace_tsk_reliable()Joe Lawrence
To match its x86 counterpart, save_stack_trace_tsk_reliable() should return -EINVAL in cases that it is currently returning 1. No caller is currently differentiating non-zero error codes, but let's keep the arch-specific implementations consistent. Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-01-31powerpc/livepatch: small cleanups in save_stack_trace_tsk_reliable()Joe Lawrence
Mostly cosmetic changes: - Group common stack pointer code at the top - Simplify the first frame logic - Code stackframe iteration into for...loop construct - Check for trace->nr_entries overflow before adding any into the array Suggested-by: Nicolai Stange <nstange@suse.de> Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-01-31powerpc/livepatch: relax reliable stack tracer checks for first-frameJoe Lawrence
The bottom-most stack frame (the first to be unwound) may be largely uninitialized, for the "Power Architecture 64-Bit ELF V2 ABI" only requires its backchain pointer to be set. The reliable stack tracer should be careful when verifying this frame: skip checks on STACK_FRAME_LR_SAVE and STACK_FRAME_MARKER offsets that may contain uninitialized residual data. Fixes: df78d3f61480 ("powerpc/livepatch: Implement reliable stack tracing for the consistency model") Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-01-31powerpc/64s: Make reliable stacktrace dependency clearerNicolai Stange
Make the HAVE_RELIABLE_STACKTRACE Kconfig option depend on PPC_BOOK3S_64 for documentation purposes. Before this patch, it depended on PPC64 && CPU_LITTLE_ENDIAN and because CPU_LITTLE_ENDIAN implies PPC_BOOK3S_64, there's no functional change here. Signed-off-by: Nicolai Stange <nstange@suse.de> Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com> [mpe: Split out of larger patch] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-01-31powerpc/64s: Clear on-stack exception marker upon exception returnNicolai Stange
The ppc64 specific implementation of the reliable stacktracer, save_stack_trace_tsk_reliable(), bails out and reports an "unreliable trace" whenever it finds an exception frame on the stack. Stack frames are classified as exception frames if the STACK_FRAME_REGS_MARKER magic, as written by exception prologues, is found at a particular location. However, as observed by Joe Lawrence, it is possible in practice that non-exception stack frames can alias with prior exception frames and thus, that the reliable stacktracer can find a stale STACK_FRAME_REGS_MARKER on the stack. It in turn falsely reports an unreliable stacktrace and blocks any live patching transition to finish. Said condition lasts until the stack frame is overwritten/initialized by function call or other means. In principle, we could mitigate this by making the exception frame classification condition in save_stack_trace_tsk_reliable() stronger: in addition to testing for STACK_FRAME_REGS_MARKER, we could also take into account that for all exceptions executing on the kernel stack - their stack frames's backlink pointers always match what is saved in their pt_regs instance's ->gpr[1] slot and that - their exception frame size equals STACK_INT_FRAME_SIZE, a value uncommonly large for non-exception frames. However, while these are currently true, relying on them would make the reliable stacktrace implementation more sensitive towards future changes in the exception entry code. Note that false negatives, i.e. not detecting exception frames, would silently break the live patching consistency model. Furthermore, certain other places (diagnostic stacktraces, perf, xmon) rely on STACK_FRAME_REGS_MARKER as well. Make the exception exit code clear the on-stack STACK_FRAME_REGS_MARKER for those exceptions running on the "normal" kernel stack and returning to kernelspace: because the topmost frame is ignored by the reliable stack tracer anyway, returns to userspace don't need to take care of clearing the marker. Furthermore, as I don't have the ability to test this on Book 3E or 32 bits, limit the change to Book 3S and 64 bits. Fixes: df78d3f61480 ("powerpc/livepatch: Implement reliable stack tracing for the consistency model") Reported-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Nicolai Stange <nstange@suse.de> Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-01-31powerpc/perf: Add mem access events to sysfsMadhavan Srinivasan
Add mem-loads/mem-stores events to sysfs. The event is formed based on raw event encoding. Primary PMU event used here is PM_MRK_INST_CMPL along with MMCRA[SM] modes and Thresholding bit Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-01-31powerpc/mm: Add _PAGE_SAO to _PAGE_CACHE_CTL maskReza Arbab
In htab_convert_pte_flags(), _PAGE_CACHE_CTL is used to check for the _PAGE_SAO flag: else if ((pteflags & _PAGE_CACHE_CTL) == _PAGE_SAO) rflags |= (HPTE_R_W | HPTE_R_I | HPTE_R_M); But, it isn't defined to include that flag: #define _PAGE_CACHE_CTL (_PAGE_NON_IDEMPOTENT | _PAGE_TOLERANT) This happens to work, but only because of the flag values: #define _PAGE_SAO 0x00010 /* Strong access order */ #define _PAGE_NON_IDEMPOTENT 0x00020 /* non idempotent memory */ #define _PAGE_TOLERANT 0x00030 /* tolerant memory, cache inhibited */ To prevent any issues if these particulars ever change, add _PAGE_SAO to the mask. Suggested-by: Charles Johns <crjohns@us.ibm.com> Signed-off-by: Reza Arbab <arbab@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-01-31powerpc/cell: Remove duplicate headerSabyasachi Gupta
Remove linux/syscalls.h which is included more than once Signed-off-by: Sabyasachi Gupta <sabyasachi.linux@gmail.com> Acked-by: Souptick Joarder <jrdr.linux@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>