- 25 Mar, 2020 21 commits
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Oliver O'Halloran authored
This check for a missing PHB has existing in various forms since the initial PPC64 port was upstreamed in 2002. The idea seems to be that we need to guard against creating pci-specific data structures for the non-pci children of a PCI device tree node (e.g. USB devices). However, we only create pci_dn structures for DT nodes that correspond to PCI devices so there's not much point in doing this check in the eeh_probe path. Reviewed-by:
Sam Bobroff <sbobroff@linux.ibm.com> Signed-off-by:
Oliver O'Halloran <oohall@gmail.com> Signed-off-by:
Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200306073904.4737-4-oohall@gmail.com
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Oliver O'Halloran authored
The pci hotplug helper (pci_hp_add_devices()) calls eeh_add_device_tree_early() to scan the device-tree for new PCI devices and do the early EEH probe before the device is scanned. This early probe is a no-op in a lot of cases because: a) The early init is only required to satisfy a PAPR requirement that EEH be configured before we start doing config accesses. On PowerNV it is a no-op. b) It's a no-op for devices that have already had their eeh_dev initialised. There are four callers of pci_hp_add_devices(): 1. arch/powerpc/kernel/eeh_driver.c Here the hotplug helper is called when re-scanning pci_devs that were removed during an EEH recovery pass. The EEH stat for each removed device (the eeh_dev) is retained across a recovery pass so the early init is a no-op in this case. 2. drivers/pci/hotplug/pnv_php.c This is also a no-op since the PowerNV hotplug driver is, suprisingly, PowerNV specific. 3. drivers/pci/hotplug/rpaphp_core.c 4. drivers/pci/hotplug/rpaphp_pci.c In these two cases new devices have been hotplugged and FW has provided new DT nodes for each. These are the only two cases where the EEH we might have new PCI device nodes in the DT so these are the only two cases where the early EEH probe needs to be done. We can move the calls to eeh_add_device_tree_early() to the locations where it's needed and remove it from the generic path. This is preparation for making the early EEH probe pseries specific. Reviewed-by:
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Oliver O'Halloran authored
On pseries and PowerNV pcibios_bus_add_device() calls eeh_add_device_late() so there's no need to do a separate tree traversal to bind the eeh_dev and pci_dev together setting up the PHB at boot. As a result we can remove eeh_add_device_tree_late(). Reviewed-by:
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Oliver O'Halloran authored
Move creating the EEH specific sysfs files into eeh_add_device_late() rather than being open-coded all over the place. Calling the function is generally done immediately after calling eeh_add_device_late() anyway. This is also a correctness fix since currently the sysfs files will be added even if the EEH probe happens to fail. Similarly, on pseries we currently add the sysfs files before calling eeh_add_device_late(). This is flat-out broken since the sysfs files require the pci_dev->dev.archdata.edev pointer to be set, and that is done in eeh_add_device_late(). Reviewed-by:
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Michael Ellerman authored
The previous commit reduced the amount of code that is run before we setup a paca. However there are still a few remaining functions that run with no paca, or worse, with an arbitrary value in r13 that will be used as a paca pointer. In particular the stack protector canary is stored in the paca, so if stack protector is activated for any of these functions we will read the stack canary from wherever r13 points. If r13 happens to point outside of memory we will get a machine check / checkstop. For example if we modify initialise_paca() to trigger stack protection, and then boot in the mambo simulator with r13 poisoned in skiboot before calling the kernel: DEBUG: 19952232: (19952232): INSTRUCTION: PC=0xC0000000191FC1E8: [0x3C4C006D]: addis r2,r12,0x6D [fetch] DEBUG: 19952236: (19952236): INSTRUCTION: PC=0xC00000001807EAD8: [0x7D8802A6]: mflr r12 [fetch] FATAL ERROR: 19952276: (19952276): Check Stop for 0:0: Machine Check with ME bit of MSR off DEBUG: 19952276: (19952276): INSTRUCTION: PC=0xC0000000191FCA7C: [0xE90D0CF8]: ld r8,0xCF8(r13) [Instruction Failed] INFO: 19952276: (19952277): ** Execution stopped: Mambo Error, Machine Check Stop, ** systemsim % bt pc: 0xC0000000191FCA7C initialise_paca+0x54 lr: 0xC0000000191FC22C early_setup+0x44 stack:0x00000000198CBED0 0x0 +0x0 stack:0x00000000198CBF00 0xC0000000191FC22C early_setup+0x44 stack:0x00000000198CBF90 0x1801C968 +0x1801C968 So annotate the relevant functions to ensure stack protection is never enabled for them. Fixes: 06ec27ae ("powerpc/64: add stack protector support") Cc: stable@vger.kernel.org # v4.20+ Signed-off-by:
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Daniel Axtens authored
Currently we set up the paca after parsing the device tree for CPU features. Prior to that, r13 contains random data, which means there is random data in r13 while we're running the generic dt parsing code. This random data varies depending on whether we boot through a vmlinux or a zImage: for the vmlinux case it's usually around zero, but for zImages we see random values like 912a72603d420015. This is poor practice, and can also lead to difficult-to-debug crashes. For example, when kcov is enabled, the kcov instrumentation attempts to read preempt_count out of the current task, which goes via the paca. This then crashes in the zImage case. Similarly stack protector can cause crashes if r13 is bogus, by reading from the stack canary in the paca. To resolve this: - move the paca setup to before the CPU feature parsing. - because we no longer have access to CPU feature flags in paca setup, change the HV feature test in the paca setup path to consider the actual value of the MSR rather than the CPU feature. Translations get switched on once we leave early_setup, so I think we'd already catch any other cases where the paca or task aren't set up. Boot tested on a P9 guest and host. Fixes: fb0b0a73 ("powerpc: Enable kcov") Fixes: 06ec27ae ("powerpc/64: add stack protector support") Cc: stable@vger.kernel.org # v4.20+ Reviewed-by:
Andrew Donnellan <ajd@linux.ibm.com> Suggested-by:
Daniel Axtens <dja@axtens.net> [mpe: Reword comments & change log a bit to mention stack protector] Signed-off-by:
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Pratik Rajesh Sampat authored
The patch avoids allocating cpufreq_policy on stack hence fixing frame size overflow in 'powernv_cpufreq_work_fn' Fixes: 22794280 ("cpufreq: powernv: Restore cpu frequency to policy->cur on unthrottling") Signed-off-by:
Pratik Rajesh Sampat <psampat@linux.ibm.com> Reviewed-by:
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Po-Hsu Lin authored
Some specific tests in powerpc can take longer than the default 45 seconds that added in commit 852c8cbf ("selftests/kselftest/runner.sh: Add 45 second timeout per test") to run, the following test result was collected across 2 Power8 nodes and 1 Power9 node in our pool: powerpc/benchmarks/futex_bench - 52s powerpc/dscr/dscr_sysfs_test - 116s powerpc/signal/signal_fuzzer - 88s powerpc/tm/tm_unavailable_test - 168s powerpc/tm/tm-poison - 240s Thus they will fail with TIMEOUT error. Disable the timeout setting for these sub-tests to allow them finish properly. https://bugs.launchpad.net/bugs/1864642 Fixes: 852c8cbf ("selftests/kselftest/runner.sh: Add 45 second timeout per test") Signed-off-by:
Po-Hsu Lin <po-hsu.lin@canonical.com> Signed-off-by:
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Aneesh Kumar K.V authored
H_PAGE_THP_HUGE is used to differentiate between a THP hugepage and hugetlb hugepage entries. The difference is WRT how we handle hash fault on these address. THP address enables MPSS in segments. We want to manage devmap hugepage entries similar to THP pt entries. Hence use H_PAGE_THP_HUGE for devmap huge PTE entries. With current code while handling hash PTE fault, we do set is_thp = true when finding devmap PTE huge PTE entries. Current code also does the below sequence we setting up huge devmap entries. entry = pmd_mkhuge(pfn_t_pmd(pfn, prot)); if (pfn_t_devmap(pfn)) entry = pmd_mkdevmap(entry); In that case we would find both H_PAGE_THP_HUGE and PAGE_DEVMAP set for huge devmap PTE entries. This results in false positive error like below. kernel BUG at /home/kvaneesh/src/linux/mm/memory.c:4321! Oops: Exception in kernel mode, sig: 5 [#1] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries Modules linked in: CPU: 56 PID: 67996 Comm: t_mmap_dio Not tainted 5.6.0-rc4-59640-g371c804dedbc #128 .... NIP [c00000000044c9e4] __follow_pte_pmd+0x264/0x900 LR [c0000000005d45f8] dax_writeback_one+0x1a8/0x740 Call Trace: str_spec.74809+0x22ffb4/0x2d116c (unreliable) dax_writeback_one+0x1a8/0x740 dax_writeback_mapping_range+0x26c/0x700 ext4_dax_writepages+0x150/0x5a0 do_writepages+0x68/0x180 __filemap_fdatawrite_range+0x138/0x180 file_write_and_wait_range+0xa4/0x110 ext4_sync_file+0x370/0x6e0 vfs_fsync_range+0x70/0xf0 sys_msync+0x220/0x2e0 system_call+0x5c/0x68 This is because our pmd_trans_huge check doesn't exclude _PAGE_DEVMAP. To make this all consistent, update pmd_mkdevmap to set H_PAGE_THP_HUGE and pmd_trans_huge check now excludes _PAGE_DEVMAP correctly. Fixes: ebd31197 ("powerpc/mm: Add devmap support for ppc64") Cc: stable@vger.kernel.org # v4.13+ Signed-off-by:Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by:
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Chen Zhou authored
Fixes gcc '-Wunused-but-set-variable' warning: drivers/pci/hotplug/rpaphp_core.c: In function is_php_type: drivers/pci/hotplug/rpaphp_core.c:291:16: warning: variable value set but not used [-Wunused-but-set-variable] Reported-by:
Hulk Robot <hulkci@huawei.com> Signed-off-by:
Chen Zhou <chenzhou10@huawei.com> Acked-by:
Bjorn Helgaas <bhelgaas@google.com> Signed-off-by:
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Christophe Leroy authored
Reorder Linux PTE bits to (almost) match Hash PTE bits. RW Kernel : PP = 00 RO Kernel : PP = 00 RW User : PP = 01 RO User : PP = 11 So naturally, we should have _PAGE_USER = 0x001 _PAGE_RW = 0x002 Today 0x001 and 0x002 and _PAGE_PRESENT and _PAGE_HASHPTE which both are software only bits. Switch _PAGE_USER and _PAGE_PRESET Switch _PAGE_RW and _PAGE_HASHPTE This allows to remove a few insns. Signed-off-by:
Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by:
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Christophe Leroy authored
At the moment kasan_remap_early_shadow_ro() does nothing, because k_end is 0 and k_cur < 0 is always true. Change the test to k_cur != k_end, as done in kasan_init_shadow_page_tables() Signed-off-by:
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Christophe Leroy authored
At the time being we have something like if (something) { p = get(); if (p) { if (something_wrong) goto out; ... return; } else if (a != b) { if (some_error) goto out; ... } goto out; } p = get(); if (!p) { if (a != b) { if (some_error) goto out; ... } goto out; } This is similar to p = get(); if (!p) { if (a != b) { if (some_error) goto out; ... } goto out; } if (something) { if (something_wrong) goto out; ... return; } Signed-off-by: -
Michael Ellerman authored
We currently have two section mismatch warnings: The function __boot_from_prom() references the function __init prom_init(). The function start_here_common() references the function __init start_kernel(). The warnings are correct, we do have branches from non-init code into init code, which is freed after boot. But we don't expect to ever execute any of that early boot code after boot, if we did that would be a bug. In particular calling into OF after boot would be fatal because OF is no longer resident. So for now fix the warnings by marking the relevant functions as __REF, which puts them in the ".ref.text" section. This causes some reordering of the functions in the final link: @@ -217,10 +217,9 @@ c00000000000b088 t generic_secondary_common_init c00000000000b124 t __mmu_off c00000000000b14c t __start_initialization_multiplatform -c00000000000b1ac t __boot_from_prom -c00000000000b1ec t __after_prom_start -c00000000000b260 t p_end -c00000000000b27c T copy_and_flush +c00000000000b1ac t __after_prom_start +c00000000000b220 t p_end +c00000000000b23c T copy_and_flush c00000000000b300 T __secondary_start c00000000000b300 t copy_to_here c00000000000b344 t start_secondary_prolog @@ -228,8 +227,9 @@ c00000000000b36c t enable_64b_mode c00000000000b388 T relative_toc c00000000000b3a8 t p_toc -c00000000000b3b0 t start_here_common -c00000000000b3d0 t start_here_multiplatform +c00000000000b3b0 t __boot_from_prom +c00000000000b3f0 t start_here_multiplatform +c00000000000b480 t start_here_common c00000000000b880 T system_call_common c00000000000b974 t system_call c00000000000b9dc t system_call_exit In particular __boot_from_prom moves after copy_to_here, which means it's not copied to zero in the first stage of copy of the kernel to zero. But that's OK, because we only call __boot_from_prom before we do the copy, so it makes no difference when it's copied. The call sequence is: __start -> __start_initialization_multiplatform -> __boot_from_prom -> __start -> __start_initialization_multiplatform -> __after_prom_start -> copy_and_flush -> copy_and_flush (relocated to 0) -> start_here_multiplatform -> early_setup Reported-by:Mauricio Faria de Oliveira <mauricfo@linux.ibm.com> Reported-by:
Roman Bolshakov <r.bolshakov@yadro.com> Signed-off-by:
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Michael Ellerman authored
In xmon we have two variables that are used by the dump commands. There's ndump which is the number of bytes to dump using 'd', and nidump which is the number of instructions to dump using 'di'. ndump starts as 64 and nidump starts as 16, but both can be set by the user. It's fairly common to be pasting addresses into xmon when trying to debug something, and if you inadvertently double paste an address like so: 0:mon> di c000000002101f6c c000000002101f6c The second value is interpreted as the number of instructions to dump. Luckily it doesn't dump 13 quintrillion instructions, the value is limited to MAX_DUMP (128K). But as each instruction is dumped on a single line, that's still a lot of output. If you're on a slow console that can take multiple minutes to print. If you were "just popping in and out of xmon quickly before the RCU/hardlockup detector fires" you are now having a bad day. Things are not as bad with 'd' because we print 16 bytes per line, so it's fewer lines. But it's still quite a lot. So shrink the maximum for 'd' to 64K (one page), which is 4096 lines. For 'di' add a new limit which is the above / 4 - because instructions are 4 bytes, meaning again we can dump one page. Signed-off-by:
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Alexey Kardashevskiy authored
The "os-term" RTAS calls has one argument with a message address of OS termination cause. rtas_os_term() already passes it but the recently added prom_init's version of that missed it; it also does not fill args correctly. This passes the message address and initializes the number of arguments. Fixes: 6a9c930b ("powerpc/prom_init: Add the ESM call to prom_init") Signed-off-by:
Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by:
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afzal mohammed authored
request_irq() is preferred over setup_irq(). Invocations of setup_irq() occur after memory allocators are ready. Per tglx[1], setup_irq() existed in olden days when allocators were not ready by the time early interrupts were initialized. Hence replace setup_irq() by request_irq(). [1] https://lkml.kernel.org/r/alpine.DEB.2.20.1710191609480.1971@nanosSigned-off-by:
afzal mohammed <afzal.mohd.ma@gmail.com> Signed-off-by:
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Joe Perches authored
Convert the various uses of fallthrough comments to fallthrough; Signed-off-by:
Joe Perches <joe@perches.com> Acked-by:
Arnd Bergmann <arnd@arndb.de> Signed-off-by:
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Balamuruhan S authored
ld instruction should have 14 bit immediate field (DS) concatenated with 0b00 on the right, encode it accordingly. Introduce macro `IMM_DS()` to encode DS form instructions with 14 bit immediate field. Fixes: 4ceae137 ("powerpc: emulate_step() tests for load/store instructions") Reviewed-by:
Sandipan Das <sandipan@linux.ibm.com> Signed-off-by:
Balamuruhan S <bala24@linux.ibm.com> Signed-off-by:
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Tyrel Datwyler authored
The expectation is that when calling of_read_drc_info_cell() repeatedly to parse multiple drc-info records that the in/out curval parameter points at the start of the next record on return. However, the current behavior has curval still pointing at the final value of the record just parsed. The result of which is that if the ibm,drc-info property contains multiple properties the parsed value of the drc_type for any record after the first has the power_domain value of the previous record appended to the type string. eg: observed the following 0xffffffff prepended to PHB drc-info: type: \xff\xff\xff\xffPHB, prefix: PHB , index_start: 0x20000001 drc-info: suffix_start: 1, sequential_elems: 3072, sequential_inc: 1 drc-info: power-domain: 0xffffffff, last_index: 0x20000c00 In practice PHBs are the only type of connector in the ibm,drc-info property that has multiple records. So, it breaks PHB hotplug, but by chance not PCI, CPU, slot, or memory because they happen to only ever be a single record. Fix by incrementing curval past the power_domain value to point at drc_type string of next record. Fixes: e83636ac ("pseries/drc-info: Search DRC properties for CPU indexes") Signed-off-by:
Tyrel Datwyler <tyreld@linux.ibm.com> Acked-by:
Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by:
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Gustavo Luiz Duarte authored
The test case tm-signal-context-force-tm expects a segfault to happen on returning from signal handler, and then does a setcontext() to run the test again. However, the test doesn't always segfault, causing the test to run a single time. This patch fixes the test by putting it within a loop and jumping, via setcontext, just prior to the loop in case it segfaults. This way we get the desired behavior (run the test COUNT_MAX times) regardless if it segfaults or not. This also reduces the use of setcontext for control flow logic, keeping it only in the segfault handler. Also, since 'count' is changed within the signal handler, it is declared as volatile to prevent any compiler optimization getting confused with asynchronous changes. Signed-off-by:
Gustavo Luiz Duarte <gustavold@linux.ibm.com> Signed-off-by:
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- 20 Mar, 2020 3 commits
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Gustavo Luiz Duarte authored
This test triggers a TM Bad Thing by raising a signal in transactional state and forcing a pagefault to happen in kernelspace when the kernel signal handling code first touches the user signal stack. This is inspired by the test tm-signal-context-force-tm but uses userfaultfd to make the test deterministic. While this test always triggers the bug in one run, I had to execute tm-signal-context-force-tm several times (the test runs 5000 times each execution) to trigger the same bug. tm-signal-context-force-tm is kept instead of replaced because, while this test is more reliable and triggers the same bug, tm-signal-context-force-tm has a better coverage, in the sense that by running the test several times it might trigger the pagefault and/or be preempted at different places. v3: skip test if userfaultfd is unavailable. Signed-off-by:
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Michael Ellerman authored
Currently you can enable PPC_KUAP_DEBUG when PPC_KUAP is disabled, even though the former has not effect without the latter. Fix it so that PPC_KUAP_DEBUG can only be enabled when PPC_KUAP is enabled, not when the platform could support KUAP (PPC_HAVE_KUAP). Fixes: 890274c2 ("powerpc/64s: Implement KUAP for Radix MMU") Signed-off-by:
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Michael Ellerman authored
There's two different paths through the sigreturn code, depending on whether the VDSO is mapped or not. We recently discovered a bug in the unmapped case, because it's not commonly used these days. So add a test that sends itself a signal, then moves the VDSO, takes another signal and finally unmaps the VDSO before sending itself another signal. That tests the standard signal path, the code that handles the VDSO being moved, and also the signal path in the case where the VDSO is unmapped. Signed-off-by:
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- 17 Mar, 2020 7 commits
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Nicholas Piggin authored
We should be checking that the instruction was stepped *and* that the target register has the right value. Signed-off-by:
Nicholas Piggin <npiggin@gmail.com> Reviewed-by:
Ravi Bangoria <ravi.bangoria@linux.ibm.com> [mpe: Write change log] Signed-off-by:
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Nicholas Piggin authored
Signed-off-by:
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Christophe Leroy authored
The commit identified below added tlbie_test but forgot to add it in .gitignore. Fixes: 93cad5f7 ("selftests/powerpc: Add test case for tlbie vs mtpidr ordering issue") Cc: stable@vger.kernel.org # v5.4+ Signed-off-by:
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YueHaibing authored
core99_l2_cache/core99_l3_cache do not need to be marked as volatile, remove it. Signed-off-by:
YueHaibing <yuehaibing@huawei.com> Signed-off-by:
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Ilie Halip authored
When building with ppc64_defconfig, the compiler reports that these 2 variables are not used: warning: unused variable 'core99_l2_cache' [-Wunused-variable] warning: unused variable 'core99_l3_cache' [-Wunused-variable] They are only used when CONFIG_PPC64 is not defined. Move them into a section which does the same macro check. Reported-by:Nathan Chancellor <natechancellor@gmail.com> Signed-off-by:
Ilie Halip <ilie.halip@gmail.com> [mpe: Move them into core99_init_caches() which is their only user] Signed-off-by:
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Laurentiu Tudor authored
In the current implementation, the call to loadcam_multi() is wrapped between switch_to_as1() and restore_to_as0() calls so, when it tries to create its own temporary AS=1 TLB1 entry, it ends up duplicating the existing one created by switch_to_as1(). Add a check to skip creating the temporary entry if already running in AS=1. Fixes: d9e1831a ("powerpc/85xx: Load all early TLB entries at once") Cc: stable@vger.kernel.org # v4.4+ Signed-off-by:
Laurentiu Tudor <laurentiu.tudor@nxp.com> Acked-by:
Scott Wood <oss@buserror.net> Signed-off-by:
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Stephen Rothwell authored
ev_byte_channel_send() assumes that its third argument is a 16 byte array. Some places where it is called it may not be (or we can't easily tell if it is). Newer compilers have started producing warnings about this, so make sure we actually pass a 16 byte array. There may be more elegant solutions to this, but the driver is quite old and hasn't been updated in many years. The warnings (from a powerpc allyesconfig build) are: In file included from include/linux/byteorder/big_endian.h:5, from arch/powerpc/include/uapi/asm/byteorder.h:14, from include/asm-generic/bitops/le.h:6, from arch/powerpc/include/asm/bitops.h:250, from include/linux/bitops.h:29, from include/linux/kernel.h:12, from include/asm-generic/bug.h:19, from arch/powerpc/include/asm/bug.h:109, from include/linux/bug.h:5, from include/linux/mmdebug.h:5, from include/linux/gfp.h:5, from include/linux/slab.h:15, from drivers/tty/ehv_bytechan.c:24: drivers/tty/ehv_bytechan.c: In function ‘ehv_bc_udbg_putc’: arch/powerpc/include/asm/epapr_hcalls.h:298:20: warning: array subscript 1 is outside array bounds of ‘const char[1]’ [-Warray-bounds] 298 | r6 = be32_to_cpu(p[1]); include/uapi/linux/byteorder/big_endian.h:40:51: note: in definition of macro ‘__be32_to_cpu’ 40 | #define __be32_to_cpu(x) ((__force __u32)(__be32)(x)) | ^ arch/powerpc/include/asm/epapr_hcalls.h:298:7: note: in expansion of macro ‘be32_to_cpu’ 298 | r6 = be32_to_cpu(p[1]); | ^~~~~~~~~~~ drivers/tty/ehv_bytechan.c:166:13: note: while referencing ‘data’ 166 | static void ehv_bc_udbg_putc(char c) | ^~~~~~~~~~~~~~~~ Fixes: dcd83aaf ("tty/powerpc: introduce the ePAPR embedded hypervisor byte channel driver") Signed-off-by:Stephen Rothwell <sfr@canb.auug.org.au> Tested-by:
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- 13 Mar, 2020 4 commits
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Oliver O'Halloran authored
The PowerNV cpufreq driver registers two notifiers: one to catch throttle messages from the OCC and one to bump the CPU frequency back to normal before a reboot. Both require the cpufreq driver to be registered in order to function since the notifier callbacks use various cpufreq_*() functions. Right now we register both notifiers before we've initialised the driver. This seems to work, but we should head off any protential problems by registering the notifiers after the driver is initialised. Signed-off-by:
Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by:
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Oliver O'Halloran authored
The cpufreq driver has a use-after-free that we can hit if: a) There's an OCC message pending when the notifier is registered, and b) The cpufreq driver fails to register with the core. When a) occurs the notifier schedules a workqueue item to handle the message. The backing work_struct is located on chips[].throttle and when b) happens we clean up by freeing the array. Once we get to the (now free) queued item and the kernel crashes. Fixes: c5e29ea7 ("cpufreq: powernv: Fix bugs in powernv_cpufreq_{init/exit}") Cc: stable@vger.kernel.org # v4.6+ Signed-off-by:
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Joe Lawrence authored
The original 2005 patch that introduced the powerpc vdso, pre-git ("ppc64: Implement a vDSO and use it for signal trampoline") notes that: ... symbols exposed by the vDSO aren't "normal" function symbols, apps can't be expected to link against them directly, the vDSO's are both seen as if they were linked at 0 and the symbols just contain offsets to the various functions. This is done on purpose to avoid a relocation step (ppc64 functions normally have descriptors with abs addresses in them). When glibc uses those functions, it's expected to use it's own trampolines that know how to reach them. Despite that explanation, there remains dead #ifdef VDS64_HAS_DESCRIPTORS code-blocks that provide alternate function definitions that setup function descriptors. Since VDS64_HAS_DESCRIPTORS has been unused for all these years, we might as well finally remove it from the codebase. Signed-off-by:Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by:
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Christophe Leroy authored
Commit 2efc7c08 ("powerpc/32: drop get_pteptr()"), replaced get_pteptr() by virt_to_kpte(). But virt_to_kpte() lacks a NULL pmd check and returns an invalid non NULL pointer when there is no page table. Reported-by:
Nick Desaulniers <ndesaulniers@google.com> Fixes: 2efc7c08 ("powerpc/32: drop get_pteptr()") Signed-off-by:
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- 10 Mar, 2020 1 commit
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Michael Ellerman authored
Merge in our fixes branch. In particular we want to merge the TM and KUAP fixes, so we can add selftests for them in next.
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- 05 Mar, 2020 1 commit
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Michael Ellerman authored
Stefan reported a strange kernel fault which turned out to be due to a missing KUAP disable in flush_coherent_icache() called from flush_icache_range(). The fault looks like: Kernel attempted to access user page (7fffc30d9c00) - exploit attempt? (uid: 1009) BUG: Unable to handle kernel data access on read at 0x7fffc30d9c00 Faulting instruction address: 0xc00000000007232c Oops: Kernel access of bad area, sig: 11 [#1] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA PowerNV CPU: 35 PID: 5886 Comm: sigtramp Not tainted 5.6.0-rc2-gcc-8.2.0-00003-gfc37a163 #79 NIP: c00000000007232c LR: c00000000003b7fc CTR: 0000000000000000 REGS: c000001e11093940 TRAP: 0300 Not tainted (5.6.0-rc2-gcc-8.2.0-00003-gfc37a163) MSR: 900000000280b033 <SF,HV,VEC,VSX,EE,FP,ME,IR,DR,RI,LE> CR: 28000884 XER: 00000000 CFAR: c0000000000722fc DAR: 00007fffc30d9c00 DSISR: 08000000 IRQMASK: 0 GPR00: c00000000003b7fc c000001e11093bd0 c0000000023ac200 00007fffc30d9c00 GPR04: 00007fffc30d9c18 0000000000000000 c000001e11093bd4 0000000000000000 GPR08: 0000000000000000 0000000000000001 0000000000000000 c000001e1104ed80 GPR12: 0000000000000000 c000001fff6ab380 c0000000016be2d0 4000000000000000 GPR16: c000000000000000 bfffffffffffffff 0000000000000000 0000000000000000 GPR20: 00007fffc30d9c00 00007fffc30d8f58 00007fffc30d9c18 00007fffc30d9c20 GPR24: 00007fffc30d9c18 0000000000000000 c000001e11093d90 c000001e1104ed80 GPR28: c000001e11093e90 0000000000000000 c0000000023d9d18 00007fffc30d9c00 NIP flush_icache_range+0x5c/0x80 LR handle_rt_signal64+0x95c/0xc2c Call Trace: 0xc000001e11093d90 (unreliable) handle_rt_signal64+0x93c/0xc2c do_notify_resume+0x310/0x430 ret_from_except_lite+0x70/0x74 Instruction dump: 409e002c 7c0802a6 3c62ff31 3863f6a0 f8010080 48195fed 60000000 48fe4c8d 60000000 e8010080 7c0803a6 7c0004ac <7c00ffac> 7c0004ac 4c00012c 38210070 This path through handle_rt_signal64() to setup_trampoline() and flush_icache_range() is only triggered by 64-bit processes that have unmapped their VDSO, which is rare. flush_icache_range() takes a range of addresses to flush. In flush_coherent_icache() we implement an optimisation for CPUs where we know we don't actually have to flush the whole range, we just need to do a single icbi. However we still execute the icbi on the user address of the start of the range we're flushing. On CPUs that also implement KUAP (Power9) that leads to the spurious fault above. We should be able to pass any address, including a kernel address, to the icbi on these CPUs, which would avoid any interaction with KUAP. But I don't want to make that change in a bug fix, just in case it surfaces some strange behaviour on some CPU. So for now just disable KUAP around the icbi. Note the icbi is treated as a load, so we allow read access, not write as you'd expect. Fixes: 890274c2 ("powerpc/64s: Implement KUAP for Radix MMU") Cc: stable@vger.kernel.org # v5.2+ Reported-by:
Stefan Berger <stefanb@linux.ibm.com> Signed-off-by:
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- 04 Mar, 2020 3 commits
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Srikar Dronamraju authored
With commit ("powerpc/numa: Early request for home node associativity"), commit 2ea62630 ("powerpc/topology: Get topology for shared processors at boot") which was requesting home node associativity becomes redundant. Hence remove the late request for home node associativity. Signed-off-by:Srikar Dronamraju <srikar@linux.vnet.ibm.com> Reported-by:
Abdul Haleem <abdhalee@linux.vnet.ibm.com> Reviewed-by:
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Srikar Dronamraju authored
Currently the kernel detects if its running on a shared lpar platform and requests home node associativity before the scheduler sched_domains are setup. However between the time NUMA setup is initialized and the request for home node associativity, workqueue initializes its per node cpumask. The per node workqueue possible cpumask may turn invalid after home node associativity resulting in weird situations like workqueue possible cpumask being a subset of workqueue online cpumask. This can be fixed by requesting home node associativity earlier just before NUMA setup. However at the NUMA setup time, kernel may not be in a position to detect if its running on a shared lpar platform. So request for home node associativity and if the request fails, fallback on the device tree property. Signed-off-by:
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Srikar Dronamraju authored
All the sibling threads of a core have to be part of the same node. To ensure that all the sibling threads map to the same node, always lookup/update the cpu-to-node map of the first thread in the core. Signed-off-by:
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