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2020-03-25powerpc/kprobes: Ignore traps that happened in real modeChristophe Leroy
When a program check exception happens while MMU translation is disabled, following Oops happens in kprobe_handler() in the following code: } else if (*addr != BREAKPOINT_INSTRUCTION) { BUG: Unable to handle kernel data access on read at 0x0000e268 Faulting instruction address: 0xc000ec34 Oops: Kernel access of bad area, sig: 11 [#1] BE PAGE_SIZE=16K PREEMPT CMPC885 Modules linked in: CPU: 0 PID: 429 Comm: cat Not tainted 5.6.0-rc1-s3k-dev-00824-g84195dc6c58a #3267 NIP: c000ec34 LR: c000ecd8 CTR: c019cab8 REGS: ca4d3b58 TRAP: 0300 Not tainted (5.6.0-rc1-s3k-dev-00824-g84195dc6c58a) MSR: 00001032 <ME,IR,DR,RI> CR: 2a4d3c52 XER: 00000000 DAR: 0000e268 DSISR: c0000000 GPR00: c000b09c ca4d3c10 c66d0620 00000000 ca4d3c60 00000000 00009032 00000000 GPR08: 00020000 00000000 c087de44 c000afe0 c66d0ad0 100d3dd6 fffffff3 00000000 GPR16: 00000000 00000041 00000000 ca4d3d70 00000000 00000000 0000416d 00000000 GPR24: 00000004 c53b6128 00000000 0000e268 00000000 c07c0000 c07bb6fc ca4d3c60 NIP [c000ec34] kprobe_handler+0x128/0x290 LR [c000ecd8] kprobe_handler+0x1cc/0x290 Call Trace: [ca4d3c30] [c000b09c] program_check_exception+0xbc/0x6fc [ca4d3c50] [c000e43c] ret_from_except_full+0x0/0x4 --- interrupt: 700 at 0xe268 Instruction dump: 913e0008 81220000 38600001 3929ffff 91220000 80010024 bb410008 7c0803a6 38210020 4e800020 38600000 4e800020 <813b0000> 6d2a7fe0 2f8a0008 419e0154 ---[ end trace 5b9152d4cdadd06d ]--- kprobe is not prepared to handle events in real mode and functions running in real mode should have been blacklisted, so kprobe_handler() can safely bail out telling 'this trap is not mine' for any trap that happened while in real-mode. If the trap happened with MSR_IR or MSR_DR cleared, return 0 immediately. Reported-by: Larry Finger <Larry.Finger@lwfinger.net> Fixes: 6cc89bad60a6 ("powerpc/kprobes: Invoke handlers directly") Cc: stable@vger.kernel.org # v4.10+ Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/424331e2006e7291a1bfe40e7f3fa58825f565e1.1582054578.git.christophe.leroy@c-s.fr
2020-03-25powerpc/eeh: Rework eeh_ops->probe()Oliver O'Halloran
With the EEH early probe now being pseries specific there's no need for eeh_ops->probe() to take a pci_dn. Instead, we can make it take a pci_dev and use the probe function to map a pci_dev to an eeh_dev. This allows the platform to implement it's own method for finding (or creating) an eeh_dev for a given pci_dev which also removes a use of pci_dn in generic EEH code. This patch also renames eeh_device_add_late() to eeh_device_probe(). This better reflects what it does does and removes the last vestiges of the early/late EEH probe split. 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/20200306073904.4737-6-oohall@gmail.com
2020-03-25powerpc/eeh: Make early EEH init pseries specificOliver O'Halloran
The eeh_ops->probe() function is called from two different contexts: 1. On pseries, where we set EEH_PROBE_MODE_DEVTREE, it's called in eeh_add_device_early() which is supposed to run before we create a pci_dev. 2. On PowerNV, where we set EEH_PROBE_MODE_DEV, it's called in eeh_device_add_late() which is supposed to run *after* the pci_dev is created. The "early" probe is required because PAPR requires that we perform an RTAS call to enable EEH support on a device before we start interacting with it via config space or MMIO. This requirement doesn't exist on PowerNV and shoehorning two completely separate initialisation paths into a common interface just results in a convoluted code everywhere. Additionally the early probe requires the probe function to take an pci_dn rather than a pci_dev argument. We'd like to make pci_dn a pseries specific data structure since there's no real requirement for them on PowerNV. To help both goals move the early probe into the pseries containment zone so the platform depedence is more explicit. 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/20200306073904.4737-5-oohall@gmail.com
2020-03-25powerpc/eeh: Remove PHB check in probeOliver O'Halloran
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
2020-03-25powerpc/eeh: Do early EEH init only when requiredOliver O'Halloran
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: 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/20200306073904.4737-3-oohall@gmail.com
2020-03-25powerpc/eeh: Remove eeh_add_device_tree_late()Oliver O'Halloran
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: 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/20200306073904.4737-2-oohall@gmail.com
2020-03-25powerpc/eeh: Add sysfs files in late probeOliver O'Halloran
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: 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/20200306073904.4737-1-oohall@gmail.com
2020-03-25powerpc/64: Prevent stack protection in early bootMichael Ellerman
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: 06ec27aea9fc ("powerpc/64: add stack protector support") Cc: stable@vger.kernel.org # v4.20+ Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200320032116.1024773-2-mpe@ellerman.id.au
2020-03-25powerpc/64: Setup a paca before parsing device tree etc.Daniel Axtens
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: fb0b0a73b223 ("powerpc: Enable kcov") Fixes: 06ec27aea9fc ("powerpc/64: add stack protector support") Cc: stable@vger.kernel.org # v4.20+ Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com> Suggested-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Daniel Axtens <dja@axtens.net> [mpe: Reword comments & change log a bit to mention stack protector] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200320032116.1024773-1-mpe@ellerman.id.au
2020-03-25powerpc/32s: reorder Linux PTE bits to better match Hash PTE bits.Christophe Leroy
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: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/c4d6c18a7f8d9d3b899bc492f55fbc40ef38896a.1583861325.git.christophe.leroy@c-s.fr
2020-03-25powerpc/kprobes: Remove redundant codeChristophe Leroy
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: Christophe Leroy <christophe.leroy@c-s.fr> [mpe: Reflow the comment that was moved] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/07a17425743600460ce35fa9432d42487a825583.1582099499.git.christophe.leroy@c-s.fr
2020-03-25powerpc/64s: Fix section mismatch warnings from boot codeMichael Ellerman
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: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200225031328.14676-1-mpe@ellerman.id.au
2020-03-25powerpc/prom_init: Pass the "os-term" message to hypervisorAlexey Kardashevskiy
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: 6a9c930bd775 ("powerpc/prom_init: Add the ESM call to prom_init") Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200312074404.87293-1-aik@ozlabs.ru
2020-03-19bpf: Support llvm-objcopy for vmlinux BTFFangrui Song
Simplify gen_btf logic to make it work with llvm-objcopy. The existing 'file format' and 'architecture' parsing logic is brittle and does not work with llvm-objcopy/llvm-objdump. 'file format' output of llvm-objdump>=11 will match GNU objdump, but 'architecture' (bfdarch) may not. .BTF in .tmp_vmlinux.btf is non-SHF_ALLOC. Add the SHF_ALLOC flag because it is part of vmlinux image used for introspection. C code can reference the section via linker script defined __start_BTF and __stop_BTF. This fixes a small problem that previous .BTF had the SHF_WRITE flag (objcopy -I binary -O elf* synthesized .data). Additionally, `objcopy -I binary` synthesized symbols _binary__btf_vmlinux_bin_start and _binary__btf_vmlinux_bin_stop (not used elsewhere) are replaced with more commonplace __start_BTF and __stop_BTF. Add 2>/dev/null because GNU objcopy (but not llvm-objcopy) warns "empty loadable segment detected at vaddr=0xffffffff81000000, is this intentional?" We use a dd command to change the e_type field in the ELF header from ET_EXEC to ET_REL so that lld will accept .btf.vmlinux.bin.o. Accepting ET_EXEC as an input file is an extremely rare GNU ld feature that lld does not intend to support, because this is error-prone. The output section description .BTF in include/asm-generic/vmlinux.lds.h avoids potential subtle orphan section placement issues and suppresses --orphan-handling=warn warnings. Fixes: df786c9b9476 ("bpf: Force .BTF section start to zero when dumping from vmlinux") Fixes: cb0cc635c7a9 ("powerpc: Include .BTF section") Reported-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Fangrui Song <maskray@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Stanislav Fomichev <sdf@google.com> Tested-by: Andrii Nakryiko <andriin@fb.com> Reviewed-by: Stanislav Fomichev <sdf@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Link: https://github.com/ClangBuiltLinux/linux/issues/871 Link: https://lore.kernel.org/bpf/20200318222746.173648-1-maskray@google.com
2020-03-13powerpc/vdso: remove deprecated VDS64_HAS_DESCRIPTORS referencesJoe Lawrence
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: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200224211848.26087-1-joe.lawrence@redhat.com
2020-03-10Merge branch 'fixes' into nextMichael Ellerman
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.
2020-03-04powerpc/numa: Remove late request for home node associativitySrikar Dronamraju
With commit ("powerpc/numa: Early request for home node associativity"), commit 2ea626306810 ("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: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200129135301.24739-6-srikar@linux.vnet.ibm.com
2020-03-04powerpc/smp: Use nid as fallback for package_idSrikar Dronamraju
package_id is to match cores that are part of the same chip. On PowerNV machines, package_id defaults to chip_id. However ibm,chip_id property is not present in device-tree of PowerVM LPARs. Hence lscpu output shows one core per socket and multiple cores. To overcome this, use nid as the package_id on PowerVM LPARs. Before the patch: Architecture: ppc64le Byte Order: Little Endian CPU(s): 128 On-line CPU(s) list: 0-127 Thread(s) per core: 8 Core(s) per socket: 1 <---------------------- Socket(s): 16 <---------------------- NUMA node(s): 2 Model: 2.2 (pvr 004e 0202) Model name: POWER9 (architected), altivec supported Hypervisor vendor: pHyp Virtualization type: para L1d cache: 32K L1i cache: 32K L2 cache: 512K L3 cache: 10240K NUMA node0 CPU(s): 0-63 NUMA node1 CPU(s): 64-127 # # cat /sys/devices/system/cpu/cpu0/topology/physical_package_id -1 After the patch: Architecture: ppc64le Byte Order: Little Endian CPU(s): 128 On-line CPU(s) list: 0-127 Thread(s) per core: 8 <--------------------- Core(s) per socket: 8 <--------------------- Socket(s): 2 NUMA node(s): 2 Model: 2.2 (pvr 004e 0202) Model name: POWER9 (architected), altivec supported Hypervisor vendor: pHyp Virtualization type: para L1d cache: 32K L1i cache: 32K L2 cache: 512K L3 cache: 10240K NUMA node0 CPU(s): 0-63 NUMA node1 CPU(s): 64-127 # # cat /sys/devices/system/cpu/cpu0/topology/physical_package_id 0 Now lscpu output is more in line with the system configuration. Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> [mpe: Use pkg_id instead of ppid, tweak change log and comment] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200129135121.24617-1-srikar@linux.vnet.ibm.com
2020-03-04powerpc/irq: Use current_stack_pointer in do_IRQ()Christophe Leroy
Until commit 7306e83ccf5c ("powerpc: Don't use CURRENT_THREAD_INFO to find the stack"), the current stack base address was obtained by calling current_thread_info(). That inline function was simply masking out the value of r1. In that commit, it was changed to using current_stack_pointer() (since renamed current_stack_frame()), which is a heavier function as it is an outline assembly function which cannot be inlined and which reads the content of the stack at 0(r1). Convert to using current_stack_pointer for geting r1 and masking out its value to obtain the base address of the stack pointer as before. Fixes: 7306e83ccf5c ("powerpc: Don't use CURRENT_THREAD_INFO to find the stack") Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200220115141.2707-5-mpe@ellerman.id.au
2020-03-04powerpc/irq: use IS_ENABLED() in check_stack_overflow()Christophe Leroy
Instead of #ifdef, use IS_ENABLED(CONFIG_DEBUG_STACKOVERFLOW). This enable GCC to check for code validity even when the option is not selected. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200220115141.2707-4-mpe@ellerman.id.au
2020-03-04powerpc/irq: Use current_stack_pointer in check_stack_overflow()Christophe Leroy
The purpose of check_stack_overflow() is to verify that the stack has not overflowed. To really know whether the stack pointer is still within boundaries, the check must be done directly on the value of r1. So use current_stack_pointer, which returns the current value of r1, rather than current_stack_frame() which causes a frame to be created and then returns that value. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200220115141.2707-3-mpe@ellerman.id.au
2020-03-04powerpc: Rename current_stack_pointer() to current_stack_frame()Michael Ellerman
current_stack_pointer(), which was called __get_SP(), used to just return the value in r1. But that caused problems in some cases, so it was turned into a function in commit bfe9a2cfe91a ("powerpc: Reimplement __get_SP() as a function not a define"). Because it's a function in a separate compilation unit to all its callers, it has the effect of causing a stack frame to be created, and then returns the address of that frame. This is good in some cases like those described in the above commit, but in other cases it's overkill, we just need to know what stack page we're on. On some other arches current_stack_pointer is just a register global giving the stack pointer, and we'd like to do that too. So rename our current_stack_pointer() to current_stack_frame() to make that possible. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr> Link: https://lore.kernel.org/r/20200220115141.2707-1-mpe@ellerman.id.au
2020-03-04powerpc/kernel/sysfs: Add new config option PMU_SYSFS to enable PMU SPRs ↵Kajol Jain
sysfs file creation Many of the performance monitoring unit (PMU) SPRs are exposed in the sysfs. This may not be a desirable since "perf" API is the primary interface to program PMU and collect counter data in the system. But that said, we cant remove these sysfs files since we dont whether anyone/anything is using them. So the patch adds a new CONFIG option 'CONFIG_PMU_SYSFS' (user selectable) to be used in sysfs file creation for PMU SPRs. New option by default is disabled, but can be enabled if user needs it. Tested this patch behaviour in powernv and pseries machines. Patch is also tested for pmac32_defconfig. Signed-off-by: Kajol Jain <kjain@linux.ibm.com> Tested-by: Nageswara R Sastry <nasastry@in.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200214080606.26872-2-kjain@linux.ibm.com
2020-03-04powerpc/kernel/sysfs: Refactor current sysfs.cMadhavan Srinivasan
An attempt to refactor the current sysfs.c file. To start with a big chuck of macro #defines and dscr functions are moved to start of the file. Secondly, HAS_ #define macros are cleanup based on CONFIG_ options Finally new HAS_ macro added: 1. HAS_PPC_PA6T (for PA6T) to separate out non-PMU SPRs. 2. HAS_PPC_PMC56 to separate out PMC SPR's from HAS_PPC_PMC_CLASSIC which come under CONFIG_PPC64. Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200214080606.26872-1-kjain@linux.ibm.com
2020-03-04powerpc/kernel: no need to check return value of debugfs_create functionsGreg Kroah-Hartman
When calling debugfs functions, there is no need to ever check the return value. The function can work or not, but the code logic should never do something different based on this. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200209105901.1620958-1-gregkh@linuxfoundation.org
2020-02-28powerpc: fix hardware PMU exception bug on PowerVM compatibility mode systemsDesnes A. Nunes do Rosario
PowerVM systems running compatibility mode on a few Power8 revisions are still vulnerable to the hardware defect that loses PMU exceptions arriving prior to a context switch. The software fix for this issue is enabled through the CPU_FTR_PMAO_BUG cpu_feature bit, nevertheless this bit also needs to be set for PowerVM compatibility mode systems. Fixes: 68f2f0d431d9ea4 ("powerpc: Add a cpu feature CPU_FTR_PMAO_BUG") Signed-off-by: Desnes A. Nunes do Rosario <desnesn@linux.ibm.com> Reviewed-by: Leonardo Bras <leonardo@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200227134715.9715-1-desnesn@linux.ibm.com
2020-02-26powerpc/32: don't restore r0, r6-r8 on exception entry path after ↵Christophe Leroy
trace_hardirqs_off() Since commit b86fb88855ea ("powerpc/32: implement fast entry for syscalls on non BOOKE") and commit 1a4b739bbb4f ("powerpc/32: implement fast entry for syscalls on BOOKE"), syscalls don't use the exception entry path anymore. It is therefore pointless to restore r0 and r6-r8 after calling trace_hardirqs_off(). In the meantime, drop the '2:' label which is unused and misleading. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/d2c6dc65d27e83964eb05f16a126161ab6455eea.1578388585.git.christophe.leroy@c-s.fr
2020-02-24powerpc: Include .BTF sectionNaveen N. Rao
Selecting CONFIG_DEBUG_INFO_BTF results in the below warning from ld: ld: warning: orphan section `.BTF' from `.btf.vmlinux.bin.o' being placed in section `.BTF' Include .BTF section in vmlinux explicitly to fix the same. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200220113132.857132-1-naveen.n.rao@linux.vnet.ibm.com
2020-02-24powerpc/watchpoint: Don't call dar_within_range() for Book3SRavi Bangoria
DAR is set to the first byte of overlap between actual access and watched range at DSI on Book3S processor. But actual access range might or might not be within user asked range. So for Book3S, it must not call dar_within_range(). This revert portion of commit 39413ae00967 ("powerpc/hw_breakpoints: Rewrite 8xx breakpoints to allow any address range size."). Before patch: # ./tools/testing/selftests/powerpc/ptrace/perf-hwbreak ... TESTED: No overlap FAILED: Partial overlap: 0 != 2 TESTED: Partial overlap TESTED: No overlap FAILED: Full overlap: 0 != 2 failure: perf_hwbreak After patch: TESTED: No overlap TESTED: Partial overlap TESTED: Partial overlap TESTED: No overlap TESTED: Full overlap success: perf_hwbreak Fixes: 39413ae00967 ("powerpc/hw_breakpoints: Rewrite 8xx breakpoints to allow any address range size.") Reported-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com> Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200222082049.330435-1-ravi.bangoria@linux.ibm.com
2020-02-19powerpc: Don't use thread struct for saving SRR0/1 on syscall.Christophe Leroy
CR0 can be saved later, and CTR can also be used for saving. Keep SRR1 in r9 and stash SRR0 in CTR, this avoids using thread_struct in memory for that. Saves 3 cycles (ie 1%) in null_syscall selftest on 8xx. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/b94c3bc03bac9431fec2dadb686384c481889422.1580470483.git.christophe.leroy@c-s.fr
2020-02-19powerpc/32: Warn and return ENOSYS on syscalls from kernelChristophe Leroy
Since commit b86fb88855ea ("powerpc/32: implement fast entry for syscalls on non BOOKE") and commit 1a4b739bbb4f ("powerpc/32: implement fast entry for syscalls on BOOKE"), syscalls from kernel are unexpected and can have catastrophic consequences as it will destroy the kernel stack. Test MSR_PR on syscall entry. In case syscall is from kernel, emit a warning and return ENOSYS error. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/8ee3bdbbdfdfc64ca7001e90c43b2aee6f333578.1580470482.git.christophe.leroy@c-s.fr
2020-02-19powerpc/fadump: sysfs for fadump memory reservationSourabh Jain
Add a sys interface to allow querying the memory reserved by FADump for saving the crash dump. Also added Documentation/ABI for the new sysfs file. Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20191211160910.21656-7-sourabhjain@linux.ibm.com
2020-02-19powerpc/fadump: Reorganize /sys/kernel/fadump_* sysfs filesSourabh Jain
As the number of FADump sysfs files increases it is hard to manage all of them inside /sys/kernel directory. It's better to have all the FADump related sysfs files in a dedicated directory /sys/kernel/fadump. But in order to maintain backward compatibility a symlink has been added for every sysfs that has moved to new location. As the FADump sysfs files are now part of a dedicated directory there is no need to prefix their name with fadump_, hence sysfs file names are also updated. For example fadump_enabled sysfs file is now referred as enabled. Also consolidate ABI documentation for all the FADump sysfs files in a single file Documentation/ABI/testing/sysfs-kernel-fadump. Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com> Tested-by: Michal Suchanek <msuchanek@suse.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20191211160910.21656-4-sourabhjain@linux.ibm.com
2020-02-19powerpc/process: Remove unneccessary #ifdef CONFIG_PPC64 in copy_thread_tls()Christophe Leroy
is_32bit_task() exists on both PPC64 and PPC32, no need of an ifdefery. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Reviewed-by: Michal Suchanek <msuchanek@suse.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/6ecbda05b4119c40222dc8ec284604e1597c9bff.1580327381.git.christophe.leroy@c-s.fr
2020-02-19powerpc/entry: Fix an #if which should be an #ifdef in entry_32.SChristophe Leroy
Fixes: 12c3f1fd87bf ("powerpc/32s: get rid of CPU_FTR_601 feature") Cc: stable@vger.kernel.org # v5.4+ Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/a99fc0ad65b87a1ba51cfa3e0e9034ee294c3e07.1582034961.git.christophe.leroy@c-s.fr
2020-02-18powerpc/6xx: Fix power_save_ppc32_restore() with CONFIG_VMAP_STACKChristophe Leroy
power_save_ppc32_restore() is called during exception entry, before re-enabling the MMU. It substracts KERNELBASE from the address of nap_save_msscr0 to access it. With CONFIG_VMAP_STACK enabled, data MMU translation has already been re-enabled, so power_save_ppc32_restore() has to access nap_save_msscr0 by its virtual address. Reported-by: Larry Finger <Larry.Finger@lwfinger.net> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Fixes: cd08f109e262 ("powerpc/32s: Enable CONFIG_VMAP_STACK") Tested-by: Larry Finger <Larry.Finger@lwfinger.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/7bce32ccbab3ba3e3e0f27da6961bf6313df97ed.1581663140.git.christophe.leroy@c-s.fr
2020-02-18powerpc/chrp: Fix enter_rtas() with CONFIG_VMAP_STACKChristophe Leroy
With CONFIG_VMAP_STACK, data MMU has to be enabled to read data on the stack. Fixes: cd08f109e262 ("powerpc/32s: Enable CONFIG_VMAP_STACK") Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/d2330584f8c42d3039896e2b56f5d39676dc919c.1581669558.git.christophe.leroy@c-s.fr
2020-02-18powerpc/32s: Fix DSI and ISI exceptions for CONFIG_VMAP_STACKChristophe Leroy
hash_page() needs to read page tables from kernel memory. When entire kernel memory is mapped by BATs, which is normally the case when CONFIG_STRICT_KERNEL_RWX is not set, it works even if the page hosting the page table is not referenced in the MMU hash table. However, if the page where the page table resides is not covered by a BAT, a DSI fault can be encountered from hash_page(), and it loops forever. This can happen when CONFIG_STRICT_KERNEL_RWX is selected and the alignment of the different regions is too small to allow covering the entire memory with BATs. This also happens when CONFIG_DEBUG_PAGEALLOC is selected or when booting with 'nobats' flag. Also, if the page containing the kernel stack is not present in the MMU hash table, registers cannot be saved and a recursive DSI fault is encountered. To allow hash_page() to properly do its job at all time and load the MMU hash table whenever needed, it must run with data MMU disabled. This means it must be called before re-enabling data MMU. To allow this, registers clobbered by hash_page() and create_hpte() have to be saved in the thread struct together with SRR0, SSR1, DAR and DSISR. It is also necessary to ensure that DSI prolog doesn't overwrite regs saved by prolog of the current running exception. That means: - DSI can only use SPRN_SPRG_SCRATCH0 - Exceptions must free SPRN_SPRG_SCRATCH0 before writing to the stack. This also fixes the Oops reported by Erhard when create_hpte() is called by add_hash_page(). Due to prolog size increase, a few more exceptions had to get split in two parts. Fixes: cd08f109e262 ("powerpc/32s: Enable CONFIG_VMAP_STACK") Reported-by: Erhard F. <erhard_f@mailbox.org> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Tested-by: Erhard F. <erhard_f@mailbox.org> Tested-by: Larry Finger <Larry.Finger@lwfinger.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://bugzilla.kernel.org/show_bug.cgi?id=206501 Link: https://lore.kernel.org/r/64a4aa44686e9fd4b01333401367029771d9b231.1581761633.git.christophe.leroy@c-s.fr
2020-02-18powerpc/tm: Fix clearing MSR[TS] in current when reclaiming on signal deliveryGustavo Luiz Duarte
After a treclaim, we expect to be in non-transactional state. If we don't clear the current thread's MSR[TS] before we get preempted, then tm_recheckpoint_new_task() will recheckpoint and we get rescheduled in suspended transaction state. When handling a signal caught in transactional state, handle_rt_signal64() calls get_tm_stackpointer() that treclaims the transaction using tm_reclaim_current() but without clearing the thread's MSR[TS]. This can cause the TM Bad Thing exception below if later we pagefault and get preempted trying to access the user's sigframe, using __put_user(). Afterwards, when we are rescheduled back into do_page_fault() (but now in suspended state since the thread's MSR[TS] was not cleared), upon executing 'rfid' after completion of the page fault handling, the exception is raised because a transition from suspended to non-transactional state is invalid. Unexpected TM Bad Thing exception at c00000000000de44 (msr 0x8000000302a03031) tm_scratch=800000010280b033 Oops: Unrecoverable exception, sig: 6 [#1] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries CPU: 25 PID: 15547 Comm: a.out Not tainted 5.4.0-rc2 #32 NIP: c00000000000de44 LR: c000000000034728 CTR: 0000000000000000 REGS: c00000003fe7bd70 TRAP: 0700 Not tainted (5.4.0-rc2) MSR: 8000000302a03031 <SF,VEC,VSX,FP,ME,IR,DR,LE,TM[SE]> CR: 44000884 XER: 00000000 CFAR: c00000000000dda4 IRQMASK: 0 PACATMSCRATCH: 800000010280b033 GPR00: c000000000034728 c000000f65a17c80 c000000001662800 00007fffacf3fd78 GPR04: 0000000000001000 0000000000001000 0000000000000000 c000000f611f8af0 GPR08: 0000000000000000 0000000078006001 0000000000000000 000c000000000000 GPR12: c000000f611f84b0 c00000003ffcb200 0000000000000000 0000000000000000 GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR20: 0000000000000000 0000000000000000 0000000000000000 c000000f611f8140 GPR24: 0000000000000000 00007fffacf3fd68 c000000f65a17d90 c000000f611f7800 GPR28: c000000f65a17e90 c000000f65a17e90 c000000001685e18 00007fffacf3f000 NIP [c00000000000de44] fast_exception_return+0xf4/0x1b0 LR [c000000000034728] handle_rt_signal64+0x78/0xc50 Call Trace: [c000000f65a17c80] [c000000000034710] handle_rt_signal64+0x60/0xc50 (unreliable) [c000000f65a17d30] [c000000000023640] do_notify_resume+0x330/0x460 [c000000f65a17e20] [c00000000000dcc4] ret_from_except_lite+0x70/0x74 Instruction dump: 7c4ff120 e8410170 7c5a03a6 38400000 f8410060 e8010070 e8410080 e8610088 60000000 60000000 e8810090 e8210078 <4c000024> 48000000 e8610178 88ed0989 ---[ end trace 93094aa44b442f87 ]--- The simplified sequence of events that triggers the above exception is: ... # userspace in NON-TRANSACTIONAL state tbegin # userspace in TRANSACTIONAL state signal delivery # kernelspace in SUSPENDED state handle_rt_signal64() get_tm_stackpointer() treclaim # kernelspace in NON-TRANSACTIONAL state __put_user() page fault happens. We will never get back here because of the TM Bad Thing exception. page fault handling kicks in and we voluntarily preempt ourselves do_page_fault() __schedule() __switch_to(other_task) our task is rescheduled and we recheckpoint because the thread's MSR[TS] was not cleared __switch_to(our_task) switch_to_tm() tm_recheckpoint_new_task() trechkpt # kernelspace in SUSPENDED state The page fault handling resumes, but now we are in suspended transaction state do_page_fault() completes rfid <----- trying to get back where the page fault happened (we were non-transactional back then) TM Bad Thing # illegal transition from suspended to non-transactional This patch fixes that issue by clearing the current thread's MSR[TS] just after treclaim in get_tm_stackpointer() so that we stay in non-transactional state in case we are preempted. In order to make treclaim and clearing the thread's MSR[TS] atomic from a preemption perspective when CONFIG_PREEMPT is set, preempt_disable/enable() is used. It's also necessary to save the previous value of the thread's MSR before get_tm_stackpointer() is called so that it can be exposed to the signal handler later in setup_tm_sigcontexts() to inform the userspace MSR at the moment of the signal delivery. Found with tm-signal-context-force-tm kernel selftest. Fixes: 2b0a576d15e0 ("powerpc: Add new transactional memory state to the signal context") Cc: stable@vger.kernel.org # v3.9 Signed-off-by: Gustavo Luiz Duarte <gustavold@linux.ibm.com> Acked-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200211033831.11165-1-gustavold@linux.ibm.com
2020-02-17powerpc/8xx: Fix clearing of bits 20-23 in ITLB missChristophe Leroy
In ITLB miss handled the line supposed to clear bits 20-23 on the L2 ITLB entry is buggy and does indeed nothing, leading to undefined value which could allow execution when it shouldn't. Properly do the clearing with the relevant instruction. Fixes: 74fabcadfd43 ("powerpc/8xx: don't use r12/SPRN_SPRG_SCRATCH2 in TLB Miss handlers") Cc: stable@vger.kernel.org # v5.0+ Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Reviewed-by: Leonardo Bras <leonardo@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/4f70c2778163affce8508a210f65d140e84524b4.1581272050.git.christophe.leroy@c-s.fr
2020-02-17powerpc/eeh: Fix deadlock handling dead PHBSam Bobroff
Recovering a dead PHB can currently cause a deadlock as the PCI rescan/remove lock is taken twice. This is caused as part of an existing bug in eeh_handle_special_event(). The pe is processed while traversing the PHBs even though the pe is unrelated to the loop. This causes the pe to be, incorrectly, processed more than once. Untangling this section can move the pe processing out of the loop and also outside the locked section, correcting both problems. Fixes: 2e25505147b8 ("powerpc/eeh: Fix crash when edev->pdev changes") Cc: stable@vger.kernel.org # 5.4+ Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com> Reviewed-by: Frederic Barrat <fbarrat@linux.ibm.com> Tested-by: Frederic Barrat <fbarrat@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/0547e82dbf90ee0729a2979a8cac5c91665c621f.1581051445.git.sbobroff@linux.ibm.com
2020-02-14powerpc: Drop using struct of_pci_range.pci_space fieldRob Herring
Let's use the struct of_pci_range.flags field instead so we can remove the pci_space field. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Rob Herring <robh@kernel.org>
2020-02-08powerpc: Fix CONFIG_TRACE_IRQFLAGS with CONFIG_VMAP_STACKChristophe Leroy
When CONFIG_PROVE_LOCKING is selected together with (now default) CONFIG_VMAP_STACK, kernel enter deadlock during boot. At the point of checking whether interrupts are enabled or not, the value of MSR saved on stack is read using the physical address of the stack. But at this point, when using VMAP stack the DATA MMU translation has already been re-enabled, leading to deadlock. Don't use the physical address of the stack when CONFIG_VMAP_STACK is set. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Reported-by: Guenter Roeck <linux@roeck-us.net> Fixes: 028474876f47 ("powerpc/32: prepare for CONFIG_VMAP_STACK") Tested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/daeacdc0dec0416d1c587cc9f9e7191ad3068dc0.1581095957.git.christophe.leroy@c-s.fr
2020-02-04Merge tag 'powerpc-5.6-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: "A pretty small batch for us, and apologies for it being a bit late, I wanted to sneak Christophe's user_access_begin() series in. Summary: - Implement user_access_begin() and friends for our platforms that support controlling kernel access to userspace. - Enable CONFIG_VMAP_STACK on 32-bit Book3S and 8xx. - Some tweaks to our pseries IOMMU code to allow SVMs ("secure" virtual machines) to use the IOMMU. - Add support for CLOCK_{REALTIME/MONOTONIC}_COARSE to the 32-bit VDSO, and some other improvements. - A series to use the PCI hotplug framework to control opencapi card's so that they can be reset and re-read after flashing a new FPGA image. As well as other minor fixes and improvements as usual. Thanks to: Alastair D'Silva, Alexandre Ghiti, Alexey Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V, Anju T Sudhakar, Bai Yingjie, Chen Zhou, Christophe Leroy, Frederic Barrat, Greg Kurz, Jason A. Donenfeld, Joel Stanley, Jordan Niethe, Julia Lawall, Krzysztof Kozlowski, Laurent Dufour, Laurentiu Tudor, Linus Walleij, Michael Bringmann, Nathan Chancellor, Nicholas Piggin, Nick Desaulniers, Oliver O'Halloran, Peter Ujfalusi, Pingfan Liu, Ram Pai, Randy Dunlap, Russell Currey, Sam Bobroff, Sebastian Andrzej Siewior, Shawn Anastasio, Stephen Rothwell, Steve Best, Sukadev Bhattiprolu, Thiago Jung Bauermann, Tyrel Datwyler, Vaibhav Jain" * tag 'powerpc-5.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (131 commits) powerpc: configs: Cleanup old Kconfig options powerpc/configs/skiroot: Enable some more hardening options powerpc/configs/skiroot: Disable xmon default & enable reboot on panic powerpc/configs/skiroot: Enable security features powerpc/configs/skiroot: Update for symbol movement only powerpc/configs/skiroot: Drop default n CONFIG_CRYPTO_ECHAINIV powerpc/configs/skiroot: Drop HID_LOGITECH powerpc/configs: Drop NET_VENDOR_HP which moved to staging powerpc/configs: NET_CADENCE became NET_VENDOR_CADENCE powerpc/configs: Drop CONFIG_QLGE which moved to staging powerpc: Do not consider weak unresolved symbol relocations as bad powerpc/32s: Fix kasan_early_hash_table() for CONFIG_VMAP_STACK powerpc: indent to improve Kconfig readability powerpc: Provide initial documentation for PAPR hcalls powerpc: Implement user_access_save() and user_access_restore() powerpc: Implement user_access_begin and friends powerpc/32s: Prepare prevent_user_access() for user_access_end() powerpc/32s: Drop NULL addr verification powerpc/kuap: Fix set direction in allow/prevent_user_access() powerpc/32s: Fix bad_kuap_fault() ...
2020-02-04proc: convert everything to "struct proc_ops"Alexey Dobriyan
The most notable change is DEFINE_SHOW_ATTRIBUTE macro split in seq_file.h. Conversion rule is: llseek => proc_lseek unlocked_ioctl => proc_ioctl xxx => proc_xxx delete ".owner = THIS_MODULE" line [akpm@linux-foundation.org: fix drivers/isdn/capi/kcapi_proc.c] [sfr@canb.auug.org.au: fix kernel/sched/psi.c] Link: http://lkml.kernel.org/r/20200122180545.36222f50@canb.auug.org.au Link: http://lkml.kernel.org/r/20191225172546.GB13378@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-01-29Merge tag 'threads-v5.6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux Pull thread management updates from Christian Brauner: "Sargun Dhillon over the last cycle has worked on the pidfd_getfd() syscall. This syscall allows for the retrieval of file descriptors of a process based on its pidfd. A task needs to have ptrace_may_access() permissions with PTRACE_MODE_ATTACH_REALCREDS (suggested by Oleg and Andy) on the target. One of the main use-cases is in combination with seccomp's user notification feature. As a reminder, seccomp's user notification feature was made available in v5.0. It allows a task to retrieve a file descriptor for its seccomp filter. The file descriptor is usually handed of to a more privileged supervising process. The supervisor can then listen for syscall events caught by the seccomp filter of the supervisee and perform actions in lieu of the supervisee, usually emulating syscalls. pidfd_getfd() is needed to expand its uses. There are currently two major users that wait on pidfd_getfd() and one future user: - Netflix, Sargun said, is working on a service mesh where users should be able to connect to a dns-based VIP. When a user connects to e.g. 1.2.3.4:80 that runs e.g. service "foo" they will be redirected to an envoy process. This service mesh uses seccomp user notifications and pidfd to intercept all connect calls and instead of connecting them to 1.2.3.4:80 connects them to e.g. 127.0.0.1:8080. - LXD uses the seccomp notifier heavily to intercept and emulate mknod() and mount() syscalls for unprivileged containers/processes. With pidfd_getfd() more uses-cases e.g. bridging socket connections will be possible. - The patchset has also seen some interest from the browser corner. Right now, Firefox is using a SECCOMP_RET_TRAP sandbox managed by a broker process. In the future glibc will start blocking all signals during dlopen() rendering this type of sandbox impossible. Hence, in the future Firefox will switch to a seccomp-user-nofication based sandbox which also makes use of file descriptor retrieval. The thread for this can be found at https://sourceware.org/ml/libc-alpha/2019-12/msg00079.html With pidfd_getfd() it is e.g. possible to bridge socket connections for the supervisee (binding to a privileged port) and taking actions on file descriptors on behalf of the supervisee in general. Sargun's first version was using an ioctl on pidfds but various people pushed for it to be a proper syscall which he duely implemented as well over various review cycles. Selftests are of course included. I've also added instructions how to deal with merge conflicts below. There's also a small fix coming from the kernel mentee project to correctly annotate struct sighand_struct with __rcu to fix various sparse warnings. We've received a few more such fixes and even though they are mostly trivial I've decided to postpone them until after -rc1 since they came in rather late and I don't want to risk introducing build warnings. Finally, there's a new prctl() command PR_{G,S}ET_IO_FLUSHER which is needed to avoid allocation recursions triggerable by storage drivers that have userspace parts that run in the IO path (e.g. dm-multipath, iscsi, etc). These allocation recursions deadlock the device. The new prctl() allows such privileged userspace components to avoid allocation recursions by setting the PF_MEMALLOC_NOIO and PF_LESS_THROTTLE flags. The patch carries the necessary acks from the relevant maintainers and is routed here as part of prctl() thread-management." * tag 'threads-v5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: prctl: PR_{G,S}ET_IO_FLUSHER to support controlling memory reclaim sched.h: Annotate sighand_struct with __rcu test: Add test for pidfd getfd arch: wire up pidfd_getfd syscall pid: Implement pidfd_getfd syscall vfs, fdtable: Add fget_task helper
2020-01-29Merge branch 'work.openat2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull openat2 support from Al Viro: "This is the openat2() series from Aleksa Sarai. I'm afraid that the rest of namei stuff will have to wait - it got zero review the last time I'd posted #work.namei, and there had been a leak in the posted series I'd caught only last weekend. I was going to repost it on Monday, but the window opened and the odds of getting any review during that... Oh, well. Anyway, openat2 part should be ready; that _did_ get sane amount of review and public testing, so here it comes" From Aleksa's description of the series: "For a very long time, extending openat(2) with new features has been incredibly frustrating. This stems from the fact that openat(2) is possibly the most famous counter-example to the mantra "don't silently accept garbage from userspace" -- it doesn't check whether unknown flags are present[1]. This means that (generally) the addition of new flags to openat(2) has been fraught with backwards-compatibility issues (O_TMPFILE has to be defined as __O_TMPFILE|O_DIRECTORY|[O_RDWR or O_WRONLY] to ensure old kernels gave errors, since it's insecure to silently ignore the flag[2]). All new security-related flags therefore have a tough road to being added to openat(2). Furthermore, the need for some sort of control over VFS's path resolution (to avoid malicious paths resulting in inadvertent breakouts) has been a very long-standing desire of many userspace applications. This patchset is a revival of Al Viro's old AT_NO_JUMPS[3] patchset (which was a variant of David Drysdale's O_BENEATH patchset[4] which was a spin-off of the Capsicum project[5]) with a few additions and changes made based on the previous discussion within [6] as well as others I felt were useful. In line with the conclusions of the original discussion of AT_NO_JUMPS, the flag has been split up into separate flags. However, instead of being an openat(2) flag it is provided through a new syscall openat2(2) which provides several other improvements to the openat(2) interface (see the patch description for more details). The following new LOOKUP_* flags are added: LOOKUP_NO_XDEV: Blocks all mountpoint crossings (upwards, downwards, or through absolute links). Absolute pathnames alone in openat(2) do not trigger this. Magic-link traversal which implies a vfsmount jump is also blocked (though magic-link jumps on the same vfsmount are permitted). LOOKUP_NO_MAGICLINKS: Blocks resolution through /proc/$pid/fd-style links. This is done by blocking the usage of nd_jump_link() during resolution in a filesystem. The term "magic-links" is used to match with the only reference to these links in Documentation/, but I'm happy to change the name. It should be noted that this is different to the scope of ~LOOKUP_FOLLOW in that it applies to all path components. However, you can do openat2(NO_FOLLOW|NO_MAGICLINKS) on a magic-link and it will *not* fail (assuming that no parent component was a magic-link), and you will have an fd for the magic-link. In order to correctly detect magic-links, the introduction of a new LOOKUP_MAGICLINK_JUMPED state flag was required. LOOKUP_BENEATH: Disallows escapes to outside the starting dirfd's tree, using techniques such as ".." or absolute links. Absolute paths in openat(2) are also disallowed. Conceptually this flag is to ensure you "stay below" a certain point in the filesystem tree -- but this requires some additional to protect against various races that would allow escape using "..". Currently LOOKUP_BENEATH implies LOOKUP_NO_MAGICLINKS, because it can trivially beam you around the filesystem (breaking the protection). In future, there might be similar safety checks done as in LOOKUP_IN_ROOT, but that requires more discussion. In addition, two new flags are added that expand on the above ideas: LOOKUP_NO_SYMLINKS: Does what it says on the tin. No symlink resolution is allowed at all, including magic-links. Just as with LOOKUP_NO_MAGICLINKS this can still be used with NOFOLLOW to open an fd for the symlink as long as no parent path had a symlink component. LOOKUP_IN_ROOT: This is an extension of LOOKUP_BENEATH that, rather than blocking attempts to move past the root, forces all such movements to be scoped to the starting point. This provides chroot(2)-like protection but without the cost of a chroot(2) for each filesystem operation, as well as being safe against race attacks that chroot(2) is not. If a race is detected (as with LOOKUP_BENEATH) then an error is generated, and similar to LOOKUP_BENEATH it is not permitted to cross magic-links with LOOKUP_IN_ROOT. The primary need for this is from container runtimes, which currently need to do symlink scoping in userspace[7] when opening paths in a potentially malicious container. There is a long list of CVEs that could have bene mitigated by having RESOLVE_THIS_ROOT (such as CVE-2017-1002101, CVE-2017-1002102, CVE-2018-15664, and CVE-2019-5736, just to name a few). In order to make all of the above more usable, I'm working on libpathrs[8] which is a C-friendly library for safe path resolution. It features a userspace-emulated backend if the kernel doesn't support openat2(2). Hopefully we can get userspace to switch to using it, and thus get openat2(2) support for free once it's ready. Future work would include implementing things like RESOLVE_NO_AUTOMOUNT and possibly a RESOLVE_NO_REMOTE (to allow programs to be sure they don't hit DoSes though stale NFS handles)" * 'work.openat2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: Documentation: path-lookup: include new LOOKUP flags selftests: add openat2(2) selftests open: introduce openat2(2) syscall namei: LOOKUP_{IN_ROOT,BENEATH}: permit limited ".." resolution namei: LOOKUP_IN_ROOT: chroot-like scoped resolution namei: LOOKUP_BENEATH: O_BENEATH-like scoped resolution namei: LOOKUP_NO_XDEV: block mountpoint crossing namei: LOOKUP_NO_MAGICLINKS: block magic-link resolution namei: LOOKUP_NO_SYMLINKS: block symlink resolution namei: allow set_root() to produce errors namei: allow nd_jump_link() to produce errors nsfs: clean-up ns_get_path() signature to return int namei: only return -ECHILD from follow_dotdot_rcu()
2020-01-29Merge tag 'tty-5.6-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial driver updates from Greg KH: "Here are the big set of tty and serial driver updates for 5.6-rc1 Included in here are: - dummy_con cleanups (touches lots of arch code) - sysrq logic cleanups (touches lots of serial drivers) - samsung driver fixes (wasn't really being built) - conmakeshash move to tty subdir out of scripts - lots of small tty/serial driver updates All of these have been in linux-next for a while with no reported issues" * tag 'tty-5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (140 commits) tty: n_hdlc: Use flexible-array member and struct_size() helper tty: baudrate: SPARC supports few more baud rates tty: baudrate: Synchronise baud_table[] and baud_bits[] tty: serial: meson_uart: Add support for kernel debugger serial: imx: fix a race condition in receive path serial: 8250_bcm2835aux: Document struct bcm2835aux_data serial: 8250_bcm2835aux: Use generic remapping code serial: 8250_bcm2835aux: Allocate uart_8250_port on stack serial: 8250_bcm2835aux: Suppress register_port error on -EPROBE_DEFER serial: 8250_bcm2835aux: Suppress clk_get error on -EPROBE_DEFER serial: 8250_bcm2835aux: Fix line mismatch on driver unbind serial_core: Remove unused member in uart_port vt: Correct comment documenting do_take_over_console() vt: Delete comment referencing non-existent unbind_con_driver() arch/xtensa/setup: Drop dummy_con initialization arch/x86/setup: Drop dummy_con initialization arch/unicore32/setup: Drop dummy_con initialization arch/sparc/setup: Drop dummy_con initialization arch/sh/setup: Drop dummy_con initialization arch/s390/setup: Drop dummy_con initialization ...
2020-01-29powerpc: Provide initial documentation for PAPR hcallsVaibhav Jain
This doc patch provides an initial description of the hcall op-codes that are used by Linux kernel running as a guest (LPAR) on top of PowerVM or any other sPAPR compliant hyper-visor (e.g qemu). Apart from documenting the hcalls the doc-patch also provides a rudimentary overview of how hcall ABI, how they are issued with the Linux kernel and how information/control flows between the guest and hypervisor. Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com> Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com> Acked-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Add SPDX tag, add it to index.rst] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190828082729.16695-1-vaibhav@linux.ibm.com
2020-01-28powerpc/32s: Fix CPU wake-up from sleep modeChristophe Leroy
Commit f7354ccac844 ("powerpc/32: Remove CURRENT_THREAD_INFO and rename TI_CPU") broke the CPU wake-up from sleep mode (i.e. when _TLF_SLEEPING is set) by delaying the tovirt(r2, r2). This is because r2 is not restored by fast_exception_return. It used to work (by chance ?) because CPU wake-up interrupt never comes from user, so r2 is expected to point to 'current' on return. Commit e2fb9f544431 ("powerpc/32: Prepare for Kernel Userspace Access Protection") broke it even more by clobbering r0 which is not restored by fast_exception_return either. Use r6 instead of r0. This is possible because r3-r6 are restored by fast_exception_return and only r3-r5 are used for exception arguments. For r2 it could be converted back to virtual address, but stay on the safe side and restore it from the stack instead. It should be live in the cache at that moment, so loading from the stack should make no difference compared to converting it from phys to virt. Fixes: f7354ccac844 ("powerpc/32: Remove CURRENT_THREAD_INFO and rename TI_CPU") Fixes: e2fb9f544431 ("powerpc/32: Prepare for Kernel Userspace Access Protection") Cc: stable@vger.kernel.org Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/6d02c3ae6ad77af34392e98117e44c2bf6d13ba1.1580121710.git.christophe.leroy@c-s.fr
generated by cgit (git 2.34.1) at 2025-09-23 12:20:35 +0000