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* powerpc/tm: Fix FP and VMX register corruptionMichael Neuling2017-05-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit f48e91e87e67b56bef63393d1a02c6e22c1d7078 upstream. In commit dc3106690b20 ("powerpc: tm: Always use fp_state and vr_state to store live registers"), a section of code was removed that copied the current state to checkpointed state. That code should not have been removed. When an FP (Floating Point) unavailable is taken inside a transaction, we need to abort the transaction. This is because at the time of the tbegin, the FP state is bogus so the state stored in the checkpointed registers is incorrect. To fix this, we treclaim (to get the checkpointed GPRs) and then copy the thread_struct FP live state into the checkpointed state. We then trecheckpoint so that the FP state is correctly restored into the CPU. The copying of the FP registers from live to checkpointed is what was missing. This simplifies the logic slightly from the original patch. tm_reclaim_thread() will now always write the checkpointed FP state. Either the checkpointed FP state will be written as part of the actual treclaim (in tm.S), or it'll be a copy of the live state. Which one we use is based on MSR[FP] from userspace. Similarly for VMX. Fixes: dc3106690b20 ("powerpc: tm: Always use fp_state and vr_state to store live registers") Signed-off-by: Michael Neuling <mikey@neuling.org> Reviewed-by: cyrilbur@gmail.com Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc/64e: Fix hang when debugging programs with relocated kernelLiuHailong2017-05-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit fd615f69a18a9d4aa5ef02a1dc83f319f75da8e7 upstream. Debug interrupts can be taken during interrupt entry, since interrupt entry does not automatically turn them off. The kernel will check whether the faulting instruction is between [interrupt_base_book3e, __end_interrupts], and if so clear MSR[DE] and return. However, when the kernel is built with CONFIG_RELOCATABLE, it can't use LOAD_REG_IMMEDIATE(r14,interrupt_base_book3e) and LOAD_REG_IMMEDIATE(r15,__end_interrupts), as they ignore relocation. Thus, if the kernel is actually running at a different address than it was built at, the address comparison will fail, and the exception entry code will hang at kernel_dbg_exc. r2(toc) is also not usable here, as r2 still holds data from the interrupted context, so LOAD_REG_ADDR() doesn't work either. So we use the *name@got* to get the EV of two labels directly. Test programs test.c shows as follows: int main(int argc, char *argv[]) { if (access("/proc/sys/kernel/perf_event_paranoid", F_OK) == -1) printf("Kernel doesn't have perf_event support\n"); } Steps to reproduce the bug, for example: 1) ./gdb ./test 2) (gdb) b access 3) (gdb) r 4) (gdb) s Signed-off-by: Liu Hailong <liu.hailong6@zte.com.cn> Signed-off-by: Jiang Xuexin <jiang.xuexin@zte.com.cn> Reviewed-by: Jiang Biao <jiang.biao2@zte.com.cn> Reviewed-by: Liu Song <liu.song11@zte.com.cn> Reviewed-by: Huang Jian <huang.jian@zte.com.cn> [scottwood: cleaned up commit message, and specified bad behavior as a hang rather than an oops to correspond to mainline kernel behavior] Fixes: 1cb6e0649248 ("powerpc/book3e: support CONFIG_RELOCATABLE") Signed-off-by: Scott Wood <oss@buserror.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc/book3s/mce: Move add_taint() later in virtual modeMahesh Salgaonkar2017-05-25
| | | | | | | | | | | | | | | | | | | | | | | commit d93b0ac01a9ce276ec39644be47001873d3d183c upstream. machine_check_early() gets called in real mode. The very first time when add_taint() is called, it prints a warning which ends up calling opal call (that uses OPAL_CALL wrapper) for writing it to console. If we get a very first machine check while we are in opal we are doomed. OPAL_CALL overwrites the PACASAVEDMSR in r13 and in this case when we are done with MCE handling the original opal call will use this new MSR on it's way back to opal_return. This usually leads to unexpected behaviour or the kernel to panic. Instead move the add_taint() call later in the virtual mode where it is safe to call. This is broken with current FW level. We got lucky so far for not getting very first MCE hit while in OPAL. But easily reproducible on Mambo. Fixes: 27ea2c420cad ("powerpc: Set the correct kernel taint on machine check errors.") Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc/eeh: Avoid use after free in eeh_handle_special_event()Russell Currey2017-05-25
| | | | | | | | | | | | | | | | | | | | | | | | | commit daeba2956f32f91f3493788ff6ee02fb1b2f02fa upstream. eeh_handle_special_event() is called when an EEH event is detected but can't be narrowed down to a specific PE. This function looks through every PE to find one in an erroneous state, then calls the regular event handler eeh_handle_normal_event() once it knows which PE has an error. However, if eeh_handle_normal_event() found that the PE cannot possibly be recovered, it will free it, rendering the passed PE stale. This leads to a use after free in eeh_handle_special_event() as it attempts to clear the "recovering" state on the PE after eeh_handle_normal_event() returns. Thus, make sure the PE is valid when attempting to clear state in eeh_handle_special_event(). Fixes: 8a6b1bc70dbb ("powerpc/eeh: EEH core to handle special event") Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Russell Currey <ruscur@russell.cc> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* pstore: Fix flags to enable dumps on powerpcAnkit Kumar2017-05-20
| | | | | | | | | | | | | | | | | | commit 041939c1ec54208b42f5cd819209173d52a29d34 upstream. After commit c950fd6f201a kernel registers pstore write based on flag set. Pstore write for powerpc is broken as flags(PSTORE_FLAGS_DMESG) is not set for powerpc architecture. On panic, kernel doesn't write message to /fs/pstore/dmesg*(Entry doesn't gets created at all). This patch enables pstore write for powerpc architecture by setting PSTORE_FLAGS_DMESG flag. Fixes: c950fd6f201a ("pstore: Split pstore fragile flags") Signed-off-by: Ankit Kumar <ankit@linux.vnet.ibm.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc: Correctly disable latent entropy GCC plugin on prom_init.oAndrew Donnellan2017-05-14
| | | | | | | | | | | | | | | | commit eac6f8b0c7adb003776dbad9d037ee2fc64f9d62 upstream. Commit 38addce8b600 ("gcc-plugins: Add latent_entropy plugin") excludes certain powerpc early boot code from the latent entropy plugin by adding appropriate CFLAGS. It looks like this was supposed to cover prom_init.o, but ended up saying init.o (which doesn't exist) instead. Fix the typo. Fixes: 38addce8b600 ("gcc-plugins: Add latent_entropy plugin") Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc/kprobe: Fix oops when kprobed on 'stdu' instructionRavi Bangoria2017-04-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 9e1ba4f27f018742a1aa95d11e35106feba08ec1 upstream. If we set a kprobe on a 'stdu' instruction on powerpc64, we see a kernel OOPS: Bad kernel stack pointer cd93c840 at c000000000009868 Oops: Bad kernel stack pointer, sig: 6 [#1] ... GPR00: c000001fcd93cb30 00000000cd93c840 c0000000015c5e00 00000000cd93c840 ... NIP [c000000000009868] resume_kernel+0x2c/0x58 LR [c000000000006208] program_check_common+0x108/0x180 On a 64-bit system when the user probes on a 'stdu' instruction, the kernel does not emulate actual store in emulate_step() because it may corrupt the exception frame. So the kernel does the actual store operation in exception return code i.e. resume_kernel(). resume_kernel() loads the saved stack pointer from memory using lwz, which only loads the low 32-bits of the address, causing the kernel crash. Fix this by loading the 64-bit value instead. Fixes: be96f63375a1 ("powerpc: Split out instruction analysis part of emulate_step()") Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com> Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Reviewed-by: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com> [mpe: Change log massage, add stable tag] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc: Don't try to fix up misaligned load-with-reservation instructionsPaul Mackerras2017-04-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | commit 48fe9e9488743eec9b7c1addd3c93f12f2123d54 upstream. In the past, there was only one load-with-reservation instruction, lwarx, and if a program attempted a lwarx on a misaligned address, it would take an alignment interrupt and the kernel handler would emulate it as though it was lwzx, which was not really correct, but benign since it is loading the right amount of data, and the lwarx should be paired with a stwcx. to the same address, which would also cause an alignment interrupt which would result in a SIGBUS being delivered to the process. We now have 5 different sizes of load-with-reservation instruction. Of those, lharx and ldarx cause an immediate SIGBUS by luck since their entries in aligninfo[] overlap instructions which were not fixed up, but lqarx overlaps with lhz and will be emulated as such. lbarx can never generate an alignment interrupt since it only operates on 1 byte. To straighten this out and fix the lqarx case, this adds code to detect the l[hwdq]arx instructions and return without fixing them up, resulting in a SIGBUS being delivered to the process. Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc/64: Fix flush_(d|i)cache_range() called from modulesOliver O'Halloran2017-04-12
| | | | | | | | | | | | | | | | | | | | | | | commit 8f5f525d5b83f7d76a6baf9c4e94d4bf312ea7f6 upstream. When the kernel is compiled to use 64bit ABIv2 the _GLOBAL() macro does not include a global entry point. A function's global entry point is used when the function is called from a different TOC context and in the kernel this typically means a call from a module into the vmlinux (or vice-versa). There are a few exported asm functions declared with _GLOBAL() and calling them from a module will likely crash the kernel since any TOC relative load will yield garbage. flush_icache_range() and flush_dcache_range() are both exported to modules, and use the TOC, so must use _GLOBAL_TOC(). Fixes: 721aeaa9fdf3 ("powerpc: Build little endian ppc64 kernel with ABIv2") Signed-off-by: Oliver O'Halloran <oohall@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc: Disable HFSCR[TM] if TM is not supportedBenjamin Herrenschmidt2017-04-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 7ed23e1bae8bf7e37fd555066550a00b95a3a98b upstream. On Power8 & Power9 the early CPU inititialisation in __init_HFSCR() turns on HFSCR[TM] (Hypervisor Facility Status and Control Register [Transactional Memory]), but that doesn't take into account that TM might be disabled by CPU features, or disabled by the kernel being built with CONFIG_PPC_TRANSACTIONAL_MEM=n. So later in boot, when we have setup the CPU features, clear HSCR[TM] if the TM CPU feature has been disabled. We use CPU_FTR_TM_COMP to account for the CONFIG_PPC_TRANSACTIONAL_MEM=n case. Without this a KVM guest might try use TM, even if told not to, and cause an oops in the host kernel. Typically the oops is seen in __kvmppc_vcore_entry() and may or may not be fatal to the host, but is always bad news. In practice all shipping CPU revisions do support TM, and all host kernels we are aware of build with TM support enabled, so no one should actually be able to hit this in the wild. Fixes: 2a3563b023e5 ("powerpc: Setup in HFSCR for POWER8") Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Sam Bobroff <sam.bobroff@au1.ibm.com> [mpe: Rewrite change log with input from Sam, add Fixes/stable] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc/64s: Fix idle wakeup potential to clobber registersNicholas Piggin2017-03-30
| | | | | | | | | | | | | | | | | | | | | commit 6d98ce0be541d4a3cfbb52cd75072c0339ebb500 upstream. We concluded there may be a window where the idle wakeup code could get to pnv_wakeup_tb_loss() (which clobbers non-volatile GPRs), but the hardware may set SRR1[46:47] to 01b (no state loss) which would result in the wakeup code failing to restore non-volatile GPRs. I was not able to trigger this condition with trivial tests on real hardware or simulator, but the ISA (at least 2.07) seems to allow for it, and Gautham says that it can happen if there is an exception pending when the sleep/winkle instruction is executed. Fixes: 1706567117ba ("powerpc/kvm: make hypervisor state restore a function") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc/iommu: Pass mm_struct to init/cleanup helpersAlexey Kardashevskiy2017-03-22
| | | | | | | | | | | | | | | | | | | | [ Upstream commit 88f54a3581eb9deaa3bd1aade40aef266d782385 ] We are going to get rid of @current references in mmu_context_boos3s64.c and cache mm_struct in the VFIO container. Since mm_context_t does not have reference counting, we will be using mm_struct which does have the reference counter. This changes mm_iommu_init/mm_iommu_cleanup to receive mm_struct rather than mm_context_t (which is embedded into mm). This should not cause any behavioral change. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc/mm/hash: Always clear UPRT and Host Radix bits when setting up CPUAneesh Kumar K.V2017-03-12
| | | | | | | | | | | | | | | commit fda2d27db6eae5c2468f9e4657539b72bbc238bb upstream. We will set LPCR with correct value for radix during int. This make sure we start with a sanitized value of LPCR. In case of kexec, cpus can have LPCR value based on the previous translation mode we were running. Fixes: fe036a0605d60 ("powerpc/64/kexec: Fix MMU cleanup on radix") Acked-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc/xmon: Fix data-breakpointRavi Bangoria2017-03-12
| | | | | | | | | | | | | | | | | | | | | | commit c21a493a2b44650707d06741601894329486f2ad upstream. Currently xmon data-breakpoint feature is broken. Whenever there is a watchpoint match occurs, hw_breakpoint_handler will be called by do_break via notifier chains mechanism. If watchpoint is registered by xmon, hw_breakpoint_handler won't find any associated perf_event and returns immediately with NOTIFY_STOP. Similarly, do_break also returns without notifying to xmon. Solve this by returning NOTIFY_DONE when hw_breakpoint_handler does not find any perf_event associated with matched watchpoint, rather than NOTIFY_STOP, which tells the core code to continue calling the other breakpoint handlers including the xmon one. Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc: Add missing error check to prom_find_boot_cpu()Darren Stevens2017-02-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit af2b7fa17eb92e52b65f96604448ff7a2a89ee99 upstream. prom_init.c calls 'instance-to-package' twice, but the return is not checked during prom_find_boot_cpu(). The result is then passed to prom_getprop(), which could be PROM_ERROR. Add a return check to prevent this. This was found on a pasemi system, where CFE doesn't have a working 'instance-to package' prom call. Before Commit 5c0484e25ec0 ('powerpc: Endian safe trampoline') the area around addr 0 was mostly 0's and this doesn't cause a problem. Once the macro 'FIXUP_ENDIAN' has been added to head_64.S, the low memory area now has non-zero values, which cause the prom_getprop() call to hang. mpe: Also confirmed that under SLOF if 'instance-to-package' did fail with PROM_ERROR we would crash in SLOF. So the bug is not specific to CFE, it's just that other open firmwares don't trigger it because they have a working 'instance-to-package'. Fixes: 5c0484e25ec0 ("powerpc: Endian safe trampoline") Signed-off-by: Darren Stevens <darren@stevens-zone.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc/eeh: Fix wrong flag passed to eeh_unfreeze_pe()Gavin Shan2017-02-09
| | | | | | | | | | | | | | | | | | | commit f05fea5b3574a5926c53865eea27139bb40b2f2b upstream. In __eeh_clear_pe_frozen_state(), we should pass the flag's value instead of its address to eeh_unfreeze_pe(). The isolated flag is cleared if no error returned from __eeh_clear_pe_frozen_state(). We never observed the error from the function. So the isolated flag should have been always cleared, no real issue is caused because of the misused @flag. This fixes the code by passing the value of @flag to eeh_unfreeze_pe(). Fixes: 5cfb20b96f6 ("powerpc/eeh: Emulate EEH recovery for VFIO devices") Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc/ptrace: Preserve previous TM fprs/vsrs on short regset writeDave Martin2017-01-26
| | | | | | | | | | | | | | | commit b34ca60148c53971d373643195cc5c4d5d20be78 upstream. Ensure that if userspace supplies insufficient data to PTRACE_SETREGSET to fill all the check pointed registers, the thread's old check pointed registers are preserved. Fixes: 9d3918f7c0e5 ("powerpc/ptrace: Enable support for NT_PPC_CVSX") Fixes: 19cbcbf75a0c ("powerpc/ptrace: Enable support for NT_PPC_CFPR") Signed-off-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc/ptrace: Preserve previous fprs/vsrs on short regset writeDave Martin2017-01-26
| | | | | | | | | | | | | commit 99dfe80a2a246c600440a815741fd2e74a8b4977 upstream. Ensure that if userspace supplies insufficient data to PTRACE_SETREGSET to fill all the registers, the thread's old registers are preserved. Fixes: c6e6771b87d4 ("powerpc: Introduce VSX thread_struct and CONFIG_VSX") Signed-off-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc/ibmebus: Fix device reference leaks in sysfs interfaceJohan Hovold2017-01-19
| | | | | | | | | | | | | | commit fe0f3168169f7c34c29b0cf0c489f126a7f29643 upstream. Make sure to drop any reference taken by bus_find_device() in the sysfs callbacks that are used to create and destroy devices based on device-tree entries. Fixes: 6bccf755ff53 ("[POWERPC] ibmebus: dynamic addition/removal of adapters, some code cleanup") Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc/ibmebus: Fix further device reference leaksJohan Hovold2017-01-19
| | | | | | | | | | | | | commit 815a7141c4d1b11610dccb7fcbb38633759824f2 upstream. Make sure to drop any reference taken by bus_find_device() when creating devices during init and driver registration. Fixes: 55347cc9962f ("[POWERPC] ibmebus: Add device creation and bus probing based on of_device") Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc: Fix build warning on 32-bit PPCLarry Finger2017-01-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 8ae679c4bc2ea2d16d92620da8e3e9332fa4039f upstream. I am getting the following warning when I build kernel 4.9-git on my PowerBook G4 with a 32-bit PPC processor: AS arch/powerpc/kernel/misc_32.o arch/powerpc/kernel/misc_32.S:299:7: warning: "CONFIG_FSL_BOOKE" is not defined [-Wundef] This problem is evident after commit 989cea5c14be ("kbuild: prevent lib-ksyms.o rebuilds"); however, this change in kbuild only exposes an error that has been in the code since 2005 when this source file was created. That was with commit 9994a33865f4 ("powerpc: Introduce entry_{32,64}.S, misc_{32,64}.S, systbl.S"). The offending line does not make a lot of sense. This error does not seem to cause any errors in the executable, thus I am not recommending that it be applied to any stable versions. Thanks to Nicholas Piggin for suggesting this solution. Fixes: 9994a33865f4 ("powerpc: Introduce entry_{32,64}.S, misc_{32,64}.S, systbl.S") Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net> Cc: Nicholas Piggin <npiggin@gmail.com> 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: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc/64e: Convert cmpi to cmpwi in head_64.SNicholas Piggin2017-01-09
| | | | | | | | | | | | | | | | | | | | | | | commit f87f253bac3ce4a4eb2a60a1ae604d74e65f9042 upstream. From 80f23935cadb ("powerpc: Convert cmp to cmpd in idle enter sequence"): PowerPC's "cmp" instruction has four operands. Normally people write "cmpw" or "cmpd" for the second cmp operand 0 or 1. But, frequently people forget, and write "cmp" with just three operands. With older binutils this is silently accepted as if this was "cmpw", while often "cmpd" is wanted. With newer binutils GAS will complain about this for 64-bit code. For 32-bit code it still silently assumes "cmpw" is what is meant. In this case, cmpwi is called for, so this is just a build fix for new toolchains. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: PPC: Book3S HV: Save/restore XER in checkpointed register statePaul Mackerras2017-01-09
| | | | | | | | | | | | | | | | | | | | | | | | commit 0d808df06a44200f52262b6eb72bcb6042f5a7c5 upstream. When switching from/to a guest that has a transaction in progress, we need to save/restore the checkpointed register state. Although XER is part of the CPU state that gets checkpointed, the code that does this saving and restoring doesn't save/restore XER. This fixes it by saving and restoring the XER. To allow userspace to read/write the checkpointed XER value, we also add a new ONE_REG specifier. The visible effect of this bug is that the guest may see its XER value being corrupted when it uses transactions. Fixes: e4e38121507a ("KVM: PPC: Book3S HV: Add transactional memory support") Fixes: 0a8eccefcb34 ("KVM: PPC: Book3S HV: Add missing code for transaction reclaim on guest exit") Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Reviewed-by: Thomas Huth <thuth@redhat.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ptrace: Don't allow accessing an undumpable mmEric W. Biederman2017-01-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 84d77d3f06e7e8dea057d10e8ec77ad71f721be3 upstream. It is the reasonable expectation that if an executable file is not readable there will be no way for a user without special privileges to read the file. This is enforced in ptrace_attach but if ptrace is already attached before exec there is no enforcement for read-only executables. As the only way to read such an mm is through access_process_vm spin a variant called ptrace_access_vm that will fail if the target process is not being ptraced by the current process, or the current process did not have sufficient privileges when ptracing began to read the target processes mm. In the ptrace implementations replace access_process_vm by ptrace_access_vm. There remain several ptrace sites that still use access_process_vm as they are reading the target executables instructions (for kernel consumption) or register stacks. As such it does not appear necessary to add a permission check to those calls. This bug has always existed in Linux. Fixes: v1.0 Reported-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge tag 'powerpc-4.9-7' of ↵Linus Torvalds2016-12-05
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc fixes from Michael Ellerman: "Four fixes, the first for code we merged this cycle and three that are also going to stable: - On 64-bit Book3E we were not placing the .text section where we said we would in the asm. - We broke building the boot wrapper on some 32-bit toolchains. - Lazy icache flushing was broken on pre-POWER5 machines. - One of the error paths in our EEH code would lead to a deadlock. Thanks to: Andrew Donnellan, Ben Hutchings, Benjamin Herrenschmidt, Nicholas Piggin" * tag 'powerpc-4.9-7' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/64: Fix placement of .text to be immediately following .head.text powerpc/eeh: Fix deadlock when PE frozen state can't be cleared powerpc/mm: Fix lazy icache flush on pre-POWER5 powerpc/boot: Fix build failure in 32-bit boot wrapper
| * powerpc/64: Fix placement of .text to be immediately following .head.textNicholas Piggin2016-12-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Do not introduce any additional alignment. Placement of text section will be set by fixed section macros. Without this, output section alignment defaults to 4096, which makes BookE text section start at 0x1000 when it is expected to start at 0x100. This was introduced by commit 57f266497d81 ("powerpc: Use gas sections for arranging exception vectors") and was caught with the scripted head section checker (not yet merged). Fixes: 57f266497d81 ("powerpc: Use gas sections for arranging exception vectors") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * powerpc/eeh: Fix deadlock when PE frozen state can't be clearedAndrew Donnellan2016-12-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In eeh_reset_device(), we take the pci_rescan_remove_lock immediately after after we call eeh_reset_pe() to reset the PCI controller. We then call eeh_clear_pe_frozen_state(), which can return an error. In this case, we bail out of eeh_reset_device() without calling pci_unlock_rescan_remove(). Add a call to pci_unlock_rescan_remove() in the eeh_clear_pe_frozen_state() error path so that we don't cause a deadlock later on. Reported-by: Pradipta Ghosh <pradghos@in.ibm.com> Fixes: 78954700631f ("powerpc/eeh: Avoid I/O access during PE reset") Cc: stable@vger.kernel.org # v3.16+ Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Acked-by: Russell Currey <ruscur@russell.cc> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | Merge tag 'powerpc-4.9-6' of ↵Linus Torvalds2016-11-26
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc fixes from Michael Ellerman: "Fixes marked for stable: - Set missing wakeup bit in LPCR on POWER9 - Fix the early OPAL console wrappers - Fixup kernel read only mapping Fixes for code merged this cycle: - Fix missing CRCs, add more asm-prototypes.h declarations" * tag 'powerpc-4.9-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/mm: Fixup kernel read only mapping powerpc/boot: Fix the early OPAL console wrappers powerpc: Fix missing CRCs, add more asm-prototypes.h declarations powerpc: Set missing wakeup bit in LPCR on POWER9
| * powerpc: Set missing wakeup bit in LPCR on POWER9Benjamin Herrenschmidt2016-11-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is a new bit, LPCR_PECE_HVEE (Hypervisor Virtualization Exit Enable), which controls wakeup from STOP states on Hypervisor Virtualization Interrupts (which happen to also be all external interrupts in host or bare metal mode). It needs to be set or we will miss wakeups. Fixes: 9baaef0a22c8 ("powerpc/irq: Add support for HV virtualization interrupts") Cc: stable@vger.kernel.org # v4.8+ Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [mpe: Rename it to HVEE to match the name in the ISA] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | Merge tag 'powerpc-4.9-5' of ↵Linus Torvalds2016-11-19
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc fixes from Michael Ellerman: "Fixes marked for stable: - fix system reset interrupt winkle wakeups - fix setting of AIL in hypervisor mode Fixes for code merged this cycle: - fix exception vector build with 2.23 era binutils - fix missing update of HID register on secondary CPUs Other: - fix missing pr_cont()s - invalidate ERAT on tlbiel for POWER9 DD1" * tag 'powerpc-4.9-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/mm: Fix missing update of HID register on secondary CPUs powerpc/mm/radix: Invalidate ERAT on tlbiel for POWER9 DD1 powerpc/64: Fix setting of AIL in hypervisor mode powerpc/oops: Fix missing pr_cont()s in instruction dump powerpc/oops: Fix missing pr_cont()s in show_regs() powerpc/oops: Fix missing pr_cont()s in print_msr_bits() et. al. powerpc/oops: Fix missing pr_cont()s in show_stack() powerpc: Fix exception vector build with 2.23 era binutils powerpc/64s: Fix system reset interrupt winkle wakeups
| * powerpc/64: Fix setting of AIL in hypervisor modeBenjamin Herrenschmidt2016-11-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit d3cbff1b5 "powerpc: Put exception configuration in a common place" broke the setting of the AIL bit (which enables taking exceptions with the MMU still on) on all processors, moving it incorrectly to a function called only on the boot CPU. This was correct for the guest case but not when running in hypervisor mode. This fixes it by partially reverting that commit, putting the setting back in cpu_ready_for_interrupts() Fixes: d3cbff1b5a90 ("powerpc: Put exception configuration in a common place") Cc: stable@vger.kernel.org # v4.8+ Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * powerpc/oops: Fix missing pr_cont()s in instruction dumpAndrew Donnellan2016-11-12
| | | | | | | | | | | | | | | | | | | | Since the KERN_CONT changes, the current code in show_instructions() prints out a whole bunch of unnecessary newlines. Change occurrences of printk("\n") to pr_cont("\n"). While we're here, change all the other cases of printk(KERN_CONT ...) to pr_cont() as well. Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * powerpc/oops: Fix missing pr_cont()s in show_regs()Michael Ellerman2016-11-12
| | | | | | | | | | | | | | | | | | Fix up our oops output by converting continuation lines to use pr_cont(). Some of these are dubious, eg. printing a continuation line which starts with a newline, but seem to work OK for now. This whole function needs a rewrite in the next release. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * powerpc/oops: Fix missing pr_cont()s in print_msr_bits() et. al.Michael Ellerman2016-11-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since the KERN_CONT changes these are being horribly split across lines, for example: MSR: 8000000000009033 < SF,EE ,ME,IR ,DR,RI ,LE> So fix it by using pr_cont() where appropriate. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * powerpc/oops: Fix missing pr_cont()s in show_stack()Michael Ellerman2016-11-12
| | | | | | | | | | | | | | | | | | Previously we got away with printing the stack trace in multiple pieces and it usually looked right. But since commit 4bcc595ccd80 ("printk: reinstate KERN_CONT for printing continuation lines"), KERN_CONT is now required when printing continuation lines. Use pr_cont() as appropriate. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * powerpc/64s: Fix system reset interrupt winkle wakeupsNicholas Piggin2016-11-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Wakeups from winkle set the low bit of the HSPRG0 register, to distinguish it from other sleep states. This is also the PACA pointer. The system reset exception handler fails to mask this bit away before using this value before using it as the PACA pointer. Fix this by adding a new type of exception prolog macro where we already have the PACA set in r13, and have the system reset vector mask it out. The winkle wakeup handler will store the masked value back into HSPRG0. Fixes: fb479e44a9e2 ("powerpc/64s: relocation, register save fixes for system reset interrupt") Cc: stable@vger.kernel.org # v3.0+ Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | Merge tag 'powerpc-4.9-4' of ↵Linus Torvalds2016-10-28
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc fixes from Michael Ellerman: "Fixes marked for stable: - Convert cmp to cmpd in idle enter sequence (Segher Boessenkool) - cxl: Fix leaking pid refs in some error paths (Vaibhav Jain) - Re-fix race condition between going idle and entering guest (Paul Mackerras) - Fix race condition in setting lock bit in idle/wakeup code (Paul Mackerras) - radix: Use tlbiel only if we ever ran on the current cpu (Aneesh Kumar K.V) - relocation, register save fixes for system reset interrupt (Nicholas Piggin) Fixes for code merged this cycle: - Fix CONFIG_ALIVEC typo in restore_tm_state() (Valentin Rothberg) - KVM: PPC: Book3S HV: Fix build error when SMP=n (Michael Ellerman)" * tag 'powerpc-4.9-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/64s: relocation, register save fixes for system reset interrupt powerpc/mm/radix: Use tlbiel only if we ever ran on the current cpu powerpc/process: Fix CONFIG_ALIVEC typo in restore_tm_state() powerpc/64: Fix race condition in setting lock bit in idle/wakeup code powerpc/64: Re-fix race condition between going idle and entering guest cxl: Fix leaking pid refs in some error paths powerpc: Convert cmp to cmpd in idle enter sequence KVM: PPC: Book3S HV: Fix build error when SMP=n
| * powerpc/64s: relocation, register save fixes for system reset interruptNicholas Piggin2016-10-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch does a couple of things. First of all, powernv immediately explodes when running a relocated kernel, because the system reset exception for handling sleeps does not do correct relocated branches. Secondly, the sleep handling code trashes the condition and cfar registers, which we would like to preserve for debugging purposes (for non-sleep case exception). This patch changes the exception to use the standard format that saves registers before any tests or branches are made. It adds the test for idle-wakeup as an "extra" to break out of the normal exception path. Then it branches to a relocated idle handler that calls the various idle handling functions. After this patch, POWER8 CPU simulator now boots powernv kernel that is running at non-zero. Fixes: 948cf67c4726 ("powerpc: Add NAP mode support on Power7 in HV mode") Cc: stable@vger.kernel.org # v3.0+ Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Acked-by: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * powerpc/process: Fix CONFIG_ALIVEC typo in restore_tm_state()Valentin Rothberg2016-10-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It should be ALTIVEC, not ALIVEC. Cyril explains: If a thread performs a transaction with altivec and then gets preempted for whatever reason, this bug may cause the kernel to not re-enable altivec when that thread runs again. This will result in an altivec unavailable fault, when that fault happens inside a user transaction the kernel has no choice but to enable altivec and doom the transaction. The result is that transactions using altivec may get aborted more often than they should. The difficulty in catching this with a selftest is my deliberate use of the word may above. Optimisations to avoid FPU/altivec/VSX faults mean that the kernel will always leave them on for 255 switches. This code prevents the kernel turning it off if it got to the 256th switch (and userspace was transactional). Fixes: dc16b553c949 ("powerpc: Always restore FPU/VEC/VSX if hardware transactional memory in use") Reviewed-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Valentin Rothberg <valentinrothberg@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * powerpc/64: Fix race condition in setting lock bit in idle/wakeup codePaul Mackerras2016-10-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This fixes a race condition where one thread that is entering or leaving a power-saving state can inadvertently ignore the lock bit that was set by another thread, and potentially also clear it. The core_idle_lock_held function is called when the lock bit is seen to be set. It polls the lock bit until it is clear, then does a lwarx to load the word containing the lock bit and thread idle bits so it can be updated. However, it is possible that the value loaded with the lwarx has the lock bit set, even though an immediately preceding lwz loaded a value with the lock bit clear. If this happens then we go ahead and update the word despite the lock bit being set, and when called from pnv_enter_arch207_idle_mode, we will subsequently clear the lock bit. No identifiable misbehaviour has been attributed to this race. This fixes it by checking the lock bit in the value loaded by the lwarx. If it is set then we just go back and keep on polling. Fixes: b32aadc1a8ed ("powerpc/powernv: Fix race in updating core_idle_state") Cc: stable@vger.kernel.org # v4.2+ Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * powerpc/64: Re-fix race condition between going idle and entering guestPaul Mackerras2016-10-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 8117ac6a6c2f ("powerpc/powernv: Switch off MMU before entering nap/sleep/rvwinkle mode", 2014-12-10) fixed a race condition where one thread entering a KVM guest could switch the MMU context to the guest while another thread was still in host kernel context with the MMU on. That commit moved the point where a thread entering a power-saving mode set its kvm_hstate.hwthread_state field in its PACA to KVM_HWTHREAD_IN_IDLE from a point where the MMU was on to after the MMU had been switched off. That commit also added a comment explaining that we have to switch to real mode before setting hwthread_state to avoid this race. Nevertheless, commit 4eae2c9ae54a ("powerpc/powernv: Make pnv_powersave_common more generic", 2016-07-08) subsequently moved the setting of hwthread_state back to a point where the MMU is on, thus reintroducing the race, despite the comment saying that this should not be done being included in full in the context lines of the patch that did it. This fixes the race again and adds a bigger and shoutier comment explaining the potential race condition. Fixes: 4eae2c9ae54a ("powerpc/powernv: Make pnv_powersave_common more generic") Cc: stable@vger.kernel.org # v4.8+ Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Reviewed-by: Shreyas B. Prabhu <shreyasbp@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds2016-10-28
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "Misc kernel fixes: a virtualization environment related fix, an uncore PMU driver removal handling fix, a PowerPC fix and new events for Knights Landing" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/intel: Honour the CPUID for number of fixed counters in hypervisors perf/powerpc: Don't call perf_event_disable() from atomic context perf/core: Protect PMU device removal with a 'pmu_bus_running' check, to fix CONFIG_DEBUG_TEST_DRIVER_REMOVE=y kernel panic perf/x86/intel/cstate: Add C-state residency events for Knights Landing
| * | perf/powerpc: Don't call perf_event_disable() from atomic contextJiri Olsa2016-10-28
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The trinity syscall fuzzer triggered following WARN() on powerpc: WARNING: CPU: 9 PID: 2998 at arch/powerpc/kernel/hw_breakpoint.c:278 ... NIP [c00000000093aedc] .hw_breakpoint_handler+0x28c/0x2b0 LR [c00000000093aed8] .hw_breakpoint_handler+0x288/0x2b0 Call Trace: [c0000002f7933580] [c00000000093aed8] .hw_breakpoint_handler+0x288/0x2b0 (unreliable) [c0000002f7933630] [c0000000000f671c] .notifier_call_chain+0x7c/0xf0 [c0000002f79336d0] [c0000000000f6abc] .__atomic_notifier_call_chain+0xbc/0x1c0 [c0000002f7933780] [c0000000000f6c40] .notify_die+0x70/0xd0 [c0000002f7933820] [c00000000001a74c] .do_break+0x4c/0x100 [c0000002f7933920] [c0000000000089fc] handle_dabr_fault+0x14/0x48 Followed by a lockdep warning: =============================== [ INFO: suspicious RCU usage. ] 4.8.0-rc5+ #7 Tainted: G W ------------------------------- ./include/linux/rcupdate.h:556 Illegal context switch in RCU read-side critical section! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 2 locks held by ls/2998: #0: (rcu_read_lock){......}, at: [<c0000000000f6a00>] .__atomic_notifier_call_chain+0x0/0x1c0 #1: (rcu_read_lock){......}, at: [<c00000000093ac50>] .hw_breakpoint_handler+0x0/0x2b0 stack backtrace: CPU: 9 PID: 2998 Comm: ls Tainted: G W 4.8.0-rc5+ #7 Call Trace: [c0000002f7933150] [c00000000094b1f8] .dump_stack+0xe0/0x14c (unreliable) [c0000002f79331e0] [c00000000013c468] .lockdep_rcu_suspicious+0x138/0x180 [c0000002f7933270] [c0000000001005d8] .___might_sleep+0x278/0x2e0 [c0000002f7933300] [c000000000935584] .mutex_lock_nested+0x64/0x5a0 [c0000002f7933410] [c00000000023084c] .perf_event_ctx_lock_nested+0x16c/0x380 [c0000002f7933500] [c000000000230a80] .perf_event_disable+0x20/0x60 [c0000002f7933580] [c00000000093aeec] .hw_breakpoint_handler+0x29c/0x2b0 [c0000002f7933630] [c0000000000f671c] .notifier_call_chain+0x7c/0xf0 [c0000002f79336d0] [c0000000000f6abc] .__atomic_notifier_call_chain+0xbc/0x1c0 [c0000002f7933780] [c0000000000f6c40] .notify_die+0x70/0xd0 [c0000002f7933820] [c00000000001a74c] .do_break+0x4c/0x100 [c0000002f7933920] [c0000000000089fc] handle_dabr_fault+0x14/0x48 While it looks like the first WARN() is probably valid, the other one is triggered by disabling event via perf_event_disable() from atomic context. The event is disabled here in case we were not able to emulate the instruction that hit the breakpoint. By disabling the event we unschedule the event and make sure it's not scheduled back. But we can't call perf_event_disable() from atomic context, instead we need to use the event's pending_disable irq_work method to disable it. Reported-by: Jan Stancek <jstancek@redhat.com> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Neuling <mikey@neuling.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20161026094824.GA21397@krava Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | Merge branch 'gup_flag-cleanups'Linus Torvalds2016-10-19
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge the gup_flags cleanups from Lorenzo Stoakes: "This patch series adjusts functions in the get_user_pages* family such that desired FOLL_* flags are passed as an argument rather than implied by flags. The purpose of this change is to make the use of FOLL_FORCE explicit so it is easier to grep for and clearer to callers that this flag is being used. The use of FOLL_FORCE is an issue as it overrides missing VM_READ/VM_WRITE flags for the VMA whose pages we are reading from/writing to, which can result in surprising behaviour. The patch series came out of the discussion around commit 38e088546522 ("mm: check VMA flags to avoid invalid PROT_NONE NUMA balancing"), which addressed a BUG_ON() being triggered when a page was faulted in with PROT_NONE set but having been overridden by FOLL_FORCE. do_numa_page() was run on the assumption the page _must_ be one marked for NUMA node migration as an actual PROT_NONE page would have been dealt with prior to this code path, however FOLL_FORCE introduced a situation where this assumption did not hold. See https://marc.info/?l=linux-mm&m=147585445805166 for the patch proposal" Additionally, there's a fix for an ancient bug related to FOLL_FORCE and FOLL_WRITE by me. [ This branch was rebased recently to add a few more acked-by's and reviewed-by's ] * gup_flag-cleanups: mm: replace access_process_vm() write parameter with gup_flags mm: replace access_remote_vm() write parameter with gup_flags mm: replace __access_remote_vm() write parameter with gup_flags mm: replace get_user_pages_remote() write/force parameters with gup_flags mm: replace get_user_pages() write/force parameters with gup_flags mm: replace get_vaddr_frames() write/force parameters with gup_flags mm: replace get_user_pages_locked() write/force parameters with gup_flags mm: replace get_user_pages_unlocked() write/force parameters with gup_flags mm: remove write/force parameters from __get_user_pages_unlocked() mm: remove write/force parameters from __get_user_pages_locked() mm: remove gup_flags FOLL_WRITE games from __get_user_pages()
| * mm: replace access_process_vm() write parameter with gup_flagsLorenzo Stoakes2016-10-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This removes the 'write' argument from access_process_vm() and replaces it with 'gup_flags' as use of this function previously silently implied FOLL_FORCE, whereas after this patch callers explicitly pass this flag. We make this explicit as use of FOLL_FORCE can result in surprising behaviour (and hence bugs) within the mm subsystem. Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge tag 'gcc-plugins-v4.9-rc1' of ↵Linus Torvalds2016-10-15
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull gcc plugins update from Kees Cook: "This adds a new gcc plugin named "latent_entropy". It is designed to extract as much possible uncertainty from a running system at boot time as possible, hoping to capitalize on any possible variation in CPU operation (due to runtime data differences, hardware differences, SMP ordering, thermal timing variation, cache behavior, etc). At the very least, this plugin is a much more comprehensive example for how to manipulate kernel code using the gcc plugin internals" * tag 'gcc-plugins-v4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: latent_entropy: Mark functions with __latent_entropy gcc-plugins: Add latent_entropy plugin
| * | gcc-plugins: Add latent_entropy pluginEmese Revfy2016-10-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds a new gcc plugin named "latent_entropy". It is designed to extract as much possible uncertainty from a running system at boot time as possible, hoping to capitalize on any possible variation in CPU operation (due to runtime data differences, hardware differences, SMP ordering, thermal timing variation, cache behavior, etc). At the very least, this plugin is a much more comprehensive example for how to manipulate kernel code using the gcc plugin internals. The need for very-early boot entropy tends to be very architecture or system design specific, so this plugin is more suited for those sorts of special cases. The existing kernel RNG already attempts to extract entropy from reliable runtime variation, but this plugin takes the idea to a logical extreme by permuting a global variable based on any variation in code execution (e.g. a different value (and permutation function) is used to permute the global based on loop count, case statement, if/then/else branching, etc). To do this, the plugin starts by inserting a local variable in every marked function. The plugin then adds logic so that the value of this variable is modified by randomly chosen operations (add, xor and rol) and random values (gcc generates separate static values for each location at compile time and also injects the stack pointer at runtime). The resulting value depends on the control flow path (e.g., loops and branches taken). Before the function returns, the plugin mixes this local variable into the latent_entropy global variable. The value of this global variable is added to the kernel entropy pool in do_one_initcall() and _do_fork(), though it does not credit any bytes of entropy to the pool; the contents of the global are just used to mix the pool. Additionally, the plugin can pre-initialize arrays with build-time random contents, so that two different kernel builds running on identical hardware will not have the same starting values. Signed-off-by: Emese Revfy <re.emese@gmail.com> [kees: expanded commit message and code comments] Signed-off-by: Kees Cook <keescook@chromium.org>
* | | Merge branch 'kbuild' of ↵Linus Torvalds2016-10-14
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild Pull kbuild updates from Michal Marek: - EXPORT_SYMBOL for asm source by Al Viro. This does bring a regression, because genksyms no longer generates checksums for these symbols (CONFIG_MODVERSIONS). Nick Piggin is working on a patch to fix this. Plus, we are talking about functions like strcpy(), which rarely change prototypes. - Fixes for PPC fallout of the above by Stephen Rothwell and Nick Piggin - fixdep speedup by Alexey Dobriyan. - preparatory work by Nick Piggin to allow architectures to build with -ffunction-sections, -fdata-sections and --gc-sections - CONFIG_THIN_ARCHIVES support by Stephen Rothwell - fix for filenames with colons in the initramfs source by me. * 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: (22 commits) initramfs: Escape colons in depfile ppc: there is no clear_pages to export powerpc/64: whitelist unresolved modversions CRCs kbuild: -ffunction-sections fix for archs with conflicting sections kbuild: add arch specific post-link Makefile kbuild: allow archs to select link dead code/data elimination kbuild: allow architectures to use thin archives instead of ld -r kbuild: Regenerate genksyms lexer kbuild: genksyms fix for typeof handling fixdep: faster CONFIG_ search ia64: move exports to definitions sparc32: debride memcpy.S a bit [sparc] unify 32bit and 64bit string.h sparc: move exports to definitions ppc: move exports to definitions arm: move exports to definitions s390: move exports to definitions m68k: move exports to definitions alpha: move exports to actual definitions x86: move exports to actual definitions ...
| * | | ppc: there is no clear_pages to exportStephen Rothwell2016-09-22
| | | | | | | | | | | | | | | | | | | | | | | | Fixes: 9445aa1a3062 ("ppc: move exports to definitions") Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Michal Marek <mmarek@suse.com>
| * | | ppc: move exports to definitionsAl Viro2016-08-07
| | | | | | | | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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