kernel.git/arch/powerpc/kernel, branch linux-4.20.y

powerpc/8xx: fix setting of pagetable for Abatron BDI debug tool.

2019-02-27T09:09:47Z

[ Upstream commit fb0bdec51a4901b7dd088de0a1e365e1b9f5cd21 ] Commit 8c8c10b90d88 ("powerpc/8xx: fix handling of early NULL pointer dereference") moved the loading of r6 earlier in the code. As some functions are called inbetween, r6 needs to be loaded again with the address of swapper_pg_dir in order to set PTE pointers for the Abatron BDI. Fixes: 8c8c10b90d88 ("powerpc/8xx: fix handling of early NULL pointer dereference") Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin

powerpc/fadump: Do not allow hot-remove memory from fadump reserved area.

2019-02-12T19:02:27Z

[ Upstream commit 0db6896ff6332ba694f1e61b93ae3b2640317633 ] For fadump to work successfully there should not be any holes in reserved memory ranges where kernel has asked firmware to move the content of old kernel memory in event of crash. Now that fadump uses CMA for reserved area, this memory area is now not protected from hot-remove operations unless it is cma allocated. Hence, fadump service can fail to re-register after the hot-remove operation, if hot-removed memory belongs to fadump reserved region. To avoid this make sure that memory from fadump reserved area is not hot-removable if fadump is registered. However, if user still wants to remove that memory, he can do so by manually stopping fadump service before hot-remove operation. Signed-off-by: Mahesh Salgaonkar Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin

powerpc/32: Add .data..Lubsan_data/.data..Lubsan_type sections explicitly

2019-02-12T19:02:10Z

[ Upstream commit beba24ac59133cb36ecd03f9af9ccb11971ee20e ] When both `CONFIG_LD_DEAD_CODE_DATA_ELIMINATION=y` and `CONFIG_UBSAN=y` are set, link step typically produce numberous warnings about orphan section: + powerpc-linux-gnu-ld -EB -m elf32ppc -Bstatic --orphan-handling=warn --build-id --gc-sections -X -o .tmp_vmlinux1 -T ./arch/powerpc/kernel/vmlinux.lds --who le-archive built-in.a --no-whole-archive --start-group lib/lib.a --end-group powerpc-linux-gnu-ld: warning: orphan section `.data..Lubsan_data393' from `init/main.o' being placed in section `.data..Lubsan_data393'. powerpc-linux-gnu-ld: warning: orphan section `.data..Lubsan_data394' from `init/main.o' being placed in section `.data..Lubsan_data394'. ... powerpc-linux-gnu-ld: warning: orphan section `.data..Lubsan_type11' from `init/main.o' being placed in section `.data..Lubsan_type11'. powerpc-linux-gnu-ld: warning: orphan section `.data..Lubsan_type12' from `init/main.o' being placed in section `.data..Lubsan_type12'. ... This commit remove those warnings produced at W=1. Link: https://www.mail-archive.com/linuxppc-dev@lists.ozlabs.org/msg135407.html Suggested-by: Nicholas Piggin Signed-off-by: Mathieu Malaterre Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin

powerpc/tm: Limit TM code inside PPC_TRANSACTIONAL_MEM

2019-01-22T20:09:54Z

commit 897bc3df8c5aebb54c32d831f917592e873d0559 upstream. Commit e1c3743e1a20 ("powerpc/tm: Set MSR[TS] just prior to recheckpoint") moved a code block around and this block uses a 'msr' variable outside of the CONFIG_PPC_TRANSACTIONAL_MEM, however the 'msr' variable is declared inside a CONFIG_PPC_TRANSACTIONAL_MEM block, causing a possible error when CONFIG_PPC_TRANSACTION_MEM is not defined. error: 'msr' undeclared (first use in this function) This is not causing a compilation error in the mainline kernel, because 'msr' is being used as an argument of MSR_TM_ACTIVE(), which is defined as the following when CONFIG_PPC_TRANSACTIONAL_MEM is *not* set: #define MSR_TM_ACTIVE(x) 0 This patch just fixes this issue avoiding the 'msr' variable usage outside the CONFIG_PPC_TRANSACTIONAL_MEM block, avoiding trusting in the MSR_TM_ACTIVE() definition. Cc: stable@vger.kernel.org Reported-by: Christoph Biedl Fixes: e1c3743e1a20 ("powerpc/tm: Set MSR[TS] just prior to recheckpoint") Signed-off-by: Breno Leitao Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

powerpc/tm: Unset MSR[TS] if not recheckpointing

2019-01-16T21:03:19Z

commit 6f5b9f018f4c7686fd944d920209d1382d320e4e upstream. There is a TM Bad Thing bug that can be caused when you return from a signal context in a suspended transaction but with ucontext MSR[TS] unset. This forces regs->msr[TS] to be set at syscall entrance (since the CPU state is transactional). It also calls treclaim() to flush the transaction state, which is done based on the live (mfmsr) MSR state. Since user context MSR[TS] is not set, then restore_tm_sigcontexts() is not called, thus, not executing recheckpoint, keeping the CPU state as not transactional. When calling rfid, SRR1 will have MSR[TS] set, but the CPU state is non transactional, causing the TM Bad Thing with the following stack: [ 33.862316] Bad kernel stack pointer 3fffd9dce3e0 at c00000000000c47c cpu 0x8: Vector: 700 (Program Check) at [c00000003ff7fd40] pc: c00000000000c47c: fast_exception_return+0xac/0xb4 lr: 00003fff865f442c sp: 3fffd9dce3e0 msr: 8000000102a03031 current = 0xc00000041f68b700 paca = 0xc00000000fb84800 softe: 0 irq_happened: 0x01 pid = 1721, comm = tm-signal-sigre Linux version 4.9.0-3-powerpc64le (debian-kernel@lists.debian.org) (gcc version 6.3.0 20170516 (Debian 6.3.0-18) ) #1 SMP Debian 4.9.30-2+deb9u2 (2017-06-26) WARNING: exception is not recoverable, can't continue The same problem happens on 32-bits signal handler, and the fix is very similar, if tm_recheckpoint() is not executed, then regs->msr[TS] should be zeroed. This patch also fixes a sparse warning related to lack of indentation when CONFIG_PPC_TRANSACTIONAL_MEM is set. Fixes: 2b0a576d15e0e ("powerpc: Add new transactional memory state to the signal context") CC: Stable # 3.10+ Signed-off-by: Breno Leitao Tested-by: Michal Suchánek Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

powerpc/tm: Set MSR[TS] just prior to recheckpoint

2019-01-13T08:24:07Z

commit e1c3743e1a20647c53b719dbf28b48f45d23f2cd upstream. On a signal handler return, the user could set a context with MSR[TS] bits set, and these bits would be copied to task regs->msr. At restore_tm_sigcontexts(), after current task regs->msr[TS] bits are set, several __get_user() are called and then a recheckpoint is executed. This is a problem since a page fault (in kernel space) could happen when calling __get_user(). If it happens, the process MSR[TS] bits were already set, but recheckpoint was not executed, and SPRs are still invalid. The page fault can cause the current process to be de-scheduled, with MSR[TS] active and without tm_recheckpoint() being called. More importantly, without TEXASR[FS] bit set also. Since TEXASR might not have the FS bit set, and when the process is scheduled back, it will try to reclaim, which will be aborted because of the CPU is not in the suspended state, and, then, recheckpoint. This recheckpoint will restore thread->texasr into TEXASR SPR, which might be zero, hitting a BUG_ON(). kernel BUG at /build/linux-sf3Co9/linux-4.9.30/arch/powerpc/kernel/tm.S:434! cpu 0xb: Vector: 700 (Program Check) at [c00000041f1576d0] pc: c000000000054550: restore_gprs+0xb0/0x180 lr: 0000000000000000 sp: c00000041f157950 msr: 8000000100021033 current = 0xc00000041f143000 paca = 0xc00000000fb86300 softe: 0 irq_happened: 0x01 pid = 1021, comm = kworker/11:1 kernel BUG at /build/linux-sf3Co9/linux-4.9.30/arch/powerpc/kernel/tm.S:434! Linux version 4.9.0-3-powerpc64le (debian-kernel@lists.debian.org) (gcc version 6.3.0 20170516 (Debian 6.3.0-18) ) #1 SMP Debian 4.9.30-2+deb9u2 (2017-06-26) enter ? for help [c00000041f157b30] c00000000001bc3c tm_recheckpoint.part.11+0x6c/0xa0 [c00000041f157b70] c00000000001d184 __switch_to+0x1e4/0x4c0 [c00000041f157bd0] c00000000082eeb8 __schedule+0x2f8/0x990 [c00000041f157cb0] c00000000082f598 schedule+0x48/0xc0 [c00000041f157ce0] c0000000000f0d28 worker_thread+0x148/0x610 [c00000041f157d80] c0000000000f96b0 kthread+0x120/0x140 [c00000041f157e30] c00000000000c0e0 ret_from_kernel_thread+0x5c/0x7c This patch simply delays the MSR[TS] set, so, if there is any page fault in the __get_user() section, it does not have regs->msr[TS] set, since the TM structures are still invalid, thus avoiding doing TM operations for in-kernel exceptions and possible process reschedule. With this patch, the MSR[TS] will only be set just before recheckpointing and setting TEXASR[FS] = 1, thus avoiding an interrupt with TM registers in invalid state. Other than that, if CONFIG_PREEMPT is set, there might be a preemption just after setting MSR[TS] and before tm_recheckpoint(), thus, this block must be atomic from a preemption perspective, thus, calling preempt_disable/enable() on this code. It is not possible to move tm_recheckpoint to happen earlier, because it is required to get the checkpointed registers from userspace, with __get_user(), thus, the only way to avoid this undesired behavior is delaying the MSR[TS] set. The 32-bits signal handler seems to be safe this current issue, but, it might be exposed to the preemption issue, thus, disabling preemption in this chunk of code. Changes from v2: * Run the critical section with preempt_disable. Fixes: 87b4e5393af7 ("powerpc/tm: Fix return of active 64bit signals") Cc: stable@vger.kernel.org (v3.9+) Signed-off-by: Breno Leitao Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

Revert "powerpc/tm: Unset MSR[TS] if not recheckpointing"

2019-01-13T08:24:07Z

This reverts commit d412deb85a4aada382352a8202beb7af8921cd53 which is commit 6f5b9f018f4c7686fd944d920209d1382d320e4e upstream. It breaks the powerpc build, so drop it from the tree until a fix goes upstream. Reported-by: Guenter Roeck Cc: Breno Leitao Cc: Michal Suchánek Cc: Michael Ellerman Cc: Christoph Biedl Signed-off-by: Greg Kroah-Hartman

powerpc/tm: Unset MSR[TS] if not recheckpointing

2019-01-09T16:46:00Z

powerpc/fsl: Fix spectre_v2 mitigations reporting

2019-01-09T16:45:51Z

commit 7d8bad99ba5a22892f0cad6881289fdc3875a930 upstream. Currently for CONFIG_PPC_FSL_BOOK3E the spectre_v2 file is incorrect: $ cat /sys/devices/system/cpu/vulnerabilities/spectre_v2 "Mitigation: Software count cache flush" Which is wrong. Fix it to report vulnerable for now. Fixes: ee13cb249fab ("powerpc/64s: Add support for software count cache flush") Cc: stable@vger.kernel.org # v4.19+ Signed-off-by: Diana Craciun Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

Merge tag 'powerpc-4.20-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2018-12-14T17:33:34Z

Pull powerpc fixes from Michael Ellerman: "One notable fix for our change to split pt_regs between user/kernel, we forgot to update BPF to use the user-visible type which was an ABI break for BPF programs. A slightly ugly but minimal fix to do_syscall_trace_enter() so that we use tracehook_report_syscall_entry() properly. We'll rework the code in next to avoid the empty if body. Seven commits fixing bugs in the new papr_scm (Storage Class Memory) driver. The driver was finally able to be tested on the other hypervisor which exposed several bugs. The fixes are all fairly minimal at least. Fix a crash in our MSI code if an MSI-capable device is plugged into a non-MSI capable PHB, only seen on older hardware (MPC8378). Fix our legacy serial code to look for "stdout-path" since the device trees were updated to use that instead of "linux,stdout-path". A change to the COFF zImage code to fix booting old powermacs. A couple of minor build fixes. Thanks to: Benjamin Herrenschmidt, Daniel Axtens, Dmitry V. Levin, Elvira Khabirova, Oliver O'Halloran, Paul Mackerras, Radu Rendec, Rob Herring, Sandipan Das" * tag 'powerpc-4.20-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/ptrace: replace ptrace_report_syscall() with a tracehook call powerpc/mm: Fallback to RAM if the altmap is unusable powerpc/papr_scm: Use ibm,unit-guid as the iset cookie powerpc/papr_scm: Fix DIMM device registration race powerpc/papr_scm: Remove endian conversions powerpc/papr_scm: Update DT properties powerpc/papr_scm: Fix resource end address powerpc/papr_scm: Use depend instead of select powerpc/bpf: Fix broken uapi for BPF_PROG_TYPE_PERF_EVENT powerpc/boot: Fix build failures with -j 1 powerpc: Look for "stdout-path" when setting up legacy consoles powerpc/msi: Fix NULL pointer access in teardown code powerpc/mm: Fix linux page tables build with some configs powerpc: Fix COFF zImage booting on old powermacs

kernel.git/arch/powerpc/kernel, branch linux-4.20.y

powerpc/8xx: fix setting of pagetable for Abatron BDI debug tool.

powerpc/fadump: Do not allow hot-remove memory from fadump reserved area.

powerpc/32: Add .data..Lubsan_data*/.data..Lubsan_type* sections explicitly

powerpc/tm: Limit TM code inside PPC_TRANSACTIONAL_MEM

powerpc/tm: Unset MSR[TS] if not recheckpointing

powerpc/tm: Set MSR[TS] just prior to recheckpoint

Revert "powerpc/tm: Unset MSR[TS] if not recheckpointing"

powerpc/tm: Unset MSR[TS] if not recheckpointing

powerpc/fsl: Fix spectre_v2 mitigations reporting

Merge tag 'powerpc-4.20-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

powerpc/32: Add .data..Lubsan_data/.data..Lubsan_type sections explicitly