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* treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152Thomas Gleixner2019-05-301-5/+1
| | | | | | | | | | | | | | | | | | | | | Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc/64: Rename soft_enabled to irq_soft_maskMadhavan Srinivasan2018-01-191-1/+1
| | | | | | | | Rename the paca->soft_enabled to paca->irq_soft_mask as it is no longer used as a flag for interrupt state, but a mask. Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/kprobes: Don't save/restore DAR/DSISR to/from pt_regs for optprobesNaveen N. Rao2017-08-241-8/+0
| | | | | | | We don't save/restore these across a trap, or with KPROBES_ON_FTRACE. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/optprobes: Fix TOC handling in optprobes trampolineNaveen N. Rao2017-02-231-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Optprobes on powerpc are limited to kernel text area. We decided to also optimize kretprobe_trampoline since that is also in kernel text area. However,we failed to take into consideration the fact that the same trampoline is also used to catch function returns from kernel modules. As an example: $ sudo modprobe kobject-example $ sudo bash -c "echo 'r foo_show+8' > /sys/kernel/debug/tracing/kprobe_events" $ sudo bash -c "echo 1 > /sys/kernel/debug/tracing/events/kprobes/enable" $ sudo cat /sys/kernel/debug/kprobes/list c000000000041350 k kretprobe_trampoline+0x0 [OPTIMIZED] d000000000e00200 r foo_show+0x8 kobject_example $ cat /sys/kernel/kobject_example/foo Segmentation fault With the below (trimmed) splat in dmesg: Unable to handle kernel paging request for data at address 0xfec40000 Faulting instruction address: 0xc000000000041540 Oops: Kernel access of bad area, sig: 11 [#1] ... NIP [c000000000041540] optimized_callback+0x70/0xe0 LR [c000000000041e60] optinsn_slot+0xf8/0x10000 Call Trace: [c0000000c7327850] [c000000000289af4] alloc_set_pte+0x1c4/0x860 (unreliable) [c0000000c7327890] [c000000000041e60] optinsn_slot+0xf8/0x10000 --- interrupt: 700 at 0xc0000000c7327a80 LR = kretprobe_trampoline+0x0/0x10 [c0000000c7327ba0] [c0000000003a30d4] sysfs_kf_seq_show+0x104/0x1d0 [c0000000c7327bf0] [c0000000003a0bb4] kernfs_seq_show+0x44/0x60 [c0000000c7327c10] [c000000000330578] seq_read+0xf8/0x560 [c0000000c7327cb0] [c0000000003a1e64] kernfs_fop_read+0x194/0x260 [c0000000c7327d00] [c0000000002f9954] __vfs_read+0x44/0x1a0 [c0000000c7327d90] [c0000000002fb4cc] vfs_read+0xbc/0x1b0 [c0000000c7327de0] [c0000000002fd138] SyS_read+0x68/0x110 [c0000000c7327e30] [c00000000000b8e0] system_call+0x38/0xfc Fix this by loading up the kernel TOC before calling into the kernel. The original TOC gets restored as part of the usual pt_regs restore. Fixes: 762df10bad69 ("powerpc/kprobes: Optimize kprobe in kretprobe_trampoline()") Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/kprobes: Implement OptprobesAnju T2017-02-101-0/+135
Current infrastructure of kprobe uses the unconditional trap instruction to probe a running kernel. Optprobe allows kprobe to replace the trap with a branch instruction to a detour buffer. Detour buffer contains instructions to create an in memory pt_regs. Detour buffer also has a call to optimized_callback() which in turn call the pre_handler(). After the execution of the pre-handler, a call is made for instruction emulation. The NIP is determined in advanced through dummy instruction emulation and a branch instruction is created to the NIP at the end of the trampoline. To address the limitation of branch instruction in POWER architecture, detour buffer slot is allocated from a reserved area. For the time being, 64KB is reserved in memory for this purpose. Instructions which can be emulated using analyse_instr() are the candidates for optimization. Before optimization ensure that the address range between the detour buffer allocated and the instruction being probed is within +/- 32MB. Signed-off-by: Anju T Sudhakar <anju@linux.vnet.ibm.com> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>