[PATCH v4 5/6] powerpc: Add show_user_instructions()
From: Murilo Opsfelder Araujo <hidden>
Date: 2018-08-01 21:34:35
Also in:
lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
show_user_instructions() is a slightly modified version of show_instructions() that allows userspace instruction dump. This will be useful within show_signal_msg() to dump userspace instructions of the faulty location. Here is a sample of what show_user_instructions() outputs: pandafault[10850]: code: 4bfffeec 4bfffee8 3c401002 38427f00 fbe1fff8 f821ffc1 7c3f0b78 3d22fffe pandafault[10850]: code: 392988d0 f93f0020 e93f0020 39400048 <99490000> 39200000 7d234b78 383f0040 The current->comm and current->pid printed can serve as a glue that links the instructions dump to its originator, allowing messages to be interleaved in the logs. Signed-off-by: Murilo Opsfelder Araujo <redacted> --- arch/powerpc/include/asm/stacktrace.h | 13 +++++++++ arch/powerpc/kernel/process.c | 40 +++++++++++++++++++++++++++ 2 files changed, 53 insertions(+) create mode 100644 arch/powerpc/include/asm/stacktrace.h
diff --git a/arch/powerpc/include/asm/stacktrace.h b/arch/powerpc/include/asm/stacktrace.h
new file mode 100644
index 000000000000..6149b53b3bc8
--- /dev/null
+++ b/arch/powerpc/include/asm/stacktrace.h@@ -0,0 +1,13 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Stack trace functions. + * + * Copyright 2018, Murilo Opsfelder Araujo, IBM Corporation. + */ + +#ifndef _ASM_POWERPC_STACKTRACE_H +#define _ASM_POWERPC_STACKTRACE_H + +void show_user_instructions(struct pt_regs *regs); + +#endif /* _ASM_POWERPC_STACKTRACE_H */
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index e9533b4d2f08..364645ac732c 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c@@ -1299,6 +1299,46 @@ static void show_instructions(struct pt_regs *regs) pr_cont("\n"); } +void show_user_instructions(struct pt_regs *regs) +{ + int i; + const char *prefix = KERN_INFO "%s[%d]: code: "; + unsigned long pc = regs->nip - (instructions_to_print * 3 / 4 * + sizeof(int)); + + printk(prefix, current->comm, current->pid); + + for (i = 0; i < instructions_to_print; i++) { + int instr; + + if (!(i % 8) && (i > 0)) { + pr_cont("\n"); + printk(prefix, current->comm, current->pid); + } + +#if !defined(CONFIG_BOOKE) + /* If executing with the IMMU off, adjust pc rather + * than print XXXXXXXX. + */ + if (!(regs->msr & MSR_IR)) + pc = (unsigned long)phys_to_virt(pc); +#endif + + if (probe_kernel_address((unsigned int __user *)pc, instr)) { + pr_cont("XXXXXXXX "); + } else { + if (regs->nip == pc) + pr_cont("<%08x> ", instr); + else + pr_cont("%08x ", instr); + } + + pc += sizeof(int); + } + + pr_cont("\n"); +} + struct regbit { unsigned long bit; const char *name;
--
2.17.1