linux-imx
Public
Source
committed c140d87995bx
/** * @file backtrace.c * * @remark Copyright 2004 Silicon Graphics Inc. All Rights Reserved. * @remark Read the file COPYING * * @author Greg Banks <gnb@melbourne.sgi.com> * @author Keith Owens <kaos@melbourne.sgi.com> * Based on work done for the ia64 port of the SGI kernprof patch, which is * Copyright (c) 2003-2004 Silicon Graphics Inc. All Rights Reserved. *//* * For IA64 we need to perform a complex little dance to get both * the struct pt_regs and a synthetic struct switch_stack in place * to allow the unwind code to work. This dance requires our unwind * using code to be called from a function called from unw_init_running(). * There we only get a single void* data pointer, so use this struct * to hold all the data we need during the unwind. */typedef struct{ unsigned int depth; struct pt_regs *regs; struct unw_frame_info frame; unsigned long *prev_pfs_loc; /* state for WAR for old spinlock ool code */} ia64_backtrace_t;/* Returns non-zero if the PC is in the Interrupt Vector Table */static __inline__ int in_ivt_code(unsigned long pc){ extern char ia64_ivt[]; return (pc >= (u_long)ia64_ivt && pc < (u_long)ia64_ivt+32768);}/* * Unwind to next stack frame. */static __inline__ int next_frame(ia64_backtrace_t *bt){ /* * Avoid unsightly console message from unw_unwind() when attempting * to unwind through the Interrupt Vector Table which has no unwind * information. */ if (in_ivt_code(bt->frame.ip)) return 0; /* * WAR for spinlock contention from leaf functions. ia64_spinlock_contention_pre3_4 * has ar.pfs == r0. Leaf functions do not modify ar.pfs so ar.pfs remains * as 0, stopping the backtrace. Record the previous ar.pfs when the current * IP is in ia64_spinlock_contention_pre3_4 then unwind, if pfs_loc has not changed * after unwind then use pt_regs.ar_pfs which is where the real ar.pfs is for * leaf functions. */ if (bt->prev_pfs_loc && bt->regs && bt->frame.pfs_loc == bt->prev_pfs_loc) bt->frame.pfs_loc = &bt->regs->ar_pfs; bt->prev_pfs_loc = NULL; return unw_unwind(&bt->frame) == 0;}static void do_ia64_backtrace(struct unw_frame_info *info, void *vdata){ ia64_backtrace_t *bt = vdata; struct switch_stack *sw; int count = 0; u_long pc, sp; sw = (struct switch_stack *)(info+1); /* padding from unw_init_running */ sw = (struct switch_stack *)(((unsigned long)sw + 15) & ~15); unw_init_frame_info(&bt->frame, current, sw); /* skip over interrupt frame and oprofile calls */ do { unw_get_sp(&bt->frame, &sp); if (sp >= (u_long)bt->regs) break; if (!next_frame(bt)) return; } while (count++ < 200); /* finally, grab the actual sample */