From 5fdf377d802ddd439fe16dd2e9e38039af535af2 Mon Sep 17 00:00:00 2001 From: Max Filippov Date: Thu, 25 Jun 2015 07:27:16 +0300 Subject: xtensa: move oprofile stack tracing to stacktrace.c Old oprofile interface will share user stack tracing with new perf interface. Move oprofile user/kernel stack tracing to stacktrace.c to make it possible. Signed-off-by: Max Filippov --- arch/xtensa/oprofile/backtrace.c | 158 ++------------------------------------- 1 file changed, 8 insertions(+), 150 deletions(-) (limited to 'arch/xtensa/oprofile') diff --git a/arch/xtensa/oprofile/backtrace.c b/arch/xtensa/oprofile/backtrace.c index 5f03a593d84f..8f952034e161 100644 --- a/arch/xtensa/oprofile/backtrace.c +++ b/arch/xtensa/oprofile/backtrace.c @@ -2,168 +2,26 @@ * @file backtrace.c * * @remark Copyright 2008 Tensilica Inc. + * Copyright (C) 2015 Cadence Design Systems Inc. * @remark Read the file COPYING * */ #include -#include -#include #include -#include -#include +#include -/* Address of common_exception_return, used to check the - * transition from kernel to user space. - */ -extern int common_exception_return; - -/* A struct that maps to the part of the frame containing the a0 and - * a1 registers. - */ -struct frame_start { - unsigned long a0; - unsigned long a1; -}; - -static void xtensa_backtrace_user(struct pt_regs *regs, unsigned int depth) -{ - unsigned long windowstart = regs->windowstart; - unsigned long windowbase = regs->windowbase; - unsigned long a0 = regs->areg[0]; - unsigned long a1 = regs->areg[1]; - unsigned long pc = MAKE_PC_FROM_RA(a0, regs->pc); - int index; - - /* First add the current PC to the trace. */ - if (pc != 0 && pc <= TASK_SIZE) - oprofile_add_trace(pc); - else - return; - - /* Two steps: - * - * 1. Look through the register window for the - * previous PCs in the call trace. - * - * 2. Look on the stack. - */ - - /* Step 1. */ - /* Rotate WINDOWSTART to move the bit corresponding to - * the current window to the bit #0. - */ - windowstart = (windowstart << WSBITS | windowstart) >> windowbase; - - /* Look for bits that are set, they correspond to - * valid windows. - */ - for (index = WSBITS - 1; (index > 0) && depth; depth--, index--) - if (windowstart & (1 << index)) { - /* Read a0 and a1 from the - * corresponding position in AREGs. - */ - a0 = regs->areg[index * 4]; - a1 = regs->areg[index * 4 + 1]; - /* Get the PC from a0 and a1. */ - pc = MAKE_PC_FROM_RA(a0, pc); - - /* Add the PC to the trace. */ - if (pc != 0 && pc <= TASK_SIZE) - oprofile_add_trace(pc); - else - return; - } - - /* Step 2. */ - /* We are done with the register window, we need to - * look through the stack. - */ - if (depth > 0) { - /* Start from the a1 register. */ - /* a1 = regs->areg[1]; */ - while (a0 != 0 && depth--) { - - struct frame_start frame_start; - /* Get the location for a1, a0 for the - * previous frame from the current a1. - */ - unsigned long *psp = (unsigned long *)a1; - psp -= 4; - - /* Check if the region is OK to access. */ - if (!access_ok(VERIFY_READ, psp, sizeof(frame_start))) - return; - /* Copy a1, a0 from user space stack frame. */ - if (__copy_from_user_inatomic(&frame_start, psp, - sizeof(frame_start))) - return; - - a0 = frame_start.a0; - a1 = frame_start.a1; - pc = MAKE_PC_FROM_RA(a0, pc); - - if (pc != 0 && pc <= TASK_SIZE) - oprofile_add_trace(pc); - else - return; - } - } -} - -static void xtensa_backtrace_kernel(struct pt_regs *regs, unsigned int depth) +static int xtensa_backtrace_cb(struct stackframe *frame, void *data) { - unsigned long pc = regs->pc; - unsigned long *psp; - unsigned long sp_start, sp_end; - unsigned long a0 = regs->areg[0]; - unsigned long a1 = regs->areg[1]; - - sp_start = a1 & ~(THREAD_SIZE-1); - sp_end = sp_start + THREAD_SIZE; - - /* Spill the register window to the stack first. */ - spill_registers(); - - /* Read the stack frames one by one and create the PC - * from the a0 and a1 registers saved there. - */ - while (a1 > sp_start && a1 < sp_end && depth--) { - pc = MAKE_PC_FROM_RA(a0, pc); - - /* Add the PC to the trace. */ - oprofile_add_trace(pc); - if (pc == (unsigned long) &common_exception_return) { - regs = (struct pt_regs *)a1; - if (user_mode(regs)) { - pc = regs->pc; - if (pc != 0 && pc <= TASK_SIZE) - oprofile_add_trace(pc); - else - return; - return xtensa_backtrace_user(regs, depth); - } - a0 = regs->areg[0]; - a1 = regs->areg[1]; - continue; - } - - psp = (unsigned long *)a1; - - a0 = *(psp - 4); - a1 = *(psp - 3); - - if (a1 <= (unsigned long)psp) - return; - - } - return; + oprofile_add_trace(frame->pc); + return 0; } void xtensa_backtrace(struct pt_regs * const regs, unsigned int depth) { if (user_mode(regs)) - xtensa_backtrace_user(regs, depth); + xtensa_backtrace_user(regs, depth, xtensa_backtrace_cb, NULL); else - xtensa_backtrace_kernel(regs, depth); + xtensa_backtrace_kernel(regs, depth, xtensa_backtrace_cb, + xtensa_backtrace_cb, NULL); } -- cgit v1.2.3