cregit-Linux how code gets into the kernel

Release 4.14 arch/frv/kernel/debug-stub.c

Directory: arch/frv/kernel
/* debug-stub.c: debug-mode stub
 *
 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * 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.
 */

#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/serial_reg.h>
#include <linux/start_kernel.h>

#include <asm/serial-regs.h>
#include <asm/timer-regs.h>
#include <asm/irc-regs.h>
#include <asm/gdb-stub.h>
#include "gdb-io.h"

/* CPU board CON5 */

#define __UART0(X) (*(volatile uint8_t *)(UART0_BASE + (UART_##X)))


#define LSR_WAIT_FOR0(STATE)			\
do {                                            \
} while (!(__UART0(LSR) & UART_LSR_##STATE))


#define FLOWCTL_QUERY0(LINE)	({ __UART0(MSR) & UART_MSR_##LINE; })

#define FLOWCTL_CLEAR0(LINE)	do { __UART0(MCR) &= ~UART_MCR_##LINE; } while (0)

#define FLOWCTL_SET0(LINE)	do { __UART0(MCR) |= UART_MCR_##LINE; } while (0)


#define FLOWCTL_WAIT_FOR0(LINE)			\
do {                                            \
        gdbstub_do_rx();                        \
} while(!FLOWCTL_QUERY(LINE))


struct frv_debug_status __debug_status;

static void __init debug_stub_init(void);

/*****************************************************************************/
/*
 * debug mode handler stub
 * - we come here with the CPU in debug mode and with exceptions disabled
 * - handle debugging services for userspace
 */

asmlinkage void debug_stub(void) { unsigned long hsr0; int type = 0; static u8 inited = 0; if (!inited) { debug_stub_init(); type = -1; inited = 1; } hsr0 = __get_HSR(0); if (hsr0 & HSR0_ETMD) __set_HSR(0, hsr0 & ~HSR0_ETMD); /* disable single stepping */ __debug_status.dcr &= ~DCR_SE; /* kernel mode can propose an exception be handled in debug mode by jumping to a special * location */ if (__debug_frame->pc == (unsigned long) __break_hijack_kernel_event_breaks_here) { /* replace the debug frame with the kernel frame and discard * the top kernel context */ *__debug_frame = *__frame; __frame = __debug_frame->next_frame; __debug_status.brr = (__debug_frame->tbr & TBR_TT) << 12; __debug_status.brr |= BRR_EB; } if (__debug_frame->pc == (unsigned long) __debug_bug_trap + 4) { __debug_frame->pc = __debug_frame->lr; type = __debug_frame->gr8; } #ifdef CONFIG_GDBSTUB gdbstub(type); #endif if (hsr0 & HSR0_ETMD) __set_HSR(0, __get_HSR(0) | HSR0_ETMD); }

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David Howells179100.00%2100.00%
Total179100.00%2100.00%

/* end debug_stub() */ /*****************************************************************************/ /* * debug stub initialisation */
static void __init debug_stub_init(void) { __set_IRR(6, 0xff000000); /* map ERRs to NMI */ __set_IITMR(1, 0x20000000); /* ERR0/1, UART0/1 IRQ detect levels */ asm volatile(" movgs gr0,ibar0 \n" " movgs gr0,ibar1 \n" " movgs gr0,ibar2 \n" " movgs gr0,ibar3 \n" " movgs gr0,dbar0 \n" " movgs gr0,dbmr00 \n" " movgs gr0,dbmr01 \n" " movgs gr0,dbdr00 \n" " movgs gr0,dbdr01 \n" " movgs gr0,dbar1 \n" " movgs gr0,dbmr10 \n" " movgs gr0,dbmr11 \n" " movgs gr0,dbdr10 \n" " movgs gr0,dbdr11 \n" ); /* deal with debugging stub initialisation and initial pause */ if (__debug_frame->pc == (unsigned long) __debug_stub_init_break) __debug_frame->pc = (unsigned long) start_kernel; /* enable the debug events we want to trap */ __debug_status.dcr = DCR_EBE; #ifdef CONFIG_GDBSTUB gdbstub_init(); #endif __clr_MASK_all(); __clr_MASK(15); __clr_RC(15); }

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David Howells79100.00%2100.00%
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/* end debug_stub_init() */ /*****************************************************************************/ /* * kernel "exit" trap for gdb stub */
void debug_stub_exit(int status) { #ifdef CONFIG_GDBSTUB gdbstub_exit(status); #endif }

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David Howells18100.00%1100.00%
Total18100.00%1100.00%

/* end debug_stub_exit() */ /*****************************************************************************/ /* * send string to serial port */
void debug_to_serial(const char *p, int n) { char ch; for (; n > 0; n--) { ch = *p++; FLOWCTL_SET0(DTR); LSR_WAIT_FOR0(THRE); // FLOWCTL_WAIT_FOR(CTS); if (ch == 0x0a) { __UART0(TX) = 0x0d; mb(); LSR_WAIT_FOR0(THRE); // FLOWCTL_WAIT_FOR(CTS); } __UART0(TX) = ch; mb(); FLOWCTL_CLEAR0(DTR); } }

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David Howells84100.00%1100.00%
Total84100.00%1100.00%

/* end debug_to_serial() */ /*****************************************************************************/ /* * send string to serial port */
void debug_to_serial2(const char *fmt, ...) { va_list va; char buf[64]; int n; va_start(va, fmt); n = vsprintf(buf, fmt, va); va_end(va); debug_to_serial(buf, n); }

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David Howells54100.00%1100.00%
Total54100.00%1100.00%

/* end debug_to_serial2() */ /*****************************************************************************/ /* * set up the ttyS0 serial port baud rate timers */
void __init console_set_baud(unsigned baud) { unsigned value, high, low; u8 lcr; /* work out the divisor to give us the nearest higher baud rate */ value = __serial_clock_speed_HZ / 16 / baud; /* determine the baud rate range */ high = __serial_clock_speed_HZ / 16 / value; low = __serial_clock_speed_HZ / 16 / (value + 1); /* pick the nearest bound */ if (low + (high - low) / 2 > baud) value++; lcr = __UART0(LCR); __UART0(LCR) |= UART_LCR_DLAB; mb(); __UART0(DLL) = value & 0xff; __UART0(DLM) = (value >> 8) & 0xff; mb(); __UART0(LCR) = lcr; mb(); }

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David Howells119100.00%1100.00%
Total119100.00%1100.00%

/* end console_set_baud() */ /*****************************************************************************/ /* * */
int __init console_get_baud(void) { unsigned value; u8 lcr; lcr = __UART0(LCR); __UART0(LCR) |= UART_LCR_DLAB; mb(); value = __UART0(DLM) << 8; value |= __UART0(DLL); __UART0(LCR) = lcr; mb(); return value; }

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David Howells60100.00%1100.00%
Total60100.00%1100.00%

/* end console_get_baud() */ /*****************************************************************************/ /* * display BUG() info */ #ifndef CONFIG_NO_KERNEL_MSG
void __debug_bug_printk(const char *file, unsigned line) { printk("kernel BUG at %s:%d!\n", file, line); }

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David Howells22100.00%1100.00%
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/* end __debug_bug_printk() */ #endif

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David Howells73599.59%266.67%
Rusty Russell30.41%133.33%
Total738100.00%3100.00%
Directory: arch/frv/kernel
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