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-rw-r--r--kernel/debug/kdb/kdb_io.c899
1 files changed, 899 insertions, 0 deletions
diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c
new file mode 100644
index 0000000000..9443bc63c5
--- /dev/null
+++ b/kernel/debug/kdb/kdb_io.c
@@ -0,0 +1,899 @@
+/*
+ * Kernel Debugger Architecture Independent Console I/O handler
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (c) 1999-2006 Silicon Graphics, Inc. All Rights Reserved.
+ * Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved.
+ */
+
+#include <linux/types.h>
+#include <linux/ctype.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/kdev_t.h>
+#include <linux/console.h>
+#include <linux/string.h>
+#include <linux/sched.h>
+#include <linux/smp.h>
+#include <linux/nmi.h>
+#include <linux/delay.h>
+#include <linux/kgdb.h>
+#include <linux/kdb.h>
+#include <linux/kallsyms.h>
+#include "kdb_private.h"
+
+#define CMD_BUFLEN 256
+char kdb_prompt_str[CMD_BUFLEN];
+
+int kdb_trap_printk;
+int kdb_printf_cpu = -1;
+
+static int kgdb_transition_check(char *buffer)
+{
+ if (buffer[0] != '+' && buffer[0] != '$') {
+ KDB_STATE_SET(KGDB_TRANS);
+ kdb_printf("%s", buffer);
+ } else {
+ int slen = strlen(buffer);
+ if (slen > 3 && buffer[slen - 3] == '#') {
+ kdb_gdb_state_pass(buffer);
+ strcpy(buffer, "kgdb");
+ KDB_STATE_SET(DOING_KGDB);
+ return 1;
+ }
+ }
+ return 0;
+}
+
+/**
+ * kdb_handle_escape() - validity check on an accumulated escape sequence.
+ * @buf: Accumulated escape characters to be examined. Note that buf
+ * is not a string, it is an array of characters and need not be
+ * nil terminated.
+ * @sz: Number of accumulated escape characters.
+ *
+ * Return: -1 if the escape sequence is unwanted, 0 if it is incomplete,
+ * otherwise it returns a mapped key value to pass to the upper layers.
+ */
+static int kdb_handle_escape(char *buf, size_t sz)
+{
+ char *lastkey = buf + sz - 1;
+
+ switch (sz) {
+ case 1:
+ if (*lastkey == '\e')
+ return 0;
+ break;
+
+ case 2: /* \e<something> */
+ if (*lastkey == '[')
+ return 0;
+ break;
+
+ case 3:
+ switch (*lastkey) {
+ case 'A': /* \e[A, up arrow */
+ return 16;
+ case 'B': /* \e[B, down arrow */
+ return 14;
+ case 'C': /* \e[C, right arrow */
+ return 6;
+ case 'D': /* \e[D, left arrow */
+ return 2;
+ case '1': /* \e[<1,3,4>], may be home, del, end */
+ case '3':
+ case '4':
+ return 0;
+ }
+ break;
+
+ case 4:
+ if (*lastkey == '~') {
+ switch (buf[2]) {
+ case '1': /* \e[1~, home */
+ return 1;
+ case '3': /* \e[3~, del */
+ return 4;
+ case '4': /* \e[4~, end */
+ return 5;
+ }
+ }
+ break;
+ }
+
+ return -1;
+}
+
+/**
+ * kdb_getchar() - Read a single character from a kdb console (or consoles).
+ *
+ * Other than polling the various consoles that are currently enabled,
+ * most of the work done in this function is dealing with escape sequences.
+ *
+ * An escape key could be the start of a vt100 control sequence such as \e[D
+ * (left arrow) or it could be a character in its own right. The standard
+ * method for detecting the difference is to wait for 2 seconds to see if there
+ * are any other characters. kdb is complicated by the lack of a timer service
+ * (interrupts are off), by multiple input sources. Escape sequence processing
+ * has to be done as states in the polling loop.
+ *
+ * Return: The key pressed or a control code derived from an escape sequence.
+ */
+char kdb_getchar(void)
+{
+#define ESCAPE_UDELAY 1000
+#define ESCAPE_DELAY (2*1000000/ESCAPE_UDELAY) /* 2 seconds worth of udelays */
+ char buf[4]; /* longest vt100 escape sequence is 4 bytes */
+ char *pbuf = buf;
+ int escape_delay = 0;
+ get_char_func *f, *f_prev = NULL;
+ int key;
+ static bool last_char_was_cr;
+
+ for (f = &kdb_poll_funcs[0]; ; ++f) {
+ if (*f == NULL) {
+ /* Reset NMI watchdog once per poll loop */
+ touch_nmi_watchdog();
+ f = &kdb_poll_funcs[0];
+ }
+
+ key = (*f)();
+ if (key == -1) {
+ if (escape_delay) {
+ udelay(ESCAPE_UDELAY);
+ if (--escape_delay == 0)
+ return '\e';
+ }
+ continue;
+ }
+
+ /*
+ * The caller expects that newlines are either CR or LF. However
+ * some terminals send _both_ CR and LF. Avoid having to handle
+ * this in the caller by stripping the LF if we saw a CR right
+ * before.
+ */
+ if (last_char_was_cr && key == '\n') {
+ last_char_was_cr = false;
+ continue;
+ }
+ last_char_was_cr = (key == '\r');
+
+ /*
+ * When the first character is received (or we get a change
+ * input source) we set ourselves up to handle an escape
+ * sequences (just in case).
+ */
+ if (f_prev != f) {
+ f_prev = f;
+ pbuf = buf;
+ escape_delay = ESCAPE_DELAY;
+ }
+
+ *pbuf++ = key;
+ key = kdb_handle_escape(buf, pbuf - buf);
+ if (key < 0) /* no escape sequence; return best character */
+ return buf[pbuf - buf == 2 ? 1 : 0];
+ if (key > 0)
+ return key;
+ }
+
+ unreachable();
+}
+
+/*
+ * kdb_read
+ *
+ * This function reads a string of characters, terminated by
+ * a newline, or by reaching the end of the supplied buffer,
+ * from the current kernel debugger console device.
+ * Parameters:
+ * buffer - Address of character buffer to receive input characters.
+ * bufsize - size, in bytes, of the character buffer
+ * Returns:
+ * Returns a pointer to the buffer containing the received
+ * character string. This string will be terminated by a
+ * newline character.
+ * Locking:
+ * No locks are required to be held upon entry to this
+ * function. It is not reentrant - it relies on the fact
+ * that while kdb is running on only one "master debug" cpu.
+ * Remarks:
+ * The buffer size must be >= 2.
+ */
+
+static char *kdb_read(char *buffer, size_t bufsize)
+{
+ char *cp = buffer;
+ char *bufend = buffer+bufsize-2; /* Reserve space for newline
+ * and null byte */
+ char *lastchar;
+ char *p_tmp;
+ char tmp;
+ static char tmpbuffer[CMD_BUFLEN];
+ int len = strlen(buffer);
+ int len_tmp;
+ int tab = 0;
+ int count;
+ int i;
+ int diag, dtab_count;
+ int key, buf_size, ret;
+
+
+ diag = kdbgetintenv("DTABCOUNT", &dtab_count);
+ if (diag)
+ dtab_count = 30;
+
+ if (len > 0) {
+ cp += len;
+ if (*(buffer+len-1) == '\n')
+ cp--;
+ }
+
+ lastchar = cp;
+ *cp = '\0';
+ kdb_printf("%s", buffer);
+poll_again:
+ key = kdb_getchar();
+ if (key != 9)
+ tab = 0;
+ switch (key) {
+ case 8: /* backspace */
+ if (cp > buffer) {
+ if (cp < lastchar) {
+ memcpy(tmpbuffer, cp, lastchar - cp);
+ memcpy(cp-1, tmpbuffer, lastchar - cp);
+ }
+ *(--lastchar) = '\0';
+ --cp;
+ kdb_printf("\b%s \r", cp);
+ tmp = *cp;
+ *cp = '\0';
+ kdb_printf(kdb_prompt_str);
+ kdb_printf("%s", buffer);
+ *cp = tmp;
+ }
+ break;
+ case 10: /* linefeed */
+ case 13: /* carriage return */
+ *lastchar++ = '\n';
+ *lastchar++ = '\0';
+ if (!KDB_STATE(KGDB_TRANS)) {
+ KDB_STATE_SET(KGDB_TRANS);
+ kdb_printf("%s", buffer);
+ }
+ kdb_printf("\n");
+ return buffer;
+ case 4: /* Del */
+ if (cp < lastchar) {
+ memcpy(tmpbuffer, cp+1, lastchar - cp - 1);
+ memcpy(cp, tmpbuffer, lastchar - cp - 1);
+ *(--lastchar) = '\0';
+ kdb_printf("%s \r", cp);
+ tmp = *cp;
+ *cp = '\0';
+ kdb_printf(kdb_prompt_str);
+ kdb_printf("%s", buffer);
+ *cp = tmp;
+ }
+ break;
+ case 1: /* Home */
+ if (cp > buffer) {
+ kdb_printf("\r");
+ kdb_printf(kdb_prompt_str);
+ cp = buffer;
+ }
+ break;
+ case 5: /* End */
+ if (cp < lastchar) {
+ kdb_printf("%s", cp);
+ cp = lastchar;
+ }
+ break;
+ case 2: /* Left */
+ if (cp > buffer) {
+ kdb_printf("\b");
+ --cp;
+ }
+ break;
+ case 14: /* Down */
+ memset(tmpbuffer, ' ',
+ strlen(kdb_prompt_str) + (lastchar-buffer));
+ *(tmpbuffer+strlen(kdb_prompt_str) +
+ (lastchar-buffer)) = '\0';
+ kdb_printf("\r%s\r", tmpbuffer);
+ *lastchar = (char)key;
+ *(lastchar+1) = '\0';
+ return lastchar;
+ case 6: /* Right */
+ if (cp < lastchar) {
+ kdb_printf("%c", *cp);
+ ++cp;
+ }
+ break;
+ case 16: /* Up */
+ memset(tmpbuffer, ' ',
+ strlen(kdb_prompt_str) + (lastchar-buffer));
+ *(tmpbuffer+strlen(kdb_prompt_str) +
+ (lastchar-buffer)) = '\0';
+ kdb_printf("\r%s\r", tmpbuffer);
+ *lastchar = (char)key;
+ *(lastchar+1) = '\0';
+ return lastchar;
+ case 9: /* Tab */
+ if (tab < 2)
+ ++tab;
+ p_tmp = buffer;
+ while (*p_tmp == ' ')
+ p_tmp++;
+ if (p_tmp > cp)
+ break;
+ memcpy(tmpbuffer, p_tmp, cp-p_tmp);
+ *(tmpbuffer + (cp-p_tmp)) = '\0';
+ p_tmp = strrchr(tmpbuffer, ' ');
+ if (p_tmp)
+ ++p_tmp;
+ else
+ p_tmp = tmpbuffer;
+ len = strlen(p_tmp);
+ buf_size = sizeof(tmpbuffer) - (p_tmp - tmpbuffer);
+ count = kallsyms_symbol_complete(p_tmp, buf_size);
+ if (tab == 2 && count > 0) {
+ kdb_printf("\n%d symbols are found.", count);
+ if (count > dtab_count) {
+ count = dtab_count;
+ kdb_printf(" But only first %d symbols will"
+ " be printed.\nYou can change the"
+ " environment variable DTABCOUNT.",
+ count);
+ }
+ kdb_printf("\n");
+ for (i = 0; i < count; i++) {
+ ret = kallsyms_symbol_next(p_tmp, i, buf_size);
+ if (WARN_ON(!ret))
+ break;
+ if (ret != -E2BIG)
+ kdb_printf("%s ", p_tmp);
+ else
+ kdb_printf("%s... ", p_tmp);
+ *(p_tmp + len) = '\0';
+ }
+ if (i >= dtab_count)
+ kdb_printf("...");
+ kdb_printf("\n");
+ kdb_printf(kdb_prompt_str);
+ kdb_printf("%s", buffer);
+ } else if (tab != 2 && count > 0) {
+ len_tmp = strlen(p_tmp);
+ strncpy(p_tmp+len_tmp, cp, lastchar-cp+1);
+ len_tmp = strlen(p_tmp);
+ strncpy(cp, p_tmp+len, len_tmp-len + 1);
+ len = len_tmp - len;
+ kdb_printf("%s", cp);
+ cp += len;
+ lastchar += len;
+ }
+ kdb_nextline = 1; /* reset output line number */
+ break;
+ default:
+ if (key >= 32 && lastchar < bufend) {
+ if (cp < lastchar) {
+ memcpy(tmpbuffer, cp, lastchar - cp);
+ memcpy(cp+1, tmpbuffer, lastchar - cp);
+ *++lastchar = '\0';
+ *cp = key;
+ kdb_printf("%s\r", cp);
+ ++cp;
+ tmp = *cp;
+ *cp = '\0';
+ kdb_printf(kdb_prompt_str);
+ kdb_printf("%s", buffer);
+ *cp = tmp;
+ } else {
+ *++lastchar = '\0';
+ *cp++ = key;
+ /* The kgdb transition check will hide
+ * printed characters if we think that
+ * kgdb is connecting, until the check
+ * fails */
+ if (!KDB_STATE(KGDB_TRANS)) {
+ if (kgdb_transition_check(buffer))
+ return buffer;
+ } else {
+ kdb_printf("%c", key);
+ }
+ }
+ /* Special escape to kgdb */
+ if (lastchar - buffer >= 5 &&
+ strcmp(lastchar - 5, "$?#3f") == 0) {
+ kdb_gdb_state_pass(lastchar - 5);
+ strcpy(buffer, "kgdb");
+ KDB_STATE_SET(DOING_KGDB);
+ return buffer;
+ }
+ if (lastchar - buffer >= 11 &&
+ strcmp(lastchar - 11, "$qSupported") == 0) {
+ kdb_gdb_state_pass(lastchar - 11);
+ strcpy(buffer, "kgdb");
+ KDB_STATE_SET(DOING_KGDB);
+ return buffer;
+ }
+ }
+ break;
+ }
+ goto poll_again;
+}
+
+/*
+ * kdb_getstr
+ *
+ * Print the prompt string and read a command from the
+ * input device.
+ *
+ * Parameters:
+ * buffer Address of buffer to receive command
+ * bufsize Size of buffer in bytes
+ * prompt Pointer to string to use as prompt string
+ * Returns:
+ * Pointer to command buffer.
+ * Locking:
+ * None.
+ * Remarks:
+ * For SMP kernels, the processor number will be
+ * substituted for %d, %x or %o in the prompt.
+ */
+
+char *kdb_getstr(char *buffer, size_t bufsize, const char *prompt)
+{
+ if (prompt && kdb_prompt_str != prompt)
+ strscpy(kdb_prompt_str, prompt, CMD_BUFLEN);
+ kdb_printf(kdb_prompt_str);
+ kdb_nextline = 1; /* Prompt and input resets line number */
+ return kdb_read(buffer, bufsize);
+}
+
+/*
+ * kdb_input_flush
+ *
+ * Get rid of any buffered console input.
+ *
+ * Parameters:
+ * none
+ * Returns:
+ * nothing
+ * Locking:
+ * none
+ * Remarks:
+ * Call this function whenever you want to flush input. If there is any
+ * outstanding input, it ignores all characters until there has been no
+ * data for approximately 1ms.
+ */
+
+static void kdb_input_flush(void)
+{
+ get_char_func *f;
+ int res;
+ int flush_delay = 1;
+ while (flush_delay) {
+ flush_delay--;
+empty:
+ touch_nmi_watchdog();
+ for (f = &kdb_poll_funcs[0]; *f; ++f) {
+ res = (*f)();
+ if (res != -1) {
+ flush_delay = 1;
+ goto empty;
+ }
+ }
+ if (flush_delay)
+ mdelay(1);
+ }
+}
+
+/*
+ * kdb_printf
+ *
+ * Print a string to the output device(s).
+ *
+ * Parameters:
+ * printf-like format and optional args.
+ * Returns:
+ * 0
+ * Locking:
+ * None.
+ * Remarks:
+ * use 'kdbcons->write()' to avoid polluting 'log_buf' with
+ * kdb output.
+ *
+ * If the user is doing a cmd args | grep srch
+ * then kdb_grepping_flag is set.
+ * In that case we need to accumulate full lines (ending in \n) before
+ * searching for the pattern.
+ */
+
+static char kdb_buffer[256]; /* A bit too big to go on stack */
+static char *next_avail = kdb_buffer;
+static int size_avail;
+static int suspend_grep;
+
+/*
+ * search arg1 to see if it contains arg2
+ * (kdmain.c provides flags for ^pat and pat$)
+ *
+ * return 1 for found, 0 for not found
+ */
+static int kdb_search_string(char *searched, char *searchfor)
+{
+ char firstchar, *cp;
+ int len1, len2;
+
+ /* not counting the newline at the end of "searched" */
+ len1 = strlen(searched)-1;
+ len2 = strlen(searchfor);
+ if (len1 < len2)
+ return 0;
+ if (kdb_grep_leading && kdb_grep_trailing && len1 != len2)
+ return 0;
+ if (kdb_grep_leading) {
+ if (!strncmp(searched, searchfor, len2))
+ return 1;
+ } else if (kdb_grep_trailing) {
+ if (!strncmp(searched+len1-len2, searchfor, len2))
+ return 1;
+ } else {
+ firstchar = *searchfor;
+ cp = searched;
+ while ((cp = strchr(cp, firstchar))) {
+ if (!strncmp(cp, searchfor, len2))
+ return 1;
+ cp++;
+ }
+ }
+ return 0;
+}
+
+static void kdb_msg_write(const char *msg, int msg_len)
+{
+ struct console *c;
+ const char *cp;
+ int cookie;
+ int len;
+
+ if (msg_len == 0)
+ return;
+
+ cp = msg;
+ len = msg_len;
+
+ while (len--) {
+ dbg_io_ops->write_char(*cp);
+ cp++;
+ }
+
+ /*
+ * The console_srcu_read_lock() only provides safe console list
+ * traversal. The use of the ->write() callback relies on all other
+ * CPUs being stopped at the moment and console drivers being able to
+ * handle reentrance when @oops_in_progress is set.
+ *
+ * There is no guarantee that every console driver can handle
+ * reentrance in this way; the developer deploying the debugger
+ * is responsible for ensuring that the console drivers they
+ * have selected handle reentrance appropriately.
+ */
+ cookie = console_srcu_read_lock();
+ for_each_console_srcu(c) {
+ if (!(console_srcu_read_flags(c) & CON_ENABLED))
+ continue;
+ if (c == dbg_io_ops->cons)
+ continue;
+ if (!c->write)
+ continue;
+ /*
+ * Set oops_in_progress to encourage the console drivers to
+ * disregard their internal spin locks: in the current calling
+ * context the risk of deadlock is a bigger problem than risks
+ * due to re-entering the console driver. We operate directly on
+ * oops_in_progress rather than using bust_spinlocks() because
+ * the calls bust_spinlocks() makes on exit are not appropriate
+ * for this calling context.
+ */
+ ++oops_in_progress;
+ c->write(c, msg, msg_len);
+ --oops_in_progress;
+ touch_nmi_watchdog();
+ }
+ console_srcu_read_unlock(cookie);
+}
+
+int vkdb_printf(enum kdb_msgsrc src, const char *fmt, va_list ap)
+{
+ int diag;
+ int linecount;
+ int colcount;
+ int logging, saved_loglevel = 0;
+ int retlen = 0;
+ int fnd, len;
+ int this_cpu, old_cpu;
+ char *cp, *cp2, *cphold = NULL, replaced_byte = ' ';
+ char *moreprompt = "more> ";
+ unsigned long flags;
+
+ /* Serialize kdb_printf if multiple cpus try to write at once.
+ * But if any cpu goes recursive in kdb, just print the output,
+ * even if it is interleaved with any other text.
+ */
+ local_irq_save(flags);
+ this_cpu = smp_processor_id();
+ for (;;) {
+ old_cpu = cmpxchg(&kdb_printf_cpu, -1, this_cpu);
+ if (old_cpu == -1 || old_cpu == this_cpu)
+ break;
+
+ cpu_relax();
+ }
+
+ diag = kdbgetintenv("LINES", &linecount);
+ if (diag || linecount <= 1)
+ linecount = 24;
+
+ diag = kdbgetintenv("COLUMNS", &colcount);
+ if (diag || colcount <= 1)
+ colcount = 80;
+
+ diag = kdbgetintenv("LOGGING", &logging);
+ if (diag)
+ logging = 0;
+
+ if (!kdb_grepping_flag || suspend_grep) {
+ /* normally, every vsnprintf starts a new buffer */
+ next_avail = kdb_buffer;
+ size_avail = sizeof(kdb_buffer);
+ }
+ vsnprintf(next_avail, size_avail, fmt, ap);
+
+ /*
+ * If kdb_parse() found that the command was cmd xxx | grep yyy
+ * then kdb_grepping_flag is set, and kdb_grep_string contains yyy
+ *
+ * Accumulate the print data up to a newline before searching it.
+ * (vsnprintf does null-terminate the string that it generates)
+ */
+
+ /* skip the search if prints are temporarily unconditional */
+ if (!suspend_grep && kdb_grepping_flag) {
+ cp = strchr(kdb_buffer, '\n');
+ if (!cp) {
+ /*
+ * Special cases that don't end with newlines
+ * but should be written without one:
+ * The "[nn]kdb> " prompt should
+ * appear at the front of the buffer.
+ *
+ * The "[nn]more " prompt should also be
+ * (MOREPROMPT -> moreprompt)
+ * written * but we print that ourselves,
+ * we set the suspend_grep flag to make
+ * it unconditional.
+ *
+ */
+ if (next_avail == kdb_buffer) {
+ /*
+ * these should occur after a newline,
+ * so they will be at the front of the
+ * buffer
+ */
+ cp2 = kdb_buffer;
+ len = strlen(kdb_prompt_str);
+ if (!strncmp(cp2, kdb_prompt_str, len)) {
+ /*
+ * We're about to start a new
+ * command, so we can go back
+ * to normal mode.
+ */
+ kdb_grepping_flag = 0;
+ goto kdb_printit;
+ }
+ }
+ /* no newline; don't search/write the buffer
+ until one is there */
+ len = strlen(kdb_buffer);
+ next_avail = kdb_buffer + len;
+ size_avail = sizeof(kdb_buffer) - len;
+ goto kdb_print_out;
+ }
+
+ /*
+ * The newline is present; print through it or discard
+ * it, depending on the results of the search.
+ */
+ cp++; /* to byte after the newline */
+ replaced_byte = *cp; /* remember what/where it was */
+ cphold = cp;
+ *cp = '\0'; /* end the string for our search */
+
+ /*
+ * We now have a newline at the end of the string
+ * Only continue with this output if it contains the
+ * search string.
+ */
+ fnd = kdb_search_string(kdb_buffer, kdb_grep_string);
+ if (!fnd) {
+ /*
+ * At this point the complete line at the start
+ * of kdb_buffer can be discarded, as it does
+ * not contain what the user is looking for.
+ * Shift the buffer left.
+ */
+ *cphold = replaced_byte;
+ strcpy(kdb_buffer, cphold);
+ len = strlen(kdb_buffer);
+ next_avail = kdb_buffer + len;
+ size_avail = sizeof(kdb_buffer) - len;
+ goto kdb_print_out;
+ }
+ if (kdb_grepping_flag >= KDB_GREPPING_FLAG_SEARCH) {
+ /*
+ * This was a interactive search (using '/' at more
+ * prompt) and it has completed. Replace the \0 with
+ * its original value to ensure multi-line strings
+ * are handled properly, and return to normal mode.
+ */
+ *cphold = replaced_byte;
+ kdb_grepping_flag = 0;
+ }
+ /*
+ * at this point the string is a full line and
+ * should be printed, up to the null.
+ */
+ }
+kdb_printit:
+
+ /*
+ * Write to all consoles.
+ */
+ retlen = strlen(kdb_buffer);
+ cp = (char *) printk_skip_headers(kdb_buffer);
+ if (!dbg_kdb_mode && kgdb_connected)
+ gdbstub_msg_write(cp, retlen - (cp - kdb_buffer));
+ else
+ kdb_msg_write(cp, retlen - (cp - kdb_buffer));
+
+ if (logging) {
+ saved_loglevel = console_loglevel;
+ console_loglevel = CONSOLE_LOGLEVEL_SILENT;
+ if (printk_get_level(kdb_buffer) || src == KDB_MSGSRC_PRINTK)
+ printk("%s", kdb_buffer);
+ else
+ pr_info("%s", kdb_buffer);
+ }
+
+ if (KDB_STATE(PAGER)) {
+ /*
+ * Check printed string to decide how to bump the
+ * kdb_nextline to control when the more prompt should
+ * show up.
+ */
+ int got = 0;
+ len = retlen;
+ while (len--) {
+ if (kdb_buffer[len] == '\n') {
+ kdb_nextline++;
+ got = 0;
+ } else if (kdb_buffer[len] == '\r') {
+ got = 0;
+ } else {
+ got++;
+ }
+ }
+ kdb_nextline += got / (colcount + 1);
+ }
+
+ /* check for having reached the LINES number of printed lines */
+ if (kdb_nextline >= linecount) {
+ char ch;
+
+ /* Watch out for recursion here. Any routine that calls
+ * kdb_printf will come back through here. And kdb_read
+ * uses kdb_printf to echo on serial consoles ...
+ */
+ kdb_nextline = 1; /* In case of recursion */
+
+ /*
+ * Pause until cr.
+ */
+ moreprompt = kdbgetenv("MOREPROMPT");
+ if (moreprompt == NULL)
+ moreprompt = "more> ";
+
+ kdb_input_flush();
+ kdb_msg_write(moreprompt, strlen(moreprompt));
+
+ if (logging)
+ printk("%s", moreprompt);
+
+ ch = kdb_getchar();
+ kdb_nextline = 1; /* Really set output line 1 */
+
+ /* empty and reset the buffer: */
+ kdb_buffer[0] = '\0';
+ next_avail = kdb_buffer;
+ size_avail = sizeof(kdb_buffer);
+ if ((ch == 'q') || (ch == 'Q')) {
+ /* user hit q or Q */
+ KDB_FLAG_SET(CMD_INTERRUPT); /* command interrupted */
+ KDB_STATE_CLEAR(PAGER);
+ /* end of command output; back to normal mode */
+ kdb_grepping_flag = 0;
+ kdb_printf("\n");
+ } else if (ch == ' ') {
+ kdb_printf("\r");
+ suspend_grep = 1; /* for this recursion */
+ } else if (ch == '\n' || ch == '\r') {
+ kdb_nextline = linecount - 1;
+ kdb_printf("\r");
+ suspend_grep = 1; /* for this recursion */
+ } else if (ch == '/' && !kdb_grepping_flag) {
+ kdb_printf("\r");
+ kdb_getstr(kdb_grep_string, KDB_GREP_STRLEN,
+ kdbgetenv("SEARCHPROMPT") ?: "search> ");
+ *strchrnul(kdb_grep_string, '\n') = '\0';
+ kdb_grepping_flag += KDB_GREPPING_FLAG_SEARCH;
+ suspend_grep = 1; /* for this recursion */
+ } else if (ch) {
+ /* user hit something unexpected */
+ suspend_grep = 1; /* for this recursion */
+ if (ch != '/')
+ kdb_printf(
+ "\nOnly 'q', 'Q' or '/' are processed at "
+ "more prompt, input ignored\n");
+ else
+ kdb_printf("\n'/' cannot be used during | "
+ "grep filtering, input ignored\n");
+ } else if (kdb_grepping_flag) {
+ /* user hit enter */
+ suspend_grep = 1; /* for this recursion */
+ kdb_printf("\n");
+ }
+ kdb_input_flush();
+ }
+
+ /*
+ * For grep searches, shift the printed string left.
+ * replaced_byte contains the character that was overwritten with
+ * the terminating null, and cphold points to the null.
+ * Then adjust the notion of available space in the buffer.
+ */
+ if (kdb_grepping_flag && !suspend_grep) {
+ *cphold = replaced_byte;
+ strcpy(kdb_buffer, cphold);
+ len = strlen(kdb_buffer);
+ next_avail = kdb_buffer + len;
+ size_avail = sizeof(kdb_buffer) - len;
+ }
+
+kdb_print_out:
+ suspend_grep = 0; /* end of what may have been a recursive call */
+ if (logging)
+ console_loglevel = saved_loglevel;
+ /* kdb_printf_cpu locked the code above. */
+ smp_store_release(&kdb_printf_cpu, old_cpu);
+ local_irq_restore(flags);
+ return retlen;
+}
+
+int kdb_printf(const char *fmt, ...)
+{
+ va_list ap;
+ int r;
+
+ va_start(ap, fmt);
+ r = vkdb_printf(KDB_MSGSRC_INTERNAL, fmt, ap);
+ va_end(ap);
+
+ return r;
+}
+EXPORT_SYMBOL_GPL(kdb_printf);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-13 16:04:08 +0000