Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / kernel / debug / kdb / kdb_bp.c
diff --git a/kernel/kernel/debug/kdb/kdb_bp.c b/kernel/kernel/debug/kdb/kdb_bp.c
new file mode 100644 (file)
index 0000000..e1dbf4a
--- /dev/null
@@ -0,0 +1,560 @@
+/*
+ * Kernel Debugger Architecture Independent Breakpoint 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) 1999-2004 Silicon Graphics, Inc.  All Rights Reserved.
+ * Copyright (c) 2009 Wind River Systems, Inc.  All Rights Reserved.
+ */
+
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/kdb.h>
+#include <linux/kgdb.h>
+#include <linux/smp.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include "kdb_private.h"
+
+/*
+ * Table of kdb_breakpoints
+ */
+kdb_bp_t kdb_breakpoints[KDB_MAXBPT];
+
+static void kdb_setsinglestep(struct pt_regs *regs)
+{
+       KDB_STATE_SET(DOING_SS);
+}
+
+static char *kdb_rwtypes[] = {
+       "Instruction(i)",
+       "Instruction(Register)",
+       "Data Write",
+       "I/O",
+       "Data Access"
+};
+
+static char *kdb_bptype(kdb_bp_t *bp)
+{
+       if (bp->bp_type < 0 || bp->bp_type > 4)
+               return "";
+
+       return kdb_rwtypes[bp->bp_type];
+}
+
+static int kdb_parsebp(int argc, const char **argv, int *nextargp, kdb_bp_t *bp)
+{
+       int nextarg = *nextargp;
+       int diag;
+
+       bp->bph_length = 1;
+       if ((argc + 1) != nextarg) {
+               if (strncasecmp(argv[nextarg], "datar", sizeof("datar")) == 0)
+                       bp->bp_type = BP_ACCESS_WATCHPOINT;
+               else if (strncasecmp(argv[nextarg], "dataw", sizeof("dataw")) == 0)
+                       bp->bp_type = BP_WRITE_WATCHPOINT;
+               else if (strncasecmp(argv[nextarg], "inst", sizeof("inst")) == 0)
+                       bp->bp_type = BP_HARDWARE_BREAKPOINT;
+               else
+                       return KDB_ARGCOUNT;
+
+               bp->bph_length = 1;
+
+               nextarg++;
+
+               if ((argc + 1) != nextarg) {
+                       unsigned long len;
+
+                       diag = kdbgetularg((char *)argv[nextarg],
+                                          &len);
+                       if (diag)
+                               return diag;
+
+
+                       if (len > 8)
+                               return KDB_BADLENGTH;
+
+                       bp->bph_length = len;
+                       nextarg++;
+               }
+
+               if ((argc + 1) != nextarg)
+                       return KDB_ARGCOUNT;
+       }
+
+       *nextargp = nextarg;
+       return 0;
+}
+
+static int _kdb_bp_remove(kdb_bp_t *bp)
+{
+       int ret = 1;
+       if (!bp->bp_installed)
+               return ret;
+       if (!bp->bp_type)
+               ret = dbg_remove_sw_break(bp->bp_addr);
+       else
+               ret = arch_kgdb_ops.remove_hw_breakpoint(bp->bp_addr,
+                        bp->bph_length,
+                        bp->bp_type);
+       if (ret == 0)
+               bp->bp_installed = 0;
+       return ret;
+}
+
+static void kdb_handle_bp(struct pt_regs *regs, kdb_bp_t *bp)
+{
+       if (KDB_DEBUG(BP))
+               kdb_printf("regs->ip = 0x%lx\n", instruction_pointer(regs));
+
+       /*
+        * Setup single step
+        */
+       kdb_setsinglestep(regs);
+
+       /*
+        * Reset delay attribute
+        */
+       bp->bp_delay = 0;
+       bp->bp_delayed = 1;
+}
+
+static int _kdb_bp_install(struct pt_regs *regs, kdb_bp_t *bp)
+{
+       int ret;
+       /*
+        * Install the breakpoint, if it is not already installed.
+        */
+
+       if (KDB_DEBUG(BP))
+               kdb_printf("%s: bp_installed %d\n",
+                          __func__, bp->bp_installed);
+       if (!KDB_STATE(SSBPT))
+               bp->bp_delay = 0;
+       if (bp->bp_installed)
+               return 1;
+       if (bp->bp_delay || (bp->bp_delayed && KDB_STATE(DOING_SS))) {
+               if (KDB_DEBUG(BP))
+                       kdb_printf("%s: delayed bp\n", __func__);
+               kdb_handle_bp(regs, bp);
+               return 0;
+       }
+       if (!bp->bp_type)
+               ret = dbg_set_sw_break(bp->bp_addr);
+       else
+               ret = arch_kgdb_ops.set_hw_breakpoint(bp->bp_addr,
+                        bp->bph_length,
+                        bp->bp_type);
+       if (ret == 0) {
+               bp->bp_installed = 1;
+       } else {
+               kdb_printf("%s: failed to set breakpoint at 0x%lx\n",
+                          __func__, bp->bp_addr);
+#ifdef CONFIG_DEBUG_RODATA
+               if (!bp->bp_type) {
+                       kdb_printf("Software breakpoints are unavailable.\n"
+                                  "  Change the kernel CONFIG_DEBUG_RODATA=n\n"
+                                  "  OR use hw breaks: help bph\n");
+               }
+#endif
+               return 1;
+       }
+       return 0;
+}
+
+/*
+ * kdb_bp_install
+ *
+ *     Install kdb_breakpoints prior to returning from the
+ *     kernel debugger.  This allows the kdb_breakpoints to be set
+ *     upon functions that are used internally by kdb, such as
+ *     printk().  This function is only called once per kdb session.
+ */
+void kdb_bp_install(struct pt_regs *regs)
+{
+       int i;
+
+       for (i = 0; i < KDB_MAXBPT; i++) {
+               kdb_bp_t *bp = &kdb_breakpoints[i];
+
+               if (KDB_DEBUG(BP)) {
+                       kdb_printf("%s: bp %d bp_enabled %d\n",
+                                  __func__, i, bp->bp_enabled);
+               }
+               if (bp->bp_enabled)
+                       _kdb_bp_install(regs, bp);
+       }
+}
+
+/*
+ * kdb_bp_remove
+ *
+ *     Remove kdb_breakpoints upon entry to the kernel debugger.
+ *
+ * Parameters:
+ *     None.
+ * Outputs:
+ *     None.
+ * Returns:
+ *     None.
+ * Locking:
+ *     None.
+ * Remarks:
+ */
+void kdb_bp_remove(void)
+{
+       int i;
+
+       for (i = KDB_MAXBPT - 1; i >= 0; i--) {
+               kdb_bp_t *bp = &kdb_breakpoints[i];
+
+               if (KDB_DEBUG(BP)) {
+                       kdb_printf("%s: bp %d bp_enabled %d\n",
+                                  __func__, i, bp->bp_enabled);
+               }
+               if (bp->bp_enabled)
+                       _kdb_bp_remove(bp);
+       }
+}
+
+
+/*
+ * kdb_printbp
+ *
+ *     Internal function to format and print a breakpoint entry.
+ *
+ * Parameters:
+ *     None.
+ * Outputs:
+ *     None.
+ * Returns:
+ *     None.
+ * Locking:
+ *     None.
+ * Remarks:
+ */
+
+static void kdb_printbp(kdb_bp_t *bp, int i)
+{
+       kdb_printf("%s ", kdb_bptype(bp));
+       kdb_printf("BP #%d at ", i);
+       kdb_symbol_print(bp->bp_addr, NULL, KDB_SP_DEFAULT);
+
+       if (bp->bp_enabled)
+               kdb_printf("\n    is enabled");
+       else
+               kdb_printf("\n    is disabled");
+
+       kdb_printf("\taddr at %016lx, hardtype=%d installed=%d\n",
+                  bp->bp_addr, bp->bp_type, bp->bp_installed);
+
+       kdb_printf("\n");
+}
+
+/*
+ * kdb_bp
+ *
+ *     Handle the bp commands.
+ *
+ *     [bp|bph] <addr-expression> [DATAR|DATAW]
+ *
+ * Parameters:
+ *     argc    Count of arguments in argv
+ *     argv    Space delimited command line arguments
+ * Outputs:
+ *     None.
+ * Returns:
+ *     Zero for success, a kdb diagnostic if failure.
+ * Locking:
+ *     None.
+ * Remarks:
+ *
+ *     bp      Set breakpoint on all cpus.  Only use hardware assist if need.
+ *     bph     Set breakpoint on all cpus.  Force hardware register
+ */
+
+static int kdb_bp(int argc, const char **argv)
+{
+       int i, bpno;
+       kdb_bp_t *bp, *bp_check;
+       int diag;
+       char *symname = NULL;
+       long offset = 0ul;
+       int nextarg;
+       kdb_bp_t template = {0};
+
+       if (argc == 0) {
+               /*
+                * Display breakpoint table
+                */
+               for (bpno = 0, bp = kdb_breakpoints; bpno < KDB_MAXBPT;
+                    bpno++, bp++) {
+                       if (bp->bp_free)
+                               continue;
+                       kdb_printbp(bp, bpno);
+               }
+
+               return 0;
+       }
+
+       nextarg = 1;
+       diag = kdbgetaddrarg(argc, argv, &nextarg, &template.bp_addr,
+                            &offset, &symname);
+       if (diag)
+               return diag;
+       if (!template.bp_addr)
+               return KDB_BADINT;
+
+       /*
+        * Find an empty bp structure to allocate
+        */
+       for (bpno = 0, bp = kdb_breakpoints; bpno < KDB_MAXBPT; bpno++, bp++) {
+               if (bp->bp_free)
+                       break;
+       }
+
+       if (bpno == KDB_MAXBPT)
+               return KDB_TOOMANYBPT;
+
+       if (strcmp(argv[0], "bph") == 0) {
+               template.bp_type = BP_HARDWARE_BREAKPOINT;
+               diag = kdb_parsebp(argc, argv, &nextarg, &template);
+               if (diag)
+                       return diag;
+       } else {
+               template.bp_type = BP_BREAKPOINT;
+       }
+
+       /*
+        * Check for clashing breakpoints.
+        *
+        * Note, in this design we can't have hardware breakpoints
+        * enabled for both read and write on the same address.
+        */
+       for (i = 0, bp_check = kdb_breakpoints; i < KDB_MAXBPT;
+            i++, bp_check++) {
+               if (!bp_check->bp_free &&
+                   bp_check->bp_addr == template.bp_addr) {
+                       kdb_printf("You already have a breakpoint at "
+                                  kdb_bfd_vma_fmt0 "\n", template.bp_addr);
+                       return KDB_DUPBPT;
+               }
+       }
+
+       template.bp_enabled = 1;
+
+       /*
+        * Actually allocate the breakpoint found earlier
+        */
+       *bp = template;
+       bp->bp_free = 0;
+
+       kdb_printbp(bp, bpno);
+
+       return 0;
+}
+
+/*
+ * kdb_bc
+ *
+ *     Handles the 'bc', 'be', and 'bd' commands
+ *
+ *     [bd|bc|be] <breakpoint-number>
+ *     [bd|bc|be] *
+ *
+ * Parameters:
+ *     argc    Count of arguments in argv
+ *     argv    Space delimited command line arguments
+ * Outputs:
+ *     None.
+ * Returns:
+ *     Zero for success, a kdb diagnostic for failure
+ * Locking:
+ *     None.
+ * Remarks:
+ */
+static int kdb_bc(int argc, const char **argv)
+{
+       unsigned long addr;
+       kdb_bp_t *bp = NULL;
+       int lowbp = KDB_MAXBPT;
+       int highbp = 0;
+       int done = 0;
+       int i;
+       int diag = 0;
+
+       int cmd;                        /* KDBCMD_B? */
+#define KDBCMD_BC      0
+#define KDBCMD_BE      1
+#define KDBCMD_BD      2
+
+       if (strcmp(argv[0], "be") == 0)
+               cmd = KDBCMD_BE;
+       else if (strcmp(argv[0], "bd") == 0)
+               cmd = KDBCMD_BD;
+       else
+               cmd = KDBCMD_BC;
+
+       if (argc != 1)
+               return KDB_ARGCOUNT;
+
+       if (strcmp(argv[1], "*") == 0) {
+               lowbp = 0;
+               highbp = KDB_MAXBPT;
+       } else {
+               diag = kdbgetularg(argv[1], &addr);
+               if (diag)
+                       return diag;
+
+               /*
+                * For addresses less than the maximum breakpoint number,
+                * assume that the breakpoint number is desired.
+                */
+               if (addr < KDB_MAXBPT) {
+                       bp = &kdb_breakpoints[addr];
+                       lowbp = highbp = addr;
+                       highbp++;
+               } else {
+                       for (i = 0, bp = kdb_breakpoints; i < KDB_MAXBPT;
+                           i++, bp++) {
+                               if (bp->bp_addr == addr) {
+                                       lowbp = highbp = i;
+                                       highbp++;
+                                       break;
+                               }
+                       }
+               }
+       }
+
+       /*
+        * Now operate on the set of breakpoints matching the input
+        * criteria (either '*' for all, or an individual breakpoint).
+        */
+       for (bp = &kdb_breakpoints[lowbp], i = lowbp;
+           i < highbp;
+           i++, bp++) {
+               if (bp->bp_free)
+                       continue;
+
+               done++;
+
+               switch (cmd) {
+               case KDBCMD_BC:
+                       bp->bp_enabled = 0;
+
+                       kdb_printf("Breakpoint %d at "
+                                  kdb_bfd_vma_fmt " cleared\n",
+                                  i, bp->bp_addr);
+
+                       bp->bp_addr = 0;
+                       bp->bp_free = 1;
+
+                       break;
+               case KDBCMD_BE:
+                       bp->bp_enabled = 1;
+
+                       kdb_printf("Breakpoint %d at "
+                                  kdb_bfd_vma_fmt " enabled",
+                                  i, bp->bp_addr);
+
+                       kdb_printf("\n");
+                       break;
+               case KDBCMD_BD:
+                       if (!bp->bp_enabled)
+                               break;
+
+                       bp->bp_enabled = 0;
+
+                       kdb_printf("Breakpoint %d at "
+                                  kdb_bfd_vma_fmt " disabled\n",
+                                  i, bp->bp_addr);
+
+                       break;
+               }
+               if (bp->bp_delay && (cmd == KDBCMD_BC || cmd == KDBCMD_BD)) {
+                       bp->bp_delay = 0;
+                       KDB_STATE_CLEAR(SSBPT);
+               }
+       }
+
+       return (!done) ? KDB_BPTNOTFOUND : 0;
+}
+
+/*
+ * kdb_ss
+ *
+ *     Process the 'ss' (Single Step) command.
+ *
+ *     ss
+ *
+ * Parameters:
+ *     argc    Argument count
+ *     argv    Argument vector
+ * Outputs:
+ *     None.
+ * Returns:
+ *     KDB_CMD_SS for success, a kdb error if failure.
+ * Locking:
+ *     None.
+ * Remarks:
+ *
+ *     Set the arch specific option to trigger a debug trap after the next
+ *     instruction.
+ */
+
+static int kdb_ss(int argc, const char **argv)
+{
+       if (argc != 0)
+               return KDB_ARGCOUNT;
+       /*
+        * Set trace flag and go.
+        */
+       KDB_STATE_SET(DOING_SS);
+       return KDB_CMD_SS;
+}
+
+/* Initialize the breakpoint table and register        breakpoint commands. */
+
+void __init kdb_initbptab(void)
+{
+       int i;
+       kdb_bp_t *bp;
+
+       /*
+        * First time initialization.
+        */
+       memset(&kdb_breakpoints, '\0', sizeof(kdb_breakpoints));
+
+       for (i = 0, bp = kdb_breakpoints; i < KDB_MAXBPT; i++, bp++)
+               bp->bp_free = 1;
+
+       kdb_register_flags("bp", kdb_bp, "[<vaddr>]",
+               "Set/Display breakpoints", 0,
+               KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS);
+       kdb_register_flags("bl", kdb_bp, "[<vaddr>]",
+               "Display breakpoints", 0,
+               KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS);
+       if (arch_kgdb_ops.flags & KGDB_HW_BREAKPOINT)
+               kdb_register_flags("bph", kdb_bp, "[<vaddr>]",
+               "[datar [length]|dataw [length]]   Set hw brk", 0,
+               KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS);
+       kdb_register_flags("bc", kdb_bc, "<bpnum>",
+               "Clear Breakpoint", 0,
+               KDB_ENABLE_FLOW_CTRL);
+       kdb_register_flags("be", kdb_bc, "<bpnum>",
+               "Enable Breakpoint", 0,
+               KDB_ENABLE_FLOW_CTRL);
+       kdb_register_flags("bd", kdb_bc, "<bpnum>",
+               "Disable Breakpoint", 0,
+               KDB_ENABLE_FLOW_CTRL);
+
+       kdb_register_flags("ss", kdb_ss, "",
+               "Single Step", 1,
+               KDB_ENABLE_FLOW_CTRL | KDB_REPEAT_NO_ARGS);
+       /*
+        * Architecture dependent initialization.
+        */
+}