Merge tag 'for_linus-3.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb

Pull KGDB/KDB regression fixes from Jason Wessel:
 - Fix a Smatch warning that appeared in the 3.4 merge window
 - Fix kgdb test suite with SMP for all archs without HW single stepping
 - Fix kgdb sw breakpoints with CONFIG_DEBUG_RODATA=y limitations on x86
 - Fix oops on kgdb test suite with CONFIG_DEBUG_RODATA
 - Fix kgdb test suite with SMP for all archs with HW single stepping

* tag 'for_linus-3.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb:
  x86,kgdb: Fix DEBUG_RODATA limitation using text_poke()
  kgdb,debug_core: pass the breakpoint struct instead of address and memory
  kgdbts: (2 of 2) fix single step awareness to work correctly with SMP
  kgdbts: (1 of 2) fix single step awareness to work correctly with SMP
  kgdbts: Fix kernel oops with CONFIG_DEBUG_RODATA
  kdb: Fix smatch warning on dbg_io_ops->is_console

2 files changed, 25 insertions, 30 deletions

diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index 1dc53bae56e1..0557f24c6bca 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -160,37 +160,39 @@ early_param("nokgdbroundup", opt_nokgdbroundup);
  * Weak aliases for breakpoint management,
  * can be overriden by architectures when needed:
  */
-int __weak kgdb_arch_set_breakpoint(unsigned long addr, char *saved_instr)
+int __weak kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt)
 {
         int err;
 
-        err = probe_kernel_read(saved_instr, (char *)addr, BREAK_INSTR_SIZE);
+        err = probe_kernel_read(bpt->saved_instr, (char *)bpt->bpt_addr,
+                                BREAK_INSTR_SIZE);
         if (err)
                 return err;
-
-        return probe_kernel_write((char *)addr, arch_kgdb_ops.gdb_bpt_instr,
-                                  BREAK_INSTR_SIZE);
+        err = probe_kernel_write((char *)bpt->bpt_addr,
+                                 arch_kgdb_ops.gdb_bpt_instr, BREAK_INSTR_SIZE);
+        return err;
 }
 
-int __weak kgdb_arch_remove_breakpoint(unsigned long addr, char *bundle)
+int __weak kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt)
 {
-        return probe_kernel_write((char *)addr,
-                                  (char *)bundle, BREAK_INSTR_SIZE);
+        return probe_kernel_write((char *)bpt->bpt_addr,
+                                  (char *)bpt->saved_instr, BREAK_INSTR_SIZE);
 }
 
 int __weak kgdb_validate_break_address(unsigned long addr)
 {
-        char tmp_variable[BREAK_INSTR_SIZE];
+        struct kgdb_bkpt tmp;
         int err;
-        /* Validate setting the breakpoint and then removing it.  In the
+        /* Validate setting the breakpoint and then removing it.  If the
          * remove fails, the kernel needs to emit a bad message because we
          * are deep trouble not being able to put things back the way we
          * found them.
          */
-        err = kgdb_arch_set_breakpoint(addr, tmp_variable);
+        tmp.bpt_addr = addr;
+        err = kgdb_arch_set_breakpoint(&tmp);
         if (err)
                 return err;
-        err = kgdb_arch_remove_breakpoint(addr, tmp_variable);
+        err = kgdb_arch_remove_breakpoint(&tmp);
         if (err)
                 printk(KERN_ERR "KGDB: Critical breakpoint error, kernel "
                    "memory destroyed at: %lx", addr);
@@ -234,7 +236,6 @@ static void kgdb_flush_swbreak_addr(unsigned long addr)
  */
 int dbg_activate_sw_breakpoints(void)
 {
-        unsigned long addr;
         int error;
         int ret = 0;
         int i;
@@ -243,16 +244,15 @@ int dbg_activate_sw_breakpoints(void)
                 if (kgdb_break[i].state != BP_SET)
                         continue;
 
-                addr = kgdb_break[i].bpt_addr;
-                error = kgdb_arch_set_breakpoint(addr,
-                                kgdb_break[i].saved_instr);
+                error = kgdb_arch_set_breakpoint(&kgdb_break[i]);
                 if (error) {
                         ret = error;
-                        printk(KERN_INFO "KGDB: BP install failed: %lx", addr);
+                        printk(KERN_INFO "KGDB: BP install failed: %lx",
+                               kgdb_break[i].bpt_addr);
                         continue;
                 }
 
-                kgdb_flush_swbreak_addr(addr);
+                kgdb_flush_swbreak_addr(kgdb_break[i].bpt_addr);
                 kgdb_break[i].state = BP_ACTIVE;
         }
         return ret;
@@ -301,7 +301,6 @@ int dbg_set_sw_break(unsigned long addr)
 
 int dbg_deactivate_sw_breakpoints(void)
 {
-        unsigned long addr;
         int error;
         int ret = 0;
         int i;
@@ -309,15 +308,14 @@ int dbg_deactivate_sw_breakpoints(void)
         for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
                 if (kgdb_break[i].state != BP_ACTIVE)
                         continue;
-                addr = kgdb_break[i].bpt_addr;
-                error = kgdb_arch_remove_breakpoint(addr,
-                                        kgdb_break[i].saved_instr);
+                error = kgdb_arch_remove_breakpoint(&kgdb_break[i]);
                 if (error) {
-                        printk(KERN_INFO "KGDB: BP remove failed: %lx\n", addr);
+                        printk(KERN_INFO "KGDB: BP remove failed: %lx\n",
+                               kgdb_break[i].bpt_addr);
                         ret = error;
                 }
 
-                kgdb_flush_swbreak_addr(addr);
+                kgdb_flush_swbreak_addr(kgdb_break[i].bpt_addr);
                 kgdb_break[i].state = BP_SET;
         }
         return ret;
@@ -351,7 +349,6 @@ int kgdb_isremovedbreak(unsigned long addr)
 
 int dbg_remove_all_break(void)
 {
-        unsigned long addr;
         int error;
         int i;
 
@@ -359,12 +356,10 @@ int dbg_remove_all_break(void)
         for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
                 if (kgdb_break[i].state != BP_ACTIVE)
                         goto setundefined;
-                addr = kgdb_break[i].bpt_addr;
-                error = kgdb_arch_remove_breakpoint(addr,
-                                kgdb_break[i].saved_instr);
+                error = kgdb_arch_remove_breakpoint(&kgdb_break[i]);
                 if (error)
                         printk(KERN_ERR "KGDB: breakpoint remove failed: %lx\n",
-                           addr);
+                               kgdb_break[i].bpt_addr);
 setundefined:
                 kgdb_break[i].state = BP_UNDEFINED;
         }
diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c
index 9b5f17da1c56..bb9520f0f6ff 100644
--- a/kernel/debug/kdb/kdb_io.c
+++ b/kernel/debug/kdb/kdb_io.c
@@ -743,7 +743,7 @@ kdb_printit:
                 kdb_input_flush();
                 c = console_drivers;
 
-                if (!dbg_io_ops->is_console) {
+                if (dbg_io_ops && !dbg_io_ops->is_console) {
                         len = strlen(moreprompt);
                         cp = moreprompt;
                         while (len--) {