From 9254c7f206d54fe6b0bf69086d0cbec83b4ace32 Mon Sep 17 00:00:00 2001
From: Dave Anderson <anderson@redhat.com>
Date: Tue, 1 Sep 2015 16:23:24 -0400
Subject: [PATCH] Added a new "--src <directory>" command line option for use
 by the "dis -s" option if the kernel source code is not located in the
 standard location that is compiled into the kernel's debuginfo data. The
 directory argument should point to the top-level directory of the kernel
 source tree. (anderson@redhat.com)

---
 defs.h   |  1 +
 help.c   |  4 ++++
 kernel.c | 39 +++++++++++++++++++++++++++++++++++++++
 main.c   |  4 ++++
 4 files changed, 48 insertions(+)

diff --git a/defs.h b/defs.h
index 0169889c..b0cdd42e 100644
--- a/defs.h
+++ b/defs.h
@@ -732,6 +732,7 @@ struct kernel_table {                   /* kernel data */
 		ulong _stext_SYMBOL;
 	} vmcoreinfo;
 	ulonglong flags2;
+	char *source_tree;
 };
 
 /*
diff --git a/help.c b/help.c
index c3a0667b..883ddd01 100644
--- a/help.c
+++ b/help.c
@@ -309,6 +309,10 @@ char *program_usage_info[] = {
     "    command, search for their object files in directory instead of in ",
     "    the standard location.",
     "",
+    "  --src directory",
+    "    Search for the kernel source code in directory instead of in the",
+    "    standard location that is compiled into the debuginfo data.",
+    "",
     "  --reloc size",
     "    When analyzing live x86 kernels configured with a CONFIG_PHYSICAL_START ",
     "    value that is larger than its CONFIG_PHYSICAL_ALIGN value, then it will",
diff --git a/kernel.c b/kernel.c
index 8afc97bb..d069c9dd 100644
--- a/kernel.c
+++ b/kernel.c
@@ -78,6 +78,7 @@ static void dump_variable_length_record(void);
 static int is_livepatch(void);
 static void show_kernel_taints(char *, int);
 static void list_source_code(struct gnu_request *, int);
+static void source_tree_init(void);
 
 
 /*
@@ -728,6 +729,9 @@ kernel_init()
 	if (INVALID_MEMBER(ktime_t_nsec))
 		MEMBER_OFFSET_INIT(ktime_t_nsec, "ktime_t", "nsec");
 
+	if (kt->source_tree)
+		source_tree_init();
+
 	kt->flags &= ~PRE_KERNEL_INIT;
 }
 
@@ -1318,6 +1322,39 @@ verify_namelist()
         program_usage(SHORT_FORM);
 }
 
+/*
+ *  Set up the gdb source code path.
+ */
+static void
+source_tree_init(void)
+{
+	FILE *pipe;
+	char command[BUFSIZE];
+	char buf[BUFSIZE];
+
+	if (!is_directory(kt->source_tree)) {
+		error(INFO, "invalid --src argument: %s\n\n", 
+			kt->source_tree);
+		kt->source_tree = NULL;
+		return;
+	}
+
+	sprintf(command, "/usr/bin/ls -d %s/arch/*/include/asm 2>/dev/null", 
+		kt->source_tree);
+	if ((pipe = popen(command, "r"))) {
+		if (fgets(buf, BUFSIZE-1, pipe)) {
+			sprintf(command, "directory %s", buf);
+			gdb_pass_through(command, NULL, GNU_RETURN_ON_ERROR);
+		} 
+		pclose(pipe);
+	} else
+		error(INFO, "%s: %s\n", command, strerror(errno));
+
+	sprintf(command, "directory %s", kt->source_tree);
+	gdb_pass_through(command, NULL, GNU_RETURN_ON_ERROR);
+
+}
+
 
 static void
 list_source_code(struct gnu_request *req, int count_entered)
@@ -5557,6 +5594,8 @@ dump_kernel_table(int verbose)
 	fprintf(fp, "mods_installed: %d\n", kt->mods_installed);
 	fprintf(fp, "   module_tree: %s\n", kt->module_tree ? 
 		kt->module_tree : "(not used)");
+	fprintf(fp, "   source_tree: %s\n", kt->source_tree ? 
+		kt->source_tree : "(not used)");
 	if (!(pc->flags & KERNEL_DEBUG_QUERY) && ACTIVE()) 
 		get_xtime(&kt->date);
         fprintf(fp, "          date: %s\n",
diff --git a/main.c b/main.c
index ccb5e337..fccbfe55 100644
--- a/main.c
+++ b/main.c
@@ -72,6 +72,7 @@ static struct option long_options[] = {
 	{"no_strip", 0, 0, 0},
 	{"hash", required_argument, 0, 0},
 	{"offline", required_argument, 0, 0},
+	{"src", required_argument, 0, 0},
         {0, 0, 0, 0}
 };
 
@@ -293,6 +294,9 @@ main(int argc, char **argv)
 				}
 			}
 
+			else if (STREQ(long_options[option_index].name, "src"))
+				kt->source_tree = optarg;
+
 			else {
 				error(INFO, "internal error: option %s unhandled\n",
 					long_options[option_index].name);