[Crash-utility] [RFC] Patch to fix broken net command

[Rachita Kothiyal]

Hi Dave

Following changes in the 2.6.14 kernel in the files_struct,
the 'net' command was broken. The following patch fixes it.
I have done basic testing on kernels before and after 2.6.14
to ensure that backward compatibility is maintained.

Kindly review and provide your comments.

Thanks
Rachita


 o From 2.6.14 kernel onwards, there were changes introduced 
   in the files_struct. This patch accomodates those kernel
   changes in crash to keep the 'net' command working.

Signed-off-by: Rachita Kothiyal <rachita at in.ibm.com>
---

 net.c |   57 ++++++++++++++++++++++++++++++++++++++-------------------
 1 files changed, 38 insertions(+), 19 deletions(-)

diff -puN net.c~fix-net-command net.c
--- crash-4.0-2.23/net.c~fix-net-command	2006-04-17 19:16:18.000000000 +0530
+++ crash-4.0-2.23-rachita/net.c	2006-04-17 20:41:16.000000000 +0530
@@ -1082,7 +1082,7 @@ dump_sockets(ulong flag, struct referenc
 void
 dump_sockets_workhorse(ulong task, ulong flag, struct reference *ref)
 {
-	ulong files_struct_addr = 0;
+	ulong files_struct_addr = 0, fdtable_addr = 0;
 	int max_fdset = 0;
 	int max_fds = 0;
 	ulong open_fds_addr = 0;
@@ -1114,32 +1114,51 @@ dump_sockets_workhorse(ulong task, ulong
             sizeof(void *), "task files contents", FAULT_ON_ERROR);
 
         if (files_struct_addr) {
-        	readmem(files_struct_addr + OFFSET(files_struct_max_fdset), 
-                    	KVADDR, &max_fdset, sizeof(int), 
-			"files_struct max_fdset", FAULT_ON_ERROR);
-
-        	readmem(files_struct_addr + OFFSET(files_struct_max_fds), 
-                    	KVADDR, &max_fds, sizeof(int), "files_struct max_fds",
-                    	FAULT_ON_ERROR);
-    	}
+                if (VALID_MEMBER(files_struct_max_fdset)) {
+		 	readmem(files_struct_addr + OFFSET(files_struct_max_fdset),
+		          	KVADDR, &max_fdset, sizeof(int),
+				"files_struct max_fdset", FAULT_ON_ERROR);
+		      	readmem(files_struct_addr + OFFSET(files_struct_max_fds),
+        	        	KVADDR, &max_fds, sizeof(int), "files_struct max_fds",
+                	   	FAULT_ON_ERROR);
+                }
+		else if (VALID_MEMBER(files_struct_fdt)) {
+			readmem(files_struct_addr + OFFSET(files_struct_fdt), KVADDR,
+				&fdtable_addr, sizeof(void *), "fdtable buffer",
+				FAULT_ON_ERROR);
+		      	readmem(fdtable_addr + OFFSET(fdtable_max_fdset),
+        	         	KVADDR, &max_fdset, sizeof(int),
+				"fdtable_struct max_fdset", FAULT_ON_ERROR);
+		      	readmem(fdtable_addr + OFFSET(fdtable_max_fds),
+	      	            	KVADDR, &max_fds, sizeof(int), "fdtable_struct max_fds",
+	               	    	FAULT_ON_ERROR);
+    		}
+	}
 
-	if (!files_struct_addr || (max_fdset == 0) || (max_fds == 0)) {
+	if ((VALID_MEMBER(files_struct_fdt) && !fdtable_addr) ||
+	    !files_struct_addr || (max_fdset == 0) || (max_fds == 0)) {
 		if (!NET_REFERENCE_CHECK(ref))
 			fprintf(fp, "No open sockets.\n");
 		return;
 	}
 
-	readmem(files_struct_addr + OFFSET(files_struct_open_fds), KVADDR, 
-            	&open_fds_addr, sizeof(void *), "files_struct open_fds addr", 
-            	FAULT_ON_ERROR);
+	if (VALID_MEMBER(fdtable_open_fds)){
+		readmem(fdtable_addr + OFFSET(fdtable_open_fds), KVADDR,
+     	  		&open_fds_addr, sizeof(void *), "files_struct open_fds addr",
+	            	FAULT_ON_ERROR);
+		readmem(fdtable_addr + OFFSET(fdtable_fd), KVADDR, &fd,
+           		sizeof(void *), "files_struct fd addr", FAULT_ON_ERROR);
+	} else {
+		readmem(files_struct_addr + OFFSET(files_struct_open_fds), KVADDR,
+            		&open_fds_addr, sizeof(void *), "files_struct open_fds addr",
+	          	FAULT_ON_ERROR);
+		readmem(files_struct_addr + OFFSET(files_struct_fd), KVADDR, &fd,
+            		sizeof(void *), "files_struct fd addr", FAULT_ON_ERROR);
+	}
 
 	if (open_fds_addr) 
-        	readmem(open_fds_addr, KVADDR, &open_fds, sizeof(fd_set), 
-                    	"files_struct open_fds", FAULT_ON_ERROR);
-
-	readmem(files_struct_addr + OFFSET(files_struct_fd), KVADDR, &fd,
-            	sizeof(void *), "files_struct fd addr", FAULT_ON_ERROR);
-
+		readmem(open_fds_addr, KVADDR, &open_fds, sizeof(fd_set),
+	               	"files_struct open_fds", FAULT_ON_ERROR);
     	if (!open_fds_addr || !fd) { 
 		if (!NET_REFERENCE_CHECK(ref))
 			fprintf(fp, "No open sockets.\n");
_