[Crash-utility] Re: [RFC] Provide minimal debugging to crash

Dave I have done the suggested modifications, have a look

> > I haven't walked through all the restricted command list code paths to > verify that they can work properly for all architectures without, say, > kernel_init(), the 3 machdep_init() calls, vm_init() etc. having run. > Certainly trying to rd or dis vmalloc addresses would display garbage > data or just fail, but that's to be expected. > > I quickly tried this on a x86 and x86_64 -- but have you tried this on > an ia64 or ppc64? I tested on ppc64 and on corrupted dump and it worked fine > > The only thing I'm not excited about is all the re-tinkering with the > help screen output. Why bother? I'd prefer to keep things simple. > During initialization, display a WARNING message that lists the supported > commands just prior to the first prompt. And then just leave the help > screen alone, and let your command-restriction mechanism display the > per-command message: > > error(INFO, "command: %s not available in minimal mode\n", args[0]); > ...and then perhaps followed up immediately with the acceptable command > list again. I have done this code change > > Another minor suggestion -- I think you can put the "eval" command in > the supported list. I use it all the time, and in this minimal > environment > it may come in very handy. (There may be others, but they're probably > not > worth having...) allowed eval to be executed in minimal mode Thanks Yeehaw ------------------------------------------------------------------------ Signed-off-by: Sharyathi Nagesh <sharyath(a)in.ibm.com&gt; Signed-off-by: Sachin P Sant <sachinp(a)in.ibm.com&gt; --- diff -Naurp crash-old/cmdline.c crash-new/cmdline.c --- crash-old/cmdline.c 2008-03-31 22:58:31.000000000 +0530 +++ crash-new/cmdline.c 2008-08-18 09:25:21.000000000 +0530 @@ -2137,3 +2137,11 @@ wait_for_children(ulong waitflag) stall(1000); } } + +int minimal_functions(char *name) +{ + return STREQ("log", name) || STREQ("help",name) || \ + STREQ("dis", name) || STREQ("q", name) || \ + STREQ("sym", name) || STREQ("exit", name)|| \ + STREQ("rd", name) || STREQ("eval", name) ; +} diff -Naurp crash-old/defs.h crash-new/defs.h --- crash-old/defs.h 2008-03-31 22:58:31.000000000 +0530 +++ crash-new/defs.h 2008-08-04 13:36:23.000000000 +0530 @@ -183,6 +183,7 @@ struct number_option { #define PLEASE_WAIT (0x200000000000000ULL) #define IFILE_ERROR (0x400000000000000ULL) #define KERNTYPES (0x800000000000000ULL) +#define MINIMAL_MODE (0x1000000000000000ULL) #define ACTIVE() (pc->flags & LIVE_SYSTEM) #define DUMPFILE() (!(pc->flags & LIVE_SYSTEM)) @@ -3129,6 +3130,7 @@ int received_SIGINT(void); void debug_redirect(char *); int CRASHPAGER_valid(void); char *setup_scroll_command(void); +int minimal_functions(char *); /* * tools.c diff -Naurp crash-old/main.c crash-new/main.c --- crash-old/main.c 2008-08-18 11:50:38.000000000 +0530 +++ crash-new/main.c 2008-08-18 11:54:31.000000000 +0530 @@ -56,6 +56,7 @@ static struct option long_options[] = { {"no_scroll", 0, 0, 0}, {"reloc", required_argument, 0, 0}, {"active", 0, 0, 0}, + {"minimal", 0, 0, 0}, {0, 0, 0, 0} }; @@ -197,6 +198,9 @@ main(int argc, char **argv) kt->flags |= RELOC_SET; } + else if (STREQ(long_options[option_index].name, "minimal")) + pc->flags |= MINIMAL_MODE; + else { error(INFO, "internal error: option %s unhandled\n", long_options[option_index].name); @@ -492,7 +496,7 @@ main_loop(void) #else error(FATAL, XEN_HYPERVISOR_NOT_SUPPORTED); #endif - } else { + } else if(!(pc->flags & MINIMAL_MODE)){ read_in_kernel_config(IKCFG_INIT); kernel_init(); machdep_init(POST_GDB); @@ -520,7 +524,7 @@ main_loop(void) #else error(FATAL, XEN_HYPERVISOR_NOT_SUPPORTED); #endif - } else { + } else if(!(pc->flags & MINIMAL_MODE)){ display_sys_stats(); show_context(CURRENT_CONTEXT()); } @@ -528,6 +532,11 @@ main_loop(void) } pc->flags |= RUNTIME; + + if(pc->flags & MINIMAL_MODE){ + error(WARNING, "In minimal mode you have access to only these \n \ + commands: 'log', 'dis', 'rd','sym', 'eval' and 'exit' \n"); + } /* * Return here if a non-recoverable error occurs @@ -610,7 +619,14 @@ reattempt: return; pc->curcmd = pc->program_name; - error(INFO, "command not found: %s\n", args[0]); + if (!(pc->flags & MINIMAL_MODE)) + error(INFO, "command not found: %s\n", args[0]); + else{ + error(INFO, + "command: %s not available in minimal mode\n", args[0]); + error(INFO, + "supported commands:'log', 'dis', 'rd', 'sym', 'eval', 'exit' \n"); + } if (pc->curcmd_flags & REPEAT) pc->curcmd_flags &= ~REPEAT; @@ -625,6 +641,9 @@ get_command_table_entry(char *name) { struct command_table_entry *cp; struct extension_table *ext; + + if ((pc->flags & MINIMAL_MODE) && !minimal_functions(name)) + return NULL; for (cp = pc->cmd_table; cp->name; cp++) { if (STREQ(cp->name, name))