From: Ben Gras <ben@minix3.org>
Date: Tue, 6 Nov 2012 14:36:53 +0000 (+0100)
Subject: kernel: some boottime sanitychecks
X-Git-Tag: v3.2.1~237
X-Git-Url: http://zhaoyanbai.com/repos/%22http:/www.isc.org/icons/Bv9ARM.ch05.html?a=commitdiff_plain;h=ba05f39d1ef91ae61ac91daec21c32ca252a9e97;p=minix.git

kernel: some boottime sanitychecks

	. Check if we have the right number of boot modules
	. Check if the ELF parsing of VM actually succeeded

Both these are root causes of less-than-obvious other
errors/asserts a little further down the line; uncovered
while experimenting with booting by iPXE, specifically
(a) iPXE having a 8-multiboot-modules limit and
(b) trying to boot a gzipped VM.
---

diff --git a/include/minix/com.h b/include/minix/com.h
index c71b1c3c0..8c3ade401 100644
--- a/include/minix/com.h
+++ b/include/minix/com.h
@@ -84,6 +84,7 @@
                                            computation in macros.*/
 #define INIT_PROC_NR ((endpoint_t) LAST_SPECIAL_PROC_NR)  /* init
                                                         -- goes multiuser */
+#define NR_BOOT_MODULES (INIT_PROC_NR+1)
 
 /* Root system process and root user process. */
 #define ROOT_SYS_PROC_NR  RS_PROC_NR
diff --git a/kernel/arch/i386/protect.c b/kernel/arch/i386/protect.c
index 8dc050220..a95397c48 100644
--- a/kernel/arch/i386/protect.c
+++ b/kernel/arch/i386/protect.c
@@ -419,7 +419,8 @@ void arch_boot_proc(struct boot_image *ip, struct proc *rp)
 		execi.clearproc = NULL;
 
 		/* parse VM ELF binary and alloc/map it into bootstrap pagetable */
-		libexec_load_elf(&execi);
+		if(libexec_load_elf(&execi) != OK)
+			panic("VM loading failed");
 
 	        /* Initialize the server stack pointer. Take it down three words
 		 * to give startup code something to use as "argc", "argv" and "envp".
diff --git a/kernel/main.c b/kernel/main.c
index 652f68f5b..45fbe2d4a 100644
--- a/kernel/main.c
+++ b/kernel/main.c
@@ -143,6 +143,10 @@ void kmain(kinfo_t *local_cbi)
 
    proc_init();
 
+   if(NR_BOOT_MODULES != kinfo.mbi.mods_count)
+   	panic("expecting %d boot processes/modules, found %d",
+		NR_BOOT_MODULES, kinfo.mbi.mods_count);
+
   /* Set up proc table entries for processes in boot image. */
   for (i=0; i < NR_BOOT_PROCS; ++i) {
 	int schedulable_proc;