o Fix a size calculation based on a 8KB page, while under EFI

   pages are 4KB.
o  As a second order fix, don't assume we have enough space
   after the bootinfo block left in a page to hold the memory
   map.
o  A third order fix as that we removed the assumption that a
   bootinfo block fits in a single 8KB page.

PR: ia64/39415
submitted by: Espen Skoglund <esk@ira.uka.de>

2 files changed, 35 insertions, 16 deletions

diff --git a/sys/boot/ia64/common/bootinfo.c b/sys/boot/ia64/common/bootinfo.c
index 1d3e956..484f226 100644
--- a/sys/boot/ia64/common/bootinfo.c
+++ b/sys/boot/ia64/common/bootinfo.c
@@ -244,7 +244,8 @@ bi_copymodules(vm_offset_t addr)
  * - Module metadata are formatted and placed in kernel space.
  */
 int
-bi_load(struct bootinfo *bi, struct preloaded_file *fp, UINTN *mapkey)
+bi_load(struct bootinfo *bi, struct preloaded_file *fp, UINTN *mapkey,
+    UINTN pages)
 {
     char			*rootdevname;
     struct efi_devdesc		*rootdev;
@@ -254,7 +255,7 @@ bi_load(struct bootinfo *bi, struct preloaded_file *fp, UINTN *mapkey)
     vm_offset_t			ssym, esym;
     struct file_metadata	*md;
     EFI_STATUS			status;
-    UINTN			key;
+    UINTN			bisz, key;
 
     /*
      * Version 1 bootinfo.
@@ -273,9 +274,9 @@ bi_load(struct bootinfo *bi, struct preloaded_file *fp, UINTN *mapkey)
     bi->bi_systab = (u_int64_t) ST;
 
     /* 
-     * Allow the environment variable 'rootdev' to override the supplied device 
-     * This should perhaps go to MI code and/or have $rootdev tested/set by
-     * MI code before launching the kernel.
+     * Allow the environment variable 'rootdev' to override the supplied
+     * device. This should perhaps go to MI code and/or have $rootdev
+     * tested/set by MI code before launching the kernel.
      */
     rootdevname = getenv("rootdev");
     efi_getdev((void **)(&rootdev), rootdevname, NULL);
@@ -331,14 +332,16 @@ bi_load(struct bootinfo *bi, struct preloaded_file *fp, UINTN *mapkey)
     /* all done copying stuff in, save end of loaded object space */
     bi->bi_kernend = addr;
 
-    /* read memory map and stash it after bootinfo */
-    bi->bi_memmap = (u_int64_t)(bi + 1);
-    bi->bi_memmap_size = 8192 - sizeof(struct bootinfo);
+    /*
+     * Read the memory map and stash it after bootinfo. Align the memory map
+     * on a 16-byte boundary (the bootinfo block is page aligned).
+     */
+    bisz = (sizeof(struct bootinfo) + 0x0f) & ~0x0f;
+    bi->bi_memmap = ((u_int64_t)bi) + bisz;
+    bi->bi_memmap_size = EFI_PAGE_SIZE * pages - bisz;
     status = BS->GetMemoryMap(&bi->bi_memmap_size,
-			      (EFI_MEMORY_DESCRIPTOR *)bi->bi_memmap,
-			      &key,
-			      &bi->bi_memdesc_size,
-			      &bi->bi_memdesc_version);
+		(EFI_MEMORY_DESCRIPTOR *)bi->bi_memmap, &key,
+		&bi->bi_memdesc_size, &bi->bi_memdesc_version);
     if (EFI_ERROR(status)) {
 	printf("bi_load: Can't read memory map\n");
 	return EINVAL;
diff --git a/sys/boot/ia64/common/exec.c b/sys/boot/ia64/common/exec.c
index 5c95d0f..91736cc 100644
--- a/sys/boot/ia64/common/exec.c
+++ b/sys/boot/ia64/common/exec.c
@@ -143,15 +143,31 @@ elf_exec(struct preloaded_file *fp)
 	struct ia64_pte		pte;
 	struct bootinfo		*bi;
 	u_int64_t		psr;
-	UINTN			mapkey;
+	UINTN			mapkey, pages, size;
+	UINTN			descsz;
+	UINT32			descver;
 	EFI_STATUS		status;
 
 	if ((md = file_findmetadata(fp, MODINFOMD_ELFHDR)) == NULL)
 		return(EFTYPE);			/* XXX actually EFUCKUP */
 	hdr = (Elf_Ehdr *)&(md->md_data);
 
-	status = BS->AllocatePages(AllocateAnyPages, EfiLoaderData,
-	    EFI_SIZE_TO_PAGES(sizeof(struct bootinfo)), (void*)&bi);
+	/*
+	 * Allocate enough pages to hold the bootinfo block and the memory
+	 * map EFI will return to us. The memory map has an unknown size,
+	 * so we have to determine that first. Note that the AllocatePages
+	 * call can itself modify the memory map, so we have to take that
+	 * into account as well. The changes to the memory map are caused
+	 * by splitting a range of free memory into two (AFAICT), so that
+	 * one is marked as being loader data.
+	 */
+	size = 0;
+	descsz = sizeof(EFI_MEMORY_DESCRIPTOR);
+	BS->GetMemoryMap(&size, NULL, &mapkey, &descsz, &descver);
+	size += descsz + ((sizeof(struct bootinfo) + 0x0f) & ~0x0f);
+	pages = EFI_SIZE_TO_PAGES(size);
+	status = BS->AllocatePages(AllocateAnyPages, EfiLoaderData, pages,
+	    (void*)&bi);
 	if (EFI_ERROR(status)) {
 		printf("unable to create bootinfo block (status=0x%lx)\n",
 		    (long)status);
@@ -159,7 +175,7 @@ elf_exec(struct preloaded_file *fp)
 	}
 
 	bzero(bi, sizeof(struct bootinfo));
-	bi_load(bi, fp, &mapkey);
+	bi_load(bi, fp, &mapkey, pages);
 
 	printf("Entering %s at 0x%lx...\n", fp->f_name, hdr->e_entry);