From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001

From: Matthew Garrett <mjg59@coreos.com>

Date: Sun, 9 Aug 2015 16:12:39 -0700

Subject: [PATCH] Rework linux command

We want a single buffer that contains the entire kernel image in order to

perform a TPM measurement. Allocate one and copy the entire kernel into it

before pulling out the individual blocks later on.

Signed-off-by: Matthew Garrett <mjg59@coreos.com>

---

 grub-core/loader/i386/linux.c | 35 +++++++++++++++++++++++------------

 1 file changed, 23 insertions(+), 12 deletions(-)

diff --git a/grub-core/loader/i386/linux.c b/grub-core/loader/i386/linux.c

index 9f74a96b19a..dccf3bb3005 100644

--- a/grub-core/loader/i386/linux.c

+++ b/grub-core/loader/i386/linux.c

@@ -649,13 +649,15 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),

 {

   grub_file_t file = 0;

   struct linux_i386_kernel_header lh;

+  grub_uint8_t *linux_params_ptr;

   grub_uint8_t setup_sects;

-  grub_size_t real_size, prot_size, prot_file_size;

+  grub_size_t real_size, prot_size, prot_file_size, kernel_offset;

   grub_ssize_t len;

   int i;

   grub_size_t align, min_align;

   int relocatable;

   grub_uint64_t preferred_address = GRUB_LINUX_BZIMAGE_ADDR;

+  grub_uint8_t *kernel = NULL;

   grub_dl_ref (my_mod);

@@ -669,7 +671,15 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),

   if (! file)

     goto fail;

-  if (grub_file_read (file, &lh, sizeof (lh)) != sizeof (lh))

+  len = grub_file_size (file);

+  kernel = grub_malloc (len);

+  if (!kernel)

+    {

+      grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("cannot allocate kernel buffer"));

+      goto fail;

+    }

+

+  if (grub_file_read (file, kernel, len) != len)

     {

       if (!grub_errno)

 	grub_error (GRUB_ERR_BAD_OS, N_("premature end of file %s"),

@@ -677,6 +687,9 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),

       goto fail;

     }

+  grub_memcpy (&lh, kernel, sizeof (lh));

+  kernel_offset = sizeof (lh);

+

   if (lh.boot_flag != grub_cpu_to_le16_compile_time (0xaa55))

     {

       grub_error (GRUB_ERR_BAD_OS, "invalid magic number");

@@ -784,13 +797,11 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),

   /* We've already read lh so there is no need to read it second time. */

   len -= sizeof(lh);

-  if ((len > 0) &&

-      (grub_file_read (file, (char *) &linux_params + sizeof (lh), len) != len))

+  linux_params_ptr = (void *)&linux_params;

+  if (len > 0)

     {

-      if (!grub_errno)

-	grub_error (GRUB_ERR_BAD_OS, N_("premature end of file %s"),

-		    argv[0]);

-      goto fail;

+      grub_memcpy (linux_params_ptr + sizeof (lh), kernel + kernel_offset, len);

+      kernel_offset += len;

     }

   linux_params.code32_start = prot_mode_target + lh.code32_start - GRUB_LINUX_BZIMAGE_ADDR;

@@ -853,7 +864,7 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),

   /* The other parameters are filled when booting.  */

-  grub_file_seek (file, real_size + GRUB_DISK_SECTOR_SIZE);

+  kernel_offset = real_size + GRUB_DISK_SECTOR_SIZE;

   grub_dprintf ("linux", "bzImage, setup=0x%x, size=0x%x\n",

 		(unsigned) real_size, (unsigned) prot_size);

@@ -1007,9 +1018,7 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),

   }

   len = prot_file_size;

-  if (grub_file_read (file, prot_mode_mem, len) != len && !grub_errno)

-    grub_error (GRUB_ERR_BAD_OS, N_("premature end of file %s"),

-		argv[0]);

+  grub_memcpy (prot_mode_mem, kernel + kernel_offset, len);

   if (grub_errno == GRUB_ERR_NONE)

     {

@@ -1020,6 +1029,8 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),

  fail:

+  grub_free (kernel);

+

   if (file)

     grub_file_close (file);