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From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Peter Jones <pjones@redhat.com>
Date: Thu, 11 Jul 2019 17:17:02 +0200
Subject: [PATCH] Try to pick better locations for kernel and initrd

- Don't limit allocations on 64-bit platforms to < 0x[37f]fffffff if
  we're using the "large" code model ; use __UINTPTR_MAX__.
- Get the comparison right to check the address we've allocated.
- Fix the allocation for the command line as well.

*But*, when we did this some systems started failing badly; coudln't
parse partition tables, etc.  What's going on here is the disk controller
is silently failing DMAs to addresses above 4GB, so we're trying to parse
uninitialized (or HW zeroed) ram when looking for the partition table,
etc.

So to limit this, we make grub_malloc() pick addresses below 4GB on
x86_64, but the direct EFI page allocation functions can get addresses
above that.

Additionally, we now try to locate kernel+initrd+cmdline+etc below
0x7fffffff, and if they're too big to fit any memory window there, then
we try a higher address.

Signed-off-by: Peter Jones <pjones@redhat.com>
---
 grub-core/kern/efi/mm.c           |  8 ++++----
 grub-core/loader/i386/efi/linux.c | 24 +++++++++++++++++-------
 include/grub/arm/efi/memory.h     |  1 +
 include/grub/arm64/efi/memory.h   |  1 +
 include/grub/i386/efi/memory.h    |  1 +
 include/grub/ia64/efi/memory.h    |  1 +
 include/grub/x86_64/efi/memory.h  |  4 +++-
 7 files changed, 28 insertions(+), 12 deletions(-)

diff --git a/grub-core/kern/efi/mm.c b/grub-core/kern/efi/mm.c
index 1b14fa0694c..d70e5b45b7c 100644
--- a/grub-core/kern/efi/mm.c
+++ b/grub-core/kern/efi/mm.c
@@ -122,7 +122,7 @@ grub_efi_allocate_pages_max (grub_efi_physical_address_t max,
   grub_efi_boot_services_t *b;
   grub_efi_physical_address_t address = max;
 
-  if (max > 0xffffffff)
+  if (max > GRUB_EFI_MAX_USABLE_ADDRESS)
     return 0;
 
   b = grub_efi_system_table->boot_services;
@@ -466,7 +466,7 @@ filter_memory_map (grub_efi_memory_descriptor_t *memory_map,
     {
       if (desc->type == GRUB_EFI_CONVENTIONAL_MEMORY
 #if 1
-	  && desc->physical_start <= GRUB_EFI_MAX_USABLE_ADDRESS
+	  && desc->physical_start <= GRUB_EFI_MAX_ALLOCATION_ADDRESS
 #endif
 	  && desc->physical_start + PAGES_TO_BYTES (desc->num_pages) > 0x100000
 	  && desc->num_pages != 0)
@@ -484,9 +484,9 @@ filter_memory_map (grub_efi_memory_descriptor_t *memory_map,
 #if 1
 	  if (BYTES_TO_PAGES (filtered_desc->physical_start)
 	      + filtered_desc->num_pages
-	      > BYTES_TO_PAGES_DOWN (GRUB_EFI_MAX_USABLE_ADDRESS))
+	      > BYTES_TO_PAGES_DOWN (GRUB_EFI_MAX_ALLOCATION_ADDRESS))
 	    filtered_desc->num_pages
-	      = (BYTES_TO_PAGES_DOWN (GRUB_EFI_MAX_USABLE_ADDRESS)
+	      = (BYTES_TO_PAGES_DOWN (GRUB_EFI_MAX_ALLOCATION_ADDRESS)
 		 - BYTES_TO_PAGES (filtered_desc->physical_start));
 #endif
 
diff --git a/grub-core/loader/i386/efi/linux.c b/grub-core/loader/i386/efi/linux.c
index 3017d0f3e52..33e981e76e7 100644
--- a/grub-core/loader/i386/efi/linux.c
+++ b/grub-core/loader/i386/efi/linux.c
@@ -27,6 +27,7 @@
 #include <grub/lib/cmdline.h>
 #include <grub/efi/efi.h>
 #include <grub/efi/linux.h>
+#include <grub/cpu/efi/memory.h>
 
 GRUB_MOD_LICENSE ("GPLv3+");
 
@@ -106,7 +107,9 @@ grub_cmd_initrd (grub_command_t cmd __attribute__ ((unused)),
       size += ALIGN_UP (grub_file_size (files[i]), 4);
     }
 
-  initrd_mem = grub_efi_allocate_pages_max (0x3fffffff, BYTES_TO_PAGES(size));
+  initrd_mem = grub_efi_allocate_pages_max (GRUB_EFI_MAX_ALLOCATION_ADDRESS, BYTES_TO_PAGES(size));
+  if (!initrd_mem)
+    initrd_mem = grub_efi_allocate_pages_max (GRUB_EFI_MAX_USABLE_ADDRESS, BYTES_TO_PAGES(size));
   if (!initrd_mem)
     {
       grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("can't allocate initrd"));
@@ -202,8 +205,11 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),
       goto fail;
     }
 
-  params = grub_efi_allocate_pages_max (0x3fffffff,
+  params = grub_efi_allocate_pages_max (GRUB_EFI_MAX_ALLOCATION_ADDRESS,
 					BYTES_TO_PAGES(sizeof(*params)));
+  if (!params)
+    params = grub_efi_allocate_pages_max (GRUB_EFI_MAX_USABLE_ADDRESS,
+					  BYTES_TO_PAGES(sizeof(*params)));
   if (! params)
     {
       grub_error (GRUB_ERR_OUT_OF_MEMORY, "cannot allocate kernel parameters");
@@ -273,8 +279,11 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),
 #endif
 
   grub_dprintf ("linux", "setting up cmdline\n");
-  linux_cmdline = grub_efi_allocate_pages_max(0x3fffffff,
-					 BYTES_TO_PAGES(lh->cmdline_size + 1));
+  linux_cmdline = grub_efi_allocate_pages_max(GRUB_EFI_MAX_ALLOCATION_ADDRESS,
+					      BYTES_TO_PAGES(lh->cmdline_size + 1));
+  if (!linux_cmdline)
+    linux_cmdline = grub_efi_allocate_pages_max(GRUB_EFI_MAX_USABLE_ADDRESS,
+						BYTES_TO_PAGES(lh->cmdline_size + 1));
   if (!linux_cmdline)
     {
       grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("can't allocate cmdline"));
@@ -301,11 +310,12 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),
 
   kernel_mem = grub_efi_allocate_pages_max(lh->pref_address,
 					   BYTES_TO_PAGES(lh->init_size));
-
   if (!kernel_mem)
-    kernel_mem = grub_efi_allocate_pages_max(0x3fffffff,
+    kernel_mem = grub_efi_allocate_pages_max(GRUB_EFI_MAX_ALLOCATION_ADDRESS,
+					     BYTES_TO_PAGES(lh->init_size));
+  if (!kernel_mem)
+    kernel_mem = grub_efi_allocate_pages_max(GRUB_EFI_MAX_USABLE_ADDRESS,
 					     BYTES_TO_PAGES(lh->init_size));
-
   if (!kernel_mem)
     {
       grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("can't allocate kernel"));
diff --git a/include/grub/arm/efi/memory.h b/include/grub/arm/efi/memory.h
index 2c64918e3f7..a4c2ec83502 100644
--- a/include/grub/arm/efi/memory.h
+++ b/include/grub/arm/efi/memory.h
@@ -2,5 +2,6 @@
 #include <grub/efi/memory.h>
 
 #define GRUB_EFI_MAX_USABLE_ADDRESS 0xffffffff
+#define GRUB_EFI_MAX_ALLOCATION_ADDRESS GRUB_EFI_MAX_USABLE_ADDRESS
 
 #endif /* ! GRUB_MEMORY_CPU_HEADER */
diff --git a/include/grub/arm64/efi/memory.h b/include/grub/arm64/efi/memory.h
index c6cb3241714..acb61dca44b 100644
--- a/include/grub/arm64/efi/memory.h
+++ b/include/grub/arm64/efi/memory.h
@@ -2,5 +2,6 @@
 #include <grub/efi/memory.h>
 
 #define GRUB_EFI_MAX_USABLE_ADDRESS 0xffffffffffffULL
+#define GRUB_EFI_MAX_ALLOCATION_ADDRESS GRUB_EFI_MAX_USABLE_ADDRESS
 
 #endif /* ! GRUB_MEMORY_CPU_HEADER */
diff --git a/include/grub/i386/efi/memory.h b/include/grub/i386/efi/memory.h
index 2c64918e3f7..a4c2ec83502 100644
--- a/include/grub/i386/efi/memory.h
+++ b/include/grub/i386/efi/memory.h
@@ -2,5 +2,6 @@
 #include <grub/efi/memory.h>
 
 #define GRUB_EFI_MAX_USABLE_ADDRESS 0xffffffff
+#define GRUB_EFI_MAX_ALLOCATION_ADDRESS GRUB_EFI_MAX_USABLE_ADDRESS
 
 #endif /* ! GRUB_MEMORY_CPU_HEADER */
diff --git a/include/grub/ia64/efi/memory.h b/include/grub/ia64/efi/memory.h
index 2c64918e3f7..a4c2ec83502 100644
--- a/include/grub/ia64/efi/memory.h
+++ b/include/grub/ia64/efi/memory.h
@@ -2,5 +2,6 @@
 #include <grub/efi/memory.h>
 
 #define GRUB_EFI_MAX_USABLE_ADDRESS 0xffffffff
+#define GRUB_EFI_MAX_ALLOCATION_ADDRESS GRUB_EFI_MAX_USABLE_ADDRESS
 
 #endif /* ! GRUB_MEMORY_CPU_HEADER */
diff --git a/include/grub/x86_64/efi/memory.h b/include/grub/x86_64/efi/memory.h
index 46e9145a308..e81cfb32213 100644
--- a/include/grub/x86_64/efi/memory.h
+++ b/include/grub/x86_64/efi/memory.h
@@ -2,9 +2,11 @@
 #include <grub/efi/memory.h>
 
 #if defined (__code_model_large__)
-#define GRUB_EFI_MAX_USABLE_ADDRESS 0xffffffff
+#define GRUB_EFI_MAX_USABLE_ADDRESS __UINTPTR_MAX__
+#define GRUB_EFI_MAX_ALLOCATION_ADDRESS 0x7fffffff
 #else
 #define GRUB_EFI_MAX_USABLE_ADDRESS 0x7fffffff
+#define GRUB_EFI_MAX_ALLOCATION_ADDRESS GRUB_EFI_MAX_USABLE_ADDRESS
 #endif
 
 #endif /* ! GRUB_MEMORY_CPU_HEADER */