Blame SOURCES/0324-efi-Free-malloc-regions-on-exit.patch

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From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
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From: Alexander Graf <agraf@suse.de>
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Date: Thu, 31 Aug 2017 16:40:19 +0200
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Subject: [PATCH] efi: Free malloc regions on exit
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When we exit grub, we don't free all the memory that we allocated earlier
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for our heap region. This can cause problems with setups where you try
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to descend the boot order using "exit" entries, such as PXE -> HD boot
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scenarios.
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Signed-off-by: Alexander Graf <agraf@suse.de>
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Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
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Upstream-commit-id: 92bfc33db98
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---
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 grub-core/kern/efi/init.c |  1 +
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 grub-core/kern/efi/mm.c   | 82 +++++++++++++++++++++++++++++++++++++++++++++++
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 include/grub/efi/efi.h    |  1 +
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 3 files changed, 84 insertions(+)
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diff --git a/grub-core/kern/efi/init.c b/grub-core/kern/efi/init.c
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index c5d8a76144a..e8bf993f6d4 100644
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--- a/grub-core/kern/efi/init.c
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+++ b/grub-core/kern/efi/init.c
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@@ -111,4 +111,5 @@ grub_efi_fini (void)
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 {
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   grub_efidisk_fini ();
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   grub_console_fini ();
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+  grub_efi_memory_fini ();
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 }
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diff --git a/grub-core/kern/efi/mm.c b/grub-core/kern/efi/mm.c
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index ddeca6073f6..abe9c70557f 100644
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--- a/grub-core/kern/efi/mm.c
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+++ b/grub-core/kern/efi/mm.c
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@@ -49,6 +49,70 @@ static grub_efi_uintn_t finish_desc_size;
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 static grub_efi_uint32_t finish_desc_version;
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 int grub_efi_is_finished = 0;
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+/*
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+ * We need to roll back EFI allocations on exit. Remember allocations that
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+ * we'll free on exit.
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+ */
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+struct efi_allocation;
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+struct efi_allocation {
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+	grub_efi_physical_address_t address;
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+	grub_efi_uint64_t pages;
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+	struct efi_allocation *next;
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+};
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+static struct efi_allocation *efi_allocated_memory;
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+
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+static void
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+grub_efi_store_alloc (grub_efi_physical_address_t address,
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+                         grub_efi_uintn_t pages)
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+{
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+  grub_efi_boot_services_t *b;
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+  struct efi_allocation *alloc;
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+  grub_efi_status_t status;
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+
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+  b = grub_efi_system_table->boot_services;
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+  status = efi_call_3 (b->allocate_pool, GRUB_EFI_LOADER_DATA,
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+                           sizeof(*alloc), (void**)&alloc);
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+
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+  if (status == GRUB_EFI_SUCCESS)
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+    {
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+      alloc->next = efi_allocated_memory;
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+      alloc->address = address;
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+      alloc->pages = pages;
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+      efi_allocated_memory = alloc;
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+    }
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+  else
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+      grub_printf ("Could not malloc memory to remember EFI allocation. "
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+                   "Exiting GRUB won't free all memory.\n");
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+}
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+
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+static void
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+grub_efi_drop_alloc (grub_efi_physical_address_t address,
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+                           grub_efi_uintn_t pages)
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+{
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+  struct efi_allocation *ea, *eap;
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+  grub_efi_boot_services_t *b;
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+
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+  b = grub_efi_system_table->boot_services;
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+
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+  for (eap = NULL, ea = efi_allocated_memory; ea; eap = ea, ea = ea->next)
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+    {
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+      if (ea->address != address || ea->pages != pages)
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+         continue;
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+
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+      /* Remove the current entry from the list. */
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+      if (eap)
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+        eap->next = ea->next;
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+      else
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+        efi_allocated_memory = ea->next;
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+
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+      /* Then free the memory backing it. */
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+      efi_call_1 (b->free_pool, ea);
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+
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+      /* And leave, we're done. */
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+      break;
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+    }
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+}
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+
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 /* Allocate pages below a specified address */
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 void *
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 grub_efi_allocate_pages_max (grub_efi_physical_address_t max,
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@@ -78,6 +142,8 @@ grub_efi_allocate_pages_max (grub_efi_physical_address_t max,
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 	return 0;
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     }
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+  grub_efi_store_alloc (address, pages);
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+
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   return (void *) ((grub_addr_t) address);
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 }
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@@ -139,6 +205,8 @@ grub_efi_free_pages (grub_efi_physical_address_t address,
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   b = grub_efi_system_table->boot_services;
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   efi_call_2 (b->free_pages, address, pages);
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+
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+  grub_efi_drop_alloc (address, pages);
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 }
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 #if defined (__i386__) || defined (__x86_64__)
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@@ -446,6 +514,20 @@ add_memory_regions (grub_efi_memory_descriptor_t *memory_map,
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     grub_fatal ("too little memory");
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 }
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+void
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+grub_efi_memory_fini (void)
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+{
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+  /*
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+   * Free all stale allocations. grub_efi_free_pages() will remove
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+   * the found entry from the list and it will always find the first
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+   * list entry (efi_allocated_memory is the list start). Hence we
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+   * remove all entries from the list until none is left altogether.
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+   */
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+  while (efi_allocated_memory)
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+      grub_efi_free_pages (efi_allocated_memory->address,
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+                           efi_allocated_memory->pages);
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+}
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+
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 #if 0
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 /* Print the memory map.  */
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 static void
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diff --git a/include/grub/efi/efi.h b/include/grub/efi/efi.h
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index 9a2da0eb38d..f761bbb1389 100644
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--- a/include/grub/efi/efi.h
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+++ b/include/grub/efi/efi.h
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@@ -51,6 +51,7 @@ EXPORT_FUNC(grub_efi_get_memory_map) (grub_efi_uintn_t *memory_map_size,
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 				      grub_efi_uintn_t *map_key,
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 				      grub_efi_uintn_t *descriptor_size,
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 				      grub_efi_uint32_t *descriptor_version);
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+void grub_efi_memory_fini (void);
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 grub_efi_loaded_image_t *EXPORT_FUNC(grub_efi_get_loaded_image) (grub_efi_handle_t image_handle);
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 void EXPORT_FUNC(grub_efi_print_device_path) (grub_efi_device_path_t *dp);
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 char *EXPORT_FUNC(grub_efi_get_filename) (grub_efi_device_path_t *dp);