svn commit: r363632 - stable/12/stand/efi/loader

[Kyle Evans]

Author: kevans
Date: Tue Jul 28 04:58:01 2020
New Revision: 363632
URL: https://svnweb.freebsd.org/changeset/base/363632

Log:
  MFC r355132: Support kernels larger than EFI_STAGING_SIZE in loader.efi
  
  With a very large kernel or module the staging area may be too small to
  hold it. When this is the case try to allocate more space before failing
  in the efi copyin/copyout/readin functions.

Modified:
  stable/12/stand/efi/loader/copy.c
Directory Properties:
  stable/12/   (props changed)

Modified: stable/12/stand/efi/loader/copy.c
==============================================================================
--- stable/12/stand/efi/loader/copy.c	Tue Jul 28 03:25:31 2020	(r363631)
+++ stable/12/stand/efi/loader/copy.c	Tue Jul 28 04:58:01 2020	(r363632)
@@ -185,7 +185,7 @@ out:
 #endif
 #endif
 
-EFI_PHYSICAL_ADDRESS	staging, staging_end;
+EFI_PHYSICAL_ADDRESS	staging, staging_end, staging_base;
 int			stage_offset_set = 0;
 ssize_t			stage_offset;
 
@@ -224,6 +224,7 @@ efi_copy_init(void)
 		    EFI_ERROR_CODE(status));
 		return (status);
 	}
+	staging_base = staging;
 	staging_end = staging + nr_pages * EFI_PAGE_SIZE;
 
 #if defined(__aarch64__) || defined(__arm__)
@@ -240,6 +241,66 @@ efi_copy_init(void)
 	return (0);
 }
 
+static bool
+efi_check_space(vm_offset_t end)
+{
+	EFI_PHYSICAL_ADDRESS addr;
+	EFI_STATUS status;
+	unsigned long nr_pages;
+
+	/* There is already enough space */
+	if (end <= staging_end)
+		return (true);
+
+	end = roundup2(end, EFI_PAGE_SIZE);
+	nr_pages = EFI_SIZE_TO_PAGES(end - staging_end);
+
+#if defined(__i386__) || defined(__amd64__)
+	/* X86 needs all memory to be allocated under the 1G boundary */
+	if (end > 1024*1024*1024)
+		goto before_staging;
+#endif
+
+	/* Try to allocate more space after the previous allocation */
+	addr = staging_end;
+	status = BS->AllocatePages(AllocateAddress, EfiLoaderData, nr_pages,
+	    &addr);
+	if (!EFI_ERROR(status)) {
+		staging_end = staging_end + nr_pages * EFI_PAGE_SIZE;
+		return (true);
+	}
+
+before_staging:
+	/* Try allocating space before the previous allocation */
+	if (staging < nr_pages * EFI_PAGE_SIZE) {
+		printf("Not enough space before allocation\n");
+		return (false);
+	}
+	addr = staging - nr_pages * EFI_PAGE_SIZE;
+#if defined(__aarch64__) || defined(__arm__)
+	/* See efi_copy_init for why this is needed */
+	addr = rounddown2(addr, 2 * 1024 * 1024);
+#endif
+	nr_pages = EFI_SIZE_TO_PAGES(staging_base - addr);
+	status = BS->AllocatePages(AllocateAddress, EfiLoaderData, nr_pages,
+	    &addr);
+	if (!EFI_ERROR(status)) {
+		/*
+		 * Move the old allocation and update the state so
+		 * translation still works.
+		 */
+		staging_base = addr;
+		memmove((void *)staging_base, (void *)staging,
+		    staging_end - staging);
+		stage_offset -= (staging - staging_base);
+		staging = staging_base;
+		return (true);
+	}
+
+	printf("efi_check_space: Unable to expand staging area\n");
+	return (false);
+}
+
 void *
 efi_translate(vm_offset_t ptr)
 {
@@ -257,7 +318,7 @@ efi_copyin(const void *src, vm_offset_t dest, const si
 	}
 
 	/* XXX: Callers do not check for failure. */
-	if (dest + stage_offset + len > staging_end) {
+	if (!efi_check_space(dest + stage_offset + len)) {
 		errno = ENOMEM;
 		return (-1);
 	}
@@ -283,7 +344,7 @@ ssize_t
 efi_readin(readin_handle_t fd, vm_offset_t dest, const size_t len)
 {
 
-	if (dest + stage_offset + len > staging_end) {
+	if (!efi_check_space(dest + stage_offset + len)) {
 		errno = ENOMEM;
 		return (-1);
 	}