[GIT PULL 0/2] EFI fixes for v4.15

[GIT PULL 0/2] EFI fixes for v4.15

[Ard Biesheuvel]

The following changes since commit 30a7acd573899fd8b8ac39236eff6468b195ac7d:

  Linux 4.15-rc6 (2017-12-31 14:47:43 -0800)

are available in the git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi.git tags/efi-urgent

for you to fetch changes up to 33f7b2e57a70ad58a59edc9c707724c5719d5168:

  efi: capsule-loader: reinstate virtual capsule mapping (2018-01-02 16:50:34 +0000)

----------------------------------------------------------------
Another pair of EFI fixes for v4.15:
- fix 'add_efi_memmap' early param handling, which inadvertently gets called
  before early params have been parsed
- reinstate vmapping of capsule images, so that the firmware can process
  them immediately (this got broken in v4.13)

----------------------------------------------------------------
Ard Biesheuvel (1):
      efi: capsule-loader: reinstate virtual capsule mapping

Dave Young (1):
      x86/efi: Fix kernel param add_efi_memmap regression

 arch/x86/kernel/setup.c               |  5 ++--
 arch/x86/platform/efi/quirks.c        | 13 +++++++++-
 drivers/firmware/efi/capsule-loader.c | 45 ++++++++++++++++++++++++++++-------
 include/linux/efi.h                   |  4 +++-
 4 files changed, 54 insertions(+), 13 deletions(-)

[PATCH 1/2] x86/efi: Fix kernel param add_efi_memmap regression

[Ard Biesheuvel]

From: Dave Young <dyoung-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>

'add_efi_memmap' is an early param, but do_add_efi_memmap() has no
chance to run because the code path is before parse_early_param().
I believe it worked when the param was introduced but probably later
some other changes caused the wrong order and nobody noticed it.

Move efi_memblock_x86_reserve_range() after parse_early_param()
to fix it.

Signed-off-by: Dave Young <dyoung-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Cc: Ingo Molnar <mingo-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Signed-off-by: Matt Fleming <matt-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
---
 arch/x86/kernel/setup.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 8af2e8d0c0a1..145810b0edf6 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -906,9 +906,6 @@ void __init setup_arch(char **cmdline_p)
 		set_bit(EFI_BOOT, &efi.flags);
 		set_bit(EFI_64BIT, &efi.flags);
 	}
-
-	if (efi_enabled(EFI_BOOT))
-		efi_memblock_x86_reserve_range();
 #endif
 
 	x86_init.oem.arch_setup();
@@ -962,6 +959,8 @@ void __init setup_arch(char **cmdline_p)
 
 	parse_early_param();
 
+	if (efi_enabled(EFI_BOOT))
+		efi_memblock_x86_reserve_range();
 #ifdef CONFIG_MEMORY_HOTPLUG
 	/*
 	 * Memory used by the kernel cannot be hot-removed because Linux
-- 
2.11.0

[PATCH 2/2] efi: capsule-loader: reinstate virtual capsule mapping

[Ard Biesheuvel]

Commit 82c3768b8d68 ("efi/capsule-loader: Use a cached copy of the
capsule header") refactored the capsule loading code that maps the
capsule header, to avoid having to map it several times. However,
as it turns out, the vmap() call we ended up removing did not just
map the header, but the entire capsule image, and dropping this
virtual mapping breaks capsules that are processed by the firmware
immediately (i.e., without a reboot).

Unfortunately, that change was part of a larger refactor that allowed
a quirk to be implemented for Quark, which has a non-standard memory
layout for capsules, and we have slightly painted ourselves into a
corner by allowing quirk code to mangle the capsule header and memory
layout.

So we need to fix this without breaking Quark. Fortunately, Quark does
not appear to care about the virtual mapping, and so we can simply
do a partial revert of commit 2a457fb31df6 ("efi/capsule-loader: Use
page addresses rather than struct page pointers"), and create a vmap()
mapping of the entire capsule (including header) based on the reinstated
struct page array, unless running on Quark, in which case we pass the
capsule header copy as before.

Reported-by: Ge Song <ge.song-PT9Dzx9SjPiXmMXjJBpWqg@public.gmane.org>
Tested-by: Bryan O'Donoghue <pure.logic-SyKdqv6vbfZdzvEItQ6vdLNAH6kLmebB@public.gmane.org>
Tested-by: Ge Song <ge.song-PT9Dzx9SjPiXmMXjJBpWqg@public.gmane.org>
Cc: Matt Fleming <matt-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org>
Cc: <stable-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Fixes: 82c3768b8d68 ("efi/capsule-loader: Use a cached copy of the capsule header")
Signed-off-by: Ard Biesheuvel <ard.biesheuvel-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
---
 arch/x86/platform/efi/quirks.c        | 13 +++++++++-
 drivers/firmware/efi/capsule-loader.c | 45 ++++++++++++++++++++++++++++-------
 include/linux/efi.h                   |  4 +++-
 3 files changed, 52 insertions(+), 10 deletions(-)

diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c
index 8a99a2e96537..5b513ccffde4 100644
--- a/arch/x86/platform/efi/quirks.c
+++ b/arch/x86/platform/efi/quirks.c
@@ -592,7 +592,18 @@ static int qrk_capsule_setup_info(struct capsule_info *cap_info, void **pkbuff,
 	/*
 	 * Update the first page pointer to skip over the CSH header.
 	 */
-	cap_info->pages[0] += csh->headersize;
+	cap_info->phys[0] += csh->headersize;
+
+	/*
+	 * cap_info->capsule should point at a virtual mapping of the entire
+	 * capsule, starting at the capsule header. Our image has the Quark
+	 * security header prepended, so we cannot rely on the default vmap()
+	 * mapping created by the generic capsule code.
+	 * Given that the Quark firmware does not appear to care about the
+	 * virtual mapping, let's just point cap_info->capsule at our copy
+	 * of the capsule header.
+	 */
+	cap_info->capsule = &cap_info->header;
 
 	return 1;
 }
diff --git a/drivers/firmware/efi/capsule-loader.c b/drivers/firmware/efi/capsule-loader.c
index ec8ac5c4dd84..055e2e8f985a 100644
--- a/drivers/firmware/efi/capsule-loader.c
+++ b/drivers/firmware/efi/capsule-loader.c
@@ -20,10 +20,6 @@
 
 #define NO_FURTHER_WRITE_ACTION -1
 
-#ifndef phys_to_page
-#define phys_to_page(x)		pfn_to_page((x) >> PAGE_SHIFT)
-#endif
-
 /**
  * efi_free_all_buff_pages - free all previous allocated buffer pages
  * @cap_info: pointer to current instance of capsule_info structure
@@ -35,7 +31,7 @@
 static void efi_free_all_buff_pages(struct capsule_info *cap_info)
 {
 	while (cap_info->index > 0)
-		__free_page(phys_to_page(cap_info->pages[--cap_info->index]));
+		__free_page(cap_info->pages[--cap_info->index]);
 
 	cap_info->index = NO_FURTHER_WRITE_ACTION;
 }
@@ -71,6 +67,14 @@ int __efi_capsule_setup_info(struct capsule_info *cap_info)
 
 	cap_info->pages = temp_page;
 
+	temp_page = krealloc(cap_info->phys,
+			     pages_needed * sizeof(phys_addr_t *),
+			     GFP_KERNEL | __GFP_ZERO);
+	if (!temp_page)
+		return -ENOMEM;
+
+	cap_info->phys = temp_page;
+
 	return 0;
 }
 
@@ -105,9 +109,24 @@ int __weak efi_capsule_setup_info(struct capsule_info *cap_info, void *kbuff,
  **/
 static ssize_t efi_capsule_submit_update(struct capsule_info *cap_info)
 {
+	bool do_vunmap = false;
 	int ret;
 
-	ret = efi_capsule_update(&cap_info->header, cap_info->pages);
+	/*
+	 * cap_info->capsule may have been assigned already by a quirk
+	 * handler, so only overwrite it if it is NULL
+	 */
+	if (!cap_info->capsule) {
+		cap_info->capsule = vmap(cap_info->pages, cap_info->index,
+					 VM_MAP, PAGE_KERNEL);
+		if (!cap_info->capsule)
+			return -ENOMEM;
+		do_vunmap = true;
+	}
+
+	ret = efi_capsule_update(cap_info->capsule, cap_info->phys);
+	if (do_vunmap)
+		vunmap(cap_info->capsule);
 	if (ret) {
 		pr_err("capsule update failed\n");
 		return ret;
@@ -165,10 +184,12 @@ static ssize_t efi_capsule_write(struct file *file, const char __user *buff,
 			goto failed;
 		}
 
-		cap_info->pages[cap_info->index++] = page_to_phys(page);
+		cap_info->pages[cap_info->index] = page;
+		cap_info->phys[cap_info->index] = page_to_phys(page);
 		cap_info->page_bytes_remain = PAGE_SIZE;
+		cap_info->index++;
 	} else {
-		page = phys_to_page(cap_info->pages[cap_info->index - 1]);
+		page = cap_info->pages[cap_info->index - 1];
 	}
 
 	kbuff = kmap(page);
@@ -252,6 +273,7 @@ static int efi_capsule_release(struct inode *inode, struct file *file)
 	struct capsule_info *cap_info = file->private_data;
 
 	kfree(cap_info->pages);
+	kfree(cap_info->phys);
 	kfree(file->private_data);
 	file->private_data = NULL;
 	return 0;
@@ -281,6 +303,13 @@ static int efi_capsule_open(struct inode *inode, struct file *file)
 		return -ENOMEM;
 	}
 
+	cap_info->phys = kzalloc(sizeof(void *), GFP_KERNEL);
+	if (!cap_info->phys) {
+		kfree(cap_info->pages);
+		kfree(cap_info);
+		return -ENOMEM;
+	}
+
 	file->private_data = cap_info;
 
 	return 0;
diff --git a/include/linux/efi.h b/include/linux/efi.h
index d813f7b04da7..29fdf8029cf6 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -140,11 +140,13 @@ struct efi_boot_memmap {
 
 struct capsule_info {
 	efi_capsule_header_t	header;
+	efi_capsule_header_t	*capsule;
 	int			reset_type;
 	long			index;
 	size_t			count;
 	size_t			total_size;
-	phys_addr_t		*pages;
+	struct page		**pages;
+	phys_addr_t		*phys;
 	size_t			page_bytes_remain;
 };
 
-- 
2.11.0