Update UEFI memory map cleaning

Signed-off-by: Peter Jones <pjones@redhat.com>

6 files changed, 142 insertions, 295 deletions

diff --git a/0001-efi-efi_print_memmap-Call-out-invalid-entries-in-the.patch b/0001-efi-efi_print_memmap-Call-out-invalid-entries-in-the.patch
deleted file mode 100644
index 037a60c33..000000000
--- a/0001-efi-efi_print_memmap-Call-out-invalid-entries-in-the.patch
+++ /dev/null
@@ -1,61 +0,0 @@
-From 64ec700cb0b75047ce2ac68cca020e75369cb409 Mon Sep 17 00:00:00 2001
-From: Peter Jones <pjones@redhat.com>
-Date: Wed, 7 Dec 2016 16:19:20 -0500
-Subject: [PATCH 1/4] efi: efi_print_memmap(): Call out invalid entries in the
- memory map early.
-
-Some machines, such as the Lenovo ThinkPad W541 with firmware GNET80WW
-(2.28), include memory map entries with phys_addr=0x0 and num_pages=0.
-Currently the log output for this case (with efi=debug) looks like:
-
-[    0.000000] efi: mem45: [Reserved           |   |  |  |  |  |  |  |  |  |  |  |  ] range=[0x0000000000000000-0xffffffffffffffff] (0MB)
-
-This is clearly wrong, and also not as informative as it could be.  This
-patch changes it so that if we find obviously invalid memory map
-entries, say so when we're printing the memory map.  It also detects the
-display of the address range calculation overflow, so the new output is:
-
-[    0.000000] efi: [Firmware Bug]: Invalid EFI memory map entry for 0x0 pages at 0x0000000000000000
-[    0.000000] efi: mem45: [Reserved           |   |  |  |  |  |  |  |   |  |  |  |  ] range=[0x0000000000000000-0x0000000000000000] (0MB)
-
-Signed-off-by: Peter Jones <pjones@redhat.com>
----
- arch/x86/platform/efi/efi.c | 18 +++++++++++++++++-
- 1 file changed, 17 insertions(+), 1 deletion(-)
-
-diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
-index bf99aa7..181c915 100644
---- a/arch/x86/platform/efi/efi.c
-+++ b/arch/x86/platform/efi/efi.c
-@@ -217,11 +217,27 @@ void __init efi_print_memmap(void)
- 
- 	for_each_efi_memory_desc(md) {
- 		char buf[64];
-+		bool valid = true;
-+		u64 size = (md->num_pages << EFI_PAGE_SHIFT) - 1;
-+
-+		if (md->num_pages == 0) {
-+			size = 0;
-+			valid = false;
-+		}
-+
-+		if (md->num_pages >= (((u64)-1LL) >> EFI_PAGE_SHIFT)) {
-+			size = (u64)-1LL;
-+			valid = false;
-+		}
-+
-+		if (!valid)
-+			pr_info(FW_BUG "Invalid EFI memory map entry for 0x%llx pages at 0x%016llx\n",
-+				md->num_pages, md->phys_addr);
- 
- 		pr_info("mem%02u: %s range=[0x%016llx-0x%016llx] (%lluMB)\n",
- 			i++, efi_md_typeattr_format(buf, sizeof(buf), md),
- 			md->phys_addr,
--			md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1,
-+			md->phys_addr + size,
- 			(md->num_pages >> (20 - EFI_PAGE_SHIFT)));
- 	}
- }
--- 
-2.9.3
-
diff --git a/0001-efi-prune-invalid-memory-map-entries.patch b/0001-efi-prune-invalid-memory-map-entries.patch
new file mode 100644
index 000000000..4b65ef504
--- /dev/null
+++ b/0001-efi-prune-invalid-memory-map-entries.patch
@@ -0,0 +1,141 @@
+From c7c7030a020405d5826c03839e38986e0f78f2ea Mon Sep 17 00:00:00 2001
+From: Peter Jones <pjones@redhat.com>
+Date: Tue, 13 Dec 2016 10:25:10 +0000
+Subject: [PATCH] efi: prune invalid memory map entries
+
+Some machines, such as the Lenovo ThinkPad W541 with firmware GNET80WW
+(2.28), include memory map entries with phys_addr=0x0 and num_pages=0.
+
+Currently the log output for this case (with efi=debug) looks like:
+
+[    0.000000] efi: mem45: [Reserved           |   |  |  |  |  |  |  |  |  |  |  |  ] range=[0x0000000000000000-0xffffffffffffffff] (0MB)
+
+This is clearly wrong, and also not as informative as it could be.  This
+patch changes it so that if we find obviously invalid memory map
+entries, we print an error and those entries.  It also detects the
+display of the address range calculation overflow, so the new output is:
+
+[    0.000000] efi: [Firmware Bug]: Invalid EFI memory map entries:
+[    0.000000] efi: mem45: [Reserved           |   |  |  |  |  |  |  |   |  |  |  |  ] range=[0x0000000000000000-0x0000000000000000] (invalid)
+
+It also detects memory map sizes that would overflow the physical
+address, for example phys_addr=0xfffffffffffff000 and
+num_pages=0x0200000000000001, and prints:
+
+[    0.000000] efi: [Firmware Bug]: Invalid EFI memory map entries:
+[    0.000000] efi: mem45: [Reserved           |   |  |  |  |  |  |  |   |  |  |  |  ] range=[phys_addr=0xfffffffffffff000-0x20ffffffffffffffff] (invalid)
+
+It then removes these entries from the memory map.
+
+Cc: Matt Fleming <matt@codeblueprint.co.uk>
+Signed-off-by: Peter Jones <pjones@redhat.com>
+[ardb: refactor for clarity with no functional changes, avoid PAGE_SHIFT]
+Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
+---
+ arch/x86/platform/efi/efi.c | 70 +++++++++++++++++++++++++++++++++++++++++++++
+ include/linux/efi.h         |  1 +
+ 2 files changed, 71 insertions(+)
+
+diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
+index bf99aa7..0a1550b 100644
+--- a/arch/x86/platform/efi/efi.c
++++ b/arch/x86/platform/efi/efi.c
+@@ -210,6 +210,74 @@ int __init efi_memblock_x86_reserve_range(void)
+ 	return 0;
+ }
+ 
++#define OVERFLOW_ADDR_SHIFT	(64 - EFI_PAGE_SHIFT)
++#define OVERFLOW_ADDR_MASK	(U64_MAX << OVERFLOW_ADDR_SHIFT)
++#define U64_HIGH_BIT		(~(U64_MAX >> 1))
++
++static bool __init efi_memmap_entry_valid(const efi_memory_desc_t *md, int i)
++{
++	static __initdata bool once = true;
++	u64 end = (md->num_pages << EFI_PAGE_SHIFT) + md->phys_addr - 1;
++	u64 end_hi = 0;
++	char buf[64];
++
++	if (md->num_pages == 0) {
++		end = 0;
++	} else if (md->num_pages > EFI_PAGES_MAX ||
++		   EFI_PAGES_MAX - md->num_pages <
++		   (md->phys_addr >> EFI_PAGE_SHIFT)) {
++		end_hi = (md->num_pages & OVERFLOW_ADDR_MASK)
++			>> OVERFLOW_ADDR_SHIFT;
++
++		if ((md->phys_addr & U64_HIGH_BIT) && !(end & U64_HIGH_BIT))
++			end_hi += 1;
++	} else {
++		return true;
++	}
++
++	if (once) {
++		pr_warn(FW_BUG "Invalid EFI memory map entries:\n");
++		once = false;
++	}
++
++	if (end_hi) {
++		pr_warn("mem%02u: %s range=[0x%016llx-0x%llx%016llx] (invalid)\n",
++			i, efi_md_typeattr_format(buf, sizeof(buf), md),
++			md->phys_addr, end_hi, end);
++	} else {
++		pr_warn("mem%02u: %s range=[0x%016llx-0x%016llx] (invalid)\n",
++			i, efi_md_typeattr_format(buf, sizeof(buf), md),
++			md->phys_addr, end);
++	}
++	return false;
++}
++
++static void __init efi_clean_memmap(void)
++{
++	efi_memory_desc_t *out = efi.memmap.map;
++	const efi_memory_desc_t *in = out;
++	const efi_memory_desc_t *end = efi.memmap.map_end;
++	int i, n_removal;
++
++	for (i = n_removal = 0; in < end; i++) {
++		if (efi_memmap_entry_valid(in, i)) {
++			if (out != in)
++				memcpy(out, in, efi.memmap.desc_size);
++			out = (void *)out + efi.memmap.desc_size;
++		} else {
++			n_removal++;
++		}
++		in = (void *)in + efi.memmap.desc_size;
++	}
++
++	if (n_removal > 0) {
++		u64 size = efi.memmap.nr_map - n_removal;
++
++		pr_warn("Removing %d invalid memory map entries.\n", n_removal);
++		efi_memmap_install(efi.memmap.phys_map, size);
++	}
++}
++
+ void __init efi_print_memmap(void)
+ {
+ 	efi_memory_desc_t *md;
+@@ -472,6 +540,8 @@ void __init efi_init(void)
+ 		}
+ 	}
+ 
++	efi_clean_memmap();
++
+ 	if (efi_enabled(EFI_DBG))
+ 		efi_print_memmap();
+ }
+diff --git a/include/linux/efi.h b/include/linux/efi.h
+index 4c1b3ea..712a3aa 100644
+--- a/include/linux/efi.h
++++ b/include/linux/efi.h
+@@ -103,6 +103,7 @@ typedef	struct {
+ 
+ #define EFI_PAGE_SHIFT		12
+ #define EFI_PAGE_SIZE		(1UL << EFI_PAGE_SHIFT)
++#define EFI_PAGES_MAX		(U64_MAX >> EFI_PAGE_SHIFT)
+ 
+ typedef struct {
+ 	u32 type;
+-- 
+2.9.3
+
diff --git a/0002-efi-efi_map_region-traceback-if-we-try-to-map-invali.patch b/0002-efi-efi_map_region-traceback-if-we-try-to-map-invali.patch
deleted file mode 100644
index 25b0ad19b..000000000
--- a/0002-efi-efi_map_region-traceback-if-we-try-to-map-invali.patch
+++ /dev/null
@@ -1,71 +0,0 @@
-From 510cd0c36a3beb0907bdbd31a48b71abdddb44a7 Mon Sep 17 00:00:00 2001
-From: Peter Jones <pjones@redhat.com>
-Date: Wed, 7 Dec 2016 16:20:10 -0500
-Subject: [PATCH 2/4] efi: efi_map_region(): traceback if we try to map invalid
- sized regions
-
-Some machines, such as the Lenovo ThinkPad W541 with firmware GNET80WW
-(2.28), include memory map entries with phys_addr=0x0 and num_pages=0.
-We shouldn't ever try to map these errors, so if we get as far as
-efi_map_region(), show a traceback.
-
-This additionally makes should_map_region() say not to map them, but I
-fixed both places in case another caller of efi_map_region() ever arises
-in the future.
-
-Signed-off-by: Peter Jones <pjones@redhat.com>
----
- arch/x86/platform/efi/efi.c    |  4 ++++
- arch/x86/platform/efi/efi_64.c | 19 ++++++++++++++++---
- 2 files changed, 20 insertions(+), 3 deletions(-)
-
-diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
-index 181c915..bf32454 100644
---- a/arch/x86/platform/efi/efi.c
-+++ b/arch/x86/platform/efi/efi.c
-@@ -707,6 +707,10 @@ static bool should_map_region(efi_memory_desc_t *md)
- 	if (IS_ENABLED(CONFIG_X86_32))
- 		return false;
- 
-+	if (md->num_pages == 0 ||
-+	    md->num_pages >= (((u64)-1LL) >> EFI_PAGE_SHIFT))
-+		return false;
-+
- 	/*
- 	 * Map all of RAM so that we can access arguments in the 1:1
- 	 * mapping when making EFI runtime calls.
-diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
-index de12d9f..f80de01 100644
---- a/arch/x86/platform/efi/efi_64.c
-+++ b/arch/x86/platform/efi/efi_64.c
-@@ -283,11 +283,24 @@ static void __init __map_region(efi_memory_desc_t *md, u64 va)
- 
- void __init efi_map_region(efi_memory_desc_t *md)
- {
--	unsigned long size = md->num_pages << PAGE_SHIFT;
-+	u64 size = md->num_pages << PAGE_SHIFT;
- 	u64 pa = md->phys_addr;
- 
--	if (efi_enabled(EFI_OLD_MEMMAP))
--		return old_map_region(md);
-+	/*
-+	 * hah hah the system firmware is having a good one on us
-+	 */
-+	if (md->num_pages == 0 ||
-+	    md->num_pages >= (((u64)-1LL) >> EFI_PAGE_SHIFT)) {
-+		pr_err("memmap from %p to %p is unreasonable.  Not mapping it.\n",
-+		       (void *)pa, (void *)(pa+size));
-+		WARN_ON(1);
-+		return;
-+	}
-+
-+	if (efi_enabled(EFI_OLD_MEMMAP)) {
-+		old_map_region(md);
-+		return;
-+	}
- 
- 	/*
- 	 * Make sure the 1:1 mappings are present as a catch-all for b0rked
--- 
-2.9.3
-
diff --git a/0003-efi-efi_memmap_insert-don-t-insert-a-region-more-tha.patch b/0003-efi-efi_memmap_insert-don-t-insert-a-region-more-tha.patch
deleted file mode 100644
index aceeb1d0c..000000000
--- a/0003-efi-efi_memmap_insert-don-t-insert-a-region-more-tha.patch
+++ /dev/null
@@ -1,114 +0,0 @@
-From f6e5aedc786ca2360a9b2aaa2fc31769a9c182d0 Mon Sep 17 00:00:00 2001
-From: Peter Jones <pjones@redhat.com>
-Date: Wed, 7 Dec 2016 14:41:25 -0500
-Subject: [PATCH 3/4] efi: efi_memmap_insert(): don't insert a region more than
- once
-
-Some machines, such as the Lenovo ThinkPad W541 with firmware GNET80WW
-(2.28), include memory map entries with phys_addr=0x0 and num_pages=0.
-
-When this is true on a machine with an ESRT config table,
-efi_esrt_init() will try to reserve that table with efi_mem_reserve().
-When it does, efi_arch_mem_reserve() will use efi_mem_desc_lookup() to
-find the memory map in question, call efi_memmap_split_count() to
-determine how many regions it will be split into, allocates new ram for
-the map, and calls efi_memmap_insert() to add the entry.
-
-efi_memmap_insert() iterates across all regions in the old map, and for
-each region, it tests whether the address for the new map is within that
-region.  Unfortunately we'll try to insert the new map in *each* of
-these entries, causing even more duplicate entries.  But
-efi_memmap_split_count() only returned the split count for the first
-entry, because it was called with the result of efi_mem_desc_lookup(),
-which only returns the first entry it came across.  As a result, this
-will overflow the memory map's allocation and eventually panic.
-
-Unfortunately the method of computing the size does not handle the
-0xffffffffffffffff or 0x0 edge cases well, and all valid addresses wind
-up being covered by any such entry.  Even if the math weren't off by 1
-byte in the num_pages=0 case, a duplicate entry in the table, or an
-entry with num_pages of ((u64)-1LL >> EFI_PAGE_SHIFT) or (u64)-1LL (i.e.
-either the maximum number of virtually addressable pages or just the
-largest value you can stuff in the field) would have the same effect.
-
-In any case, if we see more than one memory map in efi_memmap_insert()
-that covers the same region, it is an error to try to split up more than
-one of them, overflowing the allocation.  So this makes it never try to
-split more than one region per invocation of efi_arch_mem_reserve().
-
-I have not attempted to address the math error.
-
-Signed-off-by: Peter Jones <pjones@redhat.com>
----
- drivers/firmware/efi/memmap.c | 29 ++++++++++++++++++++++++++++-
- 1 file changed, 28 insertions(+), 1 deletion(-)
-
-diff --git a/drivers/firmware/efi/memmap.c b/drivers/firmware/efi/memmap.c
-index f03ddec..5b71c717 100644
---- a/drivers/firmware/efi/memmap.c
-+++ b/drivers/firmware/efi/memmap.c
-@@ -219,6 +219,7 @@ void __init efi_memmap_insert(struct efi_memory_map *old_memmap, void *buf,
- 	efi_memory_desc_t *md;
- 	u64 start, end;
- 	void *old, *new;
-+	bool did_split=false;
- 
- 	/* modifying range */
- 	m_start = mem->range.start;
-@@ -251,6 +252,15 @@ void __init efi_memmap_insert(struct efi_memory_map *old_memmap, void *buf,
- 
- 		if (m_start <= start &&
- 		    (start < m_end && m_end < end)) {
-+			if (did_split) {
-+				pr_warn_once("%s: memory map for 0x%llx pages at 0x%016llx also covers address 0x%016llx.  Not splitting.\n",
-+					     __func__,
-+					     md->num_pages, md->phys_addr,
-+					     m_start);
-+				continue;
-+			}
-+
-+			did_split = true;
- 			/* first part */
- 			md->attribute |= m_attr;
- 			md->num_pages = (m_end - md->phys_addr + 1) >>
-@@ -265,9 +275,18 @@ void __init efi_memmap_insert(struct efi_memory_map *old_memmap, void *buf,
- 		}
- 
- 		if ((start < m_start && m_start < end) && m_end < end) {
-+			if (did_split) {
-+				pr_warn_once("%s: memory map for 0x%llx pages at 0x%016llx also covers address 0x%016llx.  Not splitting.\n",
-+					     __func__,
-+					     md->num_pages, md->phys_addr,
-+					     m_start);
-+				continue;
-+			}
-+			did_split = true;
- 			/* first part */
- 			md->num_pages = (m_start - md->phys_addr) >>
- 				EFI_PAGE_SHIFT;
-+
- 			/* middle part */
- 			new += old_memmap->desc_size;
- 			memcpy(new, old, old_memmap->desc_size);
-@@ -284,9 +303,17 @@ void __init efi_memmap_insert(struct efi_memory_map *old_memmap, void *buf,
- 			md->num_pages = (end - m_end) >>
- 				EFI_PAGE_SHIFT;
- 		}
--
-+// else
- 		if ((start < m_start && m_start < end) &&
- 		    (end <= m_end)) {
-+			if (did_split) {
-+				pr_warn_once("%s: memory map for 0x%llx pages at 0x%016llx also covers address 0x%016llx.  Not splitting.\n",
-+					     __func__,
-+					     md->num_pages, md->phys_addr,
-+					     m_start);
-+				continue;
-+			}
-+			did_split = true;
- 			/* first part */
- 			md->num_pages = (m_start - md->phys_addr) >>
- 				EFI_PAGE_SHIFT;
--- 
-2.9.3
-
diff --git a/0004-efi-efi_memmap_insert-don-t-split-regions-with-inval.patch b/0004-efi-efi_memmap_insert-don-t-split-regions-with-inval.patch
deleted file mode 100644
index a69c6108c..000000000
--- a/0004-efi-efi_memmap_insert-don-t-split-regions-with-inval.patch
+++ /dev/null
@@ -1,45 +0,0 @@
-From 1c38760731eefdbd5e9ce288009d6d19afcff004 Mon Sep 17 00:00:00 2001
-From: Peter Jones <pjones@redhat.com>
-Date: Wed, 7 Dec 2016 16:34:20 -0500
-Subject: [PATCH 4/4] efi: efi_memmap_insert(): don't split regions with
- invalid sizes.
-
-Some machines, such as the Lenovo ThinkPad W541 with firmware GNET80WW
-(2.28), include memory map entries with phys_addr=0x0 and num_pages=0.
-
-If we're inserting a new memmap and we find a map that is either 0
-pages or all of possible memory (or more!), skip it.  When a map exists
-at 0 that's 0 pages, the "end" math here winds up making *every* address
-within the range, and so it'll try to split that entry, and things go
-poorly after that.  The same would be true if num_pages were (u64)-1LL
-(all bits set) or (u64)-1LL >> EFI_PAGE_SHIFT (i.e. all bits set as a
-size in bytes, but then shifted to page size to fill the table in).
-
-Don't even try to split those entries, they're nonsense.
-
-Signed-off-by: Peter Jones <pjones@redhat.com>
----
- drivers/firmware/efi/memmap.c | 7 +++++++
- 1 file changed, 7 insertions(+)
-
-diff --git a/drivers/firmware/efi/memmap.c b/drivers/firmware/efi/memmap.c
-index 5b71c717..f8c6870 100644
---- a/drivers/firmware/efi/memmap.c
-+++ b/drivers/firmware/efi/memmap.c
-@@ -244,6 +244,13 @@ void __init efi_memmap_insert(struct efi_memory_map *old_memmap, void *buf,
- 		/* copy original EFI memory descriptor */
- 		memcpy(new, old, old_memmap->desc_size);
- 		md = new;
-+		if (md->num_pages == 0 ||
-+		    md->num_pages >= (((u64)-1LL) >> EFI_PAGE_SHIFT)) {
-+			pr_warn("%s: Skipping absurd memory map entry for 0x%llx pages at 0x%016llx.\n",
-+				__func__, md->num_pages, md->phys_addr);
-+			continue;
-+		}
-+
- 		start = md->phys_addr;
- 		end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1;
- 
--- 
-2.9.3
-
diff --git a/kernel.spec b/kernel.spec
index f4af092f2..72d07643d 100644
--- a/kernel.spec
+++ b/kernel.spec
@@ -620,10 +620,7 @@ Patch665: netfilter-x_tables-deal-with-bogus-nextoffset-values.patch
 Patch849: 0001-iio-Use-event-header-from-kernel-tree.patch
 
 # Work around thinkpad firmware memory layout issues and efi_mem_reserve()
-Patch850: 0001-efi-efi_print_memmap-Call-out-invalid-entries-in-the.patch
-Patch851: 0002-efi-efi_map_region-traceback-if-we-try-to-map-invali.patch
-Patch852: 0003-efi-efi_memmap_insert-don-t-insert-a-region-more-tha.patch
-Patch853: 0004-efi-efi_memmap_insert-don-t-split-regions-with-inval.patch
+Patch850: 0001-efi-prune-invalid-memory-map-entries.patch
 
 # END OF PATCH DEFINITIONS