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* [PATCH v1 1/2] efi/capsule: Add 'capsule' lookup support
@ 2017-02-28 17:45 Qiuxu Zhuo
       [not found] ` <20170228174528.23542-1-qiuxu.zhuo-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
  0 siblings, 1 reply; 3+ messages in thread
From: Qiuxu Zhuo @ 2017-02-28 17:45 UTC (permalink / raw)
  To: matt-mF/unelCI9GS6iBeEJttW/XRex20P6io,
	ard.biesheuvel-QSEj5FYQhm4dnm+yROfE0A
  Cc: linux-efi-u79uwXL29TY76Z2rM5mHXA,
	tony.luck-ral2JQCrhuEAvxtiuMwx3w, Qiuxu Zhuo, Matt Fleming

Add the interface to get the array of EFI capsules when
parsing the configuration tables.

This code is based on Matt Fleming previous work from:
https://git.kernel.org/cgit/linux/kernel/git/mfleming/efi.git/commit/?h=capsule-pstore&id=99c5f047133555aa0442f64064e85b7da2d4a45f

Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Matt Fleming <matt.fleming-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
 drivers/firmware/efi/capsule.c | 107 +++++++++++++++++++++++++++++++++++++++++
 drivers/firmware/efi/efi.c     |   4 ++
 include/linux/efi.h            |   4 ++
 3 files changed, 115 insertions(+)

diff --git a/drivers/firmware/efi/capsule.c b/drivers/firmware/efi/capsule.c
index 6eedff4..51e1a43 100644
--- a/drivers/firmware/efi/capsule.c
+++ b/drivers/firmware/efi/capsule.c
@@ -24,6 +24,11 @@ typedef struct {
 static bool capsule_pending;
 static bool stop_capsules;
 static int efi_reset_type = -1;
+/*
+ * Information about capsules we pulled from the EFI System Table.
+ */
+static efi_capsule_header_t **prev_capsules;
+static u32 efi_capsule_num;
 
 /*
  * capsule_mutex serialises access to both capsule_pending and
@@ -288,6 +293,108 @@ int efi_capsule_update(efi_capsule_header_t *capsule, struct page **pages)
 }
 EXPORT_SYMBOL_GPL(efi_capsule_update);
 
+static int extract_capsules(void)
+{
+	void *capsule;
+	size_t size;
+
+	if (efi.capsule == EFI_INVALID_TABLE_ADDR)
+		return 0;
+
+	capsule = ioremap(efi.capsule, sizeof(efi_capsule_num));
+	if (!capsule)
+		return -ENOMEM;
+
+	/*
+	 * The array of capsules is prefixed with the number of
+	 * capsule entries in the array.
+	 */
+	efi_capsule_num = *(uint32_t *)capsule;
+	iounmap(capsule);
+
+	if (!efi_capsule_num) {
+		pr_info("No capsules on extraction\n");
+		return 0;
+	}
+
+	size = efi_capsule_num * sizeof(*capsule);
+	capsule = ioremap(efi.capsule, size);
+	if (!capsule)
+		return -ENOMEM;
+
+	capsule += sizeof(uint32_t);
+	prev_capsules = (efi_capsule_header_t **)capsule;
+	if (!*prev_capsules)
+		pr_err("Capsule array has no entries\n");
+
+	return 0;
+}
+
+/**
+ * efi_capsule_lookup - search capsule array for entries.
+ * @guid: the guid to search for.
+ * @nr_caps: the number of entries found.
+ *
+ * Map each capsule header into the kernel's virtual address space and
+ * inspect the guid. Build an array of capsule headers with every
+ * capsule that is found with @guid. If a match is found the capsule
+ * remains mapped, otherwise it is unmapped.
+ *
+ * Returns an array of capsule headers, each element of which has the
+ * guid @guid. The number of elements in the array is stored in
+ * @nr_caps. Returns %NULL if no capsules were found and stores zero
+ * in @nr_caps.
+ */
+efi_capsule_header_t **efi_capsule_lookup(efi_guid_t guid, uint32_t *nr_caps)
+{
+	efi_capsule_header_t **capsules = NULL, **tmp;
+	size_t capsule_size = 0;
+	int i, rv;
+
+	rv = extract_capsules();
+	if (rv)
+		return ERR_PTR(rv);
+
+	*nr_caps = 0;
+	for (i = 0; i < efi_capsule_num; i++) {
+		efi_capsule_header_t *c;
+		size_t size;
+
+		c = ioremap((resource_size_t)prev_capsules[i], sizeof(*c));
+		if (!c) {
+			pr_err("Failed to ioremap capsule\n");
+			continue;
+		}
+
+		size = c->imagesize;
+		iounmap(c);
+
+		c = ioremap((resource_size_t)prev_capsules[i], size);
+		if (!c) {
+			pr_err("Failed to ioremap header + data\n");
+			continue;
+		}
+
+		if (!efi_guidcmp(c->guid, guid)) {
+			capsule_size += sizeof(*capsules);
+			tmp = krealloc(capsules, capsule_size, GFP_KERNEL);
+			if (!tmp) {
+				kfree(capsules);
+				return ERR_PTR(-ENOMEM);
+			}
+
+			capsules = tmp;
+			capsules[(*nr_caps)++] = c;
+			continue;
+		}
+
+		iounmap(c);
+	}
+
+	return capsules;
+}
+EXPORT_SYMBOL_GPL(efi_capsule_lookup);
+
 static int capsule_reboot_notify(struct notifier_block *nb, unsigned long event, void *cmd)
 {
 	mutex_lock(&capsule_mutex);
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 9291480..03be9b8 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -52,6 +52,7 @@ struct efi __read_mostly efi = {
 	.properties_table	= EFI_INVALID_TABLE_ADDR,
 	.mem_attr_table		= EFI_INVALID_TABLE_ADDR,
 	.rng_seed		= EFI_INVALID_TABLE_ADDR,
+	.capsule		= EFI_INVALID_TABLE_ADDR,
 };
 EXPORT_SYMBOL(efi);
 
@@ -120,6 +121,8 @@ static ssize_t systab_show(struct kobject *kobj,
 		str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info);
 	if (efi.uga != EFI_INVALID_TABLE_ADDR)
 		str += sprintf(str, "UGA=0x%lx\n", efi.uga);
+	if (efi.capsule != EFI_INVALID_TABLE_ADDR)
+		str += sprintf(str, "CAPSULE=0x%lx\n", efi.capsule);
 
 	return str - buf;
 }
@@ -445,6 +448,7 @@ static __initdata efi_config_table_type_t common_tables[] = {
 	{EFI_PROPERTIES_TABLE_GUID, "PROP", &efi.properties_table},
 	{EFI_MEMORY_ATTRIBUTES_TABLE_GUID, "MEMATTR", &efi.mem_attr_table},
 	{LINUX_EFI_RANDOM_SEED_TABLE_GUID, "RNG", &efi.rng_seed},
+	{LINUX_EFI_CRASH_GUID, "CAPSULE", &efi.capsule},
 	{NULL_GUID, NULL, NULL},
 };
 
diff --git a/include/linux/efi.h b/include/linux/efi.h
index 5b1af30..3296724e 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -893,6 +893,7 @@ extern struct efi {
 	unsigned long properties_table;	/* properties table */
 	unsigned long mem_attr_table;	/* memory attributes table */
 	unsigned long rng_seed;		/* UEFI firmware random seed */
+	unsigned long capsule;		/* EFI capsule table */
 	efi_get_time_t *get_time;
 	efi_set_time_t *set_time;
 	efi_get_wakeup_time_t *get_wakeup_time;
@@ -1401,6 +1402,9 @@ extern int efi_capsule_supported(efi_guid_t guid, u32 flags,
 extern int efi_capsule_update(efi_capsule_header_t *capsule,
 			      struct page **pages);
 
+extern efi_capsule_header_t **efi_capsule_lookup(efi_guid_t guid,
+			      uint32_t *nr_caps);
+
 #ifdef CONFIG_EFI_RUNTIME_MAP
 int efi_runtime_map_init(struct kobject *);
 int efi_get_runtime_map_size(void);
-- 
2.9.0.GIT

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2017-02-28 17:45 [PATCH v1 1/2] efi/capsule: Add 'capsule' lookup support Qiuxu Zhuo
     [not found] ` <20170228174528.23542-1-qiuxu.zhuo-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
2017-03-01 20:44   ` Ard Biesheuvel
2017-03-01 20:46   ` Matt Fleming

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