soc: qcom: minidump: move elf global variables to structure

Current driver implementation uses global variables to create
minidump elf header.

Move all elf global variables into a structure, and also replace
'msm_minidump_enabled' API with 'minidump_enabled' global variable.
And also add minidump_table address in elf, which would be useful
for parsers to get memory dump table addresses without vmlinux symbols.

Change-Id: I8829d88ce234179f429ae9537a3582df794c2cdf
Signed-off-by: Lingutla Chandrasekhar <clingutla@codeaurora.org>

diff --git a/drivers/power/reset/msm-poweroff.c b/drivers/power/reset/msm-poweroff.c
index dc7825e..acea4f2 100644 (file)
--- a/drivers/power/reset/msm-poweroff.c
+++ b/drivers/power/reset/msm-poweroff.c
@@ -497,7 +497,7 @@ static size_t store_dload_mode(struct kobject *kobj, struct attribute *attr,
        if (sysfs_streq(buf, "full")) {
                dload_type = SCM_DLOAD_FULLDUMP;
        } else if (sysfs_streq(buf, "mini")) {
-               if (!msm_minidump_enabled()) {
+               if (!minidump_enabled) {
                        pr_err("Minidump is not enabled\n");
                        return -ENODEV;
                }

diff --git a/drivers/soc/qcom/msm_minidump.c b/drivers/soc/qcom/msm_minidump.c
index d8f2f15..3002330 100644 (file)
--- a/drivers/soc/qcom/msm_minidump.c
+++ b/drivers/soc/qcom/msm_minidump.c
@@ -62,24 +62,31 @@ struct md_table {
        struct md_region        entry[MAX_NUM_ENTRIES];
 };
 
+/*
+ * md_elfhdr: Minidump table elf header
+ * @md_ehdr: elf main header
+ * @shdr: Section header
+ * @phdr: Program header
+ * @elf_offset: section offset in elf
+ * @strtable_idx: string table current index position
+ */
+struct md_elfhdr {
+       struct elfhdr   *md_ehdr;
+       struct elf_shdr *shdr;
+       struct elf_phdr *phdr;
+       u64             elf_offset;
+       u64             strtable_idx;
+};
+
 /* Protect elfheader and smem table from deferred calls contention */
 static DEFINE_SPINLOCK(mdt_lock);
-static bool minidump_enabled;
-static struct md_table minidump_table;
+static struct md_table minidump_table;
+static struct md_elfhdr        minidump_elfheader;
+
+bool minidump_enabled;
 static unsigned int pendings;
 static unsigned int region_idx = 1; /* First entry is ELF header*/
 
-/* ELF Header */
-static struct elfhdr *md_ehdr;
-/* ELF Program header */
-static struct elf_phdr *phdr;
-/* ELF Section header */
-static struct elf_shdr *shdr;
-/* Section offset in elf image */
-static u64 elf_offset;
-/* String table index, first byte must be '\0' */
-static unsigned int stringtable_idx = 1;
-
 static inline struct elf_shdr *elf_sheader(struct elfhdr *hdr)
 {
        return (struct elf_shdr *)((size_t)hdr + (size_t)hdr->e_shoff);
@@ -90,6 +97,16 @@ static inline struct elf_shdr *elf_section(struct elfhdr *hdr, int idx)
        return &elf_sheader(hdr)[idx];
 }
 
+static inline struct elf_phdr *elf_pheader(struct elfhdr *hdr)
+{
+       return (struct elf_phdr *)((size_t)hdr + (size_t)hdr->e_phoff);
+}
+
+static inline struct elf_phdr *elf_program(struct elfhdr *hdr, int idx)
+{
+       return &elf_pheader(hdr)[idx];
+}
+
 static inline char *elf_str_table(struct elfhdr *hdr)
 {
        if (hdr->e_shstrndx == SHN_UNDEF)
@@ -101,23 +118,24 @@ static inline char *elf_lookup_string(struct elfhdr *hdr, int offset)
 {
        char *strtab = elf_str_table(hdr);
 
-       if ((strtab == NULL) || (stringtable_idx < offset))
+       if ((strtab == NULL) || (minidump_elfheader.strtable_idx < offset))
                return NULL;
        return strtab + offset;
 }
 
 static inline unsigned int set_section_name(const char *name)
 {
-       char *strtab = elf_str_table(md_ehdr);
+       char *strtab = elf_str_table(minidump_elfheader.md_ehdr);
+       int idx = minidump_elfheader.strtable_idx;
        int ret = 0;
 
        if ((strtab == NULL) || (name == NULL))
                return 0;
 
-       ret = stringtable_idx;
-       stringtable_idx += strlcpy((strtab + stringtable_idx),
-                               name, MAX_NAME_LENGTH);
-       stringtable_idx += 1;
+       ret = idx;
+       idx += strlcpy((strtab + idx), name, MAX_NAME_LENGTH);
+       minidump_elfheader.strtable_idx = idx + 1;
+
        return ret;
 }
 
@@ -137,11 +155,9 @@ static inline bool md_check_name(const char *name)
 static int md_update_smem_table(const struct md_region *entry)
 {
        struct md_smem_region *mdr;
-
-       if (!minidump_enabled) {
-               pr_err("Table in smem is not setup\n");
-               return -ENODEV;
-       }
+       struct elfhdr *hdr = minidump_elfheader.md_ehdr;
+       struct elf_shdr *shdr = elf_section(hdr, hdr->e_shnum++);
+       struct elf_phdr *phdr = elf_program(hdr, hdr->e_phnum++);
 
        mdr = &minidump_table.region[region_idx++];
 
@@ -155,36 +171,21 @@ static int md_update_smem_table(const struct md_region *entry)
        shdr->sh_addr = (elf_addr_t)entry->virt_addr;
        shdr->sh_size = mdr->size;
        shdr->sh_flags = SHF_WRITE;
-       shdr->sh_offset = elf_offset;
+       shdr->sh_offset = minidump_elfheader.elf_offset;
        shdr->sh_entsize = 0;
 
        phdr->p_type = PT_LOAD;
-       phdr->p_offset = elf_offset;
+       phdr->p_offset = minidump_elfheader.elf_offset;
        phdr->p_vaddr = entry->virt_addr;
        phdr->p_paddr = entry->phys_addr;
        phdr->p_filesz = phdr->p_memsz =  mdr->size;
        phdr->p_flags = PF_R | PF_W;
 
-       md_ehdr->e_shnum += 1;
-       md_ehdr->e_phnum += 1;
-       elf_offset += shdr->sh_size;
-       shdr++;
-       phdr++;
+       minidump_elfheader.elf_offset += shdr->sh_size;
 
        return 0;
 }
 
-bool msm_minidump_enabled(void)
-{
-       bool ret;
-
-       spin_lock(&mdt_lock);
-       ret = minidump_enabled;
-       spin_unlock(&mdt_lock);
-       return ret;
-}
-EXPORT_SYMBOL(msm_minidump_enabled);
-
 int msm_minidump_add_region(const struct md_region *entry)
 {
        u32 entries;
@@ -238,23 +239,32 @@ EXPORT_SYMBOL(msm_minidump_add_region);
 static int msm_minidump_add_header(void)
 {
        struct md_smem_region *mdreg = &minidump_table.region[0];
-       char *banner;
+       struct elfhdr *md_ehdr;
+       struct elf_shdr *shdr;
+       struct elf_phdr *phdr;
        unsigned int strtbl_off, elfh_size, phdr_off;
+       char *banner;
 
+       /* Header buffer contains:
+        * elf header, MAX_NUM_ENTRIES+1 of section and program elf headers,
+        * string table section and linux banner.
+        */
        elfh_size = sizeof(*md_ehdr) + MAX_STRTBL_SIZE + MAX_MEM_LENGTH +
                ((sizeof(*shdr) + sizeof(*phdr)) * (MAX_NUM_ENTRIES + 1));
 
-       md_ehdr = kzalloc(elfh_size, GFP_KERNEL);
-       if (!md_ehdr)
+       minidump_elfheader.md_ehdr = kzalloc(elfh_size, GFP_KERNEL);
+       if (!minidump_elfheader.md_ehdr)
                return -ENOMEM;
 
        strlcpy(mdreg->name, "KELF_HEADER", sizeof(mdreg->name));
-       mdreg->address = virt_to_phys(md_ehdr);
+       mdreg->address = virt_to_phys(minidump_elfheader.md_ehdr);
        mdreg->size = elfh_size;
 
-       /* Section headers*/
-       shdr = (struct elf_shdr *)(md_ehdr + 1);
-       phdr = (struct elf_phdr *)(shdr + MAX_NUM_ENTRIES);
+       md_ehdr = minidump_elfheader.md_ehdr;
+       /* Assign section/program headers offset */
+       minidump_elfheader.shdr = shdr = (struct elf_shdr *)(md_ehdr + 1);
+       minidump_elfheader.phdr = phdr =
+                                (struct elf_phdr *)(shdr + MAX_NUM_ENTRIES);
        phdr_off = sizeof(*md_ehdr) + (sizeof(*shdr) * MAX_NUM_ENTRIES);
 
        memcpy(md_ehdr->e_ident, ELFMAG, SELFMAG);
@@ -268,18 +278,19 @@ static int msm_minidump_add_header(void)
        md_ehdr->e_ehsize = sizeof(*md_ehdr);
        md_ehdr->e_phoff = phdr_off;
        md_ehdr->e_phentsize = sizeof(*phdr);
-       md_ehdr->e_phnum = 1;
        md_ehdr->e_shoff = sizeof(*md_ehdr);
        md_ehdr->e_shentsize = sizeof(*shdr);
-       md_ehdr->e_shnum = 3;    /* NULL, STR TABLE, Linux banner */
        md_ehdr->e_shstrndx = 1;
 
-       elf_offset = elfh_size;
+       minidump_elfheader.elf_offset = elfh_size;
+
+       /*
+        * First section header should be NULL,
+        * 2nd section is string table.
+        */
+       minidump_elfheader.strtable_idx = 1;
        strtbl_off = sizeof(*md_ehdr) +
                        ((sizeof(*phdr) + sizeof(*shdr)) * MAX_NUM_ENTRIES);
-       /* First section header should be NULL
-        * 2nd entry for string table
-        */
        shdr++;
        shdr->sh_type = SHT_STRTAB;
        shdr->sh_offset = (elf_addr_t)strtbl_off;
@@ -289,7 +300,15 @@ static int msm_minidump_add_header(void)
        shdr->sh_name = set_section_name("STR_TBL");
        shdr++;
 
-       /* 3rd entry for linux banner */
+       /* 3rd section is for minidump_table VA, used by parsers */
+       shdr->sh_type = SHT_PROGBITS;
+       shdr->sh_entsize = 0;
+       shdr->sh_flags = 0;
+       shdr->sh_addr = (elf_addr_t)&minidump_table;
+       shdr->sh_name = set_section_name("minidump_table");
+       shdr++;
+
+       /* 4th section is linux banner */
        banner = (char *)md_ehdr + strtbl_off + MAX_STRTBL_SIZE;
        strlcpy(banner, linux_banner, MAX_MEM_LENGTH);
 
@@ -300,7 +319,6 @@ static int msm_minidump_add_header(void)
        shdr->sh_entsize = 0;
        shdr->sh_flags = SHF_WRITE;
        shdr->sh_name = set_section_name("linux_banner");
-       shdr++;
 
        phdr->p_type = PT_LOAD;
        phdr->p_offset = (elf_addr_t)(strtbl_off + MAX_STRTBL_SIZE);
@@ -309,8 +327,9 @@ static int msm_minidump_add_header(void)
        phdr->p_filesz = phdr->p_memsz = strlen(linux_banner) + 1;
        phdr->p_flags = PF_R | PF_W;
 
-       md_ehdr->e_phnum += 1;
-       phdr++;
+       /* Update headers count*/
+       md_ehdr->e_phnum = 1;
+       md_ehdr->e_shnum = 4;
 
        return 0;
 }

diff --git a/include/soc/qcom/minidump.h b/include/soc/qcom/minidump.h
index 9d993a1..2db61a4 100644 (file)
--- a/include/soc/qcom/minidump.h
+++ b/include/soc/qcom/minidump.h
@@ -37,7 +37,7 @@ struct md_region {
  */
 #ifdef CONFIG_QCOM_MINIDUMP
 extern int msm_minidump_add_region(const struct md_region *entry);
-extern bool msm_minidump_enabled(void);
+extern bool minidump_enabled;
 #else
 static inline int msm_minidump_add_region(const struct md_region *entry)
 {