Commit 97b0f6f9 authored by Michael Holzheu's avatar Michael Holzheu Committed by Linus Torvalds

s390/vmcore: use ELF header in new memory feature

Exchange the old relocate mechanism with the new arch function call
override mechanism that allows to create the ELF core header in the 2nd
kernel.
Signed-off-by: default avatarMichael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Jan Willeke <willeke@de.ibm.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent be8a8d06
...@@ -63,6 +63,11 @@ static ssize_t copy_page_real(void *buf, void *src, size_t csize) ...@@ -63,6 +63,11 @@ static ssize_t copy_page_real(void *buf, void *src, size_t csize)
} }
} }
/*
* Pointer to ELF header in new kernel
*/
static void *elfcorehdr_newmem;
/* /*
* Copy one page from "oldmem" * Copy one page from "oldmem"
* *
...@@ -367,14 +372,6 @@ static int get_mem_chunk_cnt(void) ...@@ -367,14 +372,6 @@ static int get_mem_chunk_cnt(void)
return cnt; return cnt;
} }
/*
* Relocate pointer in order to allow vmcore code access the data
*/
static inline unsigned long relocate(unsigned long addr)
{
return OLDMEM_BASE + addr;
}
/* /*
* Initialize ELF loads (new kernel) * Initialize ELF loads (new kernel)
*/ */
...@@ -426,7 +423,7 @@ static void *notes_init(Elf64_Phdr *phdr, void *ptr, u64 notes_offset) ...@@ -426,7 +423,7 @@ static void *notes_init(Elf64_Phdr *phdr, void *ptr, u64 notes_offset)
ptr = nt_vmcoreinfo(ptr); ptr = nt_vmcoreinfo(ptr);
memset(phdr, 0, sizeof(*phdr)); memset(phdr, 0, sizeof(*phdr));
phdr->p_type = PT_NOTE; phdr->p_type = PT_NOTE;
phdr->p_offset = relocate(notes_offset); phdr->p_offset = notes_offset;
phdr->p_filesz = (unsigned long) PTR_SUB(ptr, ptr_start); phdr->p_filesz = (unsigned long) PTR_SUB(ptr, ptr_start);
phdr->p_memsz = phdr->p_filesz; phdr->p_memsz = phdr->p_filesz;
return ptr; return ptr;
...@@ -435,7 +432,7 @@ static void *notes_init(Elf64_Phdr *phdr, void *ptr, u64 notes_offset) ...@@ -435,7 +432,7 @@ static void *notes_init(Elf64_Phdr *phdr, void *ptr, u64 notes_offset)
/* /*
* Create ELF core header (new kernel) * Create ELF core header (new kernel)
*/ */
static void s390_elf_corehdr_create(char **elfcorebuf, size_t *elfcorebuf_sz) int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size)
{ {
Elf64_Phdr *phdr_notes, *phdr_loads; Elf64_Phdr *phdr_notes, *phdr_loads;
int mem_chunk_cnt; int mem_chunk_cnt;
...@@ -443,6 +440,11 @@ static void s390_elf_corehdr_create(char **elfcorebuf, size_t *elfcorebuf_sz) ...@@ -443,6 +440,11 @@ static void s390_elf_corehdr_create(char **elfcorebuf, size_t *elfcorebuf_sz)
u32 alloc_size; u32 alloc_size;
u64 hdr_off; u64 hdr_off;
if (!OLDMEM_BASE)
return 0;
/* If elfcorehdr= has been passed via cmdline, we use that one */
if (elfcorehdr_addr != ELFCORE_ADDR_MAX)
return 0;
mem_chunk_cnt = get_mem_chunk_cnt(); mem_chunk_cnt = get_mem_chunk_cnt();
alloc_size = 0x1000 + get_cpu_cnt() * 0x300 + alloc_size = 0x1000 + get_cpu_cnt() * 0x300 +
...@@ -460,27 +462,52 @@ static void s390_elf_corehdr_create(char **elfcorebuf, size_t *elfcorebuf_sz) ...@@ -460,27 +462,52 @@ static void s390_elf_corehdr_create(char **elfcorebuf, size_t *elfcorebuf_sz)
ptr = notes_init(phdr_notes, ptr, ((unsigned long) hdr) + hdr_off); ptr = notes_init(phdr_notes, ptr, ((unsigned long) hdr) + hdr_off);
/* Init loads */ /* Init loads */
hdr_off = PTR_DIFF(ptr, hdr); hdr_off = PTR_DIFF(ptr, hdr);
loads_init(phdr_loads, ((unsigned long) hdr) + hdr_off); loads_init(phdr_loads, hdr_off);
*elfcorebuf_sz = hdr_off; *addr = (unsigned long long) hdr;
*elfcorebuf = (void *) relocate((unsigned long) hdr); elfcorehdr_newmem = hdr;
BUG_ON(*elfcorebuf_sz > alloc_size); *size = (unsigned long long) hdr_off;
BUG_ON(elfcorehdr_size > alloc_size);
return 0;
} }
/* /*
* Create kdump ELF core header in new kernel, if it has not been passed via * Free ELF core header (new kernel)
* the "elfcorehdr" kernel parameter
*/ */
static int setup_kdump_elfcorehdr(void) void elfcorehdr_free(unsigned long long addr)
{ {
size_t elfcorebuf_sz; if (!elfcorehdr_newmem)
char *elfcorebuf; return;
kfree((void *)(unsigned long)addr);
if (!OLDMEM_BASE || is_kdump_kernel()) }
return -EINVAL;
s390_elf_corehdr_create(&elfcorebuf, &elfcorebuf_sz); /*
elfcorehdr_addr = (unsigned long long) elfcorebuf; * Read from ELF header
elfcorehdr_size = elfcorebuf_sz; */
return 0; ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos)
{
void *src = (void *)(unsigned long)*ppos;
src = elfcorehdr_newmem ? src : src - OLDMEM_BASE;
memcpy(buf, src, count);
*ppos += count;
return count;
} }
subsys_initcall(setup_kdump_elfcorehdr); /*
* Read from ELF notes data
*/
ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos)
{
void *src = (void *)(unsigned long)*ppos;
int rc;
if (elfcorehdr_newmem) {
memcpy(buf, src, count);
} else {
rc = copy_from_oldmem(buf, src, count);
if (rc)
return rc;
}
*ppos += count;
return count;
}
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