On Fri, May 24, 2013 at 01:29:42PM +0200, Michael Holzheu wrote: > This patch now exchanges 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: Michael Holzheu <[email protected]> > --- > arch/s390/kernel/crash_dump.c | 64 > ++++++++++++++++++++++++++++++------------- > 1 file changed, 45 insertions(+), 19 deletions(-) > > diff --git a/arch/s390/kernel/crash_dump.c b/arch/s390/kernel/crash_dump.c > index f703d91..aeb1207 100644 > --- a/arch/s390/kernel/crash_dump.c > +++ b/arch/s390/kernel/crash_dump.c > @@ -21,6 +21,9 @@ > #define PTR_SUB(x, y) (((char *) (x)) - ((unsigned long) (y))) > #define PTR_DIFF(x, y) ((unsigned long)(((char *) (x)) - ((unsigned long) > (y)))) > > +static size_t elfcorebuf_sz; > +static char *elfcorebuf; > + > /* > * Copy one page from "oldmem" > * > @@ -325,14 +328,6 @@ static int get_mem_chunk_cnt(void) > } > > /* > - * 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) > */ > static int loads_init(Elf64_Phdr *phdr, u64 loads_offset) > @@ -383,7 +378,7 @@ static void *notes_init(Elf64_Phdr *phdr, void *ptr, u64 > notes_offset) > ptr = nt_vmcoreinfo(ptr); > memset(phdr, 0, sizeof(*phdr)); > 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_memsz = phdr->p_filesz; > return ptr; > @@ -392,7 +387,7 @@ static void *notes_init(Elf64_Phdr *phdr, void *ptr, u64 > notes_offset) > /* > * Create ELF core header (new kernel) > */ > -static void s390_elf_corehdr_create(char **elfcorebuf, size_t *elfcorebuf_sz) > +static int s390_elf_corehdr_create(char **elfcorebuf, size_t *elfcorebuf_sz) > { > Elf64_Phdr *phdr_notes, *phdr_loads; > int mem_chunk_cnt; > @@ -414,28 +409,59 @@ static void s390_elf_corehdr_create(char **elfcorebuf, > size_t *elfcorebuf_sz) > ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr) * mem_chunk_cnt); > /* Init notes */ > hdr_off = PTR_DIFF(ptr, hdr); > - ptr = notes_init(phdr_notes, ptr, ((unsigned long) hdr) + hdr_off); > + ptr = notes_init(phdr_notes, ptr, (unsigned long) hdr + hdr_off); > /* Init loads */ > 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; > - *elfcorebuf = (void *) relocate((unsigned long) hdr); > + *elfcorebuf = hdr; > BUG_ON(*elfcorebuf_sz > alloc_size); > + return 0; > } > > /* > - * Create kdump ELF core header in new kernel, if it has not been passed via > - * the "elfcorehdr" kernel parameter > + * Return address of ELF core header (new or old memory) > */ > -static int setup_kdump_elfcorehdr(void) > +unsigned long long arch_get_crash_header(void) > { > - size_t elfcorebuf_sz; > - char *elfcorebuf; > + if (elfcorebuf) > + return elfcorehdr_addr; > + else > + return __pa(elfcorebuf); > +} > > +/* > + * Free crash header > + */ > +void arch_free_crash_header(void) > +{ > + kfree(elfcorebuf); > + elfcorebuf = 0; > +} > + > +/* > + * Read from crash header (new or old memory) > + */ > +ssize_t arch_read_from_crash_header(char *buf, size_t count, u64 *ppos) > +{ > + if (elfcorebuf) > + memcpy(buf, (void *)*ppos, count);
This is ugly. It assumes that generic code will always free headers before reading any PT_LOAD data. It can be easily broken. Why arch_read_from_crash_header() should not always read new memory for s390? Vivek -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
