于 2013年05月15日 17:05, HATAYAMA Daisuke 写道: > Treat memory chunks referenced by PT_LOAD program header entries in > page-size boundary in vmcore_list. Formally, for each range [start, > end], we set up the corresponding vmcore object in vmcore_list to > [rounddown(start, PAGE_SIZE), roundup(end, PAGE_SIZE)]. > > This change affects layout of /proc/vmcore. The gaps generated by the > rearrangement are newly made visible to applications as > holes. Concretely, they are two ranges [rounddown(start, PAGE_SIZE), > start] and [end, roundup(end, PAGE_SIZE)]. > > Suppose variable m points at a vmcore object in vmcore_list, and > variable phdr points at the program header of PT_LOAD type the > variable m corresponds to. Then, pictorially: > > m->offset +---------------+ > | hole | > phdr->p_offset = +---------------+ > m->offset + (paddr - start) | |\ > | kernel memory | phdr->p_memsz > | |/ > +---------------+ > | hole | > m->offset + m->size +---------------+ > > where m->offset and m->offset + m->size are always page-size aligned. > > Signed-off-by: HATAYAMA Daisuke <[email protected]> > Acked-by: Vivek Goyal <[email protected]> > ---
Acked-by: Zhang Yanfei <[email protected]> > > fs/proc/vmcore.c | 30 ++++++++++++++++++++++-------- > 1 files changed, 22 insertions(+), 8 deletions(-) > > diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c > index 48886e6..6cf7fbd 100644 > --- a/fs/proc/vmcore.c > +++ b/fs/proc/vmcore.c > @@ -406,20 +406,27 @@ static int __init > process_ptload_program_headers_elf64(char *elfptr, > vmcore_off = elfsz + roundup(phdr_ptr->p_memsz, PAGE_SIZE); > > for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { > + u64 paddr, start, end, size; > + > if (phdr_ptr->p_type != PT_LOAD) > continue; > > + paddr = phdr_ptr->p_offset; > + start = rounddown(paddr, PAGE_SIZE); > + end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE); > + size = end - start; > + > /* Add this contiguous chunk of memory to vmcore list.*/ > new = get_new_element(); > if (!new) > return -ENOMEM; > - new->paddr = phdr_ptr->p_offset; > - new->size = phdr_ptr->p_memsz; > + new->paddr = start; > + new->size = size; > list_add_tail(&new->list, vc_list); > > /* Update the program header offset. */ > - phdr_ptr->p_offset = vmcore_off; > - vmcore_off = vmcore_off + phdr_ptr->p_memsz; > + phdr_ptr->p_offset = vmcore_off + (paddr - start); > + vmcore_off = vmcore_off + size; > } > return 0; > } > @@ -441,20 +448,27 @@ static int __init > process_ptload_program_headers_elf32(char *elfptr, > vmcore_off = elfsz + roundup(phdr_ptr->p_memsz, PAGE_SIZE); > > for (i = 0; i < ehdr_ptr->e_phnum; i++, phdr_ptr++) { > + u64 paddr, start, end, size; > + > if (phdr_ptr->p_type != PT_LOAD) > continue; > > + paddr = phdr_ptr->p_offset; > + start = rounddown(paddr, PAGE_SIZE); > + end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE); > + size = end - start; > + > /* Add this contiguous chunk of memory to vmcore list.*/ > new = get_new_element(); > if (!new) > return -ENOMEM; > - new->paddr = phdr_ptr->p_offset; > - new->size = phdr_ptr->p_memsz; > + new->paddr = start; > + new->size = size; > list_add_tail(&new->list, vc_list); > > /* Update the program header offset */ > - phdr_ptr->p_offset = vmcore_off; > - vmcore_off = vmcore_off + phdr_ptr->p_memsz; > + phdr_ptr->p_offset = vmcore_off + (paddr - start); > + vmcore_off = vmcore_off + size; > } > return 0; > } > > -- 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/
