Hi Pratyush On 01/25/17 at 10:14am, Pratyush Anand wrote: > Currently all the p_paddr of PT_LOAD headers are assigned to 0, which is > not true and could be misleading, since 0 is a valid physical address. I do not know the history of /proc/kcore, so a question is why the p_addr was set as 0, if there were some reasons and if this could cause some risk or breakage. > > User space tools like makedumpfile needs to know physical address for > PT_LOAD segments of direct mapped regions. Therefore this patch updates > paddr for such regions. It also sets an invalid paddr (-1) for other > regions, so that user space tool can know whether a physical address > provided in PT_LOAD is correct or not. > > Signed-off-by: Pratyush Anand <panand at redhat.com> > --- > fs/proc/kcore.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c > index 0b80ad87b4d6..ea9f3d1ae830 100644 > --- a/fs/proc/kcore.c > +++ b/fs/proc/kcore.c > @@ -373,7 +373,10 @@ static void elf_kcore_store_hdr(char *bufp, int nphdr, int dataoff) > phdr->p_flags = PF_R|PF_W|PF_X; > phdr->p_offset = kc_vaddr_to_offset(m->addr) + dataoff; > phdr->p_vaddr = (size_t)m->addr; > - phdr->p_paddr = 0; > + if (m->type == KCORE_RAM || m->type == KCORE_TEXT) > + phdr->p_paddr = __pa(m->addr); > + else > + phdr->p_paddr = (elf_addr_t)-1; > phdr->p_filesz = phdr->p_memsz = m->size; > phdr->p_align = PAGE_SIZE; > } > -- > 2.9.3 > Thanks Dave
