[PATCH] build_mem_phdrs(): check if p_paddr is invalid

[Pratyush Anand]

Currently, all the p_paddr of PT_LOAD headers are assigned to 0, which
is not correct and could be misleading, since 0 is a valid physical
address.

Upstream kernel commit "464920104bf7 /proc/kcore: update physical
address for kcore ram and text" fixed it and now invalid PT_LOAD is
assigned as -1.

kexec/arch/i386/crashdump-x86.c:get_kernel_vaddr_and_size() uses kcore
interface and so calls build_mem_phdrs() for kcore PT_LOAD headers.

This patch fixes build_mem_phdrs() to check if p_paddr is invalid.

Signed-off-by: Pratyush Anand <panand at redhat.com>
---
 kexec/kexec-elf.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kexec/kexec-elf.c b/kexec/kexec-elf.c
index 1d6320a2f0e6..be60bbd48486 100644
--- a/kexec/kexec-elf.c
+++ b/kexec/kexec-elf.c
@@ -432,7 +432,8 @@ static int build_mem_phdrs(const char *buf, off_t len, struct mem_ehdr *ehdr,
 			}
 			return -1;
 		}
-		if ((phdr->p_paddr + phdr->p_memsz) < phdr->p_paddr) {
+		if (phdr->p_paddr != (unsigned long long)-1 &&
+			(phdr->p_paddr + phdr->p_memsz) < phdr->p_paddr) {
 			/* The memory address wraps */
 			if (probe_debug) {
 				fprintf(stderr, "ELF address wrap around\n");
-- 
2.9.3