[PATCH 1/2] Fix AT_EXECFN auxv for no-MMU fdpic

[PATCH 1/2] Fix AT_EXECFN auxv for no-MMU fdpic

[Mark Salter]

In the no-MMU case, the FDPIC loader was passing an offset as the value for
the AT_EXECFN auxv. This patch translates that offset into an actual user
address.

Signed-off-by: Mark Salter <msalter@redhat.com>
---
 fs/binfmt_elf_fdpic.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
index cb240dd..af4c9a4 100644
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -496,6 +496,7 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
 	sp = arch_align_stack(bprm->p);
 #else
 	sp = mm->start_stack;
+	bprm->exec = sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->exec);
 
 	/* stack the program arguments and environment */
 	if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)
-- 
1.8.1.2

[PATCH 2/2] Fix /proc/<pid>/auxv for FDPIC binaries

[Mark Salter]

The FDPIC loader is not storing aux vector info in mm->saved_aux so the aux vectors were
not being exposed through /proc/<pid>/auxv. This patch copies the aux vectors stored on
the user stack into mm->saved_aux so that they may be available through procfs.

Signed-off-by: Mark Salter <msalter@redhat.com>
---
 fs/binfmt_elf_fdpic.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
index af4c9a4..9651918 100644
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -478,7 +478,7 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
 				   struct elf_fdpic_params *interp_params)
 {
 	const struct cred *cred = current_cred();
-	unsigned long sp, csp, nitems;
+	unsigned long sp, csp, nitems, auxv_end;
 	elf_caddr_t __user *argv, *envp;
 	size_t platform_len = 0, len;
 	char *k_platform, *k_base_platform;
@@ -594,6 +594,7 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
 	} while (0)
 
 	nr = 0;
+	auxv_end = csp;
 	csp -= 2 * sizeof(unsigned long);
 	NEW_AUX_ENT(AT_NULL, 0);
 	if (k_platform) {
@@ -645,6 +646,10 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
 #endif
 #undef NEW_AUX_ENT
 
+	if (copy_from_user(current->mm->saved_auxv,
+			   (const char __user *) csp, auxv_end - csp))
+		return -EFAULT;
+
 	/* allocate room for argv[] and envv[] */
 	csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
 	envp = (elf_caddr_t __user *) csp;
-- 
1.8.1.2