Module Name: src
Committed By: christos
Date: Thu Sep 15 17:45:44 UTC 2016
Modified Files:
src/sys/kern: exec_elf.c
Log Message:
Add debugging.
To generate a diff of this commit:
cvs rdiff -u -r1.85 -r1.86 src/sys/kern/exec_elf.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/kern/exec_elf.c
diff -u src/sys/kern/exec_elf.c:1.85 src/sys/kern/exec_elf.c:1.86
--- src/sys/kern/exec_elf.c:1.85 Wed May 25 13:25:32 2016
+++ src/sys/kern/exec_elf.c Thu Sep 15 13:45:44 2016
@@ -1,4 +1,4 @@
-/* $NetBSD: exec_elf.c,v 1.85 2016/05/25 17:25:32 christos Exp $ */
+/* $NetBSD: exec_elf.c,v 1.86 2016/09/15 17:45:44 christos Exp $ */
/*-
* Copyright (c) 1994, 2000, 2005, 2015 The NetBSD Foundation, Inc.
@@ -57,7 +57,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(1, "$NetBSD: exec_elf.c,v 1.85 2016/05/25 17:25:32 christos Exp $");
+__KERNEL_RCSID(1, "$NetBSD: exec_elf.c,v 1.86 2016/09/15 17:45:44 christos Exp $");
#ifdef _KERNEL_OPT
#include "opt_pax.h"
@@ -110,6 +110,11 @@ int netbsd_elf_probe(struct lwp *, struc
static void elf_free_emul_arg(void *);
+#ifdef DEBUG_ELF
+#define DPRINTF(a, ...) printf("%s: " a "\n", __func__, ##__VA_ARGS__)
+#else
+#define DPRINTF(a, ...)
+
/* round up and down to page boundaries. */
#define ELF_ROUND(a, b) (((a) + (b) - 1) & ~((b) - 1))
#define ELF_TRUNC(a, b) ((a) & ~((b) - 1))
@@ -259,22 +264,30 @@ elf_check_header(Elf_Ehdr *eh)
{
if (memcmp(eh->e_ident, ELFMAG, SELFMAG) != 0 ||
- eh->e_ident[EI_CLASS] != ELFCLASS)
+ eh->e_ident[EI_CLASS] != ELFCLASS) {
+ DPRINTF("bad magic %#x%x%x", eh->e_ident[0], eh->e_ident[1],
+ eh->e_ident[2]);
return ENOEXEC;
+ }
switch (eh->e_machine) {
ELFDEFNNAME(MACHDEP_ID_CASES)
default:
+ DPRINTF("bad machine %#x", eh->e_machine);
return ENOEXEC;
}
- if (ELF_EHDR_FLAGS_OK(eh) == 0)
+ if (ELF_EHDR_FLAGS_OK(eh) == 0) {
+ DPRINTF("bad flags %#x", eh->e_flags);
return ENOEXEC;
+ }
- if (eh->e_shnum > ELF_MAXSHNUM || eh->e_phnum > ELF_MAXPHNUM)
+ if (eh->e_shnum > ELF_MAXSHNUM || eh->e_phnum > ELF_MAXPHNUM) {
+ DPRINTF("bad shnum/phnum %#x/%#x", eh->e_shnum, eh->e_phnum);
return ENOEXEC;
+ }
return 0;
}
@@ -451,6 +464,7 @@ elf_load_interp(struct lwp *l, struct ex
if ((error = elf_check_header(&eh)) != 0)
goto bad;
if (eh.e_type != ET_DYN || eh.e_phnum == 0) {
+ DPRINTF("bad interpreter type %#x", eh.e_type);
error = ENOEXEC;
goto bad;
}
@@ -495,6 +509,7 @@ elf_load_interp(struct lwp *l, struct ex
}
if (base_ph == NULL) {
+ DPRINTF("no interpreter loadable sections");
error = ENOEXEC;
goto bad;
}
@@ -616,19 +631,25 @@ exec_elf_makecmds(struct lwp *l, struct
struct elf_args *ap;
bool is_dyn = false;
- if (epp->ep_hdrvalid < sizeof(Elf_Ehdr))
+ if (epp->ep_hdrvalid < sizeof(Elf_Ehdr)) {
+ DPRINTF("small header %#x", epp->ep_hdrvalid);
return ENOEXEC;
+ }
if ((error = elf_check_header(eh)) != 0)
return error;
if (eh->e_type == ET_DYN)
/* PIE, and some libs have an entry point */
is_dyn = true;
- else if (eh->e_type != ET_EXEC)
+ else if (eh->e_type != ET_EXEC) {
+ DPRINTF("bad type %#x", eh->e_type);
return ENOEXEC;
+ }
- if (eh->e_phnum == 0)
+ if (eh->e_phnum == 0) {
+ DPRINTF("no program headers");
return ENOEXEC;
+ }
error = vn_marktext(epp->ep_vp);
if (error)
@@ -652,6 +673,8 @@ exec_elf_makecmds(struct lwp *l, struct
pp = &ph[i];
if (pp->p_type == PT_INTERP) {
if (pp->p_filesz < 2 || pp->p_filesz > MAXPATHLEN) {
+ DPRINTF("bad interpreter namelen %#jx",
+ (uintmax_t)pp->p_filesz);
error = ENOEXEC;
goto bad;
}
@@ -661,6 +684,7 @@ exec_elf_makecmds(struct lwp *l, struct
goto bad;
/* Ensure interp is NUL-terminated and of the expected length */
if (strnlen(interp, pp->p_filesz) != pp->p_filesz - 1) {
+ DPRINTF("bad interpreter name");
error = ENOEXEC;
goto bad;
}
@@ -746,6 +770,7 @@ exec_elf_makecmds(struct lwp *l, struct
if (epp->ep_vmcmds.evs_used == 0) {
/* No VMCMD; there was no PT_LOAD section, or those
* sections were empty */
+ DPRINTF("no vmcommands");
error = ENOEXEC;
goto bad;
}
@@ -769,6 +794,7 @@ exec_elf_makecmds(struct lwp *l, struct
}
if (epp->ep_vmcmds.evs_used == nused) {
/* elf_load_interp() has not set up any new VMCMD */
+ DPRINTF("no vmcommands for interpreter");
error = ENOEXEC;
goto bad;
}
@@ -839,8 +865,10 @@ netbsd_elf_signature(struct lwp *l, stru
#endif
epp->ep_pax_flags = 0;
- if (eh->e_shnum > ELF_MAXSHNUM || eh->e_shnum == 0)
+ if (eh->e_shnum > ELF_MAXSHNUM || eh->e_shnum == 0) {
+ DPRINTF("no signature %#x", eh->e_shnum);
return ENOEXEC;
+ }
shsize = eh->e_shnum * sizeof(Elf_Shdr);
sh = kmem_alloc(shsize, KM_SLEEP);
@@ -1004,6 +1032,10 @@ bad:
kmem_free(np, ELF_MAXNOTESIZE);
error = isnetbsd ? 0 : ENOEXEC;
+#ifdef DEBUG_ELF
+ if (error)
+ DPRINTF("not netbsd");
+#endif
out:
kmem_free(sh, shsize);
return error;
