Control the execution permission of the readable segments for

i386 binaries on the amd64 and ia64 with the sysctl, instead of
unconditionally enabling it.

Reviewed by:	marcel
This commit is contained in:
Konstantin Belousov 2011-10-15 12:35:18 +00:00
parent 2b6ae84b63
commit 126b36a21e
4 changed files with 16 additions and 4 deletions

View File

@ -445,7 +445,7 @@ freebsd32_mprotect(struct thread *td, struct freebsd32_mprotect_args *uap)
ap.len = uap->len;
ap.prot = uap->prot;
#if defined(__amd64__) || defined(__ia64__)
if (ap.prot & PROT_READ)
if (i386_read_exec && (ap.prot & PROT_READ) != 0)
ap.prot |= PROT_EXEC;
#endif
return (sys_mprotect(td, &ap));
@ -536,7 +536,7 @@ freebsd32_mmap(struct thread *td, struct freebsd32_mmap_args *uap)
#endif
#if defined(__amd64__) || defined(__ia64__)
if (prot & PROT_READ)
if (i386_read_exec && (prot & PROT_READ))
prot |= PROT_EXEC;
#endif

View File

@ -123,6 +123,14 @@ SYSCTL_INT(__CONCAT(_kern_elf, __ELF_WORD_SIZE), OID_AUTO,
nxstack, CTLFLAG_RW, &__elfN(nxstack), 0,
__XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE)) ": enable non-executable stack");
#if __ELF_WORD_SIZE == 32
#if defined(__amd64__) || defined(__ia64__)
int i386_read_exec = 0;
SYSCTL_INT(_kern_elf32, OID_AUTO, read_exec, CTLFLAG_RW, &i386_read_exec, 0,
"enable execution from readable segments");
#endif
#endif
static Elf_Brandinfo *elf_brand_list[MAX_BRANDS];
#define trunc_page_ps(va, ps) ((va) & ~(ps - 1))
@ -1666,7 +1674,7 @@ __elfN(trans_prot)(Elf_Word flags)
prot |= VM_PROT_READ;
#if __ELF_WORD_SIZE == 32
#if defined(__amd64__) || defined(__ia64__)
if (flags & PF_R)
if (i386_read_exec && (flags & PF_R))
prot |= VM_PROT_EXECUTE;
#endif
#endif

View File

@ -151,6 +151,10 @@ extern struct sysentvec null_sysvec;
extern struct sysent sysent[];
extern const char *syscallnames[];
#if defined(__amd64__) || defined(__ia64__)
extern int i386_read_exec;
#endif
#define NO_SYSCALL (-1)
struct module;

View File

@ -141,7 +141,7 @@ sys_obreak(td, uap)
prot = VM_PROT_RW;
#ifdef COMPAT_FREEBSD32
#if defined(__amd64__) || defined(__ia64__)
if (SV_PROC_FLAG(td->td_proc, SV_ILP32))
if (i386_read_exec && SV_PROC_FLAG(td->td_proc, SV_ILP32))
prot |= VM_PROT_EXECUTE;
#endif
#endif