ARM: enable elf_fdpic on systems with an MMU

Provide the necessary changes to be able to execute ELF-FDPIC binaries
on ARM systems with an MMU.

The default for CONFIG_BINFMT_ELF_FDPIC is also set to n if the regular
ELF loader is already configured so not to force FDPIC support on
everyone. Given that CONFIG_BINFMT_ELF depends on CONFIG_MMU, this means
CONFIG_BINFMT_ELF_FDPIC will still default to y when !MMU.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Mickael GUENE <mickael.guene@st.com>
Tested-by: Vincent Abriou <vincent.abriou@st.com>
Tested-by: Andras Szemzo <szemzo.andras@gmail.com>
This commit is contained in:
Nicolas Pitre 2017-08-11 00:53:39 -04:00
parent 50b2b2e691
commit 382e67aec6
4 changed files with 33 additions and 2 deletions

View File

@ -14,6 +14,10 @@ typedef struct {
#ifdef CONFIG_VDSO
unsigned long vdso;
#endif
#ifdef CONFIG_BINFMT_ELF_FDPIC
unsigned long exec_fdpic_loadmap;
unsigned long interp_fdpic_loadmap;
#endif
} mm_context_t;
#ifdef CONFIG_CPU_HAS_ASID

View File

@ -3,6 +3,7 @@
#include <linux/personality.h>
#include <linux/binfmts.h>
#include <linux/elf.h>
#include <linux/elf-fdpic.h>
#include <asm/system_info.h>
int elf_check_arch(const struct elf32_hdr *x)
@ -89,3 +90,24 @@ int arm_elf_read_implies_exec(int executable_stack)
return 0;
}
EXPORT_SYMBOL(arm_elf_read_implies_exec);
#if defined(CONFIG_MMU) && defined(CONFIG_BINFMT_ELF_FDPIC)
void elf_fdpic_arch_lay_out_mm(struct elf_fdpic_params *exec_params,
struct elf_fdpic_params *interp_params,
unsigned long *start_stack,
unsigned long *start_brk)
{
elf_set_personality(&exec_params->hdr);
exec_params->load_addr = 0x8000;
interp_params->load_addr = ELF_ET_DYN_BASE;
*start_stack = TASK_SIZE - SZ_16M;
if ((exec_params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) == ELF_FDPIC_FLAG_INDEPENDENT) {
exec_params->flags &= ~ELF_FDPIC_FLAG_ARRANGEMENT;
exec_params->flags |= ELF_FDPIC_FLAG_CONSTDISP;
}
}
#endif

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@ -34,8 +34,8 @@ config ARCH_BINFMT_ELF_STATE
config BINFMT_ELF_FDPIC
bool "Kernel support for FDPIC ELF binaries"
default y
depends on ((ARM && !MMU) || FRV || BLACKFIN || (SUPERH32 && !MMU) || C6X)
default y if !BINFMT_ELF
depends on (ARM || FRV || BLACKFIN || (SUPERH32 && !MMU) || C6X)
select ELFCORE
help
ELF FDPIC binaries are based on ELF, but allow the individual load

View File

@ -377,6 +377,11 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm)
executable_stack);
if (retval < 0)
goto error;
#ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
retval = arch_setup_additional_pages(bprm, !!interpreter_name);
if (retval < 0)
goto error;
#endif
#endif
/* load the executable and interpreter into memory */