[PATCH v2 1/2] binfmt_elf_fdpic: support 64-bit systems
Greg Ungerer
gerg at kernel.org
Tue Jul 11 06:07:53 PDT 2023
The binfmt_flat_fdpic code has a number of 32-bit specific data
structures associated with it. Extend it to be able to support and
be used on 64-bit systems as well.
The new code defines a number of key 64-bit variants of the core
elf-fdpic data structures - along side the existing 32-bit sized ones.
A common set of generic named structures are defined to be either
the 32-bit or 64-bit ones as required at compile time. This is a
similar technique to that used in the ELF binfmt loader.
For example:
elf_fdpic_loadseg is either elf32_fdpic_loadseg or elf64_fdpic_loadseg
elf_fdpic_loadmap is either elf32_fdpic_loadmap or elf64_fdpic_loadmap
the choice based on ELFCLASS32 or ELFCLASS64.
Signed-off-by: Greg Ungerer <gerg at kernel.org>
---
v1->v2: rebase onto linux-6.5-rc1
fs/binfmt_elf_fdpic.c | 38 +++++++++++++++++-----------------
include/linux/elf-fdpic.h | 14 ++++++++++++-
include/uapi/linux/elf-fdpic.h | 15 ++++++++++++++
3 files changed, 47 insertions(+), 20 deletions(-)
diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
index 1c6c5832af86..43b2a2851ba3 100644
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -138,7 +138,7 @@ static int is_constdisp(struct elfhdr *hdr)
static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
struct file *file)
{
- struct elf32_phdr *phdr;
+ struct elf_phdr *phdr;
unsigned long size;
int retval, loop;
loff_t pos = params->hdr.e_phoff;
@@ -560,8 +560,8 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
sp &= ~7UL;
/* stack the load map(s) */
- len = sizeof(struct elf32_fdpic_loadmap);
- len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
+ len = sizeof(struct elf_fdpic_loadmap);
+ len += sizeof(struct elf_fdpic_loadseg) * exec_params->loadmap->nsegs;
sp = (sp - len) & ~7UL;
exec_params->map_addr = sp;
@@ -571,8 +571,8 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
if (interp_params->loadmap) {
- len = sizeof(struct elf32_fdpic_loadmap);
- len += sizeof(struct elf32_fdpic_loadseg) *
+ len = sizeof(struct elf_fdpic_loadmap);
+ len += sizeof(struct elf_fdpic_loadseg) *
interp_params->loadmap->nsegs;
sp = (sp - len) & ~7UL;
interp_params->map_addr = sp;
@@ -740,13 +740,13 @@ static int elf_fdpic_map_file(struct elf_fdpic_params *params,
struct mm_struct *mm,
const char *what)
{
- struct elf32_fdpic_loadmap *loadmap;
+ struct elf_fdpic_loadmap *loadmap;
#ifdef CONFIG_MMU
- struct elf32_fdpic_loadseg *mseg;
+ struct elf_fdpic_loadseg *mseg;
unsigned long load_addr;
#endif
- struct elf32_fdpic_loadseg *seg;
- struct elf32_phdr *phdr;
+ struct elf_fdpic_loadseg *seg;
+ struct elf_phdr *phdr;
unsigned nloads, tmp;
unsigned long stop;
int loop, ret;
@@ -766,7 +766,7 @@ static int elf_fdpic_map_file(struct elf_fdpic_params *params,
params->loadmap = loadmap;
- loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
+ loadmap->version = ELF_FDPIC_LOADMAP_VERSION;
loadmap->nsegs = nloads;
/* map the requested LOADs into the memory space */
@@ -839,8 +839,8 @@ static int elf_fdpic_map_file(struct elf_fdpic_params *params,
if (phdr->p_vaddr >= seg->p_vaddr &&
phdr->p_vaddr + phdr->p_memsz <=
seg->p_vaddr + seg->p_memsz) {
- Elf32_Dyn __user *dyn;
- Elf32_Sword d_tag;
+ Elf_Dyn __user *dyn;
+ Elf_Sword d_tag;
params->dynamic_addr =
(phdr->p_vaddr - seg->p_vaddr) +
@@ -850,11 +850,11 @@ static int elf_fdpic_map_file(struct elf_fdpic_params *params,
* one item, and that the last item is a NULL
* entry */
if (phdr->p_memsz == 0 ||
- phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
+ phdr->p_memsz % sizeof(Elf_Dyn) != 0)
goto dynamic_error;
- tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
- dyn = (Elf32_Dyn __user *)params->dynamic_addr;
+ tmp = phdr->p_memsz / sizeof(Elf_Dyn);
+ dyn = (Elf_Dyn __user *)params->dynamic_addr;
if (get_user(d_tag, &dyn[tmp - 1].d_tag) ||
d_tag != 0)
goto dynamic_error;
@@ -923,8 +923,8 @@ static int elf_fdpic_map_file_constdisp_on_uclinux(
struct file *file,
struct mm_struct *mm)
{
- struct elf32_fdpic_loadseg *seg;
- struct elf32_phdr *phdr;
+ struct elf_fdpic_loadseg *seg;
+ struct elf_phdr *phdr;
unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0;
int loop, ret;
@@ -1007,8 +1007,8 @@ static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
struct file *file,
struct mm_struct *mm)
{
- struct elf32_fdpic_loadseg *seg;
- struct elf32_phdr *phdr;
+ struct elf_fdpic_loadseg *seg;
+ struct elf_phdr *phdr;
unsigned long load_addr, delta_vaddr;
int loop, dvset;
diff --git a/include/linux/elf-fdpic.h b/include/linux/elf-fdpic.h
index 3bea95a1af53..e533f4513194 100644
--- a/include/linux/elf-fdpic.h
+++ b/include/linux/elf-fdpic.h
@@ -10,13 +10,25 @@
#include <uapi/linux/elf-fdpic.h>
+#if ELF_CLASS == ELFCLASS32
+#define Elf_Sword Elf32_Sword
+#define elf_fdpic_loadseg elf32_fdpic_loadseg
+#define elf_fdpic_loadmap elf32_fdpic_loadmap
+#define ELF_FDPIC_LOADMAP_VERSION ELF32_FDPIC_LOADMAP_VERSION
+#else
+#define Elf_Sword Elf64_Sxword
+#define elf_fdpic_loadmap elf64_fdpic_loadmap
+#define elf_fdpic_loadseg elf64_fdpic_loadseg
+#define ELF_FDPIC_LOADMAP_VERSION ELF64_FDPIC_LOADMAP_VERSION
+#endif
+
/*
* binfmt binary parameters structure
*/
struct elf_fdpic_params {
struct elfhdr hdr; /* ref copy of ELF header */
struct elf_phdr *phdrs; /* ref copy of PT_PHDR table */
- struct elf32_fdpic_loadmap *loadmap; /* loadmap to be passed to userspace */
+ struct elf_fdpic_loadmap *loadmap; /* loadmap to be passed to userspace */
unsigned long elfhdr_addr; /* mapped ELF header user address */
unsigned long ph_addr; /* mapped PT_PHDR user address */
unsigned long map_addr; /* mapped loadmap user address */
diff --git a/include/uapi/linux/elf-fdpic.h b/include/uapi/linux/elf-fdpic.h
index 4fcc6cfebe18..ec23f0871129 100644
--- a/include/uapi/linux/elf-fdpic.h
+++ b/include/uapi/linux/elf-fdpic.h
@@ -32,4 +32,19 @@ struct elf32_fdpic_loadmap {
#define ELF32_FDPIC_LOADMAP_VERSION 0x0000
+/* segment mappings for ELF FDPIC libraries/executables/interpreters */
+struct elf64_fdpic_loadseg {
+ Elf64_Addr addr; /* core address to which mapped */
+ Elf64_Addr p_vaddr; /* VMA recorded in file */
+ Elf64_Word p_memsz; /* allocation size recorded in file */
+};
+
+struct elf64_fdpic_loadmap {
+ Elf64_Half version; /* version of these structures, just in case... */
+ Elf64_Half nsegs; /* number of segments */
+ struct elf64_fdpic_loadseg segs[];
+};
+
+#define ELF64_FDPIC_LOADMAP_VERSION 0x0000
+
#endif /* _UAPI_LINUX_ELF_FDPIC_H */
--
2.25.1
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