fs/binfmt_elf: Refactor load_elf_binary function
I delete load_addr because it is not used anymore. And I rename
load_addr_set to first_pt_load because it is used only to capture the
first iteration of the loop.
Signed-off-by: Akira Kawata <akirakawata1@gmail.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220127124014.338760-3-akirakawata1@gmail.com
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 600cec2..4c5a217 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -824,8 +824,8 @@ static int parse_elf_properties(struct file *f, const struct elf_phdr *phdr,
static int load_elf_binary(struct linux_binprm *bprm)
{
struct file *interpreter = NULL; /* to shut gcc up */
- unsigned long load_addr, load_bias = 0, phdr_addr = 0;
- int load_addr_set = 0;
+ unsigned long load_bias = 0, phdr_addr = 0;
+ int first_pt_load = 1;
unsigned long error;
struct elf_phdr *elf_ppnt, *elf_phdata, *interp_elf_phdata = NULL;
struct elf_phdr *elf_property_phdata = NULL;
@@ -1075,12 +1075,12 @@ static int load_elf_binary(struct linux_binprm *bprm)
vaddr = elf_ppnt->p_vaddr;
/*
- * The first time through the loop, load_addr_set is false:
+ * The first time through the loop, first_pt_load is true:
* layout will be calculated. Once set, use MAP_FIXED since
* we know we've already safely mapped the entire region with
* MAP_FIXED_NOREPLACE in the once-per-binary logic following.
*/
- if (load_addr_set) {
+ if (!first_pt_load) {
elf_flags |= MAP_FIXED;
} else if (elf_ex->e_type == ET_EXEC) {
/*
@@ -1171,13 +1171,11 @@ static int load_elf_binary(struct linux_binprm *bprm)
goto out_free_dentry;
}
- if (!load_addr_set) {
- load_addr_set = 1;
- load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
+ if (first_pt_load) {
+ first_pt_load = 0;
if (elf_ex->e_type == ET_DYN) {
load_bias += error -
ELF_PAGESTART(load_bias + vaddr);
- load_addr += load_bias;
reloc_func_desc = load_bias;
}
}
