From: Alexey Dobriyan <adobriyan@gmail.com>
To: akpm@linux-foundation.org
Cc: linux-kernel@vger.kernel.org
Subject: [PATCH 2/3] ELF: allocate less for static executable
Date: Wed, 19 Feb 2020 21:50:12 +0300 [thread overview]
Message-ID: <20200219185012.GB4871@avx2> (raw)
In-Reply-To: <20200219184847.GA4871@avx2>
PT_INTERP ELF header can be spared if executable is static.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
---
fs/binfmt_elf.c | 19 ++++++++++---------
1 file changed, 10 insertions(+), 9 deletions(-)
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -698,17 +698,11 @@ static int load_elf_binary(struct linux_binprm *bprm)
unsigned long reloc_func_desc __maybe_unused = 0;
int executable_stack = EXSTACK_DEFAULT;
struct elfhdr *elf_ex = (struct elfhdr *)bprm->buf;
- struct elfhdr *interp_elf_ex;
+ struct elfhdr *interp_elf_ex = NULL;
struct arch_elf_state arch_state = INIT_ARCH_ELF_STATE;
struct mm_struct *mm;
struct pt_regs *regs;
- interp_elf_ex = kmalloc(sizeof(*interp_elf_ex), GFP_KERNEL);
- if (!interp_elf_ex) {
- retval = -ENOMEM;
- goto out_ret;
- }
-
retval = -ENOEXEC;
/* First of all, some simple consistency checks */
if (memcmp(elf_ex->e_ident, ELFMAG, SELFMAG) != 0)
@@ -768,6 +762,12 @@ static int load_elf_binary(struct linux_binprm *bprm)
*/
would_dump(bprm, interpreter);
+ interp_elf_ex = kmalloc(sizeof(*interp_elf_ex), GFP_KERNEL);
+ if (!interp_elf_ex) {
+ retval = -ENOMEM;
+ goto out_free_ph;
+ }
+
/* Get the exec headers */
retval = elf_read(interpreter, interp_elf_ex,
sizeof(*interp_elf_ex), 0);
@@ -1073,6 +1073,8 @@ static int load_elf_binary(struct linux_binprm *bprm)
allow_write_access(interpreter);
fput(interpreter);
+
+ kfree(interp_elf_ex);
} else {
elf_entry = e_entry;
if (BAD_ADDR(elf_entry)) {
@@ -1151,12 +1153,11 @@ static int load_elf_binary(struct linux_binprm *bprm)
start_thread(regs, elf_entry, bprm->p);
retval = 0;
out:
- kfree(interp_elf_ex);
-out_ret:
return retval;
/* error cleanup */
out_free_dentry:
+ kfree(interp_elf_ex);
kfree(interp_elf_phdata);
allow_write_access(interpreter);
if (interpreter)
next prev parent reply other threads:[~2020-02-19 18:50 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-19 18:48 [PATCH 1/3] ELF: delete "loc" variable Alexey Dobriyan
2020-02-19 18:50 ` Alexey Dobriyan [this message]
2020-02-19 18:53 ` [PATCH 3/3] ELF: don't free interpreter's ELF pheaders on common path Alexey Dobriyan
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