Deprecate a.out ELF interpreters (8e9073ed) · Commits · 戴 / test

The Linux ELF loader is quite complicated and messy code (that could probably need a rewrite, but that's a different chapter). One particular messy part in it is the support for non ELF a.out ld.sos. This was originally added to make transition from a.out to ELF easier because an a.out ELF ld.so could be still build using an older a.out toolkit. But by now that should be fully obsolete and removing it would clean up binfmt_elf.c up a bit. I propose to deprecate this support and remove for 2.6.25. Drawback is that someone still runs their system with a.out ld.so they would need to update the ld.so when updating to a new kernel. This patch just adds an entry to the deprecation file and a printk warning users. [akpm@linux-foundation.org: better warning message] Signed-off-by:

Andi Kleen <ak@suse.de> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

Documentation/feature-removal-schedule.txt

+11 −0

Original line number	Diff line number	Diff line
		@@ -82,6 +82,17 @@ Who: Dominik Brodowski <linux@brodo.de>

		---------------------------

		What: a.out interpreter support for ELF executables
		When: 2.6.25
		Files: fs/binfmt_elf.c
		Why: Using a.out interpreters for ELF executables was a feature for
		transition from a.out to ELF. But now it is unlikely to be still
		needed anymore and removing it would simplify the hairy ELF
		loader code.
		Who: Andi Kleen <ak@suse.de>

		---------------------------

		What: remove EXPORT_SYMBOL(kernel_thread)
		When: August 2006
		Files: arch//kernel/_ksyms.c

fs/binfmt_elf.c

+8 −0

Original line number	Diff line number	Diff line
		@@ -730,6 +730,7 @@ static int load_elf_binary(struct linux_binprm bprm, struct pt_regs regs)

		/* Some simple consistency checks for the interpreter */
		if (elf_interpreter) {
		static int warn;
		interpreter_type = INTERPRETER_ELF \| INTERPRETER_AOUT;

		/* Now figure out which format our binary is */
		@@ -741,6 +742,13 @@ static int load_elf_binary(struct linux_binprm bprm, struct pt_regs regs)
		if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
		interpreter_type &= ~INTERPRETER_ELF;

		if (interpreter_type == INTERPRETER_AOUT && warn < 10) {
		printk(KERN_WARNING "a.out ELF interpreter %s is "
		"deprecated and will not be supported "
		"after Linux 2.6.25\n", elf_interpreter);
		warn++;
		}

		retval = -ELIBBAD;
		if (!interpreter_type)
		goto out_free_dentry;

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