From 475ddf1fce1ec4826c8dda40ec59f7f83a7aadb8 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Fri, 7 Apr 2023 12:27:13 -0700 Subject: fortify: Split reporting and avoid passing string pointer In preparation for KUnit testing and further improvements in fortify failure reporting, split out the report and encode the function and access failure (read or write overflow) into a single u8 argument. This mainly ends up saving a tiny bit of space in the data segment. For a defconfig with FORTIFY_SOURCE enabled: $ size gcc/vmlinux.before gcc/vmlinux.after text data bss dec hex filename 26132309 9760658 2195460 38088427 2452eeb gcc/vmlinux.before 26132386 9748382 2195460 38076228 244ff44 gcc/vmlinux.after Reviewed-by: Alexander Lobakin Signed-off-by: Kees Cook --- tools/objtool/noreturns.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'tools/objtool') diff --git a/tools/objtool/noreturns.h b/tools/objtool/noreturns.h index 1685d7ea6a9f..3a301696f005 100644 --- a/tools/objtool/noreturns.h +++ b/tools/objtool/noreturns.h @@ -6,6 +6,7 @@ * * Yes, this is unfortunate. A better solution is in the works. */ +NORETURN(__fortify_panic) NORETURN(__kunit_abort) NORETURN(__module_put_and_kthread_exit) NORETURN(__reiserfs_panic) @@ -22,7 +23,6 @@ NORETURN(do_exit) NORETURN(do_group_exit) NORETURN(do_task_dead) NORETURN(ex_handler_msr_mce) -NORETURN(fortify_panic) NORETURN(hlt_play_dead) NORETURN(hv_ghcb_terminate) NORETURN(kthread_complete_and_exit) -- cgit v1.2.3 From 10b4c4bce3f5541f54bcc2039720b11d2bc96d79 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Mon, 26 Feb 2024 23:35:27 -0800 Subject: objtool: Fix UNWIND_HINT_{SAVE,RESTORE} across basic blocks If SAVE and RESTORE unwind hints are in different basic blocks, and objtool sees the RESTORE before the SAVE, it errors out with: vmlinux.o: warning: objtool: vmw_port_hb_in+0x242: objtool isn't smart enough to handle this CFI save/restore combo In such a case, defer following the RESTORE block until the straight-line path gets followed later. Fixes: 8faea26e6111 ("objtool: Re-add UNWIND_HINT_{SAVE_RESTORE}") Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202402240702.zJFNmahW-lkp@intel.com/ Signed-off-by: Josh Poimboeuf Link: https://lore.kernel.org/r/20240227073527.avcm5naavbv3cj5s@treble Signed-off-by: Kees Cook --- tools/objtool/check.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'tools/objtool') diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 548ec3cd7c00..c4c2f75eadfd 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -3620,6 +3620,18 @@ static int validate_branch(struct objtool_file *file, struct symbol *func, } if (!save_insn->visited) { + /* + * If the restore hint insn is at the + * beginning of a basic block and was + * branched to from elsewhere, and the + * save insn hasn't been visited yet, + * defer following this branch for now. + * It will be seen later via the + * straight-line path. + */ + if (!prev_insn) + return 0; + WARN_INSN(insn, "objtool isn't smart enough to handle this CFI save/restore combo"); return 1; } -- cgit v1.2.3