diff options
Diffstat (limited to 'common/recipes-kernel/linux/linux-yocto-4.9.21/0064-objtool-Allow-alternatives-to-be-ignored.patch')
| -rw-r--r-- | common/recipes-kernel/linux/linux-yocto-4.9.21/0064-objtool-Allow-alternatives-to-be-ignored.patch | 166 |
1 files changed, 0 insertions, 166 deletions
diff --git a/common/recipes-kernel/linux/linux-yocto-4.9.21/0064-objtool-Allow-alternatives-to-be-ignored.patch b/common/recipes-kernel/linux/linux-yocto-4.9.21/0064-objtool-Allow-alternatives-to-be-ignored.patch deleted file mode 100644 index f0068591..00000000 --- a/common/recipes-kernel/linux/linux-yocto-4.9.21/0064-objtool-Allow-alternatives-to-be-ignored.patch +++ /dev/null @@ -1,166 +0,0 @@ -From 08a8d8feae37bbd8830fc63cc7e8c618497279db Mon Sep 17 00:00:00 2001 -From: Josh Poimboeuf <jpoimboe@redhat.com> -Date: Thu, 11 Jan 2018 21:46:24 +0000 -Subject: [PATCH 064/103] objtool: Allow alternatives to be ignored - -commit 258c76059cece01bebae098e81bacb1af2edad17 upstream. - -Getting objtool to understand retpolines is going to be a bit of a -challenge. For now, take advantage of the fact that retpolines are -patched in with alternatives. Just read the original (sane) -non-alternative instruction, and ignore the patched-in retpoline. - -This allows objtool to understand the control flow *around* the -retpoline, even if it can't yet follow what's inside. This means the -ORC unwinder will fail to unwind from inside a retpoline, but will work -fine otherwise. - -Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> -Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> -Signed-off-by: Thomas Gleixner <tglx@linutronix.de> -Cc: gnomes@lxorguk.ukuu.org.uk -Cc: Rik van Riel <riel@redhat.com> -Cc: Andi Kleen <ak@linux.intel.com> -Cc: thomas.lendacky@amd.com -Cc: Peter Zijlstra <peterz@infradead.org> -Cc: Linus Torvalds <torvalds@linux-foundation.org> -Cc: Jiri Kosina <jikos@kernel.org> -Cc: Andy Lutomirski <luto@amacapital.net> -Cc: Dave Hansen <dave.hansen@intel.com> -Cc: Kees Cook <keescook@google.com> -Cc: Tim Chen <tim.c.chen@linux.intel.com> -Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org> -Cc: Paul Turner <pjt@google.com> -Link: https://lkml.kernel.org/r/1515707194-20531-3-git-send-email-dwmw@amazon.co.uk -[dwmw2: Applies to tools/objtool/builtin-check.c not check.[ch]] -Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> -Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> ---- - tools/objtool/builtin-check.c | 64 ++++++++++++++++++++++++++++++++++++++----- - 1 file changed, 57 insertions(+), 7 deletions(-) - -diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c -index 36784b8..ee71d4c 100644 ---- a/tools/objtool/builtin-check.c -+++ b/tools/objtool/builtin-check.c -@@ -51,7 +51,7 @@ struct instruction { - unsigned int len, state; - unsigned char type; - unsigned long immediate; -- bool alt_group, visited; -+ bool alt_group, visited, ignore_alts; - struct symbol *call_dest; - struct instruction *jump_dest; - struct list_head alts; -@@ -353,6 +353,40 @@ static void add_ignores(struct objtool_file *file) - } - - /* -+ * FIXME: For now, just ignore any alternatives which add retpolines. This is -+ * a temporary hack, as it doesn't allow ORC to unwind from inside a retpoline. -+ * But it at least allows objtool to understand the control flow *around* the -+ * retpoline. -+ */ -+static int add_nospec_ignores(struct objtool_file *file) -+{ -+ struct section *sec; -+ struct rela *rela; -+ struct instruction *insn; -+ -+ sec = find_section_by_name(file->elf, ".rela.discard.nospec"); -+ if (!sec) -+ return 0; -+ -+ list_for_each_entry(rela, &sec->rela_list, list) { -+ if (rela->sym->type != STT_SECTION) { -+ WARN("unexpected relocation symbol type in %s", sec->name); -+ return -1; -+ } -+ -+ insn = find_insn(file, rela->sym->sec, rela->addend); -+ if (!insn) { -+ WARN("bad .discard.nospec entry"); -+ return -1; -+ } -+ -+ insn->ignore_alts = true; -+ } -+ -+ return 0; -+} -+ -+/* - * Find the destination instructions for all jumps. - */ - static int add_jump_destinations(struct objtool_file *file) -@@ -435,11 +469,18 @@ static int add_call_destinations(struct objtool_file *file) - dest_off = insn->offset + insn->len + insn->immediate; - insn->call_dest = find_symbol_by_offset(insn->sec, - dest_off); -+ /* -+ * FIXME: Thanks to retpolines, it's now considered -+ * normal for a function to call within itself. So -+ * disable this warning for now. -+ */ -+#if 0 - if (!insn->call_dest) { - WARN_FUNC("can't find call dest symbol at offset 0x%lx", - insn->sec, insn->offset, dest_off); - return -1; - } -+#endif - } else if (rela->sym->type == STT_SECTION) { - insn->call_dest = find_symbol_by_offset(rela->sym->sec, - rela->addend+4); -@@ -601,12 +642,6 @@ static int add_special_section_alts(struct objtool_file *file) - return ret; - - list_for_each_entry_safe(special_alt, tmp, &special_alts, list) { -- alt = malloc(sizeof(*alt)); -- if (!alt) { -- WARN("malloc failed"); -- ret = -1; -- goto out; -- } - - orig_insn = find_insn(file, special_alt->orig_sec, - special_alt->orig_off); -@@ -617,6 +652,10 @@ static int add_special_section_alts(struct objtool_file *file) - goto out; - } - -+ /* Ignore retpoline alternatives. */ -+ if (orig_insn->ignore_alts) -+ continue; -+ - new_insn = NULL; - if (!special_alt->group || special_alt->new_len) { - new_insn = find_insn(file, special_alt->new_sec, -@@ -642,6 +681,13 @@ static int add_special_section_alts(struct objtool_file *file) - goto out; - } - -+ alt = malloc(sizeof(*alt)); -+ if (!alt) { -+ WARN("malloc failed"); -+ ret = -1; -+ goto out; -+ } -+ - alt->insn = new_insn; - list_add_tail(&alt->list, &orig_insn->alts); - -@@ -852,6 +898,10 @@ static int decode_sections(struct objtool_file *file) - - add_ignores(file); - -+ ret = add_nospec_ignores(file); -+ if (ret) -+ return ret; -+ - ret = add_jump_destinations(file); - if (ret) - return ret; --- -2.7.4 - |