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| author | Peter Zijlstra <peterz@infradead.org> | 2022-06-28 01:21:17 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-07-25 12:26:50 +0300 |
| commit | b24fdd0f1c3328cf8ee0c518b93a7187f8cee097 (patch) | |
| tree | 125c49941315a9519fc73a629b63fdb948e39817 /tools/objtool | |
| parent | f7851ed697be2ce86bd8baf29111762b7b3ff6cc (diff) | |
| download | linux-b24fdd0f1c3328cf8ee0c518b93a7187f8cee097.tar.xz | |
x86/retbleed: Add fine grained Kconfig knobs
commit f43b9876e857c739d407bc56df288b0ebe1a9164 upstream.
Do fine-grained Kconfig for all the various retbleed parts.
NOTE: if your compiler doesn't support return thunks this will
silently 'upgrade' your mitigation to IBPB, you might not like this.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
[cascardo: there is no CONFIG_OBJTOOL]
[cascardo: objtool calling and option parsing has changed]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
[bwh: Backported to 5.10:
- In scripts/Makefile.build, add the objtool option with an ifdef
block, same as for other options
- Adjust filename, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'tools/objtool')
| -rw-r--r-- | tools/objtool/builtin-check.c | 3 | ||||
| -rw-r--r-- | tools/objtool/builtin.h | 2 | ||||
| -rw-r--r-- | tools/objtool/check.c | 9 |
3 files changed, 10 insertions, 4 deletions
diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c index d04eab7e77ae..447a49c03abb 100644 --- a/tools/objtool/builtin-check.c +++ b/tools/objtool/builtin-check.c @@ -19,7 +19,7 @@ #include "objtool.h" bool no_fp, no_unreachable, retpoline, module, backtrace, uaccess, stats, - validate_dup, vmlinux, sls, unret; + validate_dup, vmlinux, sls, unret, rethunk; static const char * const check_usage[] = { "objtool check [<options>] file.o", @@ -30,6 +30,7 @@ const struct option check_options[] = { OPT_BOOLEAN('f', "no-fp", &no_fp, "Skip frame pointer validation"), OPT_BOOLEAN('u', "no-unreachable", &no_unreachable, "Skip 'unreachable instruction' warnings"), OPT_BOOLEAN('r', "retpoline", &retpoline, "Validate retpoline assumptions"), + OPT_BOOLEAN(0, "rethunk", &rethunk, "validate and annotate rethunk usage"), OPT_BOOLEAN(0, "unret", &unret, "validate entry unret placement"), OPT_BOOLEAN('m', "module", &module, "Indicates the object will be part of a kernel module"), OPT_BOOLEAN('b', "backtrace", &backtrace, "unwind on error"), diff --git a/tools/objtool/builtin.h b/tools/objtool/builtin.h index b6b486e28d54..61d8d49dbc65 100644 --- a/tools/objtool/builtin.h +++ b/tools/objtool/builtin.h @@ -9,7 +9,7 @@ extern const struct option check_options[]; extern bool no_fp, no_unreachable, retpoline, module, backtrace, uaccess, stats, - validate_dup, vmlinux, sls, unret; + validate_dup, vmlinux, sls, unret, rethunk; extern int cmd_check(int argc, const char **argv); extern int cmd_orc(int argc, const char **argv); diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 864d407009c9..ea80b29b9913 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -3262,8 +3262,11 @@ static int validate_retpoline(struct objtool_file *file) continue; if (insn->type == INSN_RETURN) { - WARN_FUNC("'naked' return found in RETPOLINE build", - insn->sec, insn->offset); + if (rethunk) { + WARN_FUNC("'naked' return found in RETHUNK build", + insn->sec, insn->offset); + } else + continue; } else { WARN_FUNC("indirect %s found in RETPOLINE build", insn->sec, insn->offset, @@ -3533,7 +3536,9 @@ int check(struct objtool_file *file) if (ret < 0) goto out; warnings += ret; + } + if (rethunk) { ret = create_return_sites_sections(file); if (ret < 0) goto out; |