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author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-01-12 16:31:19 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-01-12 16:31:19 -0800 |
commit | 64ad9461521b1a357846ef6cedc4bccd48a046e0 (patch) | |
tree | f134404b6c6df89198a4a2f2be6fef21af133c73 /tools/objtool | |
parent | 8e5b0adeea19309c8ce0e3c9119061554973efa9 (diff) | |
parent | 9cdbeec4096804083944d05da96bbaf59a1eb4f9 (diff) | |
download | linux-64ad9461521b1a357846ef6cedc4bccd48a046e0.tar.gz linux-64ad9461521b1a357846ef6cedc4bccd48a046e0.tar.bz2 linux-64ad9461521b1a357846ef6cedc4bccd48a046e0.zip |
Merge tag 'x86_core_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 core updates from Borislav Petkov:
- Get rid of all the .fixup sections because this generates
misleading/wrong stacktraces and confuse RELIABLE_STACKTRACE and
LIVEPATCH as the backtrace misses the function which is being fixed
up.
- Add Straight Line Speculation mitigation support which uses a new
compiler switch -mharden-sls= which sticks an INT3 after a RET or an
indirect branch in order to block speculation after them. Reportedly,
CPUs do speculate behind such insns.
- The usual set of cleanups and improvements
* tag 'x86_core_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits)
x86/entry_32: Fix segment exceptions
objtool: Remove .fixup handling
x86: Remove .fixup section
x86/word-at-a-time: Remove .fixup usage
x86/usercopy: Remove .fixup usage
x86/usercopy_32: Simplify __copy_user_intel_nocache()
x86/sgx: Remove .fixup usage
x86/checksum_32: Remove .fixup usage
x86/vmx: Remove .fixup usage
x86/kvm: Remove .fixup usage
x86/segment: Remove .fixup usage
x86/fpu: Remove .fixup usage
x86/xen: Remove .fixup usage
x86/uaccess: Remove .fixup usage
x86/futex: Remove .fixup usage
x86/msr: Remove .fixup usage
x86/extable: Extend extable functionality
x86/entry_32: Remove .fixup usage
x86/entry_64: Remove .fixup usage
x86/copy_mc_64: Remove .fixup usage
...
Diffstat (limited to 'tools/objtool')
-rw-r--r-- | tools/objtool/arch/x86/decode.c | 13 | ||||
-rw-r--r-- | tools/objtool/builtin-check.c | 3 | ||||
-rw-r--r-- | tools/objtool/check.c | 22 | ||||
-rw-r--r-- | tools/objtool/include/objtool/arch.h | 1 | ||||
-rw-r--r-- | tools/objtool/include/objtool/builtin.h | 2 |
5 files changed, 29 insertions, 12 deletions
diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c index 4d6d7fc13255..c10ef78df050 100644 --- a/tools/objtool/arch/x86/decode.c +++ b/tools/objtool/arch/x86/decode.c @@ -531,6 +531,11 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec } break; + case 0xcc: + /* int3 */ + *type = INSN_TRAP; + break; + case 0xe3: /* jecxz/jrcxz */ *type = INSN_JUMP_CONDITIONAL; @@ -697,10 +702,10 @@ const char *arch_ret_insn(int len) { static const char ret[5][5] = { { BYTE_RET }, - { BYTE_RET, BYTES_NOP1 }, - { BYTE_RET, BYTES_NOP2 }, - { BYTE_RET, BYTES_NOP3 }, - { BYTE_RET, BYTES_NOP4 }, + { BYTE_RET, 0xcc }, + { BYTE_RET, 0xcc, BYTES_NOP1 }, + { BYTE_RET, 0xcc, BYTES_NOP2 }, + { BYTE_RET, 0xcc, BYTES_NOP3 }, }; if (len < 1 || len > 5) { diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c index 8b38b5d6fec7..38070f26105b 100644 --- a/tools/objtool/builtin-check.c +++ b/tools/objtool/builtin-check.c @@ -20,7 +20,7 @@ #include <objtool/objtool.h> bool no_fp, no_unreachable, retpoline, module, backtrace, uaccess, stats, - validate_dup, vmlinux, mcount, noinstr, backup; + validate_dup, vmlinux, mcount, noinstr, backup, sls; static const char * const check_usage[] = { "objtool check [<options>] file.o", @@ -45,6 +45,7 @@ const struct option check_options[] = { OPT_BOOLEAN('l', "vmlinux", &vmlinux, "vmlinux.o validation"), OPT_BOOLEAN('M', "mcount", &mcount, "generate __mcount_loc"), OPT_BOOLEAN('B', "backup", &backup, "create .orig files before modification"), + OPT_BOOLEAN('S', "sls", &sls, "validate straight-line-speculation"), OPT_END(), }; diff --git a/tools/objtool/check.c b/tools/objtool/check.c index a9a1f7259d62..8c1931eab5f1 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -3113,6 +3113,12 @@ static int validate_branch(struct objtool_file *file, struct symbol *func, switch (insn->type) { case INSN_RETURN: + if (next_insn && next_insn->type == INSN_TRAP) { + next_insn->ignore = true; + } else if (sls && !insn->retpoline_safe) { + WARN_FUNC("missing int3 after ret", + insn->sec, insn->offset); + } return validate_return(func, insn, &state); case INSN_CALL: @@ -3156,6 +3162,14 @@ static int validate_branch(struct objtool_file *file, struct symbol *func, break; case INSN_JUMP_DYNAMIC: + if (next_insn && next_insn->type == INSN_TRAP) { + next_insn->ignore = true; + } else if (sls && !insn->retpoline_safe) { + WARN_FUNC("missing int3 after indirect jump", + insn->sec, insn->offset); + } + + /* fallthrough */ case INSN_JUMP_DYNAMIC_CONDITIONAL: if (is_sibling_call(insn)) { ret = validate_sibling_call(file, insn, &state); @@ -3325,14 +3339,10 @@ static bool ignore_unreachable_insn(struct objtool_file *file, struct instructio return true; /* - * Ignore any unused exceptions. This can happen when a whitelisted - * function has an exception table entry. - * - * Also ignore alternative replacement instructions. This can happen + * Ignore alternative replacement instructions. This can happen * when a whitelisted function uses one of the ALTERNATIVE macros. */ - if (!strcmp(insn->sec->name, ".fixup") || - !strcmp(insn->sec->name, ".altinstr_replacement") || + if (!strcmp(insn->sec->name, ".altinstr_replacement") || !strcmp(insn->sec->name, ".altinstr_aux")) return true; diff --git a/tools/objtool/include/objtool/arch.h b/tools/objtool/include/objtool/arch.h index 589ff58426ab..76bae3078286 100644 --- a/tools/objtool/include/objtool/arch.h +++ b/tools/objtool/include/objtool/arch.h @@ -26,6 +26,7 @@ enum insn_type { INSN_CLAC, INSN_STD, INSN_CLD, + INSN_TRAP, INSN_OTHER, }; diff --git a/tools/objtool/include/objtool/builtin.h b/tools/objtool/include/objtool/builtin.h index 15ac0b7d3d6a..89ba869ed08f 100644 --- a/tools/objtool/include/objtool/builtin.h +++ b/tools/objtool/include/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, mcount, noinstr, backup; + validate_dup, vmlinux, mcount, noinstr, backup, sls; extern int cmd_parse_options(int argc, const char **argv, const char * const usage[]); |