+++ /dev/null
-From stable+bounces-25322-greg=kroah.com@vger.kernel.org Wed Feb 28 03:47:32 2024
-From: Rui Qi <qirui.001@bytedance.com>
-Date: Wed, 28 Feb 2024 10:45:34 +0800
-Subject: objtool: Add support for intra-function calls
-To: bp@alien8.de, mingo@redhat.com, tglx@linutronix.de, hpa@zytor.com, jpoimboe@redhat.com, peterz@infradead.org, mbenes@suse.cz, gregkh@linuxfoundation.org, stable@vger.kernel.org, alexandre.chartre@oracle.com
-Cc: x86@kernel.org, linux-kernel@vger.kernel.org, yuanzhu@bytedance.com, Rui Qi <qirui.001@bytedance.com>
-Message-ID: <20240228024535.79980-3-qirui.001@bytedance.com>
-
-From: Alexandre Chartre <alexandre.chartre@oracle.com>
-
-commit 8aa8eb2a8f5b3305a95f39957dd2b715fa668e21 upstream.
-
-Change objtool to support intra-function calls. On x86, an intra-function
-call is represented in objtool as a push onto the stack (of the return
-address), and a jump to the destination address. That way the stack
-information is correctly updated and the call flow is still accurate.
-
-Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
-Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
-Reviewed-by: Miroslav Benes <mbenes@suse.cz>
-Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
-Link: https://lkml.kernel.org/r/20200414103618.12657-4-alexandre.chartre@oracle.com
-Signed-off-by: Rui Qi <qirui.001@bytedance.com>
-Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
----
- include/linux/frame.h | 11 ++++
- tools/objtool/Documentation/stack-validation.txt | 8 ++
- tools/objtool/arch/x86/decode.c | 6 ++
- tools/objtool/check.c | 62 +++++++++++++++++++++--
- 4 files changed, 83 insertions(+), 4 deletions(-)
-
---- a/include/linux/frame.h
-+++ b/include/linux/frame.h
-@@ -15,9 +15,20 @@
- static void __used __section(.discard.func_stack_frame_non_standard) \
- *__func_stack_frame_non_standard_##func = func
-
-+/*
-+ * This macro indicates that the following intra-function call is valid.
-+ * Any non-annotated intra-function call will cause objtool to issue a warning.
-+ */
-+#define ANNOTATE_INTRA_FUNCTION_CALL \
-+ 999: \
-+ .pushsection .discard.intra_function_calls; \
-+ .long 999b; \
-+ .popsection;
-+
- #else /* !CONFIG_STACK_VALIDATION */
-
- #define STACK_FRAME_NON_STANDARD(func)
-+#define ANNOTATE_INTRA_FUNCTION_CALL
-
- #endif /* CONFIG_STACK_VALIDATION */
-
---- a/tools/objtool/Documentation/stack-validation.txt
-+++ b/tools/objtool/Documentation/stack-validation.txt
-@@ -290,6 +290,14 @@ they mean, and suggestions for how to fi
- https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70646
-
-
-+11. file.o: warning: unannotated intra-function call
-+
-+ This warning means that a direct call is done to a destination which
-+ is not at the beginning of a function. If this is a legit call, you
-+ can remove this warning by putting the ANNOTATE_INTRA_FUNCTION_CALL
-+ directive right before the call.
-+
-+
- If the error doesn't seem to make sense, it could be a bug in objtool.
- Feel free to ask the objtool maintainer for help.
-
---- a/tools/objtool/arch/x86/decode.c
-+++ b/tools/objtool/arch/x86/decode.c
-@@ -437,6 +437,12 @@ int arch_decode_instruction(struct elf *
-
- case 0xe8:
- *type = INSN_CALL;
-+ /*
-+ * For the impact on the stack, a CALL behaves like
-+ * a PUSH of an immediate value (the return address).
-+ */
-+ op->src.type = OP_SRC_CONST;
-+ op->dest.type = OP_DEST_PUSH;
- break;
-
- case 0xfc:
---- a/tools/objtool/check.c
-+++ b/tools/objtool/check.c
-@@ -645,6 +645,7 @@ static int add_jump_destinations(struct
- return 0;
- }
-
-+
- /*
- * Find the destination instructions for all calls.
- */
-@@ -666,10 +667,7 @@ static int add_call_destinations(struct
- dest_off);
-
- if (!insn->call_dest && !insn->ignore) {
-- WARN_FUNC("unsupported intra-function call",
-- insn->sec, insn->offset);
-- if (retpoline)
-- WARN("If this is a retpoline, please patch it in with alternatives and annotate it with ANNOTATE_NOSPEC_ALTERNATIVE.");
-+ WARN_FUNC("unannotated intra-function call", insn->sec, insn->offset);
- return -1;
- }
-
-@@ -1291,6 +1289,58 @@ static int read_retpoline_hints(struct o
- return 0;
- }
-
-+
-+static int read_intra_function_calls(struct objtool_file *file)
-+{
-+ struct instruction *insn;
-+ struct section *sec;
-+ struct rela *rela;
-+
-+ sec = find_section_by_name(file->elf, ".rela.discard.intra_function_calls");
-+ if (!sec)
-+ return 0;
-+
-+ list_for_each_entry(rela, &sec->rela_list, list) {
-+ unsigned long dest_off;
-+
-+ 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.intra_function_call entry");
-+ return -1;
-+ }
-+
-+ if (insn->type != INSN_CALL) {
-+ WARN_FUNC("intra_function_call not a direct call",
-+ insn->sec, insn->offset);
-+ return -1;
-+ }
-+
-+ /*
-+ * Treat intra-function CALLs as JMPs, but with a stack_op.
-+ * See add_call_destinations(), which strips stack_ops from
-+ * normal CALLs.
-+ */
-+ insn->type = INSN_JUMP_UNCONDITIONAL;
-+
-+ dest_off = insn->offset + insn->len + insn->immediate;
-+ insn->jump_dest = find_insn(file, insn->sec, dest_off);
-+ if (!insn->jump_dest) {
-+ WARN_FUNC("can't find call dest at %s+0x%lx",
-+ insn->sec, insn->offset,
-+ insn->sec->name, dest_off);
-+ return -1;
-+ }
-+ }
-+
-+ return 0;
-+}
-+
- static void mark_rodata(struct objtool_file *file)
- {
- struct section *sec;
-@@ -1346,6 +1396,10 @@ static int decode_sections(struct objtoo
- if (ret)
- return ret;
-
-+ ret = read_intra_function_calls(file);
-+ if (ret)
-+ return ret;
-+
- ret = add_call_destinations(file);
- if (ret)
- return ret;
+++ /dev/null
-From stable+bounces-25321-greg=kroah.com@vger.kernel.org Wed Feb 28 03:47:16 2024
-From: Rui Qi <qirui.001@bytedance.com>
-Date: Wed, 28 Feb 2024 10:45:33 +0800
-Subject: objtool: is_fentry_call() crashes if call has no destination
-To: bp@alien8.de, mingo@redhat.com, tglx@linutronix.de, hpa@zytor.com, jpoimboe@redhat.com, peterz@infradead.org, mbenes@suse.cz, gregkh@linuxfoundation.org, stable@vger.kernel.org, alexandre.chartre@oracle.com
-Cc: x86@kernel.org, linux-kernel@vger.kernel.org, yuanzhu@bytedance.com, Rui Qi <qirui.001@bytedance.com>
-Message-ID: <20240228024535.79980-2-qirui.001@bytedance.com>
-
-From: Alexandre Chartre <alexandre.chartre@oracle.com>
-
-commit 87cf61fe848ca8ddf091548671e168f52e8a718e upstream.
-
-Fix is_fentry_call() so that it works if a call has no destination
-set (call_dest). This needs to be done in order to support intra-
-function calls.
-
-Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
-Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
-Reviewed-by: Miroslav Benes <mbenes@suse.cz>
-Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
-Link: https://lkml.kernel.org/r/20200414103618.12657-2-alexandre.chartre@oracle.com
-Signed-off-by: Rui Qi <qirui.001@bytedance.com>
-Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
----
- tools/objtool/check.c | 2 +-
- 1 file changed, 1 insertion(+), 1 deletion(-)
-
---- a/tools/objtool/check.c
-+++ b/tools/objtool/check.c
-@@ -1367,7 +1367,7 @@ static int decode_sections(struct objtoo
-
- static bool is_fentry_call(struct instruction *insn)
- {
-- if (insn->type == INSN_CALL &&
-+ if (insn->type == INSN_CALL && insn->call_dest &&
- insn->call_dest->type == STT_NOTYPE &&
- !strcmp(insn->call_dest->name, "__fentry__"))
- return true;
+++ /dev/null
-From stable+bounces-25323-greg=kroah.com@vger.kernel.org Wed Feb 28 03:47:45 2024
-From: Rui Qi <qirui.001@bytedance.com>
-Date: Wed, 28 Feb 2024 10:45:35 +0800
-Subject: x86/speculation: Support intra-function call validation
-To: bp@alien8.de, mingo@redhat.com, tglx@linutronix.de, hpa@zytor.com, jpoimboe@redhat.com, peterz@infradead.org, mbenes@suse.cz, gregkh@linuxfoundation.org, stable@vger.kernel.org, alexandre.chartre@oracle.com
-Cc: x86@kernel.org, linux-kernel@vger.kernel.org, yuanzhu@bytedance.com, Rui Qi <qirui.001@bytedance.com>
-Message-ID: <20240228024535.79980-4-qirui.001@bytedance.com>
-
-From: Rui Qi <qirui.001@bytedance.com>
-
-commit 8afd1c7da2b0 ("x86/speculation: Change FILL_RETURN_BUFFER to work with
-objtool") does not support intra-function call stack validation, which causes
-kernel live patching to fail. This commit adds support for this, and after
-testing, the kernel live patching feature is restored to normal.
-
-Fixes: 8afd1c7da2b0 ("x86/speculation: Change FILL_RETURN_BUFFER to work with objtool")
-Cc: <stable@vger.kernel.org> # v5.4.250+
-Signed-off-by: Rui Qi <qirui.001@bytedance.com>
-Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
----
- arch/x86/include/asm/nospec-branch.h | 7 +++++++
- 1 file changed, 7 insertions(+)
-
---- a/arch/x86/include/asm/nospec-branch.h
-+++ b/arch/x86/include/asm/nospec-branch.h
-@@ -13,6 +13,8 @@
- #include <asm/unwind_hints.h>
- #include <asm/percpu.h>
-
-+#include <linux/frame.h>
-+#include <asm/unwind_hints.h>
- /*
- * This should be used immediately before a retpoline alternative. It tells
- * objtool where the retpolines are so that it can make sense of the control
-@@ -51,14 +53,18 @@
- #define __FILL_RETURN_BUFFER(reg, nr, sp) \
- mov $(nr/2), reg; \
- 771: \
-+ ANNOTATE_INTRA_FUNCTION_CALL; \
- call 772f; \
- 773: /* speculation trap */ \
-+ UNWIND_HINT_EMPTY; \
- pause; \
- lfence; \
- jmp 773b; \
- 772: \
-+ ANNOTATE_INTRA_FUNCTION_CALL; \
- call 774f; \
- 775: /* speculation trap */ \
-+ UNWIND_HINT_EMPTY; \
- pause; \
- lfence; \
- jmp 775b; \
-@@ -152,6 +158,7 @@
- .endm
-
- .macro ISSUE_UNBALANCED_RET_GUARD
-+ ANNOTATE_INTRA_FUNCTION_CALL;
- call .Lunbalanced_ret_guard_\@
- int3
- .Lunbalanced_ret_guard_\@:
projects / thirdparty / kernel / stable-queue.git / commitdiff
