diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2022-10-18 13:49:21 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2022-10-20 17:10:27 +0200 |
| commit | 883bbbffa5a4ffd1915f8b42934dab81b7f87226 (patch) | |
| tree | 6d650ad1ce9df229da9d3786bfc26d38c4f9466f | |
| parent | b5f1fc3184405ab955db1b86d41d8b744d07c12d (diff) | |
ftrace,kcfi: Separate ftrace_stub() and ftrace_stub_graph()
Different function signatures means they needs to be different
functions; otherwise CFI gets upset.
As triggered by the ftrace boot tests:
[] CFI failure at ftrace_return_to_handler+0xac/0x16c (target: ftrace_stub+0x0/0x14; expected type: 0x0a5d5347)
Fixes: 3c516f89e17e ("x86: Add support for CONFIG_CFI_CLANG")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lkml.kernel.org/r/Y06dg4e1xF6JTdQq@hirez.programming.kicks-ass.net
| -rw-r--r-- | arch/arm64/kernel/entry-ftrace.S | 7 | ||||
| -rw-r--r-- | arch/x86/kernel/ftrace_64.S | 17 | ||||
| -rw-r--r-- | include/asm-generic/vmlinux.lds.h | 18 |
3 files changed, 27 insertions, 15 deletions
diff --git a/arch/arm64/kernel/entry-ftrace.S b/arch/arm64/kernel/entry-ftrace.S index bd5df50e4643..795344ab4ec4 100644 --- a/arch/arm64/kernel/entry-ftrace.S +++ b/arch/arm64/kernel/entry-ftrace.S @@ -7,6 +7,7 @@ */ #include <linux/linkage.h> +#include <linux/cfi_types.h> #include <asm/asm-offsets.h> #include <asm/assembler.h> #include <asm/ftrace.h> @@ -294,10 +295,14 @@ SYM_FUNC_END(ftrace_graph_caller) #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ #endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ -SYM_FUNC_START(ftrace_stub) +SYM_TYPED_FUNC_START(ftrace_stub) ret SYM_FUNC_END(ftrace_stub) +SYM_TYPED_FUNC_START(ftrace_stub_graph) + ret +SYM_FUNC_END(ftrace_stub_graph) + #ifdef CONFIG_FUNCTION_GRAPH_TRACER /* * void return_to_handler(void) diff --git a/arch/x86/kernel/ftrace_64.S b/arch/x86/kernel/ftrace_64.S index a90c55a6b481..2a4be92fd144 100644 --- a/arch/x86/kernel/ftrace_64.S +++ b/arch/x86/kernel/ftrace_64.S @@ -4,6 +4,7 @@ */ #include <linux/linkage.h> +#include <linux/cfi_types.h> #include <asm/ptrace.h> #include <asm/ftrace.h> #include <asm/export.h> @@ -129,6 +130,14 @@ .endm +SYM_TYPED_FUNC_START(ftrace_stub) + RET +SYM_FUNC_END(ftrace_stub) + +SYM_TYPED_FUNC_START(ftrace_stub_graph) + RET +SYM_FUNC_END(ftrace_stub_graph) + #ifdef CONFIG_DYNAMIC_FTRACE SYM_FUNC_START(__fentry__) @@ -176,11 +185,6 @@ SYM_INNER_LABEL(ftrace_caller_end, SYM_L_GLOBAL) SYM_FUNC_END(ftrace_caller); STACK_FRAME_NON_STANDARD_FP(ftrace_caller) -SYM_FUNC_START(ftrace_stub) - UNWIND_HINT_FUNC - RET -SYM_FUNC_END(ftrace_stub) - SYM_FUNC_START(ftrace_regs_caller) /* Save the current flags before any operations that can change them */ pushfq @@ -282,9 +286,6 @@ STACK_FRAME_NON_STANDARD_FP(ftrace_regs_caller) SYM_FUNC_START(__fentry__) cmpq $ftrace_stub, ftrace_trace_function jnz trace - -SYM_INNER_LABEL(ftrace_stub, SYM_L_GLOBAL) - ENDBR RET trace: diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index c15de165ec8f..d06ada2341cb 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -162,6 +162,16 @@ #define PATCHABLE_DISCARDS *(__patchable_function_entries) #endif +#ifndef CONFIG_ARCH_SUPPORTS_CFI_CLANG +/* + * Simply points to ftrace_stub, but with the proper protocol. + * Defined by the linker script in linux/vmlinux.lds.h + */ +#define FTRACE_STUB_HACK ftrace_stub_graph = ftrace_stub; +#else +#define FTRACE_STUB_HACK +#endif + #ifdef CONFIG_FTRACE_MCOUNT_RECORD /* * The ftrace call sites are logged to a section whose name depends on the @@ -169,10 +179,6 @@ * FTRACE_CALLSITE_SECTION. We capture all of them here to avoid header * dependencies for FTRACE_CALLSITE_SECTION's definition. * - * Need to also make ftrace_stub_graph point to ftrace_stub - * so that the same stub location may have different protocols - * and not mess up with C verifiers. - * * ftrace_ops_list_func will be defined as arch_ftrace_ops_list_func * as some archs will have a different prototype for that function * but ftrace_ops_list_func() will have a single prototype. @@ -182,11 +188,11 @@ KEEP(*(__mcount_loc)) \ KEEP_PATCHABLE \ __stop_mcount_loc = .; \ - ftrace_stub_graph = ftrace_stub; \ + FTRACE_STUB_HACK \ ftrace_ops_list_func = arch_ftrace_ops_list_func; #else # ifdef CONFIG_FUNCTION_TRACER -# define MCOUNT_REC() ftrace_stub_graph = ftrace_stub; \ +# define MCOUNT_REC() FTRACE_STUB_HACK \ ftrace_ops_list_func = arch_ftrace_ops_list_func; # else # define MCOUNT_REC() |