objtool/idle: Validate __cpuidle code as noinstr

Idle code is very like entry code in that RCU isn't available. As
such, add a little validation.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Tested-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230112195540.373461409@infradead.org

diff --git a/arch/alpha/kernel/vmlinux.lds.S b/arch/alpha/kernel/vmlinux.lds.S
index 5b78d64..2efa7df 100644 (file)
--- a/arch/alpha/kernel/vmlinux.lds.S
+++ b/arch/alpha/kernel/vmlinux.lds.S
@@ -27,7 +27,6 @@ SECTIONS
                HEAD_TEXT
                TEXT_TEXT
                SCHED_TEXT
-               CPUIDLE_TEXT
                LOCK_TEXT
                *(.fixup)
                *(.gnu.warning)

diff --git a/arch/arc/kernel/vmlinux.lds.S b/arch/arc/kernel/vmlinux.lds.S
index 529ae50..549c3f4 100644 (file)
--- a/arch/arc/kernel/vmlinux.lds.S
+++ b/arch/arc/kernel/vmlinux.lds.S
@@ -85,7 +85,6 @@ SECTIONS
                _stext = .;
                TEXT_TEXT
                SCHED_TEXT
-               CPUIDLE_TEXT
                LOCK_TEXT
                KPROBES_TEXT
                IRQENTRY_TEXT

diff --git a/arch/arm/include/asm/vmlinux.lds.h b/arch/arm/include/asm/vmlinux.lds.h
index fad45c8..4c8632d 100644 (file)
--- a/arch/arm/include/asm/vmlinux.lds.h
+++ b/arch/arm/include/asm/vmlinux.lds.h
@@ -96,7 +96,6 @@
                SOFTIRQENTRY_TEXT                                       \
                TEXT_TEXT                                               \
                SCHED_TEXT                                              \
-               CPUIDLE_TEXT                                            \
                LOCK_TEXT                                               \
                KPROBES_TEXT                                            \
                ARM_STUBS_TEXT                                          \

diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S
index 4c13daf..2777214 100644 (file)
--- a/arch/arm64/kernel/vmlinux.lds.S
+++ b/arch/arm64/kernel/vmlinux.lds.S
@@ -175,7 +175,6 @@ SECTIONS
                        ENTRY_TEXT
                        TEXT_TEXT
                        SCHED_TEXT
-                       CPUIDLE_TEXT
                        LOCK_TEXT
                        KPROBES_TEXT
                        HYPERVISOR_TEXT

diff --git a/arch/csky/kernel/vmlinux.lds.S b/arch/csky/kernel/vmlinux.lds.S
index 68c980d..d718961 100644 (file)
--- a/arch/csky/kernel/vmlinux.lds.S
+++ b/arch/csky/kernel/vmlinux.lds.S
@@ -34,7 +34,6 @@ SECTIONS
                SOFTIRQENTRY_TEXT
                TEXT_TEXT
                SCHED_TEXT
-               CPUIDLE_TEXT
                LOCK_TEXT
                KPROBES_TEXT
                *(.fixup)

diff --git a/arch/hexagon/kernel/vmlinux.lds.S b/arch/hexagon/kernel/vmlinux.lds.S
index 57465bf..1140051 100644 (file)
--- a/arch/hexagon/kernel/vmlinux.lds.S
+++ b/arch/hexagon/kernel/vmlinux.lds.S
@@ -41,7 +41,6 @@ SECTIONS
                IRQENTRY_TEXT
                SOFTIRQENTRY_TEXT
                SCHED_TEXT
-               CPUIDLE_TEXT
                LOCK_TEXT
                KPROBES_TEXT
                *(.fixup)

diff --git a/arch/ia64/kernel/vmlinux.lds.S b/arch/ia64/kernel/vmlinux.lds.S
index 9b26578..53dfde1 100644 (file)
--- a/arch/ia64/kernel/vmlinux.lds.S
+++ b/arch/ia64/kernel/vmlinux.lds.S
@@ -51,7 +51,6 @@ SECTIONS {
                __end_ivt_text = .;
                TEXT_TEXT
                SCHED_TEXT
-               CPUIDLE_TEXT
                LOCK_TEXT
                KPROBES_TEXT
                IRQENTRY_TEXT

diff --git a/arch/loongarch/kernel/vmlinux.lds.S b/arch/loongarch/kernel/vmlinux.lds.S
index 733b16e..78506b3 100644 (file)
--- a/arch/loongarch/kernel/vmlinux.lds.S
+++ b/arch/loongarch/kernel/vmlinux.lds.S
@@ -43,7 +43,6 @@ SECTIONS
        .text : {
                TEXT_TEXT
                SCHED_TEXT
-               CPUIDLE_TEXT
                LOCK_TEXT
                KPROBES_TEXT
                IRQENTRY_TEXT

diff --git a/arch/m68k/kernel/vmlinux-nommu.lds b/arch/m68k/kernel/vmlinux-nommu.lds
index 387f334..2624fc1 100644 (file)
--- a/arch/m68k/kernel/vmlinux-nommu.lds
+++ b/arch/m68k/kernel/vmlinux-nommu.lds
@@ -48,7 +48,6 @@ SECTIONS {
                IRQENTRY_TEXT
                SOFTIRQENTRY_TEXT
                SCHED_TEXT
-               CPUIDLE_TEXT
                LOCK_TEXT
                *(.fixup)
                . = ALIGN(16);

diff --git a/arch/m68k/kernel/vmlinux-std.lds b/arch/m68k/kernel/vmlinux-std.lds
index ed1d9ed..1ccdd04 100644 (file)
--- a/arch/m68k/kernel/vmlinux-std.lds
+++ b/arch/m68k/kernel/vmlinux-std.lds
@@ -19,7 +19,6 @@ SECTIONS
        IRQENTRY_TEXT
        SOFTIRQENTRY_TEXT
        SCHED_TEXT
-       CPUIDLE_TEXT
        LOCK_TEXT
        *(.fixup)
        *(.gnu.warning)

diff --git a/arch/m68k/kernel/vmlinux-sun3.lds b/arch/m68k/kernel/vmlinux-sun3.lds
index 4a52f44..f13ddcc 100644 (file)
--- a/arch/m68k/kernel/vmlinux-sun3.lds
+++ b/arch/m68k/kernel/vmlinux-sun3.lds
@@ -19,7 +19,6 @@ SECTIONS
        IRQENTRY_TEXT
        SOFTIRQENTRY_TEXT
        SCHED_TEXT
-       CPUIDLE_TEXT
        LOCK_TEXT
        *(.fixup)
        *(.gnu.warning)

diff --git a/arch/microblaze/kernel/vmlinux.lds.S b/arch/microblaze/kernel/vmlinux.lds.S
index fb31747..ae50d3d 100644 (file)
--- a/arch/microblaze/kernel/vmlinux.lds.S
+++ b/arch/microblaze/kernel/vmlinux.lds.S
@@ -36,7 +36,6 @@ SECTIONS {
                EXIT_TEXT
                EXIT_CALL
                SCHED_TEXT
-               CPUIDLE_TEXT
                LOCK_TEXT
                KPROBES_TEXT
                IRQENTRY_TEXT

diff --git a/arch/mips/kernel/vmlinux.lds.S b/arch/mips/kernel/vmlinux.lds.S
index 1f98947..52cbde6 100644 (file)
--- a/arch/mips/kernel/vmlinux.lds.S
+++ b/arch/mips/kernel/vmlinux.lds.S
@@ -61,7 +61,6 @@ SECTIONS
        .text : {
                TEXT_TEXT
                SCHED_TEXT
-               CPUIDLE_TEXT
                LOCK_TEXT
                KPROBES_TEXT
                IRQENTRY_TEXT

diff --git a/arch/nios2/kernel/vmlinux.lds.S b/arch/nios2/kernel/vmlinux.lds.S
index 126e114..37b9580 100644 (file)
--- a/arch/nios2/kernel/vmlinux.lds.S
+++ b/arch/nios2/kernel/vmlinux.lds.S
@@ -24,7 +24,6 @@ SECTIONS
        .text : {
                TEXT_TEXT
                SCHED_TEXT
-               CPUIDLE_TEXT
                LOCK_TEXT
                IRQENTRY_TEXT
                SOFTIRQENTRY_TEXT

diff --git a/arch/openrisc/kernel/vmlinux.lds.S b/arch/openrisc/kernel/vmlinux.lds.S
index d5c7bb0..bc13060 100644 (file)
--- a/arch/openrisc/kernel/vmlinux.lds.S
+++ b/arch/openrisc/kernel/vmlinux.lds.S
@@ -52,7 +52,6 @@ SECTIONS
           _stext = .;
          TEXT_TEXT
          SCHED_TEXT
-         CPUIDLE_TEXT
          LOCK_TEXT
          KPROBES_TEXT
          IRQENTRY_TEXT

diff --git a/arch/parisc/kernel/vmlinux.lds.S b/arch/parisc/kernel/vmlinux.lds.S
index 2769eb9..1aaa2ca 100644 (file)
--- a/arch/parisc/kernel/vmlinux.lds.S
+++ b/arch/parisc/kernel/vmlinux.lds.S
@@ -86,7 +86,6 @@ SECTIONS
                TEXT_TEXT
                LOCK_TEXT
                SCHED_TEXT
-               CPUIDLE_TEXT
                KPROBES_TEXT
                IRQENTRY_TEXT
                SOFTIRQENTRY_TEXT

diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index 8c3862b..86d5ca1 100644 (file)
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -111,7 +111,6 @@ SECTIONS
 #endif
                NOINSTR_TEXT
                SCHED_TEXT
-               CPUIDLE_TEXT
                LOCK_TEXT
                KPROBES_TEXT
                IRQENTRY_TEXT

diff --git a/arch/riscv/kernel/vmlinux-xip.lds.S b/arch/riscv/kernel/vmlinux-xip.lds.S
index 75e0fa8..eab9edc 100644 (file)
--- a/arch/riscv/kernel/vmlinux-xip.lds.S
+++ b/arch/riscv/kernel/vmlinux-xip.lds.S
@@ -39,7 +39,6 @@ SECTIONS
                _stext = .;
                TEXT_TEXT
                SCHED_TEXT
-               CPUIDLE_TEXT
                LOCK_TEXT
                KPROBES_TEXT
                ENTRY_TEXT

diff --git a/arch/riscv/kernel/vmlinux.lds.S b/arch/riscv/kernel/vmlinux.lds.S
index 4e6c88a..643ab60 100644 (file)
--- a/arch/riscv/kernel/vmlinux.lds.S
+++ b/arch/riscv/kernel/vmlinux.lds.S
@@ -42,7 +42,6 @@ SECTIONS
                _stext = .;
                TEXT_TEXT
                SCHED_TEXT
-               CPUIDLE_TEXT
                LOCK_TEXT
                KPROBES_TEXT
                ENTRY_TEXT

diff --git a/arch/s390/kernel/vmlinux.lds.S b/arch/s390/kernel/vmlinux.lds.S
index 5ea3830..d1f1ab2 100644 (file)
--- a/arch/s390/kernel/vmlinux.lds.S
+++ b/arch/s390/kernel/vmlinux.lds.S
@@ -42,7 +42,6 @@ SECTIONS
                HEAD_TEXT
                TEXT_TEXT
                SCHED_TEXT
-               CPUIDLE_TEXT
                LOCK_TEXT
                KPROBES_TEXT
                IRQENTRY_TEXT

diff --git a/arch/sh/kernel/vmlinux.lds.S b/arch/sh/kernel/vmlinux.lds.S
index 3161b9c..947e2e2 100644 (file)
--- a/arch/sh/kernel/vmlinux.lds.S
+++ b/arch/sh/kernel/vmlinux.lds.S
@@ -29,7 +29,6 @@ SECTIONS
                HEAD_TEXT
                TEXT_TEXT
                SCHED_TEXT
-               CPUIDLE_TEXT
                LOCK_TEXT
                KPROBES_TEXT
                IRQENTRY_TEXT

diff --git a/arch/sparc/kernel/vmlinux.lds.S b/arch/sparc/kernel/vmlinux.lds.S
index d55ae65..d317a84 100644 (file)
--- a/arch/sparc/kernel/vmlinux.lds.S
+++ b/arch/sparc/kernel/vmlinux.lds.S
@@ -50,7 +50,6 @@ SECTIONS
                HEAD_TEXT
                TEXT_TEXT
                SCHED_TEXT
-               CPUIDLE_TEXT
                LOCK_TEXT
                KPROBES_TEXT
                IRQENTRY_TEXT

diff --git a/arch/um/kernel/dyn.lds.S b/arch/um/kernel/dyn.lds.S
index 2b7fc5b..3385d65 100644 (file)
--- a/arch/um/kernel/dyn.lds.S
+++ b/arch/um/kernel/dyn.lds.S
@@ -74,7 +74,6 @@ SECTIONS
     _stext = .;
     TEXT_TEXT
     SCHED_TEXT
-    CPUIDLE_TEXT
     LOCK_TEXT
     IRQENTRY_TEXT
     SOFTIRQENTRY_TEXT

diff --git a/arch/um/kernel/uml.lds.S b/arch/um/kernel/uml.lds.S
index 71a59b8..5c92d58 100644 (file)
--- a/arch/um/kernel/uml.lds.S
+++ b/arch/um/kernel/uml.lds.S
@@ -35,7 +35,6 @@ SECTIONS
     _stext = .;
     TEXT_TEXT
     SCHED_TEXT
-    CPUIDLE_TEXT
     LOCK_TEXT
     IRQENTRY_TEXT
     SOFTIRQENTRY_TEXT

diff --git a/arch/x86/include/asm/irqflags.h b/arch/x86/include/asm/irqflags.h
index 7793e52..8c5ae64 100644 (file)
--- a/arch/x86/include/asm/irqflags.h
+++ b/arch/x86/include/asm/irqflags.h
@@ -8,9 +8,6 @@
 
 #include <asm/nospec-branch.h>
 
-/* Provide __cpuidle; we can't safely include <linux/cpu.h> */
-#define __cpuidle __section(".cpuidle.text")
-
 /*
  * Interrupt control:
  */
@@ -45,13 +42,13 @@ static __always_inline void native_irq_enable(void)
        asm volatile("sti": : :"memory");
 }
 
-static inline __cpuidle void native_safe_halt(void)
+static __always_inline void native_safe_halt(void)
 {
        mds_idle_clear_cpu_buffers();
        asm volatile("sti; hlt": : :"memory");
 }
 
-static inline __cpuidle void native_halt(void)
+static __always_inline void native_halt(void)
 {
        mds_idle_clear_cpu_buffers();
        asm volatile("hlt": : :"memory");
@@ -84,7 +81,7 @@ static __always_inline void arch_local_irq_enable(void)
  * Used in the idle loop; sti takes one instruction cycle
  * to complete:
  */
-static inline __cpuidle void arch_safe_halt(void)
+static __always_inline void arch_safe_halt(void)
 {
        native_safe_halt();
 }
@@ -93,7 +90,7 @@ static inline __cpuidle void arch_safe_halt(void)
  * Used when interrupts are already enabled or to
  * shutdown the processor:
  */
-static inline __cpuidle void halt(void)
+static __always_inline void halt(void)
 {
        native_halt();
 }

diff --git a/arch/x86/include/asm/mwait.h b/arch/x86/include/asm/mwait.h
index 3a8fdf8..f224216 100644 (file)
--- a/arch/x86/include/asm/mwait.h
+++ b/arch/x86/include/asm/mwait.h
@@ -105,7 +105,7 @@ static inline void __sti_mwait(unsigned long eax, unsigned long ecx)
  * New with Core Duo processors, MWAIT can take some hints based on CPU
  * capability.
  */
-static inline void mwait_idle_with_hints(unsigned long eax, unsigned long ecx)
+static __always_inline void mwait_idle_with_hints(unsigned long eax, unsigned long ecx)
 {
        if (static_cpu_has_bug(X86_BUG_MONITOR) || !current_set_polling_and_test()) {
                if (static_cpu_has_bug(X86_BUG_CLFLUSH_MONITOR)) {

diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index 2e0ee14..25f1552 100644 (file)
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -129,7 +129,6 @@ SECTIONS
                HEAD_TEXT
                TEXT_TEXT
                SCHED_TEXT
-               CPUIDLE_TEXT
                LOCK_TEXT
                KPROBES_TEXT
                SOFTIRQENTRY_TEXT

diff --git a/arch/xtensa/kernel/vmlinux.lds.S b/arch/xtensa/kernel/vmlinux.lds.S
index 965a395..c14fd96 100644 (file)
--- a/arch/xtensa/kernel/vmlinux.lds.S
+++ b/arch/xtensa/kernel/vmlinux.lds.S
@@ -125,7 +125,6 @@ SECTIONS
     ENTRY_TEXT
     TEXT_TEXT
     SCHED_TEXT
-    CPUIDLE_TEXT
     LOCK_TEXT
     *(.fixup)
   }

diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index a94219e..ad0d394 100644 (file)
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -558,6 +558,9 @@
                ALIGN_FUNCTION();                                       \
                __noinstr_text_start = .;                               \
                *(.noinstr.text)                                        \
+               __cpuidle_text_start = .;                               \
+               *(.cpuidle.text)                                        \
+               __cpuidle_text_end = .;                                 \
                __noinstr_text_end = .;
 
 /*
@@ -598,12 +601,6 @@
                *(.spinlock.text)                                       \
                __lock_text_end = .;
 
-#define CPUIDLE_TEXT                                                   \
-               ALIGN_FUNCTION();                                       \
-               __cpuidle_text_start = .;                               \
-               *(.cpuidle.text)                                        \
-               __cpuidle_text_end = .;
-
 #define KPROBES_TEXT                                                   \
                ALIGN_FUNCTION();                                       \
                __kprobes_text_start = .;                               \

diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h
index 7c1afe0..d785890 100644 (file)
--- a/include/linux/compiler_types.h
+++ b/include/linux/compiler_types.h
@@ -232,11 +232,15 @@ struct ftrace_likely_data {
 #endif
 
 /* Section for code which can't be instrumented at all */
-#define noinstr                                                                \
-       noinline notrace __attribute((__section__(".noinstr.text")))    \
+#define __noinstr_section(section)                                     \
+       noinline notrace __attribute((__section__(section)))            \
        __no_kcsan __no_sanitize_address __no_profile __no_sanitize_coverage \
        __no_sanitize_memory
 
+#define noinstr __noinstr_section(".noinstr.text")
+
+#define __cpuidle __noinstr_section(".cpuidle.text")
+
 #endif /* __KERNEL__ */
 
 #endif /* __ASSEMBLY__ */

diff --git a/include/linux/cpu.h b/include/linux/cpu.h
index 314802f..f83e451 100644 (file)
--- a/include/linux/cpu.h
+++ b/include/linux/cpu.h
@@ -176,9 +176,6 @@ void __noreturn cpu_startup_entry(enum cpuhp_state state);
 
 void cpu_idle_poll_ctrl(bool enable);
 
-/* Attach to any functions which should be considered cpuidle. */
-#define __cpuidle      __section(".cpuidle.text")
-
 bool cpu_in_idle(unsigned long pc);
 
 void arch_cpu_idle(void);

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 4350be7..64954aa 100644 (file)
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -376,6 +376,7 @@ static int decode_instructions(struct objtool_file *file)
 
                if (!strcmp(sec->name, ".noinstr.text") ||
                    !strcmp(sec->name, ".entry.text") ||
+                   !strcmp(sec->name, ".cpuidle.text") ||
                    !strncmp(sec->name, ".text.__x86.", 12))
                        sec->noinstr = true;
 
@@ -3366,6 +3367,12 @@ static inline bool noinstr_call_dest(struct objtool_file *file,
                return true;
 
        /*
+        * If the symbol is a static_call trampoline, we can't tell.
+        */
+       if (func->static_call_tramp)
+               return true;
+
+       /*
         * The __ubsan_handle_*() calls are like WARN(), they only happen when
         * something 'BAD' happened. At the risk of taking the machine down,
         * let them proceed to get the message out.
@@ -4162,6 +4169,12 @@ static int validate_noinstr_sections(struct objtool_file *file)
                warnings += validate_unwind_hints(file, sec);
        }
 
+       sec = find_section_by_name(file->elf, ".cpuidle.text");
+       if (sec) {
+               warnings += validate_section(file, sec);
+               warnings += validate_unwind_hints(file, sec);
+       }
+
        return warnings;
 }