From b6e43c0e3129ffe87e65c85f20fcbdf0eb86fba0 Mon Sep 17 00:00:00 2001 From: James Morse Date: Fri, 25 Oct 2019 17:42:10 +0100 Subject: [PATCH] arm64: remove __exception annotations Since commit 732674980139 ("arm64: unwind: reference pt_regs via embedded stack frame") arm64 has not used the __exception annotation to dump the pt_regs during stack tracing. in_exception_text() has no callers. This annotation is only used to blacklist kprobes, it means the same as __kprobes. Section annotations like this require the functions to be grouped together between the start/end markers, and placed according to the linker script. For kprobes we also have NOKPROBE_SYMBOL() which logs the symbol address in a section that kprobes parses and blacklists at boot. Using NOKPROBE_SYMBOL() instead lets kprobes publish the list of blacklisted symbols, and saves us from having an arm64 specific spelling of __kprobes. do_debug_exception() already has a NOKPROBE_SYMBOL() annotation. Signed-off-by: James Morse Acked-by: Mark Rutland Acked-by: Masami Hiramatsu Signed-off-by: Catalin Marinas --- arch/arm64/include/asm/exception.h | 4 ++-- arch/arm64/include/asm/traps.h | 10 ---------- arch/arm64/kernel/probes/kprobes.c | 4 ---- arch/arm64/kernel/traps.c | 10 +++++++--- arch/arm64/kernel/vmlinux.lds.S | 3 --- arch/arm64/mm/fault.c | 34 +++++++++++++++++----------------- 6 files changed, 26 insertions(+), 39 deletions(-) diff --git a/arch/arm64/include/asm/exception.h b/arch/arm64/include/asm/exception.h index a17393ff6677..b0b3ba56e919 100644 --- a/arch/arm64/include/asm/exception.h +++ b/arch/arm64/include/asm/exception.h @@ -8,14 +8,14 @@ #define __ASM_EXCEPTION_H #include +#include #include -#define __exception __attribute__((section(".exception.text"))) #ifdef CONFIG_FUNCTION_GRAPH_TRACER #define __exception_irq_entry __irq_entry #else -#define __exception_irq_entry __exception +#define __exception_irq_entry __kprobes #endif static inline u32 disr_to_esr(u64 disr) diff --git a/arch/arm64/include/asm/traps.h b/arch/arm64/include/asm/traps.h index 59690613ac31..cee5928e1b7d 100644 --- a/arch/arm64/include/asm/traps.h +++ b/arch/arm64/include/asm/traps.h @@ -42,16 +42,6 @@ static inline int __in_irqentry_text(unsigned long ptr) ptr < (unsigned long)&__irqentry_text_end; } -static inline int in_exception_text(unsigned long ptr) -{ - int in; - - in = ptr >= (unsigned long)&__exception_text_start && - ptr < (unsigned long)&__exception_text_end; - - return in ? : __in_irqentry_text(ptr); -} - static inline int in_entry_text(unsigned long ptr) { return ptr >= (unsigned long)&__entry_text_start && diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c index c4452827419b..d1c95dcf1d78 100644 --- a/arch/arm64/kernel/probes/kprobes.c +++ b/arch/arm64/kernel/probes/kprobes.c @@ -455,10 +455,6 @@ int __init arch_populate_kprobe_blacklist(void) (unsigned long)__irqentry_text_end); if (ret) return ret; - ret = kprobe_add_area_blacklist((unsigned long)__exception_text_start, - (unsigned long)__exception_text_end); - if (ret) - return ret; ret = kprobe_add_area_blacklist((unsigned long)__idmap_text_start, (unsigned long)__idmap_text_end); if (ret) diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index 34739e80211b..ba1a571a7774 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -35,6 +35,7 @@ #include #include #include +#include #include #include #include @@ -393,7 +394,7 @@ void arm64_notify_segfault(unsigned long addr) force_signal_inject(SIGSEGV, code, addr); } -asmlinkage void __exception do_undefinstr(struct pt_regs *regs) +asmlinkage void do_undefinstr(struct pt_regs *regs) { /* check for AArch32 breakpoint instructions */ if (!aarch32_break_handler(regs)) @@ -405,6 +406,7 @@ asmlinkage void __exception do_undefinstr(struct pt_regs *regs) BUG_ON(!user_mode(regs)); force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc); } +NOKPROBE_SYMBOL(do_undefinstr); #define __user_cache_maint(insn, address, res) \ if (address >= user_addr_max()) { \ @@ -667,7 +669,7 @@ static const struct sys64_hook cp15_64_hooks[] = { {}, }; -asmlinkage void __exception do_cp15instr(unsigned int esr, struct pt_regs *regs) +asmlinkage void do_cp15instr(unsigned int esr, struct pt_regs *regs) { const struct sys64_hook *hook, *hook_base; @@ -705,9 +707,10 @@ asmlinkage void __exception do_cp15instr(unsigned int esr, struct pt_regs *regs) */ do_undefinstr(regs); } +NOKPROBE_SYMBOL(do_cp15instr); #endif -asmlinkage void __exception do_sysinstr(unsigned int esr, struct pt_regs *regs) +asmlinkage void do_sysinstr(unsigned int esr, struct pt_regs *regs) { const struct sys64_hook *hook; @@ -724,6 +727,7 @@ asmlinkage void __exception do_sysinstr(unsigned int esr, struct pt_regs *regs) */ do_undefinstr(regs); } +NOKPROBE_SYMBOL(do_sysinstr); static const char *esr_class_str[] = { [0 ... ESR_ELx_EC_MAX] = "UNRECOGNIZED EC", diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S index aa76f7259668..009057517bdd 100644 --- a/arch/arm64/kernel/vmlinux.lds.S +++ b/arch/arm64/kernel/vmlinux.lds.S @@ -111,9 +111,6 @@ SECTIONS } .text : { /* Real text segment */ _stext = .; /* Text and read-only data */ - __exception_text_start = .; - *(.exception.text) - __exception_text_end = .; IRQENTRY_TEXT SOFTIRQENTRY_TEXT ENTRY_TEXT diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 855f2a7954e6..844cd2535826 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -33,6 +33,7 @@ #include #include #include +#include #include #include #include @@ -732,8 +733,8 @@ static const struct fault_info fault_info[] = { { do_bad, SIGKILL, SI_KERNEL, "unknown 63" }, }; -asmlinkage void __exception do_mem_abort(unsigned long addr, unsigned int esr, - struct pt_regs *regs) +asmlinkage void do_mem_abort(unsigned long addr, unsigned int esr, + struct pt_regs *regs) { const struct fault_info *inf = esr_to_fault_info(esr); @@ -749,16 +750,17 @@ asmlinkage void __exception do_mem_abort(unsigned long addr, unsigned int esr, arm64_notify_die(inf->name, regs, inf->sig, inf->code, (void __user *)addr, esr); } +NOKPROBE_SYMBOL(do_mem_abort); -asmlinkage void __exception do_el0_irq_bp_hardening(void) +asmlinkage void do_el0_irq_bp_hardening(void) { /* PC has already been checked in entry.S */ arm64_apply_bp_hardening(); } +NOKPROBE_SYMBOL(do_el0_irq_bp_hardening); -asmlinkage void __exception do_el0_ia_bp_hardening(unsigned long addr, - unsigned int esr, - struct pt_regs *regs) +asmlinkage void do_el0_ia_bp_hardening(unsigned long addr, unsigned int esr, + struct pt_regs *regs) { /* * We've taken an instruction abort from userspace and not yet @@ -771,11 +773,10 @@ asmlinkage void __exception do_el0_ia_bp_hardening(unsigned long addr, local_daif_restore(DAIF_PROCCTX); do_mem_abort(addr, esr, regs); } +NOKPROBE_SYMBOL(do_el0_ia_bp_hardening); - -asmlinkage void __exception do_sp_pc_abort(unsigned long addr, - unsigned int esr, - struct pt_regs *regs) +asmlinkage void do_sp_pc_abort(unsigned long addr, unsigned int esr, + struct pt_regs *regs) { if (user_mode(regs)) { if (!is_ttbr0_addr(instruction_pointer(regs))) @@ -786,6 +787,7 @@ asmlinkage void __exception do_sp_pc_abort(unsigned long addr, arm64_notify_die("SP/PC alignment exception", regs, SIGBUS, BUS_ADRALN, (void __user *)addr, esr); } +NOKPROBE_SYMBOL(do_sp_pc_abort); int __init early_brk64(unsigned long addr, unsigned int esr, struct pt_regs *regs); @@ -868,8 +870,7 @@ NOKPROBE_SYMBOL(debug_exception_exit); #ifdef CONFIG_ARM64_ERRATUM_1463225 DECLARE_PER_CPU(int, __in_cortex_a76_erratum_1463225_wa); -static int __exception -cortex_a76_erratum_1463225_debug_handler(struct pt_regs *regs) +static int cortex_a76_erratum_1463225_debug_handler(struct pt_regs *regs) { if (user_mode(regs)) return 0; @@ -888,16 +889,15 @@ cortex_a76_erratum_1463225_debug_handler(struct pt_regs *regs) return 1; } #else -static int __exception -cortex_a76_erratum_1463225_debug_handler(struct pt_regs *regs) +static int cortex_a76_erratum_1463225_debug_handler(struct pt_regs *regs) { return 0; } #endif /* CONFIG_ARM64_ERRATUM_1463225 */ +NOKPROBE_SYMBOL(cortex_a76_erratum_1463225_debug_handler); -asmlinkage void __exception do_debug_exception(unsigned long addr_if_watchpoint, - unsigned int esr, - struct pt_regs *regs) +asmlinkage void do_debug_exception(unsigned long addr_if_watchpoint, + unsigned int esr, struct pt_regs *regs) { const struct fault_info *inf = esr_to_debug_fault_info(esr); unsigned long pc = instruction_pointer(regs); -- 2.11.0