[PATCH] powerpc: do not use kprobe section to exempt exception handlers
From: Nicholas Piggin <npiggin@gmail.com>
Date: 2016-09-15 14:30:05
Use the blacklist macros instead. This allows the linker to move exception handler functions close to callers and avoids trampolines in larger kernels. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> --- arch/powerpc/include/asm/asm-prototypes.h | 6 +++--- arch/powerpc/kernel/hw_breakpoint.c | 9 ++++++--- arch/powerpc/kernel/traps.c | 21 ++++++++++++++------- arch/powerpc/mm/fault.c | 4 ++-- 4 files changed, 25 insertions(+), 15 deletions(-)
diff --git a/arch/powerpc/include/asm/asm-prototypes.h b/arch/powerpc/include/asm/asm-prototypes.h
index e71b909..b1c3abe 100644
--- a/arch/powerpc/include/asm/asm-prototypes.h
+++ b/arch/powerpc/include/asm/asm-prototypes.h@@ -52,8 +52,8 @@ void SMIException(struct pt_regs *regs); void handle_hmi_exception(struct pt_regs *regs); void instruction_breakpoint_exception(struct pt_regs *regs); void RunModeException(struct pt_regs *regs); -void __kprobes single_step_exception(struct pt_regs *regs); -void __kprobes program_check_exception(struct pt_regs *regs); +void single_step_exception(struct pt_regs *regs); +void program_check_exception(struct pt_regs *regs); void alignment_exception(struct pt_regs *regs); void StackOverflow(struct pt_regs *regs); void nonrecoverable_exception(struct pt_regs *regs);
@@ -70,6 +70,6 @@ void unrecoverable_exception(struct pt_regs *regs); void kernel_bad_stack(struct pt_regs *regs); void system_reset_exception(struct pt_regs *regs); void machine_check_exception(struct pt_regs *regs); -void __kprobes emulation_assist_interrupt(struct pt_regs *regs); +void emulation_assist_interrupt(struct pt_regs *regs); #endif /* _ASM_POWERPC_ASM_PROTOTYPES_H */
diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c
index aec9a1b..9781c69 100644
--- a/arch/powerpc/kernel/hw_breakpoint.c
+++ b/arch/powerpc/kernel/hw_breakpoint.c@@ -206,7 +206,7 @@ void thread_change_pc(struct task_struct *tsk, struct pt_regs *regs) /* * Handle debug exception notifications. */ -int __kprobes hw_breakpoint_handler(struct die_args *args) +int hw_breakpoint_handler(struct die_args *args) { int rc = NOTIFY_STOP; struct perf_event *bp;
@@ -290,11 +290,12 @@ out: rcu_read_unlock(); return rc; } +NOKPROBE_SYMBOL(hw_breakpoint_handler); /* * Handle single-step exceptions following a DABR hit. */ -static int __kprobes single_step_dabr_instruction(struct die_args *args) +static int single_step_dabr_instruction(struct die_args *args) { struct pt_regs *regs = args->regs; struct perf_event *bp = NULL;
@@ -329,11 +330,12 @@ static int __kprobes single_step_dabr_instruction(struct die_args *args) return NOTIFY_STOP; } +NOKPROBE_SYMBOL(single_step_dabr_instruction); /* * Handle debug exception notifications. */ -int __kprobes hw_breakpoint_exceptions_notify( +int hw_breakpoint_exceptions_notify( struct notifier_block *unused, unsigned long val, void *data) { int ret = NOTIFY_DONE;
@@ -349,6 +351,7 @@ int __kprobes hw_breakpoint_exceptions_notify( return ret; } +NOKPROBE_SYMBOL(hw_breakpoint_exceptions_notify); /* * Release the user breakpoints used by ptrace
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 62859eb..7cbd6cf 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c@@ -117,7 +117,7 @@ static int die_owner = -1; static unsigned int die_nest_count; static int die_counter; -static unsigned __kprobes long oops_begin(struct pt_regs *regs) +static unsigned long oops_begin(struct pt_regs *regs) { int cpu; unsigned long flags;
@@ -144,8 +144,9 @@ static unsigned __kprobes long oops_begin(struct pt_regs *regs) pmac_backlight_unblank(); return flags; } +NOKPROBE_SYMBOL(oops_begin); -static void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, +static void oops_end(unsigned long flags, struct pt_regs *regs, int signr) { bust_spinlocks(0);
@@ -196,8 +197,9 @@ static void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, panic("Fatal exception"); do_exit(signr); } +NOKPROBE_SYMBOL(oops_end); -static int __kprobes __die(const char *str, struct pt_regs *regs, long err) +static int __die(const char *str, struct pt_regs *regs, long err) { printk("Oops: %s, sig: %ld [#%d]\n", str, err, ++die_counter); #ifdef CONFIG_PREEMPT
@@ -221,6 +223,7 @@ static int __kprobes __die(const char *str, struct pt_regs *regs, long err) return 0; } +NOKPROBE_SYMBOL(__die); void die(const char *str, struct pt_regs *regs, long err) {
@@ -802,7 +805,7 @@ void RunModeException(struct pt_regs *regs) _exception(SIGTRAP, regs, 0, 0); } -void __kprobes single_step_exception(struct pt_regs *regs) +void single_step_exception(struct pt_regs *regs) { enum ctx_state prev_state = exception_enter();
@@ -819,6 +822,7 @@ void __kprobes single_step_exception(struct pt_regs *regs) bail: exception_exit(prev_state); } +NOKPROBE_SYMBOL(single_step_exception); /* * After we have successfully emulated an instruction, we have to
@@ -1140,7 +1144,7 @@ static int emulate_math(struct pt_regs *regs) static inline int emulate_math(struct pt_regs *regs) { return -1; } #endif -void __kprobes program_check_exception(struct pt_regs *regs) +void program_check_exception(struct pt_regs *regs) { enum ctx_state prev_state = exception_enter(); unsigned int reason = get_reason(regs);
@@ -1260,16 +1264,18 @@ sigill: bail: exception_exit(prev_state); } +NOKPROBE_SYMBOL(program_check_exception); /* * This occurs when running in hypervisor mode on POWER6 or later * and an illegal instruction is encountered. */ -void __kprobes emulation_assist_interrupt(struct pt_regs *regs) +void emulation_assist_interrupt(struct pt_regs *regs) { regs->msr |= REASON_ILLEGAL; program_check_exception(regs); } +NOKPROBE_SYMBOL(emulation_assist_interrupt); void alignment_exception(struct pt_regs *regs) {
@@ -1656,7 +1662,7 @@ static void handle_debug(struct pt_regs *regs, unsigned long debug_status) mtspr(SPRN_DBCR0, current->thread.debug.dbcr0); } -void __kprobes DebugException(struct pt_regs *regs, unsigned long debug_status) +void DebugException(struct pt_regs *regs, unsigned long debug_status) { current->thread.debug.dbsr = debug_status;
@@ -1717,6 +1723,7 @@ void __kprobes DebugException(struct pt_regs *regs, unsigned long debug_status) } else handle_debug(regs, debug_status); } +NOKPROBE_SYMBOL(DebugException); #endif /* CONFIG_PPC_ADV_DEBUG_REGS */ #if !defined(CONFIG_TAU_INT)
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index bb1ffc5..d0b137d 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c@@ -205,7 +205,7 @@ static int mm_fault_error(struct pt_regs *regs, unsigned long addr, int fault) * The return value is 0 if the fault was handled, or the signal * number if this is a kernel fault that can't be handled here. */ -int __kprobes do_page_fault(struct pt_regs *regs, unsigned long address, +int do_page_fault(struct pt_regs *regs, unsigned long address, unsigned long error_code) { enum ctx_state prev_state = exception_enter();
@@ -498,8 +498,8 @@ bad_area_nosemaphore: bail: exception_exit(prev_state); return rc; - } +NOKPROBE_SYMBOL(do_page_fault); /* * bad_page_fault is called when we have a bad access from the kernel.
--
2.9.3