[PATCH v15 05/10] arm64: Blacklist non-kprobe-able symbol
From: David Long <hidden>
Date: 2016-07-08 16:36:39
Also in:
lkml
Subsystem:
arm pmu profiling and debugging, arm64 port (aarch64 architecture), the rest · Maintainers:
Will Deacon, Mark Rutland, Catalin Marinas, Linus Torvalds
From: Pratyush Anand <redacted> Add all function symbols which are called from do_debug_exception under NOKPROBE_SYMBOL, as they can not kprobed. Signed-off-by: Pratyush Anand <redacted> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> --- arch/arm64/kernel/arm64ksyms.c | 2 ++ arch/arm64/kernel/debug-monitors.c | 17 +++++++++++++++++ arch/arm64/kernel/hw_breakpoint.c | 8 ++++++++ arch/arm64/kernel/kgdb.c | 4 ++++ 4 files changed, 31 insertions(+)
diff --git a/arch/arm64/kernel/arm64ksyms.c b/arch/arm64/kernel/arm64ksyms.c
index 678f30b0..b96ff1a 100644
--- a/arch/arm64/kernel/arm64ksyms.c
+++ b/arch/arm64/kernel/arm64ksyms.c@@ -27,6 +27,7 @@ #include <linux/uaccess.h> #include <linux/io.h> #include <linux/arm-smccc.h> +#include <linux/kprobes.h> #include <asm/checksum.h>
@@ -68,6 +69,7 @@ EXPORT_SYMBOL(test_and_change_bit); #ifdef CONFIG_FUNCTION_TRACER EXPORT_SYMBOL(_mcount); +NOKPROBE_SYMBOL(_mcount); #endif /* arm-smccc */
diff --git a/arch/arm64/kernel/debug-monitors.c b/arch/arm64/kernel/debug-monitors.c
index 395de61..2fbc1b9 100644
--- a/arch/arm64/kernel/debug-monitors.c
+++ b/arch/arm64/kernel/debug-monitors.c@@ -49,6 +49,7 @@ static void mdscr_write(u32 mdscr) asm volatile("msr mdscr_el1, %0" :: "r" (mdscr)); local_dbg_restore(flags); } +NOKPROBE_SYMBOL(mdscr_write); static u32 mdscr_read(void) {
@@ -56,6 +57,7 @@ static u32 mdscr_read(void) asm volatile("mrs %0, mdscr_el1" : "=r" (mdscr)); return mdscr; } +NOKPROBE_SYMBOL(mdscr_read); /* * Allow root to disable self-hosted debug from userspace.
@@ -104,6 +106,7 @@ void enable_debug_monitors(enum dbg_active_el el) mdscr_write(mdscr); } } +NOKPROBE_SYMBOL(enable_debug_monitors); void disable_debug_monitors(enum dbg_active_el el) {
@@ -124,6 +127,7 @@ void disable_debug_monitors(enum dbg_active_el el) mdscr_write(mdscr); } } +NOKPROBE_SYMBOL(disable_debug_monitors); /* * OS lock clearing.
@@ -174,6 +178,7 @@ static void set_regs_spsr_ss(struct pt_regs *regs) spsr |= DBG_SPSR_SS; regs->pstate = spsr; } +NOKPROBE_SYMBOL(set_regs_spsr_ss); static void clear_regs_spsr_ss(struct pt_regs *regs) {
@@ -183,6 +188,7 @@ static void clear_regs_spsr_ss(struct pt_regs *regs) spsr &= ~DBG_SPSR_SS; regs->pstate = spsr; } +NOKPROBE_SYMBOL(clear_regs_spsr_ss); /* EL1 Single Step Handler hooks */ static LIST_HEAD(step_hook);
@@ -226,6 +232,7 @@ static int call_step_hook(struct pt_regs *regs, unsigned int esr) return retval; } +NOKPROBE_SYMBOL(call_step_hook); static void send_user_sigtrap(int si_code) {
@@ -284,6 +291,7 @@ static int single_step_handler(unsigned long addr, unsigned int esr, return 0; } +NOKPROBE_SYMBOL(single_step_handler); /* * Breakpoint handler is re-entrant as another breakpoint can
@@ -321,6 +329,7 @@ static int call_break_hook(struct pt_regs *regs, unsigned int esr) return fn ? fn(regs, esr) : DBG_HOOK_ERROR; } +NOKPROBE_SYMBOL(call_break_hook); static int brk_handler(unsigned long addr, unsigned int esr, struct pt_regs *regs)
@@ -341,6 +350,7 @@ static int brk_handler(unsigned long addr, unsigned int esr, return 0; } +NOKPROBE_SYMBOL(brk_handler); int aarch32_break_handler(struct pt_regs *regs) {
@@ -377,6 +387,7 @@ int aarch32_break_handler(struct pt_regs *regs) send_user_sigtrap(TRAP_BRKPT); return 0; } +NOKPROBE_SYMBOL(aarch32_break_handler); static int __init debug_traps_init(void) {
@@ -398,6 +409,7 @@ void user_rewind_single_step(struct task_struct *task) if (test_ti_thread_flag(task_thread_info(task), TIF_SINGLESTEP)) set_regs_spsr_ss(task_pt_regs(task)); } +NOKPROBE_SYMBOL(user_rewind_single_step); void user_fastforward_single_step(struct task_struct *task) {
@@ -413,6 +425,7 @@ void kernel_enable_single_step(struct pt_regs *regs) mdscr_write(mdscr_read() | DBG_MDSCR_SS); enable_debug_monitors(DBG_ACTIVE_EL1); } +NOKPROBE_SYMBOL(kernel_enable_single_step); void kernel_disable_single_step(void) {
@@ -420,12 +433,14 @@ void kernel_disable_single_step(void) mdscr_write(mdscr_read() & ~DBG_MDSCR_SS); disable_debug_monitors(DBG_ACTIVE_EL1); } +NOKPROBE_SYMBOL(kernel_disable_single_step); int kernel_active_single_step(void) { WARN_ON(!irqs_disabled()); return mdscr_read() & DBG_MDSCR_SS; } +NOKPROBE_SYMBOL(kernel_active_single_step); /* ptrace API */ void user_enable_single_step(struct task_struct *task)
@@ -433,8 +448,10 @@ void user_enable_single_step(struct task_struct *task) set_ti_thread_flag(task_thread_info(task), TIF_SINGLESTEP); set_regs_spsr_ss(task_pt_regs(task)); } +NOKPROBE_SYMBOL(user_enable_single_step); void user_disable_single_step(struct task_struct *task) { clear_ti_thread_flag(task_thread_info(task), TIF_SINGLESTEP); } +NOKPROBE_SYMBOL(user_disable_single_step);
diff --git a/arch/arm64/kernel/hw_breakpoint.c b/arch/arm64/kernel/hw_breakpoint.c
index ce21aa8..26a6bf7 100644
--- a/arch/arm64/kernel/hw_breakpoint.c
+++ b/arch/arm64/kernel/hw_breakpoint.c@@ -24,6 +24,7 @@ #include <linux/cpu_pm.h> #include <linux/errno.h> #include <linux/hw_breakpoint.h> +#include <linux/kprobes.h> #include <linux/perf_event.h> #include <linux/ptrace.h> #include <linux/smp.h>
@@ -127,6 +128,7 @@ static u64 read_wb_reg(int reg, int n) return val; } +NOKPROBE_SYMBOL(read_wb_reg); static void write_wb_reg(int reg, int n, u64 val) {
@@ -140,6 +142,7 @@ static void write_wb_reg(int reg, int n, u64 val) } isb(); } +NOKPROBE_SYMBOL(write_wb_reg); /* * Convert a breakpoint privilege level to the corresponding exception
@@ -157,6 +160,7 @@ static enum dbg_active_el debug_exception_level(int privilege) return -EINVAL; } } +NOKPROBE_SYMBOL(debug_exception_level); enum hw_breakpoint_ops { HW_BREAKPOINT_INSTALL,
@@ -575,6 +579,7 @@ static void toggle_bp_registers(int reg, enum dbg_active_el el, int enable) write_wb_reg(reg, i, ctrl); } } +NOKPROBE_SYMBOL(toggle_bp_registers); /* * Debug exception handlers.
@@ -654,6 +659,7 @@ unlock: return 0; } +NOKPROBE_SYMBOL(breakpoint_handler); static int watchpoint_handler(unsigned long addr, unsigned int esr, struct pt_regs *regs)
@@ -756,6 +762,7 @@ unlock: return 0; } +NOKPROBE_SYMBOL(watchpoint_handler); /* * Handle single-step exception.
@@ -813,6 +820,7 @@ int reinstall_suspended_bps(struct pt_regs *regs) return !handled_exception; } +NOKPROBE_SYMBOL(reinstall_suspended_bps); /* * Context-switcher for restoring suspended breakpoints.
diff --git a/arch/arm64/kernel/kgdb.c b/arch/arm64/kernel/kgdb.c
index b5f063e..8c57f64 100644
--- a/arch/arm64/kernel/kgdb.c
+++ b/arch/arm64/kernel/kgdb.c@@ -22,6 +22,7 @@ #include <linux/irq.h> #include <linux/kdebug.h> #include <linux/kgdb.h> +#include <linux/kprobes.h> #include <asm/traps.h> struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] = {
@@ -230,6 +231,7 @@ static int kgdb_brk_fn(struct pt_regs *regs, unsigned int esr) kgdb_handle_exception(1, SIGTRAP, 0, regs); return 0; } +NOKPROBE_SYMBOL(kgdb_brk_fn) static int kgdb_compiled_brk_fn(struct pt_regs *regs, unsigned int esr) {
@@ -238,12 +240,14 @@ static int kgdb_compiled_brk_fn(struct pt_regs *regs, unsigned int esr) return 0; } +NOKPROBE_SYMBOL(kgdb_compiled_brk_fn); static int kgdb_step_brk_fn(struct pt_regs *regs, unsigned int esr) { kgdb_handle_exception(1, SIGTRAP, 0, regs); return 0; } +NOKPROBE_SYMBOL(kgdb_step_brk_fn); static struct break_hook kgdb_brkpt_hook = { .esr_mask = 0xffffffff,
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2.5.0