[PATCH 1/2] arm64: Blacklist non-kprobe-able symbols
Pratyush Anand
panand at redhat.com
Sun Jul 5 22:03:21 PDT 2015
Add all function symbols which are called from do_debug_exception under
NOKPROBE_SYMBOL, as they can not kprobed.
Signed-off-by: Pratyush Anand <panand at redhat.com>
---
arch/arm64/kernel/debug-monitors.c | 18 ++++++++++++++++++
arch/arm64/kernel/hw_breakpoint.c | 8 ++++++++
arch/arm64/kernel/kgdb.c | 4 ++++
arch/arm64/mm/fault.c | 1 +
4 files changed, 31 insertions(+)
diff --git a/arch/arm64/kernel/debug-monitors.c b/arch/arm64/kernel/debug-monitors.c
index 237a21f675fd..6d356b2cc674 100644
--- a/arch/arm64/kernel/debug-monitors.c
+++ b/arch/arm64/kernel/debug-monitors.c
@@ -22,6 +22,7 @@
#include <linux/debugfs.h>
#include <linux/hardirq.h>
#include <linux/init.h>
+#include <linux/kprobes.h>
#include <linux/ptrace.h>
#include <linux/kprobes.h>
#include <linux/stat.h>
@@ -47,6 +48,7 @@ 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)
{
@@ -54,6 +56,7 @@ 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.
@@ -102,6 +105,7 @@ void enable_debug_monitors(enum debug_elx el)
mdscr_write(mdscr);
}
}
+NOKPROBE_SYMBOL(enable_debug_monitors);
void disable_debug_monitors(enum debug_elx el)
{
@@ -122,6 +126,7 @@ void disable_debug_monitors(enum debug_elx el)
mdscr_write(mdscr);
}
}
+NOKPROBE_SYMBOL(disable_debug_monitors);
/*
* OS lock clearing.
@@ -173,6 +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)
{
@@ -182,6 +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);
@@ -224,6 +231,7 @@ static int call_step_hook(struct pt_regs *regs, unsigned int esr)
return retval;
}
+NOKPROBE_SYMBOL(call_step_hook);
static int single_step_handler(unsigned long addr, unsigned int esr,
struct pt_regs *regs)
@@ -270,6 +278,7 @@ 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
@@ -306,6 +315,7 @@ 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)
@@ -338,6 +348,7 @@ static int brk_handler(unsigned long addr, unsigned int esr,
return 0;
}
+NOKPROBE_SYMBOL(brk_handler);
int aarch32_break_handler(struct pt_regs *regs)
{
@@ -382,6 +393,7 @@ int aarch32_break_handler(struct pt_regs *regs)
force_sig_info(SIGTRAP, &info, current);
return 0;
}
+NOKPROBE_SYMBOL(aarch32_break_handler);
static int __init debug_traps_init(void)
{
@@ -403,6 +415,7 @@ 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)
{
@@ -418,6 +431,7 @@ 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)
{
@@ -425,12 +439,14 @@ 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)
@@ -438,8 +454,10 @@ 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 43b74a3ddaef..91b4c418abcb 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>
@@ -139,6 +140,7 @@ 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)
{
@@ -152,6 +154,7 @@ 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
@@ -169,6 +172,7 @@ static enum debug_elx debug_exception_level(int privilege)
return -EINVAL;
}
}
+NOKPROBE_SYMBOL(debug_exception_level);
enum hw_breakpoint_ops {
HW_BREAKPOINT_INSTALL,
@@ -573,6 +577,7 @@ static void toggle_bp_registers(int reg, enum debug_elx el, int enable)
write_wb_reg(reg, i, ctrl);
}
}
+NOKPROBE_SYMBOL(toggle_bp_registers);
/*
* Debug exception handlers.
@@ -652,6 +657,7 @@ unlock:
return 0;
}
+NOKPROBE_SYMBOL(breakpoint_handler);
static int watchpoint_handler(unsigned long addr, unsigned int esr,
struct pt_regs *regs)
@@ -754,6 +760,7 @@ unlock:
return 0;
}
+NOKPROBE_SYMBOL(watchpoint_handler);
/*
* Handle single-step exception.
@@ -811,6 +818,7 @@ 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 9469465a5e03..faa4d442688c 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] = {
@@ -218,6 +219,7 @@ 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)
{
@@ -226,6 +228,7 @@ 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)
{
@@ -235,6 +238,7 @@ 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,
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 75750a91907a..0d0b02ce2074 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -561,3 +561,4 @@ asmlinkage int __exception do_debug_exception(unsigned long addr,
return 0;
}
+NOKPROBE_SYMBOL(do_debug_exception)
--
2.4.3
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