[PATCH 3/4] powerpc/kprobes: blacklist functions invoked on a trap

[Naveen N. Rao]

Blacklist all functions invoked when we get a trap, through to the time
we invoke the kprobe handler.

Signed-off-by: Naveen N. Rao <naveen.n....@linux.vnet.ibm.com>
---
 arch/powerpc/kernel/entry_64.S       | 1 +
 arch/powerpc/kernel/exceptions-64s.S | 1 +
 arch/powerpc/kernel/time.c           | 3 +++
 arch/powerpc/kernel/traps.c          | 2 ++
 arch/powerpc/platforms/pseries/dtl.c | 2 ++
 5 files changed, 9 insertions(+)

diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index e030ce34dd66..22aaa377149f 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -399,6 +399,7 @@ _GLOBAL(save_nvgprs)
        clrrdi  r0,r11,1
        std     r0,_TRAP(r1)
        blr
+_ASM_NOKPROBE_SYMBOL(save_nvgprs);
 
        
 /*
diff --git a/arch/powerpc/kernel/exceptions-64s.S 
b/arch/powerpc/kernel/exceptions-64s.S
index 28f8d7bed6b1..aff23b2288f2 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -1534,6 +1534,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
 1:     addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      kernel_bad_stack
        b       1b
+_ASM_NOKPROBE_SYMBOL(bad_stack);
 
 /*
  * Called from arch_local_irq_enable when an interrupt needs
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 07b90725855e..afdec3c00738 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -59,6 +59,7 @@
 #include <linux/suspend.h>
 #include <linux/rtc.h>
 #include <linux/sched/cputime.h>
+#include <linux/kprobes.h>
 #include <asm/trace.h>
 
 #include <asm/io.h>
@@ -236,6 +237,7 @@ static u64 scan_dispatch_log(u64 stop_tb)
        local_paca->dtl_curr = dtl;
        return stolen;
 }
+NOKPROBE_SYMBOL(scan_dispatch_log);
 
 /*
  * Accumulate stolen time by scanning the dispatch trace log.
@@ -263,6 +265,7 @@ void accumulate_stolen_time(void)
 
        local_paca->soft_enabled = save_soft_enabled;
 }
+NOKPROBE_SYMBOL(accumulate_stolen_time);
 
 static inline u64 calculate_stolen_time(u64 stop_tb)
 {
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 76f6045b021b..ece130515cd0 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -237,6 +237,7 @@ void die(const char *str, struct pt_regs *regs, long err)
                err = 0;
        oops_end(flags, regs, err);
 }
+NOKPROBE_SYMBOL(die);
 
 void user_single_step_siginfo(struct task_struct *tsk,
                                struct pt_regs *regs, siginfo_t *info)
@@ -1981,6 +1982,7 @@ void kernel_bad_stack(struct pt_regs *regs)
               regs->gpr[1], regs->nip);
        die("Bad kernel stack pointer", regs, SIGABRT);
 }
+NOKPROBE_SYMBOL(kernel_bad_stack);
 
 void __init trap_init(void)
 {
diff --git a/arch/powerpc/platforms/pseries/dtl.c 
b/arch/powerpc/platforms/pseries/dtl.c
index 18014cdeb590..03d333ff7867 100644
--- a/arch/powerpc/platforms/pseries/dtl.c
+++ b/arch/powerpc/platforms/pseries/dtl.c
@@ -29,6 +29,7 @@
 #include <asm/debugfs.h>
 #include <asm/plpar_wrappers.h>
 #include <asm/machdep.h>
+#include <linux/kprobes.h>
 
 struct dtl {
        struct dtl_entry        *buf;
@@ -97,6 +98,7 @@ static void consume_dtle(struct dtl_entry *dtle, u64 index)
        smp_wmb();
        ++dtlr->write_index;
 }
+NOKPROBE_SYMBOL(consume_dtle);
 
 static int dtl_start(struct dtl *dtl)
 {
-- 
2.12.1