summaryrefslogtreecommitdiffstats
path: root/arch/s390/kernel/kprobes.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/s390/kernel/kprobes.c')
-rw-r--r--arch/s390/kernel/kprobes.c178
1 files changed, 119 insertions, 59 deletions
diff --git a/arch/s390/kernel/kprobes.c b/arch/s390/kernel/kprobes.c
index 014d4729b134..1e4c710dfb92 100644
--- a/arch/s390/kernel/kprobes.c
+++ b/arch/s390/kernel/kprobes.c
@@ -29,6 +29,7 @@
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/hardirq.h>
+#include <linux/ftrace.h>
#include <asm/cacheflush.h>
#include <asm/sections.h>
#include <asm/dis.h>
@@ -58,12 +59,23 @@ struct kprobe_insn_cache kprobe_dmainsn_slots = {
.insn_size = MAX_INSN_SIZE,
};
-static void __kprobes copy_instruction(struct kprobe *p)
+static void copy_instruction(struct kprobe *p)
{
+ unsigned long ip = (unsigned long) p->addr;
s64 disp, new_disp;
u64 addr, new_addr;
- memcpy(p->ainsn.insn, p->addr, insn_length(p->opcode >> 8));
+ if (ftrace_location(ip) == ip) {
+ /*
+ * If kprobes patches the instruction that is morphed by
+ * ftrace make sure that kprobes always sees the branch
+ * "jg .+24" that skips the mcount block
+ */
+ ftrace_generate_nop_insn((struct ftrace_insn *)p->ainsn.insn);
+ p->ainsn.is_ftrace_insn = 1;
+ } else
+ memcpy(p->ainsn.insn, p->addr, insn_length(*p->addr >> 8));
+ p->opcode = p->ainsn.insn[0];
if (!probe_is_insn_relative_long(p->ainsn.insn))
return;
/*
@@ -79,25 +91,14 @@ static void __kprobes copy_instruction(struct kprobe *p)
new_disp = ((addr + (disp * 2)) - new_addr) / 2;
*(s32 *)&p->ainsn.insn[1] = new_disp;
}
+NOKPROBE_SYMBOL(copy_instruction);
static inline int is_kernel_addr(void *addr)
{
return addr < (void *)_end;
}
-static inline int is_module_addr(void *addr)
-{
-#ifdef CONFIG_64BIT
- BUILD_BUG_ON(MODULES_LEN > (1UL << 31));
- if (addr < (void *)MODULES_VADDR)
- return 0;
- if (addr > (void *)MODULES_END)
- return 0;
-#endif
- return 1;
-}
-
-static int __kprobes s390_get_insn_slot(struct kprobe *p)
+static int s390_get_insn_slot(struct kprobe *p)
{
/*
* Get an insn slot that is within the same 2GB area like the original
@@ -111,8 +112,9 @@ static int __kprobes s390_get_insn_slot(struct kprobe *p)
p->ainsn.insn = get_insn_slot();
return p->ainsn.insn ? 0 : -ENOMEM;
}
+NOKPROBE_SYMBOL(s390_get_insn_slot);
-static void __kprobes s390_free_insn_slot(struct kprobe *p)
+static void s390_free_insn_slot(struct kprobe *p)
{
if (!p->ainsn.insn)
return;
@@ -122,8 +124,9 @@ static void __kprobes s390_free_insn_slot(struct kprobe *p)
free_insn_slot(p->ainsn.insn, 0);
p->ainsn.insn = NULL;
}
+NOKPROBE_SYMBOL(s390_free_insn_slot);
-int __kprobes arch_prepare_kprobe(struct kprobe *p)
+int arch_prepare_kprobe(struct kprobe *p)
{
if ((unsigned long) p->addr & 0x01)
return -EINVAL;
@@ -132,54 +135,79 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
return -EINVAL;
if (s390_get_insn_slot(p))
return -ENOMEM;
- p->opcode = *p->addr;
copy_instruction(p);
return 0;
}
+NOKPROBE_SYMBOL(arch_prepare_kprobe);
-struct ins_replace_args {
- kprobe_opcode_t *ptr;
- kprobe_opcode_t opcode;
+int arch_check_ftrace_location(struct kprobe *p)
+{
+ return 0;
+}
+
+struct swap_insn_args {
+ struct kprobe *p;
+ unsigned int arm_kprobe : 1;
};
-static int __kprobes swap_instruction(void *aref)
+static int swap_instruction(void *data)
{
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
unsigned long status = kcb->kprobe_status;
- struct ins_replace_args *args = aref;
-
+ struct swap_insn_args *args = data;
+ struct ftrace_insn new_insn, *insn;
+ struct kprobe *p = args->p;
+ size_t len;
+
+ new_insn.opc = args->arm_kprobe ? BREAKPOINT_INSTRUCTION : p->opcode;
+ len = sizeof(new_insn.opc);
+ if (!p->ainsn.is_ftrace_insn)
+ goto skip_ftrace;
+ len = sizeof(new_insn);
+ insn = (struct ftrace_insn *) p->addr;
+ if (args->arm_kprobe) {
+ if (is_ftrace_nop(insn))
+ new_insn.disp = KPROBE_ON_FTRACE_NOP;
+ else
+ new_insn.disp = KPROBE_ON_FTRACE_CALL;
+ } else {
+ ftrace_generate_call_insn(&new_insn, (unsigned long)p->addr);
+ if (insn->disp == KPROBE_ON_FTRACE_NOP)
+ ftrace_generate_nop_insn(&new_insn);
+ }
+skip_ftrace:
kcb->kprobe_status = KPROBE_SWAP_INST;
- probe_kernel_write(args->ptr, &args->opcode, sizeof(args->opcode));
+ probe_kernel_write(p->addr, &new_insn, len);
kcb->kprobe_status = status;
return 0;
}
+NOKPROBE_SYMBOL(swap_instruction);
-void __kprobes arch_arm_kprobe(struct kprobe *p)
+void arch_arm_kprobe(struct kprobe *p)
{
- struct ins_replace_args args;
+ struct swap_insn_args args = {.p = p, .arm_kprobe = 1};
- args.ptr = p->addr;
- args.opcode = BREAKPOINT_INSTRUCTION;
stop_machine(swap_instruction, &args, NULL);
}
+NOKPROBE_SYMBOL(arch_arm_kprobe);
-void __kprobes arch_disarm_kprobe(struct kprobe *p)
+void arch_disarm_kprobe(struct kprobe *p)
{
- struct ins_replace_args args;
+ struct swap_insn_args args = {.p = p, .arm_kprobe = 0};
- args.ptr = p->addr;
- args.opcode = p->opcode;
stop_machine(swap_instruction, &args, NULL);
}
+NOKPROBE_SYMBOL(arch_disarm_kprobe);
-void __kprobes arch_remove_kprobe(struct kprobe *p)
+void arch_remove_kprobe(struct kprobe *p)
{
s390_free_insn_slot(p);
}
+NOKPROBE_SYMBOL(arch_remove_kprobe);
-static void __kprobes enable_singlestep(struct kprobe_ctlblk *kcb,
- struct pt_regs *regs,
- unsigned long ip)
+static void enable_singlestep(struct kprobe_ctlblk *kcb,
+ struct pt_regs *regs,
+ unsigned long ip)
{
struct per_regs per_kprobe;
@@ -199,10 +227,11 @@ static void __kprobes enable_singlestep(struct kprobe_ctlblk *kcb,
regs->psw.mask &= ~(PSW_MASK_IO | PSW_MASK_EXT);
regs->psw.addr = ip | PSW_ADDR_AMODE;
}
+NOKPROBE_SYMBOL(enable_singlestep);
-static void __kprobes disable_singlestep(struct kprobe_ctlblk *kcb,
- struct pt_regs *regs,
- unsigned long ip)
+static void disable_singlestep(struct kprobe_ctlblk *kcb,
+ struct pt_regs *regs,
+ unsigned long ip)
{
/* Restore control regs and psw mask, set new psw address */
__ctl_load(kcb->kprobe_saved_ctl, 9, 11);
@@ -210,41 +239,43 @@ static void __kprobes disable_singlestep(struct kprobe_ctlblk *kcb,
regs->psw.mask |= kcb->kprobe_saved_imask;
regs->psw.addr = ip | PSW_ADDR_AMODE;
}
+NOKPROBE_SYMBOL(disable_singlestep);
/*
* Activate a kprobe by storing its pointer to current_kprobe. The
* previous kprobe is stored in kcb->prev_kprobe. A stack of up to
* two kprobes can be active, see KPROBE_REENTER.
*/
-static void __kprobes push_kprobe(struct kprobe_ctlblk *kcb, struct kprobe *p)
+static void push_kprobe(struct kprobe_ctlblk *kcb, struct kprobe *p)
{
kcb->prev_kprobe.kp = __this_cpu_read(current_kprobe);
kcb->prev_kprobe.status = kcb->kprobe_status;
__this_cpu_write(current_kprobe, p);
}
+NOKPROBE_SYMBOL(push_kprobe);
/*
* Deactivate a kprobe by backing up to the previous state. If the
* current state is KPROBE_REENTER prev_kprobe.kp will be non-NULL,
* for any other state prev_kprobe.kp will be NULL.
*/
-static void __kprobes pop_kprobe(struct kprobe_ctlblk *kcb)
+static void pop_kprobe(struct kprobe_ctlblk *kcb)
{
__this_cpu_write(current_kprobe, kcb->prev_kprobe.kp);
kcb->kprobe_status = kcb->prev_kprobe.status;
}
+NOKPROBE_SYMBOL(pop_kprobe);
-void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
- struct pt_regs *regs)
+void arch_prepare_kretprobe(struct kretprobe_instance *ri, struct pt_regs *regs)
{
ri->ret_addr = (kprobe_opcode_t *) regs->gprs[14];
/* Replace the return addr with trampoline addr */
regs->gprs[14] = (unsigned long) &kretprobe_trampoline;
}
+NOKPROBE_SYMBOL(arch_prepare_kretprobe);
-static void __kprobes kprobe_reenter_check(struct kprobe_ctlblk *kcb,
- struct kprobe *p)
+static void kprobe_reenter_check(struct kprobe_ctlblk *kcb, struct kprobe *p)
{
switch (kcb->kprobe_status) {
case KPROBE_HIT_SSDONE:
@@ -264,8 +295,9 @@ static void __kprobes kprobe_reenter_check(struct kprobe_ctlblk *kcb,
BUG();
}
}
+NOKPROBE_SYMBOL(kprobe_reenter_check);
-static int __kprobes kprobe_handler(struct pt_regs *regs)
+static int kprobe_handler(struct pt_regs *regs)
{
struct kprobe_ctlblk *kcb;
struct kprobe *p;
@@ -339,6 +371,7 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
preempt_enable_no_resched();
return 0;
}
+NOKPROBE_SYMBOL(kprobe_handler);
/*
* Function return probe trampoline:
@@ -355,8 +388,7 @@ static void __used kretprobe_trampoline_holder(void)
/*
* Called when the probe at kretprobe trampoline is hit
*/
-static int __kprobes trampoline_probe_handler(struct kprobe *p,
- struct pt_regs *regs)
+static int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
{
struct kretprobe_instance *ri;
struct hlist_head *head, empty_rp;
@@ -444,6 +476,7 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p,
*/
return 1;
}
+NOKPROBE_SYMBOL(trampoline_probe_handler);
/*
* Called after single-stepping. p->addr is the address of the
@@ -453,12 +486,30 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p,
* single-stepped a copy of the instruction. The address of this
* copy is p->ainsn.insn.
*/
-static void __kprobes resume_execution(struct kprobe *p, struct pt_regs *regs)
+static void resume_execution(struct kprobe *p, struct pt_regs *regs)
{
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
unsigned long ip = regs->psw.addr & PSW_ADDR_INSN;
int fixup = probe_get_fixup_type(p->ainsn.insn);
+ /* Check if the kprobes location is an enabled ftrace caller */
+ if (p->ainsn.is_ftrace_insn) {
+ struct ftrace_insn *insn = (struct ftrace_insn *) p->addr;
+ struct ftrace_insn call_insn;
+
+ ftrace_generate_call_insn(&call_insn, (unsigned long) p->addr);
+ /*
+ * A kprobe on an enabled ftrace call site actually single
+ * stepped an unconditional branch (ftrace nop equivalent).
+ * Now we need to fixup things and pretend that a brasl r0,...
+ * was executed instead.
+ */
+ if (insn->disp == KPROBE_ON_FTRACE_CALL) {
+ ip += call_insn.disp * 2 - MCOUNT_INSN_SIZE;
+ regs->gprs[0] = (unsigned long)p->addr + sizeof(*insn);
+ }
+ }
+
if (fixup & FIXUP_PSW_NORMAL)
ip += (unsigned long) p->addr - (unsigned long) p->ainsn.insn;
@@ -476,8 +527,9 @@ static void __kprobes resume_execution(struct kprobe *p, struct pt_regs *regs)
disable_singlestep(kcb, regs, ip);
}
+NOKPROBE_SYMBOL(resume_execution);
-static int __kprobes post_kprobe_handler(struct pt_regs *regs)
+static int post_kprobe_handler(struct pt_regs *regs)
{
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
struct kprobe *p = kprobe_running();
@@ -504,8 +556,9 @@ static int __kprobes post_kprobe_handler(struct pt_regs *regs)
return 1;
}
+NOKPROBE_SYMBOL(post_kprobe_handler);
-static int __kprobes kprobe_trap_handler(struct pt_regs *regs, int trapnr)
+static int kprobe_trap_handler(struct pt_regs *regs, int trapnr)
{
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
struct kprobe *p = kprobe_running();
@@ -567,8 +620,9 @@ static int __kprobes kprobe_trap_handler(struct pt_regs *regs, int trapnr)
}
return 0;
}
+NOKPROBE_SYMBOL(kprobe_trap_handler);
-int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
+int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
{
int ret;
@@ -579,12 +633,13 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
local_irq_restore(regs->psw.mask & ~PSW_MASK_PER);
return ret;
}
+NOKPROBE_SYMBOL(kprobe_fault_handler);
/*
* Wrapper routine to for handling exceptions.
*/
-int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
- unsigned long val, void *data)
+int kprobe_exceptions_notify(struct notifier_block *self,
+ unsigned long val, void *data)
{
struct die_args *args = (struct die_args *) data;
struct pt_regs *regs = args->regs;
@@ -616,8 +671,9 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
return ret;
}
+NOKPROBE_SYMBOL(kprobe_exceptions_notify);
-int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
+int setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
{
struct jprobe *jp = container_of(p, struct jprobe, kp);
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
@@ -635,13 +691,15 @@ int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
memcpy(kcb->jprobes_stack, (void *) stack, MIN_STACK_SIZE(stack));
return 1;
}
+NOKPROBE_SYMBOL(setjmp_pre_handler);
-void __kprobes jprobe_return(void)
+void jprobe_return(void)
{
asm volatile(".word 0x0002");
}
+NOKPROBE_SYMBOL(jprobe_return);
-int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
+int longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
{
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
unsigned long stack;
@@ -655,6 +713,7 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
preempt_enable_no_resched();
return 1;
}
+NOKPROBE_SYMBOL(longjmp_break_handler);
static struct kprobe trampoline = {
.addr = (kprobe_opcode_t *) &kretprobe_trampoline,
@@ -666,7 +725,8 @@ int __init arch_init_kprobes(void)
return register_kprobe(&trampoline);
}
-int __kprobes arch_trampoline_kprobe(struct kprobe *p)
+int arch_trampoline_kprobe(struct kprobe *p)
{
return p->addr == (kprobe_opcode_t *) &kretprobe_trampoline;
}
+NOKPROBE_SYMBOL(arch_trampoline_kprobe);