These patches have been prepared on top of ARM64 kprobe v3 patches [1]
under review.
Unit test for following has been done so far and they have been found
working
1. Normal instruction, which can be probed like sub, ldr, add etc.
2. Instructions which can be simulated like ret.
3. uretprobe
[1]https://lkml.org/lkml/2014/11/18/33
Pratyush Anand (8):
ARM64: Move BRK opcodes defines from kprobes.h to insn.h
ARM64: Refactor kprobes-arm64
Kernel/uprobe: Define arch_uprobe_exception_notify as __weak
ARM64: Add instruction_pointer_set function
ARM64: Re-factor flush_ptrace_access
ARM64: Handle TRAP_HWBRKPT for user mode as well
ARM64: Handle TRAP_BRKPT for user mode as well
ARM64: Add uprobe support
arch/arm/kernel/uprobes.c | 6 -
arch/arm64/Kconfig | 3 +
arch/arm64/include/asm/insn.h | 8 +
arch/arm64/include/asm/probes.h | 26 ++-
arch/arm64/include/asm/ptrace.h | 7 +
arch/arm64/include/asm/thread_info.h | 5 +-
arch/arm64/include/asm/uprobes.h | 43 ++++
arch/arm64/kernel/Makefile | 5 +-
arch/arm64/kernel/debug-monitors.c | 14 +-
arch/arm64/kernel/kprobes.c | 11 +-
arch/arm64/kernel/kprobes.h | 7 +-
.../kernel/{kprobes-arm64.c => probes-arm64.c} | 84 +++----
.../kernel/{kprobes-arm64.h => probes-arm64.h} | 17 +-
arch/arm64/kernel/probes-condn-check.c | 2 +-
arch/arm64/kernel/probes-decode.h | 4 +-
arch/arm64/kernel/signal.c | 4 +-
arch/arm64/kernel/uprobes.c | 255 +++++++++++++++++++++
arch/arm64/mm/flush.c | 30 ++-
kernel/events/uprobes.c | 18 ++
19 files changed, 445 insertions(+), 104 deletions(-)
create mode 100644 arch/arm64/include/asm/uprobes.h
rename arch/arm64/kernel/{kprobes-arm64.c => probes-arm64.c} (79%)
rename arch/arm64/kernel/{kprobes-arm64.h => probes-arm64.h} (60%)
create mode 100644 arch/arm64/kernel/uprobes.c
--
2.1.0
Its better to keep all BRK opcodes used by kprobes and uprobes at one
place. Therefore move these defines to asm/insn.h.
Signed-off-by: Pratyush Anand <[email protected]>
---
arch/arm64/include/asm/insn.h | 6 ++++++
arch/arm64/kernel/kprobes.h | 7 +------
2 files changed, 7 insertions(+), 6 deletions(-)
diff --git a/arch/arm64/include/asm/insn.h b/arch/arm64/include/asm/insn.h
index e2ff32a93b5c..87fa48746806 100644
--- a/arch/arm64/include/asm/insn.h
+++ b/arch/arm64/include/asm/insn.h
@@ -23,6 +23,12 @@
/* A64 instructions are always 32 bits. */
#define AARCH64_INSN_SIZE 4
+/* BRK opcodes with ESR encoding */
+#define BRK64_ESR_MASK 0xFFFF
+#define BRK64_ESR_KPROBES 0x0004
+#define BRK64_OPCODE_KPROBES 0xD4200080 /* "brk 0x4" */
+#define ARCH64_NOP_OPCODE 0xD503201F
+
#ifndef __ASSEMBLY__
/*
* ARM Architecture Reference Manual for ARMv8 Profile-A, Issue A.a
diff --git a/arch/arm64/kernel/kprobes.h b/arch/arm64/kernel/kprobes.h
index 93c54b4972f9..a1140971b045 100644
--- a/arch/arm64/kernel/kprobes.h
+++ b/arch/arm64/kernel/kprobes.h
@@ -15,12 +15,7 @@
#ifndef _ARM_KERNEL_KPROBES_H
#define _ARM_KERNEL_KPROBES_H
-
-/* BRK opcodes with ESR encoding */
-#define BRK64_ESR_MASK 0xFFFF
-#define BRK64_ESR_KPROBES 0x0004
-#define BRK64_OPCODE_KPROBES 0xD4200080 /* "brk 0x4" */
-#define ARCH64_NOP_OPCODE 0xD503201F
+#include <asm/insn.h>
#define JPROBES_MAGIC_NUM 0xa5a5a5a5a5a5a5a5
--
2.1.0
instruction_pointer_set is needed for uprobe implementation. Hence
define it for ARM64.
Signed-off-by: Pratyush Anand <[email protected]>
---
arch/arm64/include/asm/ptrace.h | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h
index 24cc048ac3e7..29d9bf5e3635 100644
--- a/arch/arm64/include/asm/ptrace.h
+++ b/arch/arm64/include/asm/ptrace.h
@@ -206,6 +206,12 @@ static inline int valid_user_regs(struct user_pt_regs *regs)
#define instruction_pointer(regs) ((regs)->pc)
#define stack_pointer(regs) ((regs)->sp)
+static inline void instruction_pointer_set(struct pt_regs *regs,
+ unsigned long val)
+{
+ instruction_pointer(regs) = val;
+}
+
#ifdef CONFIG_SMP
extern unsigned long profile_pc(struct pt_regs *regs);
#else
--
2.1.0
Re-factor flush_ptrace_access to reuse vma independent part.
Signed-off-by: Pratyush Anand <[email protected]>
---
arch/arm64/mm/flush.c | 24 +++++++++++++++---------
1 file changed, 15 insertions(+), 9 deletions(-)
diff --git a/arch/arm64/mm/flush.c b/arch/arm64/mm/flush.c
index b6f14e8d2121..9a4dd6f39cfb 100644
--- a/arch/arm64/mm/flush.c
+++ b/arch/arm64/mm/flush.c
@@ -34,19 +34,25 @@ void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
__flush_icache_all();
}
+static void __flush_ptrace_access(struct page *page, unsigned long uaddr,
+ void *kaddr, unsigned long len)
+{
+ unsigned long addr = (unsigned long)kaddr;
+
+ if (icache_is_aliasing()) {
+ __flush_dcache_area(kaddr, len);
+ __flush_icache_all();
+ } else {
+ flush_icache_range(addr, addr + len);
+ }
+}
+
static void flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
unsigned long uaddr, void *kaddr,
unsigned long len)
{
- if (vma->vm_flags & VM_EXEC) {
- unsigned long addr = (unsigned long)kaddr;
- if (icache_is_aliasing()) {
- __flush_dcache_area(kaddr, len);
- __flush_icache_all();
- } else {
- flush_icache_range(addr, addr + len);
- }
- }
+ if (vma->vm_flags & VM_EXEC)
+ __flush_ptrace_access(page, uaddr, kaddr, len);
}
/*
--
2.1.0
uprobe registers a handler at step_hook. So, single_step_handler now
checks for user mode as well if there is a valid hook.
Signed-off-by: Pratyush Anand <[email protected]>
---
arch/arm64/kernel/debug-monitors.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/kernel/debug-monitors.c b/arch/arm64/kernel/debug-monitors.c
index b056369fd47d..2676b8655241 100644
--- a/arch/arm64/kernel/debug-monitors.c
+++ b/arch/arm64/kernel/debug-monitors.c
@@ -236,6 +236,9 @@ static int single_step_handler(unsigned long addr, unsigned int esr,
if (!reinstall_suspended_bps(regs))
return 0;
+ if (call_step_hook(regs, esr) == DBG_HOOK_HANDLED)
+ return 0;
+
if (user_mode(regs)) {
info.si_signo = SIGTRAP;
info.si_errno = 0;
@@ -251,9 +254,6 @@ static int single_step_handler(unsigned long addr, unsigned int esr,
*/
user_rewind_single_step(current);
} else {
- if (call_step_hook(regs, esr) == DBG_HOOK_HANDLED)
- return 0;
-
pr_warning("Unexpected kernel single-step exception at EL1\n");
/*
* Re-enable stepping since we know that we will be
--
2.1.0
This patch adds support for uprobe on ARM64 architecture.
Unit test for following has been done so far and they have been found
working
1. Normal instruction, which can be probed like sub, ldr, add etc.
2. Instructions which can be simulated like ret.
3. uretprobe
Signed-off-by: Pratyush Anand <[email protected]>
---
arch/arm64/Kconfig | 3 +
arch/arm64/include/asm/insn.h | 2 +
arch/arm64/include/asm/probes.h | 1 +
arch/arm64/include/asm/ptrace.h | 1 +
arch/arm64/include/asm/thread_info.h | 5 +-
arch/arm64/include/asm/uprobes.h | 43 ++++++
arch/arm64/kernel/Makefile | 3 +
arch/arm64/kernel/signal.c | 4 +-
arch/arm64/kernel/uprobes.c | 255 +++++++++++++++++++++++++++++++++++
arch/arm64/mm/flush.c | 6 +
10 files changed, 321 insertions(+), 2 deletions(-)
create mode 100644 arch/arm64/include/asm/uprobes.h
create mode 100644 arch/arm64/kernel/uprobes.c
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index de4f0561cd14..51b1db7a3bc9 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -145,6 +145,9 @@ config KERNEL_MODE_NEON
config FIX_EARLYCON_MEM
def_bool y
+config ARCH_SUPPORTS_UPROBES
+ def_bool y
+
source "init/Kconfig"
source "kernel/Kconfig.freezer"
diff --git a/arch/arm64/include/asm/insn.h b/arch/arm64/include/asm/insn.h
index 87fa48746806..412df9457260 100644
--- a/arch/arm64/include/asm/insn.h
+++ b/arch/arm64/include/asm/insn.h
@@ -27,6 +27,8 @@
#define BRK64_ESR_MASK 0xFFFF
#define BRK64_ESR_KPROBES 0x0004
#define BRK64_OPCODE_KPROBES 0xD4200080 /* "brk 0x4" */
+#define BRK64_ESR_UPROBES 0x0008
+#define BRK64_OPCODE_UPROBES 0xD4200100 /* "brk 0x8" */
#define ARCH64_NOP_OPCODE 0xD503201F
#ifndef __ASSEMBLY__
diff --git a/arch/arm64/include/asm/probes.h b/arch/arm64/include/asm/probes.h
index daa2ff822a2e..25a69508d137 100644
--- a/arch/arm64/include/asm/probes.h
+++ b/arch/arm64/include/asm/probes.h
@@ -18,6 +18,7 @@
struct arch_specific_insn;
typedef u32 kprobe_opcode_t;
+typedef u32 uprobe_opcode_t;
typedef u32 probe_opcode_t;
typedef unsigned long (probes_pstate_check_t)(unsigned long);
typedef unsigned long
diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h
index 29d9bf5e3635..79c312bb503e 100644
--- a/arch/arm64/include/asm/ptrace.h
+++ b/arch/arm64/include/asm/ptrace.h
@@ -205,6 +205,7 @@ static inline int valid_user_regs(struct user_pt_regs *regs)
#define instruction_pointer(regs) ((regs)->pc)
#define stack_pointer(regs) ((regs)->sp)
+#define procedure_link_pointer(regs) ((regs)->regs[30])
static inline void instruction_pointer_set(struct pt_regs *regs,
unsigned long val)
diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h
index 459bf8e53208..3d5d1ec181cb 100644
--- a/arch/arm64/include/asm/thread_info.h
+++ b/arch/arm64/include/asm/thread_info.h
@@ -108,6 +108,7 @@ static inline struct thread_info *current_thread_info(void)
#define TIF_NEED_RESCHED 1
#define TIF_NOTIFY_RESUME 2 /* callback before returning to user */
#define TIF_FOREIGN_FPSTATE 3 /* CPU's FP state is not current's */
+#define TIF_UPROBE 4 /* uprobe breakpoint or singlestep */
#define TIF_NOHZ 7
#define TIF_SYSCALL_TRACE 8
#define TIF_SYSCALL_AUDIT 9
@@ -129,10 +130,12 @@ static inline struct thread_info *current_thread_info(void)
#define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
#define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT)
#define _TIF_SECCOMP (1 << TIF_SECCOMP)
+#define _TIF_UPROBE (1 << TIF_UPROBE)
#define _TIF_32BIT (1 << TIF_32BIT)
#define _TIF_WORK_MASK (_TIF_NEED_RESCHED | _TIF_SIGPENDING | \
- _TIF_NOTIFY_RESUME | _TIF_FOREIGN_FPSTATE)
+ _TIF_NOTIFY_RESUME | _TIF_FOREIGN_FPSTATE | \
+ _TIF_UPROBE)
#define _TIF_SYSCALL_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \
_TIF_SYSCALL_TRACEPOINT | _TIF_SECCOMP | \
diff --git a/arch/arm64/include/asm/uprobes.h b/arch/arm64/include/asm/uprobes.h
new file mode 100644
index 000000000000..f575dc389b85
--- /dev/null
+++ b/arch/arm64/include/asm/uprobes.h
@@ -0,0 +1,43 @@
+/*
+ * Copyright (C) 2014 Pratyush Anand <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef _ASM_UPROBES_H
+#define _ASM_UPROBES_H
+#include <asm/insn.h>
+#include <asm/probes.h>
+
+#define MAX_UINSN_BYTES AARCH64_INSN_SIZE
+
+#define UPROBE_SWBP_INSN BRK64_OPCODE_UPROBES
+#define UPROBE_SWBP_INSN_SIZE 4
+#define UPROBE_XOL_SLOT_BYTES MAX_UINSN_BYTES
+
+/* Single step context for uprobe */
+struct uprobe_step_ctx {
+ struct list_head node;
+ unsigned long match_addr;
+};
+
+struct arch_uprobe_task {
+ unsigned long saved_fault_code;
+ u64 saved_user_pc;
+ struct uprobe_step_ctx ss_ctx;
+};
+
+struct arch_uprobe {
+ union {
+ u8 insn[MAX_UINSN_BYTES];
+ u8 ixol[MAX_UINSN_BYTES];
+ };
+ struct arch_specific_insn ainsn;
+ bool simulate;
+};
+
+extern void flush_uprobe_xol_access(struct page *page, unsigned long uaddr,
+ void *kaddr, unsigned long len);
+#endif
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index 0ed83ba3d46d..0e5f0af91540 100644
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -31,6 +31,9 @@ arm64-obj-$(CONFIG_ARM64_CPU_SUSPEND) += sleep.o suspend.o
arm64-obj-$(CONFIG_CPU_IDLE) += cpuidle.o
arm64-obj-$(CONFIG_JUMP_LABEL) += jump_label.o
arm64-obj-$(CONFIG_KGDB) += kgdb.o
+arm64-obj-$(CONFIG_UPROBES) += uprobes.o probes-arm64.o \
+ probes-simulate-insn.o \
+ probes-condn-check.o
arm64-obj-$(CONFIG_KPROBES) += kprobes.o probes-arm64.o \
probes-simulate-insn.o \
probes-condn-check.o
diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c
index 6fa792137eda..2d1e18b0cc10 100644
--- a/arch/arm64/kernel/signal.c
+++ b/arch/arm64/kernel/signal.c
@@ -409,6 +409,9 @@ static void do_signal(struct pt_regs *regs)
asmlinkage void do_notify_resume(struct pt_regs *regs,
unsigned int thread_flags)
{
+ if (thread_flags & _TIF_UPROBE)
+ uprobe_notify_resume(regs);
+
if (thread_flags & _TIF_SIGPENDING)
do_signal(regs);
@@ -419,5 +422,4 @@ asmlinkage void do_notify_resume(struct pt_regs *regs,
if (thread_flags & _TIF_FOREIGN_FPSTATE)
fpsimd_restore_current_state();
-
}
diff --git a/arch/arm64/kernel/uprobes.c b/arch/arm64/kernel/uprobes.c
new file mode 100644
index 000000000000..fdc6dc3cfb0b
--- /dev/null
+++ b/arch/arm64/kernel/uprobes.c
@@ -0,0 +1,255 @@
+/*
+ * Copyright (C) 2014 Pratyush Anand <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/highmem.h>
+#include <linux/ptrace.h>
+#include <linux/uprobes.h>
+#include <asm/debug-monitors.h>
+#include <asm/probes.h>
+
+#include "probes-arm64.h"
+
+#define UPROBE_INV_FAULT_CODE UINT_MAX
+
+static LIST_HEAD(step_ctx);
+static DEFINE_RWLOCK(step_ctx_lock);
+
+static void add_ss_context(struct uprobe_task *utask)
+{
+ struct uprobe_step_ctx *ss_ctx = &utask->autask.ss_ctx;
+
+ ss_ctx->match_addr = utask->xol_vaddr;
+ write_lock(&step_ctx_lock);
+ list_add(&ss_ctx->node, &step_ctx);
+ write_unlock(&step_ctx_lock);
+}
+
+static struct uprobe_step_ctx *find_ss_context(unsigned long vaddr)
+{
+ struct uprobe_step_ctx *ss_ctx;
+
+ read_lock(&step_ctx_lock);
+ list_for_each_entry(ss_ctx, &step_ctx, node) {
+ if (ss_ctx->match_addr == vaddr) {
+ read_unlock(&step_ctx_lock);
+ return ss_ctx;
+ }
+ }
+ read_unlock(&step_ctx_lock);
+
+ return NULL;
+}
+
+static void del_ss_context(struct uprobe_task *utask)
+{
+ struct uprobe_step_ctx *ss_ctx = find_ss_context(utask->xol_vaddr);
+
+ if (ss_ctx) {
+ write_lock(&step_ctx_lock);
+ list_del(&ss_ctx->node);
+ write_unlock(&step_ctx_lock);
+ } else {
+ WARN_ON(1);
+ }
+}
+
+void arch_uprobe_copy_ixol(struct page *page, unsigned long vaddr,
+ void *src, unsigned long len)
+{
+ void *xol_page_kaddr = kmap_atomic(page);
+ void *dst = xol_page_kaddr + (vaddr & ~PAGE_MASK);
+
+ preempt_disable();
+
+ /* Initialize the slot */
+ memcpy(dst, src, len);
+
+ /* flush caches (dcache/icache) */
+ flush_uprobe_xol_access(page, vaddr, dst, len);
+
+ preempt_enable();
+
+ kunmap_atomic(xol_page_kaddr);
+}
+
+unsigned long uprobe_get_swbp_addr(struct pt_regs *regs)
+{
+ return instruction_pointer(regs);
+}
+
+int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm,
+ unsigned long addr)
+{
+ probe_opcode_t insn;
+
+ insn = *(probe_opcode_t *)(&auprobe->insn[0]);
+
+ switch (arm_probe_decode_insn(insn, &auprobe->ainsn)) {
+ case INSN_REJECTED:
+ return -EINVAL;
+
+ case INSN_GOOD_NO_SLOT:
+ auprobe->simulate = true;
+ if (auprobe->ainsn.prepare)
+ auprobe->ainsn.prepare(insn, &auprobe->ainsn);
+ break;
+
+ case INSN_GOOD:
+ default:
+ break;
+ }
+
+ return 0;
+}
+
+int arch_uprobe_pre_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
+{
+ struct uprobe_task *utask = current->utask;
+
+ /* saved fault code is restored in post_xol */
+ utask->autask.saved_fault_code = current->thread.fault_code;
+
+ /* An invalid fault code between pre/post xol event */
+ current->thread.fault_code = UPROBE_INV_FAULT_CODE;
+
+ /* Save user pc */
+ utask->autask.saved_user_pc = task_pt_regs(current)->user_regs.pc;
+
+ /* Instruction point to execute ol */
+ instruction_pointer_set(regs, utask->xol_vaddr);
+
+ add_ss_context(utask);
+
+ user_enable_single_step(current);
+
+ return 0;
+}
+
+int arch_uprobe_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
+{
+ struct uprobe_task *utask = current->utask;
+
+ WARN_ON_ONCE(current->thread.fault_code != UPROBE_INV_FAULT_CODE);
+
+ /* restore fault code */
+ current->thread.fault_code = utask->autask.saved_fault_code;
+
+ /* restore user pc */
+ task_pt_regs(current)->user_regs.pc = utask->autask.saved_user_pc;
+
+ /* Instruction point to execute next to breakpoint address */
+ instruction_pointer_set(regs, utask->vaddr + 4);
+
+ del_ss_context(utask);
+
+ user_disable_single_step(current);
+
+ return 0;
+}
+bool arch_uprobe_xol_was_trapped(struct task_struct *t)
+{
+ /*
+ * Between arch_uprobe_pre_xol and arch_uprobe_post_xol, if an xol
+ * insn itself is trapped, then detect the case with the help of
+ * invalid fault code which is being set in arch_uprobe_pre_xol and
+ * restored in arch_uprobe_post_xol.
+ */
+ if (t->thread.fault_code != UPROBE_INV_FAULT_CODE)
+ return true;
+
+ return false;
+}
+
+bool arch_uprobe_skip_sstep(struct arch_uprobe *auprobe, struct pt_regs *regs)
+{
+ probe_opcode_t insn;
+ unsigned long addr;
+
+ if (!auprobe->simulate)
+ return false;
+
+ insn = *(probe_opcode_t *)(&auprobe->insn[0]);
+ addr = instruction_pointer(regs);
+
+ if (auprobe->ainsn.handler)
+ auprobe->ainsn.handler(insn, addr, regs);
+
+ return true;
+}
+
+void arch_uprobe_abort_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
+{
+ struct uprobe_task *utask = current->utask;
+
+ current->thread.fault_code = utask->autask.saved_fault_code;
+ /*
+ * Task has received a fatal signal, so reset back to probbed
+ * address.
+ */
+ instruction_pointer_set(regs, utask->vaddr);
+
+ user_disable_single_step(current);
+}
+
+unsigned long
+arch_uretprobe_hijack_return_addr(unsigned long trampoline_vaddr,
+ struct pt_regs *regs)
+{
+ unsigned long orig_ret_vaddr;
+
+ orig_ret_vaddr = procedure_link_pointer(regs);
+ /* Replace the return addr with trampoline addr */
+ procedure_link_pointer(regs) = trampoline_vaddr;
+ return orig_ret_vaddr;
+}
+
+static int uprobe_breakpoint_handler(struct pt_regs *regs, unsigned int esr)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ uprobe_pre_sstep_notifier(regs);
+ local_irq_restore(flags);
+
+ return 0;
+}
+
+static int uprobe_single_step_handler(struct pt_regs *regs, unsigned int esr)
+{
+ unsigned long flags;
+
+ if (!find_ss_context(regs->pc - 4))
+ return DBG_HOOK_ERROR;
+
+ local_irq_save(flags);
+ uprobe_post_sstep_notifier(regs);
+ local_irq_restore(flags);
+
+ return 0;
+}
+
+/* uprobe breakpoint handler hook */
+static struct break_hook uprobes_break_hook = {
+ .esr_mask = BRK64_ESR_MASK,
+ .esr_val = BRK64_ESR_UPROBES,
+ .fn = uprobe_breakpoint_handler,
+};
+
+/* uprobe single step handler hook */
+static struct step_hook uprobes_step_hook = {
+ .fn = uprobe_single_step_handler,
+};
+
+static int __init arch_init_uprobes(void)
+{
+ register_break_hook(&uprobes_break_hook);
+ register_step_hook(&uprobes_step_hook);
+
+ return 0;
+}
+
+device_initcall(arch_init_uprobes);
diff --git a/arch/arm64/mm/flush.c b/arch/arm64/mm/flush.c
index 9a4dd6f39cfb..04fe6671907e 100644
--- a/arch/arm64/mm/flush.c
+++ b/arch/arm64/mm/flush.c
@@ -55,6 +55,12 @@ static void flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
__flush_ptrace_access(page, uaddr, kaddr, len);
}
+void flush_uprobe_xol_access(struct page *page, unsigned long uaddr,
+ void *kaddr, unsigned long len)
+{
+ __flush_ptrace_access(page, uaddr, kaddr, len);
+}
+
/*
* Copy user data from/to a page which is mapped into a different processes
* address space. Really, we want to allow our "user space" model to handle
--
2.1.0
uprobe is registered at break_hook with a unique ESR code. So, when a
TRAP_BRKPT occurs, call_break_hook checks if it was for uprobe. If not,
then send a SIGTRAP to user.
Signed-off-by: Pratyush Anand <[email protected]>
---
arch/arm64/kernel/debug-monitors.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/kernel/debug-monitors.c b/arch/arm64/kernel/debug-monitors.c
index 2676b8655241..98ba5c8c5141 100644
--- a/arch/arm64/kernel/debug-monitors.c
+++ b/arch/arm64/kernel/debug-monitors.c
@@ -306,6 +306,9 @@ static int brk_handler(unsigned long addr, unsigned int esr,
{
siginfo_t info;
+ if (call_break_hook(regs, esr) == DBG_HOOK_HANDLED)
+ return 0;
+
if (user_mode(regs)) {
info = (siginfo_t) {
.si_signo = SIGTRAP,
@@ -315,12 +318,11 @@ static int brk_handler(unsigned long addr, unsigned int esr,
};
force_sig_info(SIGTRAP, &info, current);
- } else if (call_break_hook(regs, esr) != DBG_HOOK_HANDLED) {
+ return 0;
+ } else {
pr_warning("Unexpected kernel BRK exception at EL1\n");
return -EFAULT;
}
-
- return 0;
}
int aarch32_break_handler(struct pt_regs *regs)
--
2.1.0
Both ARM and ARM64 handle uprobe exceptions through their own hooks.So
nothing to be done in arch_uprobe_exception_notify except to return
NOTIFY_DONE. Implement this as weak default function and remove
definition from arm arch code.
Signed-off-by: Pratyush Anand <[email protected]>
---
arch/arm/kernel/uprobes.c | 6 ------
kernel/events/uprobes.c | 18 ++++++++++++++++++
2 files changed, 18 insertions(+), 6 deletions(-)
diff --git a/arch/arm/kernel/uprobes.c b/arch/arm/kernel/uprobes.c
index 56adf9c1fde0..0f3663ca82fc 100644
--- a/arch/arm/kernel/uprobes.c
+++ b/arch/arm/kernel/uprobes.c
@@ -178,12 +178,6 @@ void arch_uprobe_abort_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
instruction_pointer_set(regs, utask->vaddr);
}
-int arch_uprobe_exception_notify(struct notifier_block *self,
- unsigned long val, void *data)
-{
- return NOTIFY_DONE;
-}
-
static int uprobe_trap_handler(struct pt_regs *regs, unsigned int instr)
{
unsigned long flags;
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index cb346f26a22d..027e39ccb778 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -1973,6 +1973,24 @@ int uprobe_post_sstep_notifier(struct pt_regs *regs)
return 1;
}
+/**
+ * arch_uprobe_exception_notify - Pass uprobe exception notigfication to
+ * architecture
+ * @self: Pointer to notifier_block
+ * @val: Type of exception
+ * @data: Exception specific data
+ * Default implementation of arch_uprobe_exception_notify
+ * Returns NOTIFY_DONE.
+ *
+ * Few architectures like arm and arm64 handle uprobe exceptions through
+ * their own hooks.So nothing to be done here.
+ */
+int __weak arch_uprobe_exception_notify(struct notifier_block *self,
+ unsigned long val, void *data)
+{
+ return NOTIFY_DONE;
+}
+
static struct notifier_block uprobe_exception_nb = {
.notifier_call = arch_uprobe_exception_notify,
.priority = INT_MAX-1, /* notified after kprobes, kgdb */
--
2.1.0
Most of the stuff of kprobes-arm64.c can also be used by uprobes.c. So
move all those part to common code area. In the process rename kprobe to
probe whereever possible.
No functional change.
Signed-off-by: Pratyush Anand <[email protected]>
---
arch/arm64/include/asm/probes.h | 25 +++----
arch/arm64/kernel/Makefile | 2 +-
arch/arm64/kernel/kprobes.c | 11 +--
.../kernel/{kprobes-arm64.c => probes-arm64.c} | 84 ++++++++++------------
.../kernel/{kprobes-arm64.h => probes-arm64.h} | 17 ++---
arch/arm64/kernel/probes-condn-check.c | 2 +-
arch/arm64/kernel/probes-decode.h | 4 +-
7 files changed, 70 insertions(+), 75 deletions(-)
rename arch/arm64/kernel/{kprobes-arm64.c => probes-arm64.c} (79%)
rename arch/arm64/kernel/{kprobes-arm64.h => probes-arm64.h} (60%)
diff --git a/arch/arm64/include/asm/probes.h b/arch/arm64/include/asm/probes.h
index 9dba74d8ee86..daa2ff822a2e 100644
--- a/arch/arm64/include/asm/probes.h
+++ b/arch/arm64/include/asm/probes.h
@@ -15,36 +15,37 @@
#ifndef _ARM_PROBES_H
#define _ARM_PROBES_H
-struct kprobe;
struct arch_specific_insn;
typedef u32 kprobe_opcode_t;
-typedef unsigned long (kprobes_pstate_check_t)(unsigned long);
+typedef u32 probe_opcode_t;
+typedef unsigned long (probes_pstate_check_t)(unsigned long);
typedef unsigned long
-(kprobes_condition_check_t)(struct kprobe *p, struct pt_regs *);
+(probes_condition_check_t)(u32 opcode, struct arch_specific_insn *,
+ struct pt_regs *);
typedef void
-(kprobes_prepare_t)(struct kprobe *, struct arch_specific_insn *);
-typedef void (kprobes_handler_t) (u32 opcode, long addr, struct pt_regs *);
+(probes_prepare_t)(u32 opcode, struct arch_specific_insn *);
+typedef void (probes_handler_t) (u32 opcode, long addr, struct pt_regs *);
enum pc_restore_type {
NO_RESTORE,
RESTORE_PC,
};
-struct kprobe_pc_restore {
+struct probe_pc_restore {
enum pc_restore_type type;
unsigned long addr;
};
/* architecture specific copy of original instruction */
struct arch_specific_insn {
- kprobe_opcode_t *insn;
- kprobes_pstate_check_t *pstate_cc;
- kprobes_condition_check_t *check_condn;
- kprobes_prepare_t *prepare;
- kprobes_handler_t *handler;
+ probe_opcode_t *insn;
+ probes_pstate_check_t *pstate_cc;
+ probes_condition_check_t *check_condn;
+ probes_prepare_t *prepare;
+ probes_handler_t *handler;
/* restore address after step xol */
- struct kprobe_pc_restore restore;
+ struct probe_pc_restore restore;
};
#endif
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index 6e4dcde27742..0ed83ba3d46d 100644
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -31,7 +31,7 @@ arm64-obj-$(CONFIG_ARM64_CPU_SUSPEND) += sleep.o suspend.o
arm64-obj-$(CONFIG_CPU_IDLE) += cpuidle.o
arm64-obj-$(CONFIG_JUMP_LABEL) += jump_label.o
arm64-obj-$(CONFIG_KGDB) += kgdb.o
-arm64-obj-$(CONFIG_KPROBES) += kprobes.o kprobes-arm64.o \
+arm64-obj-$(CONFIG_KPROBES) += kprobes.o probes-arm64.o \
probes-simulate-insn.o \
probes-condn-check.o
arm64-obj-$(CONFIG_EFI) += efi.o efi-stub.o efi-entry.o
diff --git a/arch/arm64/kernel/kprobes.c b/arch/arm64/kernel/kprobes.c
index be7c33070252..1cf5db159bc9 100644
--- a/arch/arm64/kernel/kprobes.c
+++ b/arch/arm64/kernel/kprobes.c
@@ -30,7 +30,7 @@
#include <asm/insn.h>
#include "kprobes.h"
-#include "kprobes-arm64.h"
+#include "probes-arm64.h"
#define MIN_STACK_SIZE(addr) min((unsigned long)MAX_STACK_SIZE, \
(unsigned long)current_thread_info() + THREAD_START_SP - (addr))
@@ -60,7 +60,7 @@ static void __kprobes arch_prepare_ss_slot(struct kprobe *p)
static void __kprobes arch_prepare_simulate(struct kprobe *p)
{
if (p->ainsn.prepare)
- p->ainsn.prepare(p, &p->ainsn);
+ p->ainsn.prepare(p->opcode, &p->ainsn);
/* This instructions is not executed xol. No need to adjust the PC */
p->ainsn.restore.addr = 0;
@@ -91,7 +91,7 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
return -EINVAL;
/* decode instruction */
- switch (arm_kprobe_decode_insn(insn, &p->ainsn)) {
+ switch (arm_probe_decode_insn(insn, &p->ainsn)) {
case INSN_REJECTED: /* insn not supported */
return -EINVAL;
@@ -275,7 +275,8 @@ static int __kprobes reenter_kprobe(struct kprobe *p,
switch (kcb->kprobe_status) {
case KPROBE_HIT_SSDONE:
case KPROBE_HIT_ACTIVE:
- if (!p->ainsn.check_condn || p->ainsn.check_condn(p, regs)) {
+ if (!p->ainsn.check_condn || p->ainsn.check_condn(p->opcode,
+ &p->ainsn, regs)) {
kprobes_inc_nmissed_count(p);
setup_singlestep(p, regs, kcb, 1);
} else {
@@ -408,7 +409,7 @@ void __kprobes kprobe_handler(struct pt_regs *regs)
if (reenter_kprobe(p, regs, kcb))
return;
} else if (!p->ainsn.check_condn ||
- p->ainsn.check_condn(p, regs)) {
+ p->ainsn.check_condn(p->opcode, &p->ainsn, regs)) {
/* Probe hit and conditional execution check ok. */
set_current_kprobe(p);
kcb->kprobe_status = KPROBE_HIT_ACTIVE;
diff --git a/arch/arm64/kernel/kprobes-arm64.c b/arch/arm64/kernel/probes-arm64.c
similarity index 79%
rename from arch/arm64/kernel/kprobes-arm64.c
rename to arch/arm64/kernel/probes-arm64.c
index bee7816cfd75..c258b390cbc1 100644
--- a/arch/arm64/kernel/kprobes-arm64.c
+++ b/arch/arm64/kernel/probes-arm64.c
@@ -1,5 +1,5 @@
/*
- * arch/arm64/kernel/kprobes-arm64.c
+ * arch/arm64/kernel/probes-arm64.c
*
* Copyright (C) 2013 Linaro Limited.
*
@@ -14,81 +14,73 @@
*/
#include <linux/kernel.h>
-#include <linux/kprobes.h>
#include <linux/module.h>
-#include <asm/kprobes.h>
+#include <asm/probes.h>
#include "probes-decode.h"
-#include "kprobes-arm64.h"
+#include "probes-arm64.h"
#include "probes-simulate-insn.h"
/*
- * condition check functions for kprobes simulation
+ * condition check functions for (k/u)probes simulation
*/
-static unsigned long __kprobes
-__check_pstate(struct kprobe *p, struct pt_regs *regs)
+static unsigned long
+__check_pstate(u32 opcode, struct arch_specific_insn *asi, struct pt_regs *regs)
{
- struct arch_specific_insn *asi = &p->ainsn;
unsigned long pstate = regs->pstate & 0xffffffff;
return asi->pstate_cc(pstate);
}
-static unsigned long __kprobes
-__check_cbz(struct kprobe *p, struct pt_regs *regs)
+static unsigned long
+__check_cbz(u32 opcode, struct arch_specific_insn *asi, struct pt_regs *regs)
{
- return check_cbz((u32)p->opcode, regs);
+ return check_cbz(opcode, regs);
}
-static unsigned long __kprobes
-__check_cbnz(struct kprobe *p, struct pt_regs *regs)
+static unsigned long
+__check_cbnz(u32 opcode, struct arch_specific_insn *asi, struct pt_regs *regs)
{
- return check_cbnz((u32)p->opcode, regs);
+ return check_cbnz(opcode, regs);
}
-static unsigned long __kprobes
-__check_tbz(struct kprobe *p, struct pt_regs *regs)
+static unsigned long
+__check_tbz(u32 opcode, struct arch_specific_insn *asi, struct pt_regs *regs)
{
- return check_tbz((u32)p->opcode, regs);
+ return check_tbz(opcode, regs);
}
-static unsigned long __kprobes
-__check_tbnz(struct kprobe *p, struct pt_regs *regs)
+static unsigned long
+__check_tbnz(u32 opcode, struct arch_specific_insn *asi, struct pt_regs *regs)
{
- return check_tbnz((u32)p->opcode, regs);
+ return check_tbnz(opcode, regs);
}
/*
* prepare functions for instruction simulation
*/
-static void __kprobes
-prepare_none(struct kprobe *p, struct arch_specific_insn *asi)
+static void
+prepare_none(u32 opcode, struct arch_specific_insn *asi)
{
}
-static void __kprobes
-prepare_bcond(struct kprobe *p, struct arch_specific_insn *asi)
+static void
+prepare_bcond(u32 opcode, struct arch_specific_insn *asi)
{
- kprobe_opcode_t insn = p->opcode;
-
asi->check_condn = __check_pstate;
- asi->pstate_cc = kprobe_condition_checks[insn & 0xf];
+ asi->pstate_cc = probe_condition_checks[opcode & 0xf];
}
-static void __kprobes
-prepare_cbz_cbnz(struct kprobe *p, struct arch_specific_insn *asi)
+static void
+prepare_cbz_cbnz(u32 opcode, struct arch_specific_insn *asi)
{
- kprobe_opcode_t insn = p->opcode;
-
- asi->check_condn = (insn & (1 << 24)) ? __check_cbnz : __check_cbz;
+ asi->check_condn = (opcode & (1 << 24)) ? __check_cbnz : __check_cbz;
}
-static void __kprobes
-prepare_tbz_tbnz(struct kprobe *p, struct arch_specific_insn *asi)
+static void
+prepare_tbz_tbnz(u32 opcode, struct arch_specific_insn *asi)
{
- kprobe_opcode_t insn = p->opcode;
-
- asi->check_condn = (insn & (1 << 24)) ? __check_tbnz : __check_tbz;
+ asi->check_condn = (opcode & (1 << 24)) ? __check_tbnz : __check_tbz;
}
@@ -116,7 +108,7 @@ static const struct aarch64_decode_item load_literal_subtable[] = {
DECODE_END,
};
-/* AArch64 instruction decode table for kprobes:
+/* AArch64 instruction decode table for (k/u)probes:
* The instruction will fall into one of the 3 groups:
* 1. Single stepped out-of-the-line slot.
* -Most instructions fall in this group, those does not
@@ -194,7 +186,7 @@ static const struct aarch64_decode_item aarch64_decode_table[] = {
* Encoding: 1101 0101 00xx xxxx xxxx xxxx xxxx xxxx
*
* Note: MSR immediate (update PSTATE daif) is not safe handling
- * within kprobes, rejected.
+ * within (k/u)probes, rejected.
*
* Don't re-arrange these decode table entries.
*/
@@ -265,8 +257,8 @@ static const struct aarch64_decode_item aarch64_decode_table[] = {
DECODE_END,
};
-static int __kprobes
-kprobe_decode_insn(kprobe_opcode_t insn, struct arch_specific_insn *asi,
+static int
+probe_decode_insn(probe_opcode_t insn, struct arch_specific_insn *asi,
const struct aarch64_decode_item *tbl)
{
unsigned int entry, ret = INSN_REJECTED;
@@ -295,19 +287,19 @@ kprobe_decode_insn(kprobe_opcode_t insn, struct arch_specific_insn *asi,
case DECODE_TYPE_TABLE:
/* recurse with next level decode table */
- ret = kprobe_decode_insn(insn, asi,
+ ret = probe_decode_insn(insn, asi,
decode_sub_table(tbl[entry]));
};
return ret;
}
/* Return:
- * INSN_REJECTED If instruction is one not allowed to kprobe,
+ * INSN_REJECTED If instruction is one not allowed to (k/u)probe,
* INSN_GOOD If instruction is supported and uses instruction slot,
* INSN_GOOD_NO_SLOT If instruction is supported but doesn't use its slot.
*/
-enum kprobe_insn __kprobes
-arm_kprobe_decode_insn(kprobe_opcode_t insn, struct arch_specific_insn *asi)
+enum probe_insn
+arm_probe_decode_insn(probe_opcode_t insn, struct arch_specific_insn *asi)
{
- return kprobe_decode_insn(insn, asi, aarch64_decode_table);
+ return probe_decode_insn(insn, asi, aarch64_decode_table);
}
diff --git a/arch/arm64/kernel/kprobes-arm64.h b/arch/arm64/kernel/probes-arm64.h
similarity index 60%
rename from arch/arm64/kernel/kprobes-arm64.h
rename to arch/arm64/kernel/probes-arm64.h
index ff8a55f61cda..a748d0ddfeef 100644
--- a/arch/arm64/kernel/kprobes-arm64.h
+++ b/arch/arm64/kernel/probes-arm64.h
@@ -1,5 +1,5 @@
/*
- * arch/arm64/kernel/kprobes-arm64.h
+ * arch/arm64/kernel/probes-arm64.h
*
* Copyright (C) 2013 Linaro Limited.
*
@@ -13,18 +13,19 @@
* General Public License for more details.
*/
-#ifndef _ARM_KERNEL_KPROBES_ARM64_H
-#define _ARM_KERNEL_KPROBES_ARM64_H
+#ifndef _ARM_KERNEL_PROBES_ARM64_H
+#define _ARM_KERNEL_PROBES_ARM64_H
-enum kprobe_insn {
+enum probe_insn {
INSN_REJECTED,
INSN_GOOD_NO_SLOT,
INSN_GOOD,
};
-extern kprobes_pstate_check_t * const kprobe_condition_checks[16];
+typedef u32 probe_opcode_t;
+extern probes_pstate_check_t * const probe_condition_checks[16];
-enum kprobe_insn __kprobes
-arm_kprobe_decode_insn(kprobe_opcode_t insn, struct arch_specific_insn *asi);
+enum probe_insn
+arm_probe_decode_insn(probe_opcode_t insn, struct arch_specific_insn *asi);
-#endif /* _ARM_KERNEL_KPROBES_ARM64_H */
+#endif /* _ARM_KERNEL_PROBES_ARM64_H */
diff --git a/arch/arm64/kernel/probes-condn-check.c b/arch/arm64/kernel/probes-condn-check.c
index e68aa0c86b94..8da70b6d59a6 100644
--- a/arch/arm64/kernel/probes-condn-check.c
+++ b/arch/arm64/kernel/probes-condn-check.c
@@ -114,7 +114,7 @@ static unsigned long __kprobes __check_al(unsigned long pstate)
return true;
}
-kprobes_pstate_check_t * const kprobe_condition_checks[16] = {
+probes_pstate_check_t * const probe_condition_checks[16] = {
&__check_eq, &__check_ne, &__check_cs, &__check_cc,
&__check_mi, &__check_pl, &__check_vs, &__check_vc,
&__check_hi, &__check_ls, &__check_ge, &__check_lt,
diff --git a/arch/arm64/kernel/probes-decode.h b/arch/arm64/kernel/probes-decode.h
index 3650ab356251..887ffb217e17 100644
--- a/arch/arm64/kernel/probes-decode.h
+++ b/arch/arm64/kernel/probes-decode.h
@@ -37,8 +37,8 @@ struct aarch64_decode_header {
};
struct aarch64_decode_actions {
- kprobes_prepare_t *prepare;
- kprobes_handler_t *handler;
+ probes_prepare_t *prepare;
+ probes_handler_t *handler;
};
struct aarch64_decode_table {
--
2.1.0
+Dave
Sorry, I took all cc list from your kprobe patches and forgot to add you. :(
Please review.
On Wednesday 31 December 2014 08:51 PM, Pratyush Anand wrote:
> These patches have been prepared on top of ARM64 kprobe v3 patches [1]
> under review.
>
> Unit test for following has been done so far and they have been found
> working
> 1. Normal instruction, which can be probed like sub, ldr, add etc.
> 2. Instructions which can be simulated like ret.
> 3. uretprobe
>
>
>
> [1]https://lkml.org/lkml/2014/11/18/33
>
> Pratyush Anand (8):
> ARM64: Move BRK opcodes defines from kprobes.h to insn.h
> ARM64: Refactor kprobes-arm64
> Kernel/uprobe: Define arch_uprobe_exception_notify as __weak
> ARM64: Add instruction_pointer_set function
> ARM64: Re-factor flush_ptrace_access
> ARM64: Handle TRAP_HWBRKPT for user mode as well
> ARM64: Handle TRAP_BRKPT for user mode as well
> ARM64: Add uprobe support
>
> arch/arm/kernel/uprobes.c | 6 -
> arch/arm64/Kconfig | 3 +
> arch/arm64/include/asm/insn.h | 8 +
> arch/arm64/include/asm/probes.h | 26 ++-
> arch/arm64/include/asm/ptrace.h | 7 +
> arch/arm64/include/asm/thread_info.h | 5 +-
> arch/arm64/include/asm/uprobes.h | 43 ++++
> arch/arm64/kernel/Makefile | 5 +-
> arch/arm64/kernel/debug-monitors.c | 14 +-
> arch/arm64/kernel/kprobes.c | 11 +-
> arch/arm64/kernel/kprobes.h | 7 +-
> .../kernel/{kprobes-arm64.c => probes-arm64.c} | 84 +++----
> .../kernel/{kprobes-arm64.h => probes-arm64.h} | 17 +-
> arch/arm64/kernel/probes-condn-check.c | 2 +-
> arch/arm64/kernel/probes-decode.h | 4 +-
> arch/arm64/kernel/signal.c | 4 +-
> arch/arm64/kernel/uprobes.c | 255 +++++++++++++++++++++
> arch/arm64/mm/flush.c | 30 ++-
> kernel/events/uprobes.c | 18 ++
> 19 files changed, 445 insertions(+), 104 deletions(-)
> create mode 100644 arch/arm64/include/asm/uprobes.h
> rename arch/arm64/kernel/{kprobes-arm64.c => probes-arm64.c} (79%)
> rename arch/arm64/kernel/{kprobes-arm64.h => probes-arm64.h} (60%)
> create mode 100644 arch/arm64/kernel/uprobes.c
>