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authorGuo Ren <guoren@linux.alibaba.com>2020-04-01 09:17:02 +0800
committerGuo Ren <guoren@linux.alibaba.com>2020-04-03 11:14:17 +0800
commit33e53ae1ce413a081254e686d9b27cc1b3585e2f (patch)
treedd6ddbf5a1707f1d0351143cedc00147a465abf4 /arch/csky/kernel/probes/simulate-insn.c
parent000591f1ca3312d9a29e15a9e3fe5c4171f75586 (diff)
downloadlinux-sh-33e53ae1ce413a081254e686d9b27cc1b3585e2f.tar.gz
csky: Add kprobes supported
This patch enable kprobes, kretprobes, ftrace interface. It utilized software breakpoint and single step debug exceptions, instructions simulation on csky. We use USR_BKPT replace origin instruction, and the kprobe handler prepares an excutable memory slot for out-of-line execution with a copy of the original instruction being probed. Most of instructions could be executed by single-step, but some instructions need origin pc value to execute and we need software simulate these instructions. Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'arch/csky/kernel/probes/simulate-insn.c')
-rw-r--r--arch/csky/kernel/probes/simulate-insn.c398
1 files changed, 398 insertions, 0 deletions
diff --git a/arch/csky/kernel/probes/simulate-insn.c b/arch/csky/kernel/probes/simulate-insn.c
new file mode 100644
index 000000000000..4e464fed52ec
--- /dev/null
+++ b/arch/csky/kernel/probes/simulate-insn.c
@@ -0,0 +1,398 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#include <linux/bitops.h>
+#include <linux/kernel.h>
+#include <linux/kprobes.h>
+
+#include "decode-insn.h"
+#include "simulate-insn.h"
+
+static inline bool csky_insn_reg_get_val(struct pt_regs *regs,
+ unsigned long index,
+ unsigned long *ptr)
+{
+ if (index < 14)
+ *ptr = *(&regs->a0 + index);
+
+ if (index > 15 && index < 31)
+ *ptr = *(&regs->exregs[0] + index - 16);
+
+ switch (index) {
+ case 14:
+ *ptr = regs->usp;
+ break;
+ case 15:
+ *ptr = regs->lr;
+ break;
+ case 31:
+ *ptr = regs->tls;
+ break;
+ default:
+ goto fail;
+ }
+
+ return true;
+fail:
+ return false;
+}
+
+static inline bool csky_insn_reg_set_val(struct pt_regs *regs,
+ unsigned long index,
+ unsigned long val)
+{
+ if (index < 14)
+ *(&regs->a0 + index) = val;
+
+ if (index > 15 && index < 31)
+ *(&regs->exregs[0] + index - 16) = val;
+
+ switch (index) {
+ case 14:
+ regs->usp = val;
+ break;
+ case 15:
+ regs->lr = val;
+ break;
+ case 31:
+ regs->tls = val;
+ break;
+ default:
+ goto fail;
+ }
+
+ return true;
+fail:
+ return false;
+}
+
+void __kprobes
+simulate_br16(u32 opcode, long addr, struct pt_regs *regs)
+{
+ instruction_pointer_set(regs,
+ addr + sign_extend32((opcode & 0x3ff) << 1, 9));
+}
+
+void __kprobes
+simulate_br32(u32 opcode, long addr, struct pt_regs *regs)
+{
+ instruction_pointer_set(regs,
+ addr + sign_extend32((opcode & 0xffff0000) >> 15, 15));
+}
+
+void __kprobes
+simulate_bt16(u32 opcode, long addr, struct pt_regs *regs)
+{
+ if (regs->sr & 1)
+ instruction_pointer_set(regs,
+ addr + sign_extend32((opcode & 0x3ff) << 1, 9));
+ else
+ instruction_pointer_set(regs, addr + 2);
+}
+
+void __kprobes
+simulate_bt32(u32 opcode, long addr, struct pt_regs *regs)
+{
+ if (regs->sr & 1)
+ instruction_pointer_set(regs,
+ addr + sign_extend32((opcode & 0xffff0000) >> 15, 15));
+ else
+ instruction_pointer_set(regs, addr + 4);
+}
+
+void __kprobes
+simulate_bf16(u32 opcode, long addr, struct pt_regs *regs)
+{
+ if (!(regs->sr & 1))
+ instruction_pointer_set(regs,
+ addr + sign_extend32((opcode & 0x3ff) << 1, 9));
+ else
+ instruction_pointer_set(regs, addr + 2);
+}
+
+void __kprobes
+simulate_bf32(u32 opcode, long addr, struct pt_regs *regs)
+{
+ if (!(regs->sr & 1))
+ instruction_pointer_set(regs,
+ addr + sign_extend32((opcode & 0xffff0000) >> 15, 15));
+ else
+ instruction_pointer_set(regs, addr + 4);
+}
+
+void __kprobes
+simulate_jmp16(u32 opcode, long addr, struct pt_regs *regs)
+{
+ unsigned long tmp = (opcode >> 2) & 0xf;
+
+ csky_insn_reg_get_val(regs, tmp, &tmp);
+
+ instruction_pointer_set(regs, tmp & 0xfffffffe);
+}
+
+void __kprobes
+simulate_jmp32(u32 opcode, long addr, struct pt_regs *regs)
+{
+ unsigned long tmp = opcode & 0x1f;
+
+ csky_insn_reg_get_val(regs, tmp, &tmp);
+
+ instruction_pointer_set(regs, tmp & 0xfffffffe);
+}
+
+void __kprobes
+simulate_jsr16(u32 opcode, long addr, struct pt_regs *regs)
+{
+ unsigned long tmp = (opcode >> 2) & 0xf;
+
+ csky_insn_reg_get_val(regs, tmp, &tmp);
+
+ regs->lr = addr + 2;
+
+ instruction_pointer_set(regs, tmp & 0xfffffffe);
+}
+
+void __kprobes
+simulate_jsr32(u32 opcode, long addr, struct pt_regs *regs)
+{
+ unsigned long tmp = opcode & 0x1f;
+
+ csky_insn_reg_get_val(regs, tmp, &tmp);
+
+ regs->lr = addr + 4;
+
+ instruction_pointer_set(regs, tmp & 0xfffffffe);
+}
+
+void __kprobes
+simulate_lrw16(u32 opcode, long addr, struct pt_regs *regs)
+{
+ unsigned long val;
+ unsigned long tmp = (opcode & 0x300) >> 3;
+ unsigned long offset = ((opcode & 0x1f) | tmp) << 2;
+
+ tmp = (opcode & 0xe0) >> 5;
+
+ val = *(unsigned int *)(instruction_pointer(regs) + offset);
+
+ csky_insn_reg_set_val(regs, tmp, val);
+}
+
+void __kprobes
+simulate_lrw32(u32 opcode, long addr, struct pt_regs *regs)
+{
+ unsigned long val;
+ unsigned long offset = (opcode & 0xffff0000) >> 14;
+ unsigned long tmp = opcode & 0x0000001f;
+
+ val = *(unsigned int *)
+ ((instruction_pointer(regs) + offset) & 0xfffffffc);
+
+ csky_insn_reg_set_val(regs, tmp, val);
+}
+
+void __kprobes
+simulate_pop16(u32 opcode, long addr, struct pt_regs *regs)
+{
+ unsigned long *tmp = (unsigned long *)regs->usp;
+ int i;
+
+ for (i = 0; i < (opcode & 0xf); i++) {
+ csky_insn_reg_set_val(regs, i + 4, *tmp);
+ tmp += 1;
+ }
+
+ if (opcode & 0x10) {
+ csky_insn_reg_set_val(regs, 15, *tmp);
+ tmp += 1;
+ }
+
+ regs->usp = (unsigned long)tmp;
+
+ instruction_pointer_set(regs, regs->lr);
+}
+
+void __kprobes
+simulate_pop32(u32 opcode, long addr, struct pt_regs *regs)
+{
+ unsigned long *tmp = (unsigned long *)regs->usp;
+ int i;
+
+ for (i = 0; i < ((opcode & 0xf0000) >> 16); i++) {
+ csky_insn_reg_set_val(regs, i + 4, *tmp);
+ tmp += 1;
+ }
+
+ if (opcode & 0x100000) {
+ csky_insn_reg_set_val(regs, 15, *tmp);
+ tmp += 1;
+ }
+
+ for (i = 0; i < ((opcode & 0xe00000) >> 21); i++) {
+ csky_insn_reg_set_val(regs, i + 16, *tmp);
+ tmp += 1;
+ }
+
+ if (opcode & 0x1000000) {
+ csky_insn_reg_set_val(regs, 29, *tmp);
+ tmp += 1;
+ }
+
+ regs->usp = (unsigned long)tmp;
+
+ instruction_pointer_set(regs, regs->lr);
+}
+
+void __kprobes
+simulate_bez32(u32 opcode, long addr, struct pt_regs *regs)
+{
+ unsigned long tmp = opcode & 0x1f;
+
+ csky_insn_reg_get_val(regs, tmp, &tmp);
+
+ if (tmp == 0) {
+ instruction_pointer_set(regs,
+ addr + sign_extend32((opcode & 0xffff0000) >> 15, 15));
+ } else
+ instruction_pointer_set(regs, addr + 4);
+}
+
+void __kprobes
+simulate_bnez32(u32 opcode, long addr, struct pt_regs *regs)
+{
+ unsigned long tmp = opcode & 0x1f;
+
+ csky_insn_reg_get_val(regs, tmp, &tmp);
+
+ if (tmp != 0) {
+ instruction_pointer_set(regs,
+ addr + sign_extend32((opcode & 0xffff0000) >> 15, 15));
+ } else
+ instruction_pointer_set(regs, addr + 4);
+}
+
+void __kprobes
+simulate_bnezad32(u32 opcode, long addr, struct pt_regs *regs)
+{
+ unsigned long tmp = opcode & 0x1f;
+ unsigned long val;
+
+ csky_insn_reg_get_val(regs, tmp, &val);
+
+ val -= 1;
+
+ if (val > 0) {
+ instruction_pointer_set(regs,
+ addr + sign_extend32((opcode & 0xffff0000) >> 15, 15));
+ } else
+ instruction_pointer_set(regs, addr + 4);
+
+ csky_insn_reg_set_val(regs, tmp, val);
+}
+
+void __kprobes
+simulate_bhsz32(u32 opcode, long addr, struct pt_regs *regs)
+{
+ unsigned long tmp = opcode & 0x1f;
+ unsigned long val;
+
+ csky_insn_reg_get_val(regs, tmp, &val);
+
+ if (val >= 0) {
+ instruction_pointer_set(regs,
+ addr + sign_extend32((opcode & 0xffff0000) >> 15, 15));
+ } else
+ instruction_pointer_set(regs, addr + 4);
+
+ csky_insn_reg_set_val(regs, tmp, val);
+}
+
+void __kprobes
+simulate_bhz32(u32 opcode, long addr, struct pt_regs *regs)
+{
+ unsigned long tmp = opcode & 0x1f;
+ unsigned long val;
+
+ csky_insn_reg_get_val(regs, tmp, &val);
+
+ if (val > 0) {
+ instruction_pointer_set(regs,
+ addr + sign_extend32((opcode & 0xffff0000) >> 15, 15));
+ } else
+ instruction_pointer_set(regs, addr + 4);
+
+ csky_insn_reg_set_val(regs, tmp, val);
+}
+
+void __kprobes
+simulate_blsz32(u32 opcode, long addr, struct pt_regs *regs)
+{
+ unsigned long tmp = opcode & 0x1f;
+ unsigned long val;
+
+ csky_insn_reg_get_val(regs, tmp, &val);
+
+ if (val <= 0) {
+ instruction_pointer_set(regs,
+ addr + sign_extend32((opcode & 0xffff0000) >> 15, 15));
+ } else
+ instruction_pointer_set(regs, addr + 4);
+
+ csky_insn_reg_set_val(regs, tmp, val);
+}
+
+void __kprobes
+simulate_blz32(u32 opcode, long addr, struct pt_regs *regs)
+{
+ unsigned long tmp = opcode & 0x1f;
+ unsigned long val;
+
+ csky_insn_reg_get_val(regs, tmp, &val);
+
+ if (val < 0) {
+ instruction_pointer_set(regs,
+ addr + sign_extend32((opcode & 0xffff0000) >> 15, 15));
+ } else
+ instruction_pointer_set(regs, addr + 4);
+
+ csky_insn_reg_set_val(regs, tmp, val);
+}
+
+void __kprobes
+simulate_bsr32(u32 opcode, long addr, struct pt_regs *regs)
+{
+ unsigned long tmp;
+
+ tmp = (opcode & 0xffff) << 16;
+ tmp |= (opcode & 0xffff0000) >> 16;
+
+ instruction_pointer_set(regs,
+ addr + sign_extend32((tmp & 0x3ffffff) << 1, 15));
+
+ regs->lr = addr + 4;
+}
+
+void __kprobes
+simulate_jmpi32(u32 opcode, long addr, struct pt_regs *regs)
+{
+ unsigned long val;
+ unsigned long offset = ((opcode & 0xffff0000) >> 14);
+
+ val = *(unsigned int *)
+ ((instruction_pointer(regs) + offset) & 0xfffffffc);
+
+ instruction_pointer_set(regs, val);
+}
+
+void __kprobes
+simulate_jsri32(u32 opcode, long addr, struct pt_regs *regs)
+{
+ unsigned long val;
+ unsigned long offset = ((opcode & 0xffff0000) >> 14);
+
+ val = *(unsigned int *)
+ ((instruction_pointer(regs) + offset) & 0xfffffffc);
+
+ regs->lr = addr + 4;
+
+ instruction_pointer_set(regs, val);
+}