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@@ -30,16 +30,15 @@
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* <jkenisto@us.ibm.com> and Prasanna S Panchamukhi
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* <prasanna@in.ibm.com> added function-return probes.
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* 2005-May Rusty Lynch <rusty.lynch@intel.com>
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- * Added function return probes functionality
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+ * Added function return probes functionality
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* 2006-Feb Masami Hiramatsu <hiramatu@sdl.hitachi.co.jp> added
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- * kprobe-booster and kretprobe-booster for i386.
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+ * kprobe-booster and kretprobe-booster for i386.
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* 2007-Dec Masami Hiramatsu <mhiramat@redhat.com> added kprobe-booster
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- * and kretprobe-booster for x86-64
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+ * and kretprobe-booster for x86-64
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* 2007-Dec Masami Hiramatsu <mhiramat@redhat.com>, Arjan van de Ven
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- * <arjan@infradead.org> and Jim Keniston <jkenisto@us.ibm.com>
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- * unified x86 kprobes code.
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+ * <arjan@infradead.org> and Jim Keniston <jkenisto@us.ibm.com>
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+ * unified x86 kprobes code.
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*/
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-
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#include <linux/kprobes.h>
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#include <linux/ptrace.h>
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#include <linux/string.h>
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@@ -59,6 +58,8 @@
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#include <asm/insn.h>
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#include <asm/debugreg.h>
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+#include "kprobes-common.h"
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+
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void jprobe_return_end(void);
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DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
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@@ -108,6 +109,7 @@ struct kretprobe_blackpoint kretprobe_blacklist[] = {
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doesn't switch kernel stack.*/
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{NULL, NULL} /* Terminator */
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};
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+
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const int kretprobe_blacklist_size = ARRAY_SIZE(kretprobe_blacklist);
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static void __kprobes __synthesize_relative_insn(void *from, void *to, u8 op)
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@@ -123,11 +125,17 @@ static void __kprobes __synthesize_relative_insn(void *from, void *to, u8 op)
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}
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/* Insert a jump instruction at address 'from', which jumps to address 'to'.*/
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-static void __kprobes synthesize_reljump(void *from, void *to)
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+void __kprobes synthesize_reljump(void *from, void *to)
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{
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__synthesize_relative_insn(from, to, RELATIVEJUMP_OPCODE);
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}
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+/* Insert a call instruction at address 'from', which calls address 'to'.*/
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+void __kprobes synthesize_relcall(void *from, void *to)
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+{
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+ __synthesize_relative_insn(from, to, RELATIVECALL_OPCODE);
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+}
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+
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/*
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* Skip the prefixes of the instruction.
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*/
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@@ -151,7 +159,7 @@ static kprobe_opcode_t *__kprobes skip_prefixes(kprobe_opcode_t *insn)
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* Returns non-zero if opcode is boostable.
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* RIP relative instructions are adjusted at copying time in 64 bits mode
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*/
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-static int __kprobes can_boost(kprobe_opcode_t *opcodes)
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+int __kprobes can_boost(kprobe_opcode_t *opcodes)
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{
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kprobe_opcode_t opcode;
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kprobe_opcode_t *orig_opcodes = opcodes;
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@@ -207,13 +215,15 @@ retry:
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}
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}
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-/* Recover the probed instruction at addr for further analysis. */
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-static int recover_probed_instruction(kprobe_opcode_t *buf, unsigned long addr)
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+static unsigned long
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+__recover_probed_insn(kprobe_opcode_t *buf, unsigned long addr)
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{
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struct kprobe *kp;
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+
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kp = get_kprobe((void *)addr);
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+ /* There is no probe, return original address */
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if (!kp)
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- return -EINVAL;
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+ return addr;
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/*
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* Basically, kp->ainsn.insn has an original instruction.
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@@ -230,14 +240,29 @@ static int recover_probed_instruction(kprobe_opcode_t *buf, unsigned long addr)
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*/
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memcpy(buf, kp->addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t));
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buf[0] = kp->opcode;
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- return 0;
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+ return (unsigned long)buf;
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+}
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+
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+/*
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+ * Recover the probed instruction at addr for further analysis.
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+ * Caller must lock kprobes by kprobe_mutex, or disable preemption
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+ * for preventing to release referencing kprobes.
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+ */
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+unsigned long recover_probed_instruction(kprobe_opcode_t *buf, unsigned long addr)
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+{
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+ unsigned long __addr;
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+
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+ __addr = __recover_optprobed_insn(buf, addr);
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+ if (__addr != addr)
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+ return __addr;
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+
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+ return __recover_probed_insn(buf, addr);
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}
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/* Check if paddr is at an instruction boundary */
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static int __kprobes can_probe(unsigned long paddr)
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{
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- int ret;
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- unsigned long addr, offset = 0;
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+ unsigned long addr, __addr, offset = 0;
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struct insn insn;
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kprobe_opcode_t buf[MAX_INSN_SIZE];
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@@ -247,26 +272,24 @@ static int __kprobes can_probe(unsigned long paddr)
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/* Decode instructions */
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addr = paddr - offset;
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while (addr < paddr) {
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- kernel_insn_init(&insn, (void *)addr);
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- insn_get_opcode(&insn);
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-
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/*
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* Check if the instruction has been modified by another
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* kprobe, in which case we replace the breakpoint by the
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* original instruction in our buffer.
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+ * Also, jump optimization will change the breakpoint to
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+ * relative-jump. Since the relative-jump itself is
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+ * normally used, we just go through if there is no kprobe.
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*/
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- if (insn.opcode.bytes[0] == BREAKPOINT_INSTRUCTION) {
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- ret = recover_probed_instruction(buf, addr);
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- if (ret)
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- /*
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- * Another debugging subsystem might insert
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- * this breakpoint. In that case, we can't
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- * recover it.
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- */
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- return 0;
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- kernel_insn_init(&insn, buf);
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- }
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+ __addr = recover_probed_instruction(buf, addr);
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+ kernel_insn_init(&insn, (void *)__addr);
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insn_get_length(&insn);
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+
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+ /*
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+ * Another debugging subsystem might insert this breakpoint.
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+ * In that case, we can't recover it.
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+ */
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+ if (insn.opcode.bytes[0] == BREAKPOINT_INSTRUCTION)
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+ return 0;
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addr += insn.length;
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}
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@@ -299,24 +322,16 @@ static int __kprobes is_IF_modifier(kprobe_opcode_t *insn)
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* If not, return null.
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* Only applicable to 64-bit x86.
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*/
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-static int __kprobes __copy_instruction(u8 *dest, u8 *src, int recover)
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+int __kprobes __copy_instruction(u8 *dest, u8 *src)
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{
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struct insn insn;
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- int ret;
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kprobe_opcode_t buf[MAX_INSN_SIZE];
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- kernel_insn_init(&insn, src);
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- if (recover) {
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- insn_get_opcode(&insn);
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- if (insn.opcode.bytes[0] == BREAKPOINT_INSTRUCTION) {
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- ret = recover_probed_instruction(buf,
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- (unsigned long)src);
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- if (ret)
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- return 0;
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- kernel_insn_init(&insn, buf);
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- }
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- }
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+ kernel_insn_init(&insn, (void *)recover_probed_instruction(buf, (unsigned long)src));
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insn_get_length(&insn);
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+ /* Another subsystem puts a breakpoint, failed to recover */
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+ if (insn.opcode.bytes[0] == BREAKPOINT_INSTRUCTION)
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+ return 0;
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memcpy(dest, insn.kaddr, insn.length);
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#ifdef CONFIG_X86_64
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@@ -337,8 +352,7 @@ static int __kprobes __copy_instruction(u8 *dest, u8 *src, int recover)
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* extension of the original signed 32-bit displacement would
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* have given.
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*/
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- newdisp = (u8 *) src + (s64) insn.displacement.value -
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- (u8 *) dest;
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+ newdisp = (u8 *) src + (s64) insn.displacement.value - (u8 *) dest;
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BUG_ON((s64) (s32) newdisp != newdisp); /* Sanity check. */
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disp = (u8 *) dest + insn_offset_displacement(&insn);
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*(s32 *) disp = (s32) newdisp;
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@@ -349,18 +363,20 @@ static int __kprobes __copy_instruction(u8 *dest, u8 *src, int recover)
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static void __kprobes arch_copy_kprobe(struct kprobe *p)
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{
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+ /* Copy an instruction with recovering if other optprobe modifies it.*/
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+ __copy_instruction(p->ainsn.insn, p->addr);
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+
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/*
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- * Copy an instruction without recovering int3, because it will be
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- * put by another subsystem.
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+ * __copy_instruction can modify the displacement of the instruction,
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+ * but it doesn't affect boostable check.
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*/
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- __copy_instruction(p->ainsn.insn, p->addr, 0);
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-
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- if (can_boost(p->addr))
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+ if (can_boost(p->ainsn.insn))
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p->ainsn.boostable = 0;
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else
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p->ainsn.boostable = -1;
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- p->opcode = *p->addr;
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+ /* Also, displacement change doesn't affect the first byte */
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+ p->opcode = p->ainsn.insn[0];
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}
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int __kprobes arch_prepare_kprobe(struct kprobe *p)
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@@ -442,8 +458,8 @@ static void __kprobes restore_btf(void)
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}
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}
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-void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
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- struct pt_regs *regs)
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+void __kprobes
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+arch_prepare_kretprobe(struct kretprobe_instance *ri, struct pt_regs *regs)
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{
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unsigned long *sara = stack_addr(regs);
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@@ -453,16 +469,8 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
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*sara = (unsigned long) &kretprobe_trampoline;
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}
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-#ifdef CONFIG_OPTPROBES
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-static int __kprobes setup_detour_execution(struct kprobe *p,
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- struct pt_regs *regs,
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- int reenter);
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-#else
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-#define setup_detour_execution(p, regs, reenter) (0)
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-#endif
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-
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-static void __kprobes setup_singlestep(struct kprobe *p, struct pt_regs *regs,
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- struct kprobe_ctlblk *kcb, int reenter)
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+static void __kprobes
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+setup_singlestep(struct kprobe *p, struct pt_regs *regs, struct kprobe_ctlblk *kcb, int reenter)
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{
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if (setup_detour_execution(p, regs, reenter))
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return;
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@@ -504,8 +512,8 @@ static void __kprobes setup_singlestep(struct kprobe *p, struct pt_regs *regs,
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* within the handler. We save the original kprobes variables and just single
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* step on the instruction of the new probe without calling any user handlers.
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*/
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-static int __kprobes reenter_kprobe(struct kprobe *p, struct pt_regs *regs,
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- struct kprobe_ctlblk *kcb)
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+static int __kprobes
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+reenter_kprobe(struct kprobe *p, struct pt_regs *regs, struct kprobe_ctlblk *kcb)
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{
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switch (kcb->kprobe_status) {
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case KPROBE_HIT_SSDONE:
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@@ -600,69 +608,6 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
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return 0;
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}
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-#ifdef CONFIG_X86_64
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-#define SAVE_REGS_STRING \
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- /* Skip cs, ip, orig_ax. */ \
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- " subq $24, %rsp\n" \
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- " pushq %rdi\n" \
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- " pushq %rsi\n" \
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- " pushq %rdx\n" \
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- " pushq %rcx\n" \
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- " pushq %rax\n" \
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- " pushq %r8\n" \
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- " pushq %r9\n" \
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- " pushq %r10\n" \
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- " pushq %r11\n" \
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- " pushq %rbx\n" \
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- " pushq %rbp\n" \
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- " pushq %r12\n" \
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- " pushq %r13\n" \
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- " pushq %r14\n" \
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- " pushq %r15\n"
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-#define RESTORE_REGS_STRING \
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- " popq %r15\n" \
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- " popq %r14\n" \
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- " popq %r13\n" \
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- " popq %r12\n" \
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- " popq %rbp\n" \
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- " popq %rbx\n" \
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- " popq %r11\n" \
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- " popq %r10\n" \
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- " popq %r9\n" \
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- " popq %r8\n" \
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- " popq %rax\n" \
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- " popq %rcx\n" \
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- " popq %rdx\n" \
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- " popq %rsi\n" \
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- " popq %rdi\n" \
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- /* Skip orig_ax, ip, cs */ \
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- " addq $24, %rsp\n"
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-#else
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-#define SAVE_REGS_STRING \
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- /* Skip cs, ip, orig_ax and gs. */ \
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- " subl $16, %esp\n" \
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- " pushl %fs\n" \
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- " pushl %es\n" \
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- " pushl %ds\n" \
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- " pushl %eax\n" \
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- " pushl %ebp\n" \
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- " pushl %edi\n" \
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- " pushl %esi\n" \
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- " pushl %edx\n" \
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- " pushl %ecx\n" \
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- " pushl %ebx\n"
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-#define RESTORE_REGS_STRING \
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- " popl %ebx\n" \
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- " popl %ecx\n" \
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- " popl %edx\n" \
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- " popl %esi\n" \
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- " popl %edi\n" \
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- " popl %ebp\n" \
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- " popl %eax\n" \
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- /* Skip ds, es, fs, gs, orig_ax, and ip. Note: don't pop cs here*/\
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- " addl $24, %esp\n"
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-#endif
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-
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/*
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* When a retprobed function returns, this code saves registers and
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* calls trampoline_handler() runs, which calls the kretprobe's handler.
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@@ -816,8 +761,8 @@ static __used __kprobes void *trampoline_handler(struct pt_regs *regs)
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* jump instruction after the copied instruction, that jumps to the next
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* instruction after the probepoint.
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*/
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-static void __kprobes resume_execution(struct kprobe *p,
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- struct pt_regs *regs, struct kprobe_ctlblk *kcb)
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+static void __kprobes
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+resume_execution(struct kprobe *p, struct pt_regs *regs, struct kprobe_ctlblk *kcb)
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{
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unsigned long *tos = stack_addr(regs);
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unsigned long copy_ip = (unsigned long)p->ainsn.insn;
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@@ -996,8 +941,8 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
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/*
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* Wrapper routine for handling exceptions.
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*/
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-int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
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- unsigned long val, void *data)
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+int __kprobes
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+kprobe_exceptions_notify(struct notifier_block *self, unsigned long val, void *data)
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{
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struct die_args *args = data;
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int ret = NOTIFY_DONE;
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@@ -1107,466 +1052,9 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
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return 0;
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}
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-
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-#ifdef CONFIG_OPTPROBES
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-
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-/* Insert a call instruction at address 'from', which calls address 'to'.*/
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-static void __kprobes synthesize_relcall(void *from, void *to)
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-{
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- __synthesize_relative_insn(from, to, RELATIVECALL_OPCODE);
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-}
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-
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-/* Insert a move instruction which sets a pointer to eax/rdi (1st arg). */
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-static void __kprobes synthesize_set_arg1(kprobe_opcode_t *addr,
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- unsigned long val)
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-{
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-#ifdef CONFIG_X86_64
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- *addr++ = 0x48;
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- *addr++ = 0xbf;
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-#else
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- *addr++ = 0xb8;
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-#endif
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- *(unsigned long *)addr = val;
|
|
|
-}
|
|
|
-
|
|
|
-static void __used __kprobes kprobes_optinsn_template_holder(void)
|
|
|
-{
|
|
|
- asm volatile (
|
|
|
- ".global optprobe_template_entry\n"
|
|
|
- "optprobe_template_entry: \n"
|
|
|
-#ifdef CONFIG_X86_64
|
|
|
- /* We don't bother saving the ss register */
|
|
|
- " pushq %rsp\n"
|
|
|
- " pushfq\n"
|
|
|
- SAVE_REGS_STRING
|
|
|
- " movq %rsp, %rsi\n"
|
|
|
- ".global optprobe_template_val\n"
|
|
|
- "optprobe_template_val: \n"
|
|
|
- ASM_NOP5
|
|
|
- ASM_NOP5
|
|
|
- ".global optprobe_template_call\n"
|
|
|
- "optprobe_template_call: \n"
|
|
|
- ASM_NOP5
|
|
|
- /* Move flags to rsp */
|
|
|
- " movq 144(%rsp), %rdx\n"
|
|
|
- " movq %rdx, 152(%rsp)\n"
|
|
|
- RESTORE_REGS_STRING
|
|
|
- /* Skip flags entry */
|
|
|
- " addq $8, %rsp\n"
|
|
|
- " popfq\n"
|
|
|
-#else /* CONFIG_X86_32 */
|
|
|
- " pushf\n"
|
|
|
- SAVE_REGS_STRING
|
|
|
- " movl %esp, %edx\n"
|
|
|
- ".global optprobe_template_val\n"
|
|
|
- "optprobe_template_val: \n"
|
|
|
- ASM_NOP5
|
|
|
- ".global optprobe_template_call\n"
|
|
|
- "optprobe_template_call: \n"
|
|
|
- ASM_NOP5
|
|
|
- RESTORE_REGS_STRING
|
|
|
- " addl $4, %esp\n" /* skip cs */
|
|
|
- " popf\n"
|
|
|
-#endif
|
|
|
- ".global optprobe_template_end\n"
|
|
|
- "optprobe_template_end: \n");
|
|
|
-}
|
|
|
-
|
|
|
-#define TMPL_MOVE_IDX \
|
|
|
- ((long)&optprobe_template_val - (long)&optprobe_template_entry)
|
|
|
-#define TMPL_CALL_IDX \
|
|
|
- ((long)&optprobe_template_call - (long)&optprobe_template_entry)
|
|
|
-#define TMPL_END_IDX \
|
|
|
- ((long)&optprobe_template_end - (long)&optprobe_template_entry)
|
|
|
-
|
|
|
-#define INT3_SIZE sizeof(kprobe_opcode_t)
|
|
|
-
|
|
|
-/* Optimized kprobe call back function: called from optinsn */
|
|
|
-static void __kprobes optimized_callback(struct optimized_kprobe *op,
|
|
|
- struct pt_regs *regs)
|
|
|
-{
|
|
|
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
|
|
|
- unsigned long flags;
|
|
|
-
|
|
|
- /* This is possible if op is under delayed unoptimizing */
|
|
|
- if (kprobe_disabled(&op->kp))
|
|
|
- return;
|
|
|
-
|
|
|
- local_irq_save(flags);
|
|
|
- if (kprobe_running()) {
|
|
|
- kprobes_inc_nmissed_count(&op->kp);
|
|
|
- } else {
|
|
|
- /* Save skipped registers */
|
|
|
-#ifdef CONFIG_X86_64
|
|
|
- regs->cs = __KERNEL_CS;
|
|
|
-#else
|
|
|
- regs->cs = __KERNEL_CS | get_kernel_rpl();
|
|
|
- regs->gs = 0;
|
|
|
-#endif
|
|
|
- regs->ip = (unsigned long)op->kp.addr + INT3_SIZE;
|
|
|
- regs->orig_ax = ~0UL;
|
|
|
-
|
|
|
- __this_cpu_write(current_kprobe, &op->kp);
|
|
|
- kcb->kprobe_status = KPROBE_HIT_ACTIVE;
|
|
|
- opt_pre_handler(&op->kp, regs);
|
|
|
- __this_cpu_write(current_kprobe, NULL);
|
|
|
- }
|
|
|
- local_irq_restore(flags);
|
|
|
-}
|
|
|
-
|
|
|
-static int __kprobes copy_optimized_instructions(u8 *dest, u8 *src)
|
|
|
-{
|
|
|
- int len = 0, ret;
|
|
|
-
|
|
|
- while (len < RELATIVEJUMP_SIZE) {
|
|
|
- ret = __copy_instruction(dest + len, src + len, 1);
|
|
|
- if (!ret || !can_boost(dest + len))
|
|
|
- return -EINVAL;
|
|
|
- len += ret;
|
|
|
- }
|
|
|
- /* Check whether the address range is reserved */
|
|
|
- if (ftrace_text_reserved(src, src + len - 1) ||
|
|
|
- alternatives_text_reserved(src, src + len - 1) ||
|
|
|
- jump_label_text_reserved(src, src + len - 1))
|
|
|
- return -EBUSY;
|
|
|
-
|
|
|
- return len;
|
|
|
-}
|
|
|
-
|
|
|
-/* Check whether insn is indirect jump */
|
|
|
-static int __kprobes insn_is_indirect_jump(struct insn *insn)
|
|
|
-{
|
|
|
- return ((insn->opcode.bytes[0] == 0xff &&
|
|
|
- (X86_MODRM_REG(insn->modrm.value) & 6) == 4) || /* Jump */
|
|
|
- insn->opcode.bytes[0] == 0xea); /* Segment based jump */
|
|
|
-}
|
|
|
-
|
|
|
-/* Check whether insn jumps into specified address range */
|
|
|
-static int insn_jump_into_range(struct insn *insn, unsigned long start, int len)
|
|
|
-{
|
|
|
- unsigned long target = 0;
|
|
|
-
|
|
|
- switch (insn->opcode.bytes[0]) {
|
|
|
- case 0xe0: /* loopne */
|
|
|
- case 0xe1: /* loope */
|
|
|
- case 0xe2: /* loop */
|
|
|
- case 0xe3: /* jcxz */
|
|
|
- case 0xe9: /* near relative jump */
|
|
|
- case 0xeb: /* short relative jump */
|
|
|
- break;
|
|
|
- case 0x0f:
|
|
|
- if ((insn->opcode.bytes[1] & 0xf0) == 0x80) /* jcc near */
|
|
|
- break;
|
|
|
- return 0;
|
|
|
- default:
|
|
|
- if ((insn->opcode.bytes[0] & 0xf0) == 0x70) /* jcc short */
|
|
|
- break;
|
|
|
- return 0;
|
|
|
- }
|
|
|
- target = (unsigned long)insn->next_byte + insn->immediate.value;
|
|
|
-
|
|
|
- return (start <= target && target <= start + len);
|
|
|
-}
|
|
|
-
|
|
|
-/* Decode whole function to ensure any instructions don't jump into target */
|
|
|
-static int __kprobes can_optimize(unsigned long paddr)
|
|
|
-{
|
|
|
- int ret;
|
|
|
- unsigned long addr, size = 0, offset = 0;
|
|
|
- struct insn insn;
|
|
|
- kprobe_opcode_t buf[MAX_INSN_SIZE];
|
|
|
-
|
|
|
- /* Lookup symbol including addr */
|
|
|
- if (!kallsyms_lookup_size_offset(paddr, &size, &offset))
|
|
|
- return 0;
|
|
|
-
|
|
|
- /*
|
|
|
- * Do not optimize in the entry code due to the unstable
|
|
|
- * stack handling.
|
|
|
- */
|
|
|
- if ((paddr >= (unsigned long )__entry_text_start) &&
|
|
|
- (paddr < (unsigned long )__entry_text_end))
|
|
|
- return 0;
|
|
|
-
|
|
|
- /* Check there is enough space for a relative jump. */
|
|
|
- if (size - offset < RELATIVEJUMP_SIZE)
|
|
|
- return 0;
|
|
|
-
|
|
|
- /* Decode instructions */
|
|
|
- addr = paddr - offset;
|
|
|
- while (addr < paddr - offset + size) { /* Decode until function end */
|
|
|
- if (search_exception_tables(addr))
|
|
|
- /*
|
|
|
- * Since some fixup code will jumps into this function,
|
|
|
- * we can't optimize kprobe in this function.
|
|
|
- */
|
|
|
- return 0;
|
|
|
- kernel_insn_init(&insn, (void *)addr);
|
|
|
- insn_get_opcode(&insn);
|
|
|
- if (insn.opcode.bytes[0] == BREAKPOINT_INSTRUCTION) {
|
|
|
- ret = recover_probed_instruction(buf, addr);
|
|
|
- if (ret)
|
|
|
- return 0;
|
|
|
- kernel_insn_init(&insn, buf);
|
|
|
- }
|
|
|
- insn_get_length(&insn);
|
|
|
- /* Recover address */
|
|
|
- insn.kaddr = (void *)addr;
|
|
|
- insn.next_byte = (void *)(addr + insn.length);
|
|
|
- /* Check any instructions don't jump into target */
|
|
|
- if (insn_is_indirect_jump(&insn) ||
|
|
|
- insn_jump_into_range(&insn, paddr + INT3_SIZE,
|
|
|
- RELATIVE_ADDR_SIZE))
|
|
|
- return 0;
|
|
|
- addr += insn.length;
|
|
|
- }
|
|
|
-
|
|
|
- return 1;
|
|
|
-}
|
|
|
-
|
|
|
-/* Check optimized_kprobe can actually be optimized. */
|
|
|
-int __kprobes arch_check_optimized_kprobe(struct optimized_kprobe *op)
|
|
|
-{
|
|
|
- int i;
|
|
|
- struct kprobe *p;
|
|
|
-
|
|
|
- for (i = 1; i < op->optinsn.size; i++) {
|
|
|
- p = get_kprobe(op->kp.addr + i);
|
|
|
- if (p && !kprobe_disabled(p))
|
|
|
- return -EEXIST;
|
|
|
- }
|
|
|
-
|
|
|
- return 0;
|
|
|
-}
|
|
|
-
|
|
|
-/* Check the addr is within the optimized instructions. */
|
|
|
-int __kprobes arch_within_optimized_kprobe(struct optimized_kprobe *op,
|
|
|
- unsigned long addr)
|
|
|
-{
|
|
|
- return ((unsigned long)op->kp.addr <= addr &&
|
|
|
- (unsigned long)op->kp.addr + op->optinsn.size > addr);
|
|
|
-}
|
|
|
-
|
|
|
-/* Free optimized instruction slot */
|
|
|
-static __kprobes
|
|
|
-void __arch_remove_optimized_kprobe(struct optimized_kprobe *op, int dirty)
|
|
|
-{
|
|
|
- if (op->optinsn.insn) {
|
|
|
- free_optinsn_slot(op->optinsn.insn, dirty);
|
|
|
- op->optinsn.insn = NULL;
|
|
|
- op->optinsn.size = 0;
|
|
|
- }
|
|
|
-}
|
|
|
-
|
|
|
-void __kprobes arch_remove_optimized_kprobe(struct optimized_kprobe *op)
|
|
|
-{
|
|
|
- __arch_remove_optimized_kprobe(op, 1);
|
|
|
-}
|
|
|
-
|
|
|
-/*
|
|
|
- * Copy replacing target instructions
|
|
|
- * Target instructions MUST be relocatable (checked inside)
|
|
|
- */
|
|
|
-int __kprobes arch_prepare_optimized_kprobe(struct optimized_kprobe *op)
|
|
|
-{
|
|
|
- u8 *buf;
|
|
|
- int ret;
|
|
|
- long rel;
|
|
|
-
|
|
|
- if (!can_optimize((unsigned long)op->kp.addr))
|
|
|
- return -EILSEQ;
|
|
|
-
|
|
|
- op->optinsn.insn = get_optinsn_slot();
|
|
|
- if (!op->optinsn.insn)
|
|
|
- return -ENOMEM;
|
|
|
-
|
|
|
- /*
|
|
|
- * Verify if the address gap is in 2GB range, because this uses
|
|
|
- * a relative jump.
|
|
|
- */
|
|
|
- rel = (long)op->optinsn.insn - (long)op->kp.addr + RELATIVEJUMP_SIZE;
|
|
|
- if (abs(rel) > 0x7fffffff)
|
|
|
- return -ERANGE;
|
|
|
-
|
|
|
- buf = (u8 *)op->optinsn.insn;
|
|
|
-
|
|
|
- /* Copy instructions into the out-of-line buffer */
|
|
|
- ret = copy_optimized_instructions(buf + TMPL_END_IDX, op->kp.addr);
|
|
|
- if (ret < 0) {
|
|
|
- __arch_remove_optimized_kprobe(op, 0);
|
|
|
- return ret;
|
|
|
- }
|
|
|
- op->optinsn.size = ret;
|
|
|
-
|
|
|
- /* Copy arch-dep-instance from template */
|
|
|
- memcpy(buf, &optprobe_template_entry, TMPL_END_IDX);
|
|
|
-
|
|
|
- /* Set probe information */
|
|
|
- synthesize_set_arg1(buf + TMPL_MOVE_IDX, (unsigned long)op);
|
|
|
-
|
|
|
- /* Set probe function call */
|
|
|
- synthesize_relcall(buf + TMPL_CALL_IDX, optimized_callback);
|
|
|
-
|
|
|
- /* Set returning jmp instruction at the tail of out-of-line buffer */
|
|
|
- synthesize_reljump(buf + TMPL_END_IDX + op->optinsn.size,
|
|
|
- (u8 *)op->kp.addr + op->optinsn.size);
|
|
|
-
|
|
|
- flush_icache_range((unsigned long) buf,
|
|
|
- (unsigned long) buf + TMPL_END_IDX +
|
|
|
- op->optinsn.size + RELATIVEJUMP_SIZE);
|
|
|
- return 0;
|
|
|
-}
|
|
|
-
|
|
|
-#define MAX_OPTIMIZE_PROBES 256
|
|
|
-static struct text_poke_param *jump_poke_params;
|
|
|
-static struct jump_poke_buffer {
|
|
|
- u8 buf[RELATIVEJUMP_SIZE];
|
|
|
-} *jump_poke_bufs;
|
|
|
-
|
|
|
-static void __kprobes setup_optimize_kprobe(struct text_poke_param *tprm,
|
|
|
- u8 *insn_buf,
|
|
|
- struct optimized_kprobe *op)
|
|
|
-{
|
|
|
- s32 rel = (s32)((long)op->optinsn.insn -
|
|
|
- ((long)op->kp.addr + RELATIVEJUMP_SIZE));
|
|
|
-
|
|
|
- /* Backup instructions which will be replaced by jump address */
|
|
|
- memcpy(op->optinsn.copied_insn, op->kp.addr + INT3_SIZE,
|
|
|
- RELATIVE_ADDR_SIZE);
|
|
|
-
|
|
|
- insn_buf[0] = RELATIVEJUMP_OPCODE;
|
|
|
- *(s32 *)(&insn_buf[1]) = rel;
|
|
|
-
|
|
|
- tprm->addr = op->kp.addr;
|
|
|
- tprm->opcode = insn_buf;
|
|
|
- tprm->len = RELATIVEJUMP_SIZE;
|
|
|
-}
|
|
|
-
|
|
|
-/*
|
|
|
- * Replace breakpoints (int3) with relative jumps.
|
|
|
- * Caller must call with locking kprobe_mutex and text_mutex.
|
|
|
- */
|
|
|
-void __kprobes arch_optimize_kprobes(struct list_head *oplist)
|
|
|
-{
|
|
|
- struct optimized_kprobe *op, *tmp;
|
|
|
- int c = 0;
|
|
|
-
|
|
|
- list_for_each_entry_safe(op, tmp, oplist, list) {
|
|
|
- WARN_ON(kprobe_disabled(&op->kp));
|
|
|
- /* Setup param */
|
|
|
- setup_optimize_kprobe(&jump_poke_params[c],
|
|
|
- jump_poke_bufs[c].buf, op);
|
|
|
- list_del_init(&op->list);
|
|
|
- if (++c >= MAX_OPTIMIZE_PROBES)
|
|
|
- break;
|
|
|
- }
|
|
|
-
|
|
|
- /*
|
|
|
- * text_poke_smp doesn't support NMI/MCE code modifying.
|
|
|
- * However, since kprobes itself also doesn't support NMI/MCE
|
|
|
- * code probing, it's not a problem.
|
|
|
- */
|
|
|
- text_poke_smp_batch(jump_poke_params, c);
|
|
|
-}
|
|
|
-
|
|
|
-static void __kprobes setup_unoptimize_kprobe(struct text_poke_param *tprm,
|
|
|
- u8 *insn_buf,
|
|
|
- struct optimized_kprobe *op)
|
|
|
-{
|
|
|
- /* Set int3 to first byte for kprobes */
|
|
|
- insn_buf[0] = BREAKPOINT_INSTRUCTION;
|
|
|
- memcpy(insn_buf + 1, op->optinsn.copied_insn, RELATIVE_ADDR_SIZE);
|
|
|
-
|
|
|
- tprm->addr = op->kp.addr;
|
|
|
- tprm->opcode = insn_buf;
|
|
|
- tprm->len = RELATIVEJUMP_SIZE;
|
|
|
-}
|
|
|
-
|
|
|
-/*
|
|
|
- * Recover original instructions and breakpoints from relative jumps.
|
|
|
- * Caller must call with locking kprobe_mutex.
|
|
|
- */
|
|
|
-extern void arch_unoptimize_kprobes(struct list_head *oplist,
|
|
|
- struct list_head *done_list)
|
|
|
-{
|
|
|
- struct optimized_kprobe *op, *tmp;
|
|
|
- int c = 0;
|
|
|
-
|
|
|
- list_for_each_entry_safe(op, tmp, oplist, list) {
|
|
|
- /* Setup param */
|
|
|
- setup_unoptimize_kprobe(&jump_poke_params[c],
|
|
|
- jump_poke_bufs[c].buf, op);
|
|
|
- list_move(&op->list, done_list);
|
|
|
- if (++c >= MAX_OPTIMIZE_PROBES)
|
|
|
- break;
|
|
|
- }
|
|
|
-
|
|
|
- /*
|
|
|
- * text_poke_smp doesn't support NMI/MCE code modifying.
|
|
|
- * However, since kprobes itself also doesn't support NMI/MCE
|
|
|
- * code probing, it's not a problem.
|
|
|
- */
|
|
|
- text_poke_smp_batch(jump_poke_params, c);
|
|
|
-}
|
|
|
-
|
|
|
-/* Replace a relative jump with a breakpoint (int3). */
|
|
|
-void __kprobes arch_unoptimize_kprobe(struct optimized_kprobe *op)
|
|
|
-{
|
|
|
- u8 buf[RELATIVEJUMP_SIZE];
|
|
|
-
|
|
|
- /* Set int3 to first byte for kprobes */
|
|
|
- buf[0] = BREAKPOINT_INSTRUCTION;
|
|
|
- memcpy(buf + 1, op->optinsn.copied_insn, RELATIVE_ADDR_SIZE);
|
|
|
- text_poke_smp(op->kp.addr, buf, RELATIVEJUMP_SIZE);
|
|
|
-}
|
|
|
-
|
|
|
-static int __kprobes setup_detour_execution(struct kprobe *p,
|
|
|
- struct pt_regs *regs,
|
|
|
- int reenter)
|
|
|
-{
|
|
|
- struct optimized_kprobe *op;
|
|
|
-
|
|
|
- if (p->flags & KPROBE_FLAG_OPTIMIZED) {
|
|
|
- /* This kprobe is really able to run optimized path. */
|
|
|
- op = container_of(p, struct optimized_kprobe, kp);
|
|
|
- /* Detour through copied instructions */
|
|
|
- regs->ip = (unsigned long)op->optinsn.insn + TMPL_END_IDX;
|
|
|
- if (!reenter)
|
|
|
- reset_current_kprobe();
|
|
|
- preempt_enable_no_resched();
|
|
|
- return 1;
|
|
|
- }
|
|
|
- return 0;
|
|
|
-}
|
|
|
-
|
|
|
-static int __kprobes init_poke_params(void)
|
|
|
-{
|
|
|
- /* Allocate code buffer and parameter array */
|
|
|
- jump_poke_bufs = kmalloc(sizeof(struct jump_poke_buffer) *
|
|
|
- MAX_OPTIMIZE_PROBES, GFP_KERNEL);
|
|
|
- if (!jump_poke_bufs)
|
|
|
- return -ENOMEM;
|
|
|
-
|
|
|
- jump_poke_params = kmalloc(sizeof(struct text_poke_param) *
|
|
|
- MAX_OPTIMIZE_PROBES, GFP_KERNEL);
|
|
|
- if (!jump_poke_params) {
|
|
|
- kfree(jump_poke_bufs);
|
|
|
- jump_poke_bufs = NULL;
|
|
|
- return -ENOMEM;
|
|
|
- }
|
|
|
-
|
|
|
- return 0;
|
|
|
-}
|
|
|
-#else /* !CONFIG_OPTPROBES */
|
|
|
-static int __kprobes init_poke_params(void)
|
|
|
-{
|
|
|
- return 0;
|
|
|
-}
|
|
|
-#endif
|
|
|
-
|
|
|
int __init arch_init_kprobes(void)
|
|
|
{
|
|
|
- return init_poke_params();
|
|
|
+ return arch_init_optprobes();
|
|
|
}
|
|
|
|
|
|
int __kprobes arch_trampoline_kprobe(struct kprobe *p)
|