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Merge branch 'uprobes/core' of git://git.kernel.org/pub/scm/linux/kernel/git/oleg/misc into perf/core
Pull uprobes updates from Oleg Nesterov: - "uretprobes" - an optimization to uprobes, like kretprobes are an optimization to kprobes. "perf probe -x file sym%return" now works like kretprobes. - PowerPC fixes plus a couple of cleanups/optimizations in uprobes and trace_uprobes. Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Ingo Molnar
commit
b5210b2a34
@ -1,6 +1,8 @@
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Uprobe-tracer: Uprobe-based Event Tracing
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=========================================
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Documentation written by Srikar Dronamraju
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Uprobe-tracer: Uprobe-based Event Tracing
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=========================================
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Documentation written by Srikar Dronamraju
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Overview
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--------
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@ -13,78 +15,94 @@ current_tracer. Instead of that, add probe points via
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/sys/kernel/debug/tracing/events/uprobes/<EVENT>/enabled.
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However unlike kprobe-event tracer, the uprobe event interface expects the
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user to calculate the offset of the probepoint in the object
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user to calculate the offset of the probepoint in the object.
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Synopsis of uprobe_tracer
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-------------------------
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p[:[GRP/]EVENT] PATH:SYMBOL[+offs] [FETCHARGS] : Set a probe
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p[:[GRP/]EVENT] PATH:SYMBOL[+offs] [FETCHARGS] : Set a uprobe
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r[:[GRP/]EVENT] PATH:SYMBOL[+offs] [FETCHARGS] : Set a return uprobe (uretprobe)
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-:[GRP/]EVENT : Clear uprobe or uretprobe event
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GRP : Group name. If omitted, use "uprobes" for it.
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EVENT : Event name. If omitted, the event name is generated
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based on SYMBOL+offs.
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PATH : path to an executable or a library.
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SYMBOL[+offs] : Symbol+offset where the probe is inserted.
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GRP : Group name. If omitted, "uprobes" is the default value.
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EVENT : Event name. If omitted, the event name is generated based
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on SYMBOL+offs.
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PATH : Path to an executable or a library.
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SYMBOL[+offs] : Symbol+offset where the probe is inserted.
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FETCHARGS : Arguments. Each probe can have up to 128 args.
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%REG : Fetch register REG
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FETCHARGS : Arguments. Each probe can have up to 128 args.
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%REG : Fetch register REG
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Event Profiling
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---------------
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You can check the total number of probe hits and probe miss-hits via
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You can check the total number of probe hits and probe miss-hits via
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/sys/kernel/debug/tracing/uprobe_profile.
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The first column is event name, the second is the number of probe hits,
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The first column is event name, the second is the number of probe hits,
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the third is the number of probe miss-hits.
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Usage examples
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--------------
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To add a probe as a new event, write a new definition to uprobe_events
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as below.
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* Add a probe as a new uprobe event, write a new definition to uprobe_events
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as below: (sets a uprobe at an offset of 0x4245c0 in the executable /bin/bash)
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echo 'p: /bin/bash:0x4245c0' > /sys/kernel/debug/tracing/uprobe_events
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echo 'p: /bin/bash:0x4245c0' > /sys/kernel/debug/tracing/uprobe_events
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This sets a uprobe at an offset of 0x4245c0 in the executable /bin/bash
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* Add a probe as a new uretprobe event:
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echo > /sys/kernel/debug/tracing/uprobe_events
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echo 'r: /bin/bash:0x4245c0' > /sys/kernel/debug/tracing/uprobe_events
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This clears all probe points.
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* Unset registered event:
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The following example shows how to dump the instruction pointer and %ax
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a register at the probed text address. Here we are trying to probe
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function zfree in /bin/zsh
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echo '-:bash_0x4245c0' >> /sys/kernel/debug/tracing/uprobe_events
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* Print out the events that are registered:
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cat /sys/kernel/debug/tracing/uprobe_events
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* Clear all events:
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echo > /sys/kernel/debug/tracing/uprobe_events
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Following example shows how to dump the instruction pointer and %ax register
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at the probed text address. Probe zfree function in /bin/zsh:
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# cd /sys/kernel/debug/tracing/
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# cat /proc/`pgrep zsh`/maps | grep /bin/zsh | grep r-xp
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# cat /proc/`pgrep zsh`/maps | grep /bin/zsh | grep r-xp
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00400000-0048a000 r-xp 00000000 08:03 130904 /bin/zsh
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# objdump -T /bin/zsh | grep -w zfree
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0000000000446420 g DF .text 0000000000000012 Base zfree
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0x46420 is the offset of zfree in object /bin/zsh that is loaded at
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0x00400000. Hence the command to probe would be :
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0x46420 is the offset of zfree in object /bin/zsh that is loaded at
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0x00400000. Hence the command to uprobe would be:
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# echo 'p /bin/zsh:0x46420 %ip %ax' > uprobe_events
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# echo 'p:zfree_entry /bin/zsh:0x46420 %ip %ax' > uprobe_events
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Please note: User has to explicitly calculate the offset of the probepoint
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And the same for the uretprobe would be:
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# echo 'r:zfree_exit /bin/zsh:0x46420 %ip %ax' >> uprobe_events
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Please note: User has to explicitly calculate the offset of the probe-point
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in the object. We can see the events that are registered by looking at the
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uprobe_events file.
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# cat uprobe_events
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p:uprobes/p_zsh_0x46420 /bin/zsh:0x00046420 arg1=%ip arg2=%ax
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p:uprobes/zfree_entry /bin/zsh:0x00046420 arg1=%ip arg2=%ax
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r:uprobes/zfree_exit /bin/zsh:0x00046420 arg1=%ip arg2=%ax
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The format of events can be seen by viewing the file events/uprobes/p_zsh_0x46420/format
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Format of events can be seen by viewing the file events/uprobes/zfree_entry/format
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# cat events/uprobes/p_zsh_0x46420/format
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name: p_zsh_0x46420
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# cat events/uprobes/zfree_entry/format
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name: zfree_entry
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ID: 922
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format:
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field:unsigned short common_type; offset:0; size:2; signed:0;
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field:unsigned char common_flags; offset:2; size:1; signed:0;
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field:unsigned char common_preempt_count; offset:3; size:1; signed:0;
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field:int common_pid; offset:4; size:4; signed:1;
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field:int common_padding; offset:8; size:4; signed:1;
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field:unsigned short common_type; offset:0; size:2; signed:0;
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field:unsigned char common_flags; offset:2; size:1; signed:0;
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field:unsigned char common_preempt_count; offset:3; size:1; signed:0;
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field:int common_pid; offset:4; size:4; signed:1;
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field:int common_padding; offset:8; size:4; signed:1;
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field:unsigned long __probe_ip; offset:12; size:4; signed:0;
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field:u32 arg1; offset:16; size:4; signed:0;
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field:u32 arg2; offset:20; size:4; signed:0;
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field:unsigned long __probe_ip; offset:12; size:4; signed:0;
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field:u32 arg1; offset:16; size:4; signed:0;
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field:u32 arg2; offset:20; size:4; signed:0;
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print fmt: "(%lx) arg1=%lx arg2=%lx", REC->__probe_ip, REC->arg1, REC->arg2
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@ -94,6 +112,7 @@ events, you need to enable it by:
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# echo 1 > events/uprobes/enable
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Lets disable the event after sleeping for some time.
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# sleep 20
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# echo 0 > events/uprobes/enable
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@ -104,10 +123,11 @@ And you can see the traced information via /sys/kernel/debug/tracing/trace.
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#
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# TASK-PID CPU# TIMESTAMP FUNCTION
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# | | | | |
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zsh-24842 [006] 258544.995456: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79
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zsh-24842 [007] 258545.000270: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79
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zsh-24842 [002] 258545.043929: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79
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zsh-24842 [004] 258547.046129: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79
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zsh-24842 [006] 258544.995456: zfree_entry: (0x446420) arg1=446420 arg2=79
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zsh-24842 [007] 258545.000270: zfree_exit: (0x446540 <- 0x446420) arg1=446540 arg2=0
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zsh-24842 [002] 258545.043929: zfree_entry: (0x446420) arg1=446420 arg2=79
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zsh-24842 [004] 258547.046129: zfree_exit: (0x446540 <- 0x446420) arg1=446540 arg2=0
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Each line shows us probes were triggered for a pid 24842 with ip being
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0x446421 and contents of ax register being 79.
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Output shows us uprobe was triggered for a pid 24842 with ip being 0x446420
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and contents of ax register being 79. And uretprobe was triggered with ip at
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0x446540 with counterpart function entry at 0x446420.
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@ -51,4 +51,5 @@ extern int arch_uprobe_post_xol(struct arch_uprobe *aup, struct pt_regs *regs);
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extern bool arch_uprobe_xol_was_trapped(struct task_struct *tsk);
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extern int arch_uprobe_exception_notify(struct notifier_block *self, unsigned long val, void *data);
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extern void arch_uprobe_abort_xol(struct arch_uprobe *aup, struct pt_regs *regs);
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extern unsigned long arch_uretprobe_hijack_return_addr(unsigned long trampoline_vaddr, struct pt_regs *regs);
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#endif /* _ASM_UPROBES_H */
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@ -30,6 +30,16 @@
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#define UPROBE_TRAP_NR UINT_MAX
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/**
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* is_trap_insn - check if the instruction is a trap variant
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* @insn: instruction to be checked.
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* Returns true if @insn is a trap variant.
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*/
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bool is_trap_insn(uprobe_opcode_t *insn)
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{
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return (is_trap(*insn));
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}
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/**
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* arch_uprobe_analyze_insn
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* @mm: the probed address space.
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@ -43,12 +53,6 @@ int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe,
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if (addr & 0x03)
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return -EINVAL;
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/*
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* We currently don't support a uprobe on an already
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* existing breakpoint instruction underneath
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*/
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if (is_trap(auprobe->ainsn))
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return -ENOTSUPP;
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return 0;
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}
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@ -188,3 +192,16 @@ bool arch_uprobe_skip_sstep(struct arch_uprobe *auprobe, struct pt_regs *regs)
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return false;
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}
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unsigned long
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arch_uretprobe_hijack_return_addr(unsigned long trampoline_vaddr, struct pt_regs *regs)
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{
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unsigned long orig_ret_vaddr;
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orig_ret_vaddr = regs->link;
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/* Replace the return addr with trampoline addr */
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regs->link = trampoline_vaddr;
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return orig_ret_vaddr;
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}
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@ -55,4 +55,5 @@ extern int arch_uprobe_post_xol(struct arch_uprobe *aup, struct pt_regs *regs);
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extern bool arch_uprobe_xol_was_trapped(struct task_struct *tsk);
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extern int arch_uprobe_exception_notify(struct notifier_block *self, unsigned long val, void *data);
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extern void arch_uprobe_abort_xol(struct arch_uprobe *aup, struct pt_regs *regs);
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extern unsigned long arch_uretprobe_hijack_return_addr(unsigned long trampoline_vaddr, struct pt_regs *regs);
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#endif /* _ASM_UPROBES_H */
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@ -697,3 +697,32 @@ bool arch_uprobe_skip_sstep(struct arch_uprobe *auprobe, struct pt_regs *regs)
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send_sig(SIGTRAP, current, 0);
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return ret;
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}
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unsigned long
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arch_uretprobe_hijack_return_addr(unsigned long trampoline_vaddr, struct pt_regs *regs)
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{
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int rasize, ncopied;
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unsigned long orig_ret_vaddr = 0; /* clear high bits for 32-bit apps */
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rasize = is_ia32_task() ? 4 : 8;
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ncopied = copy_from_user(&orig_ret_vaddr, (void __user *)regs->sp, rasize);
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if (unlikely(ncopied))
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return -1;
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/* check whether address has been already hijacked */
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if (orig_ret_vaddr == trampoline_vaddr)
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return orig_ret_vaddr;
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ncopied = copy_to_user((void __user *)regs->sp, &trampoline_vaddr, rasize);
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if (likely(!ncopied))
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return orig_ret_vaddr;
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if (ncopied != rasize) {
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pr_err("uprobe: return address clobbered: pid=%d, %%sp=%#lx, "
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"%%ip=%#lx\n", current->pid, regs->sp, regs->ip);
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force_sig_info(SIGSEGV, SEND_SIG_FORCED, current);
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}
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return -1;
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}
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@ -38,6 +38,8 @@ struct inode;
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#define UPROBE_HANDLER_REMOVE 1
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#define UPROBE_HANDLER_MASK 1
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#define MAX_URETPROBE_DEPTH 64
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enum uprobe_filter_ctx {
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UPROBE_FILTER_REGISTER,
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UPROBE_FILTER_UNREGISTER,
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@ -46,6 +48,9 @@ enum uprobe_filter_ctx {
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struct uprobe_consumer {
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int (*handler)(struct uprobe_consumer *self, struct pt_regs *regs);
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int (*ret_handler)(struct uprobe_consumer *self,
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unsigned long func,
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struct pt_regs *regs);
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bool (*filter)(struct uprobe_consumer *self,
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enum uprobe_filter_ctx ctx,
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struct mm_struct *mm);
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@ -68,6 +73,8 @@ struct uprobe_task {
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enum uprobe_task_state state;
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struct arch_uprobe_task autask;
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struct return_instance *return_instances;
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unsigned int depth;
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struct uprobe *active_uprobe;
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unsigned long xol_vaddr;
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@ -100,6 +107,7 @@ struct uprobes_state {
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extern int __weak set_swbp(struct arch_uprobe *aup, struct mm_struct *mm, unsigned long vaddr);
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extern int __weak set_orig_insn(struct arch_uprobe *aup, struct mm_struct *mm, unsigned long vaddr);
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extern bool __weak is_swbp_insn(uprobe_opcode_t *insn);
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extern bool __weak is_trap_insn(uprobe_opcode_t *insn);
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extern int uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer *uc);
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extern int uprobe_apply(struct inode *inode, loff_t offset, struct uprobe_consumer *uc, bool);
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extern void uprobe_unregister(struct inode *inode, loff_t offset, struct uprobe_consumer *uc);
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@ -75,6 +75,15 @@ struct uprobe {
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struct arch_uprobe arch;
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};
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struct return_instance {
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struct uprobe *uprobe;
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unsigned long func;
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unsigned long orig_ret_vaddr; /* original return address */
|
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bool chained; /* true, if instance is nested */
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struct return_instance *next; /* keep as stack */
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};
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/*
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* valid_vma: Verify if the specified vma is an executable vma
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* Relax restrictions while unregistering: vm_flags might have
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@ -173,10 +182,31 @@ bool __weak is_swbp_insn(uprobe_opcode_t *insn)
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return *insn == UPROBE_SWBP_INSN;
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}
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static void copy_opcode(struct page *page, unsigned long vaddr, uprobe_opcode_t *opcode)
|
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/**
|
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* is_trap_insn - check if instruction is breakpoint instruction.
|
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* @insn: instruction to be checked.
|
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* Default implementation of is_trap_insn
|
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* Returns true if @insn is a breakpoint instruction.
|
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*
|
||||
* This function is needed for the case where an architecture has multiple
|
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* trap instructions (like powerpc).
|
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*/
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bool __weak is_trap_insn(uprobe_opcode_t *insn)
|
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{
|
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return is_swbp_insn(insn);
|
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}
|
||||
|
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static void copy_from_page(struct page *page, unsigned long vaddr, void *dst, int len)
|
||||
{
|
||||
void *kaddr = kmap_atomic(page);
|
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memcpy(opcode, kaddr + (vaddr & ~PAGE_MASK), UPROBE_SWBP_INSN_SIZE);
|
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memcpy(dst, kaddr + (vaddr & ~PAGE_MASK), len);
|
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kunmap_atomic(kaddr);
|
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}
|
||||
|
||||
static void copy_to_page(struct page *page, unsigned long vaddr, const void *src, int len)
|
||||
{
|
||||
void *kaddr = kmap_atomic(page);
|
||||
memcpy(kaddr + (vaddr & ~PAGE_MASK), src, len);
|
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kunmap_atomic(kaddr);
|
||||
}
|
||||
|
||||
@ -185,7 +215,16 @@ static int verify_opcode(struct page *page, unsigned long vaddr, uprobe_opcode_t
|
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uprobe_opcode_t old_opcode;
|
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bool is_swbp;
|
||||
|
||||
copy_opcode(page, vaddr, &old_opcode);
|
||||
/*
|
||||
* Note: We only check if the old_opcode is UPROBE_SWBP_INSN here.
|
||||
* We do not check if it is any other 'trap variant' which could
|
||||
* be conditional trap instruction such as the one powerpc supports.
|
||||
*
|
||||
* The logic is that we do not care if the underlying instruction
|
||||
* is a trap variant; uprobes always wins over any other (gdb)
|
||||
* breakpoint.
|
||||
*/
|
||||
copy_from_page(page, vaddr, &old_opcode, UPROBE_SWBP_INSN_SIZE);
|
||||
is_swbp = is_swbp_insn(&old_opcode);
|
||||
|
||||
if (is_swbp_insn(new_opcode)) {
|
||||
@ -204,7 +243,7 @@ static int verify_opcode(struct page *page, unsigned long vaddr, uprobe_opcode_t
|
||||
* Expect the breakpoint instruction to be the smallest size instruction for
|
||||
* the architecture. If an arch has variable length instruction and the
|
||||
* breakpoint instruction is not of the smallest length instruction
|
||||
* supported by that architecture then we need to modify is_swbp_at_addr and
|
||||
* supported by that architecture then we need to modify is_trap_at_addr and
|
||||
* write_opcode accordingly. This would never be a problem for archs that
|
||||
* have fixed length instructions.
|
||||
*/
|
||||
@ -225,7 +264,6 @@ static int write_opcode(struct mm_struct *mm, unsigned long vaddr,
|
||||
uprobe_opcode_t opcode)
|
||||
{
|
||||
struct page *old_page, *new_page;
|
||||
void *vaddr_old, *vaddr_new;
|
||||
struct vm_area_struct *vma;
|
||||
int ret;
|
||||
|
||||
@ -246,15 +284,8 @@ retry:
|
||||
|
||||
__SetPageUptodate(new_page);
|
||||
|
||||
/* copy the page now that we've got it stable */
|
||||
vaddr_old = kmap_atomic(old_page);
|
||||
vaddr_new = kmap_atomic(new_page);
|
||||
|
||||
memcpy(vaddr_new, vaddr_old, PAGE_SIZE);
|
||||
memcpy(vaddr_new + (vaddr & ~PAGE_MASK), &opcode, UPROBE_SWBP_INSN_SIZE);
|
||||
|
||||
kunmap_atomic(vaddr_new);
|
||||
kunmap_atomic(vaddr_old);
|
||||
copy_highpage(new_page, old_page);
|
||||
copy_to_page(new_page, vaddr, &opcode, UPROBE_SWBP_INSN_SIZE);
|
||||
|
||||
ret = anon_vma_prepare(vma);
|
||||
if (ret)
|
||||
@ -477,30 +508,18 @@ __copy_insn(struct address_space *mapping, struct file *filp, char *insn,
|
||||
unsigned long nbytes, loff_t offset)
|
||||
{
|
||||
struct page *page;
|
||||
void *vaddr;
|
||||
unsigned long off;
|
||||
pgoff_t idx;
|
||||
|
||||
if (!filp)
|
||||
return -EINVAL;
|
||||
|
||||
if (!mapping->a_ops->readpage)
|
||||
return -EIO;
|
||||
|
||||
idx = offset >> PAGE_CACHE_SHIFT;
|
||||
off = offset & ~PAGE_MASK;
|
||||
|
||||
/*
|
||||
* Ensure that the page that has the original instruction is
|
||||
* populated and in page-cache.
|
||||
*/
|
||||
page = read_mapping_page(mapping, idx, filp);
|
||||
page = read_mapping_page(mapping, offset >> PAGE_CACHE_SHIFT, filp);
|
||||
if (IS_ERR(page))
|
||||
return PTR_ERR(page);
|
||||
|
||||
vaddr = kmap_atomic(page);
|
||||
memcpy(insn, vaddr + off, nbytes);
|
||||
kunmap_atomic(vaddr);
|
||||
copy_from_page(page, offset, insn, nbytes);
|
||||
page_cache_release(page);
|
||||
|
||||
return 0;
|
||||
@ -550,7 +569,7 @@ static int prepare_uprobe(struct uprobe *uprobe, struct file *file,
|
||||
goto out;
|
||||
|
||||
ret = -ENOTSUPP;
|
||||
if (is_swbp_insn((uprobe_opcode_t *)uprobe->arch.insn))
|
||||
if (is_trap_insn((uprobe_opcode_t *)uprobe->arch.insn))
|
||||
goto out;
|
||||
|
||||
ret = arch_uprobe_analyze_insn(&uprobe->arch, mm, vaddr);
|
||||
@ -758,7 +777,7 @@ register_for_each_vma(struct uprobe *uprobe, struct uprobe_consumer *new)
|
||||
down_write(&mm->mmap_sem);
|
||||
vma = find_vma(mm, info->vaddr);
|
||||
if (!vma || !valid_vma(vma, is_register) ||
|
||||
vma->vm_file->f_mapping->host != uprobe->inode)
|
||||
file_inode(vma->vm_file) != uprobe->inode)
|
||||
goto unlock;
|
||||
|
||||
if (vma->vm_start > info->vaddr ||
|
||||
@ -828,6 +847,10 @@ int uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer *
|
||||
struct uprobe *uprobe;
|
||||
int ret;
|
||||
|
||||
/* Uprobe must have at least one set consumer */
|
||||
if (!uc->handler && !uc->ret_handler)
|
||||
return -EINVAL;
|
||||
|
||||
/* Racy, just to catch the obvious mistakes */
|
||||
if (offset > i_size_read(inode))
|
||||
return -EINVAL;
|
||||
@ -917,7 +940,7 @@ static int unapply_uprobe(struct uprobe *uprobe, struct mm_struct *mm)
|
||||
loff_t offset;
|
||||
|
||||
if (!valid_vma(vma, false) ||
|
||||
vma->vm_file->f_mapping->host != uprobe->inode)
|
||||
file_inode(vma->vm_file) != uprobe->inode)
|
||||
continue;
|
||||
|
||||
offset = (loff_t)vma->vm_pgoff << PAGE_SHIFT;
|
||||
@ -1010,7 +1033,7 @@ int uprobe_mmap(struct vm_area_struct *vma)
|
||||
if (no_uprobe_events() || !valid_vma(vma, true))
|
||||
return 0;
|
||||
|
||||
inode = vma->vm_file->f_mapping->host;
|
||||
inode = file_inode(vma->vm_file);
|
||||
if (!inode)
|
||||
return 0;
|
||||
|
||||
@ -1041,7 +1064,7 @@ vma_has_uprobes(struct vm_area_struct *vma, unsigned long start, unsigned long e
|
||||
struct inode *inode;
|
||||
struct rb_node *n;
|
||||
|
||||
inode = vma->vm_file->f_mapping->host;
|
||||
inode = file_inode(vma->vm_file);
|
||||
|
||||
min = vaddr_to_offset(vma, start);
|
||||
max = min + (end - start) - 1;
|
||||
@ -1114,6 +1137,7 @@ static struct xol_area *get_xol_area(void)
|
||||
{
|
||||
struct mm_struct *mm = current->mm;
|
||||
struct xol_area *area;
|
||||
uprobe_opcode_t insn = UPROBE_SWBP_INSN;
|
||||
|
||||
area = mm->uprobes_state.xol_area;
|
||||
if (area)
|
||||
@ -1131,7 +1155,12 @@ static struct xol_area *get_xol_area(void)
|
||||
if (!area->page)
|
||||
goto free_bitmap;
|
||||
|
||||
/* allocate first slot of task's xol_area for the return probes */
|
||||
set_bit(0, area->bitmap);
|
||||
copy_to_page(area->page, 0, &insn, UPROBE_SWBP_INSN_SIZE);
|
||||
atomic_set(&area->slot_count, 1);
|
||||
init_waitqueue_head(&area->wq);
|
||||
|
||||
if (!xol_add_vma(area))
|
||||
return area;
|
||||
|
||||
@ -1216,9 +1245,7 @@ static unsigned long xol_take_insn_slot(struct xol_area *area)
|
||||
static unsigned long xol_get_insn_slot(struct uprobe *uprobe)
|
||||
{
|
||||
struct xol_area *area;
|
||||
unsigned long offset;
|
||||
unsigned long xol_vaddr;
|
||||
void *vaddr;
|
||||
|
||||
area = get_xol_area();
|
||||
if (!area)
|
||||
@ -1229,10 +1256,7 @@ static unsigned long xol_get_insn_slot(struct uprobe *uprobe)
|
||||
return 0;
|
||||
|
||||
/* Initialize the slot */
|
||||
offset = xol_vaddr & ~PAGE_MASK;
|
||||
vaddr = kmap_atomic(area->page);
|
||||
memcpy(vaddr + offset, uprobe->arch.insn, MAX_UINSN_BYTES);
|
||||
kunmap_atomic(vaddr);
|
||||
copy_to_page(area->page, xol_vaddr, uprobe->arch.insn, MAX_UINSN_BYTES);
|
||||
/*
|
||||
* We probably need flush_icache_user_range() but it needs vma.
|
||||
* This should work on supported architectures too.
|
||||
@ -1298,6 +1322,7 @@ unsigned long __weak uprobe_get_swbp_addr(struct pt_regs *regs)
|
||||
void uprobe_free_utask(struct task_struct *t)
|
||||
{
|
||||
struct uprobe_task *utask = t->utask;
|
||||
struct return_instance *ri, *tmp;
|
||||
|
||||
if (!utask)
|
||||
return;
|
||||
@ -1305,6 +1330,15 @@ void uprobe_free_utask(struct task_struct *t)
|
||||
if (utask->active_uprobe)
|
||||
put_uprobe(utask->active_uprobe);
|
||||
|
||||
ri = utask->return_instances;
|
||||
while (ri) {
|
||||
tmp = ri;
|
||||
ri = ri->next;
|
||||
|
||||
put_uprobe(tmp->uprobe);
|
||||
kfree(tmp);
|
||||
}
|
||||
|
||||
xol_free_insn_slot(t);
|
||||
kfree(utask);
|
||||
t->utask = NULL;
|
||||
@ -1333,6 +1367,93 @@ static struct uprobe_task *get_utask(void)
|
||||
return current->utask;
|
||||
}
|
||||
|
||||
/*
|
||||
* Current area->vaddr notion assume the trampoline address is always
|
||||
* equal area->vaddr.
|
||||
*
|
||||
* Returns -1 in case the xol_area is not allocated.
|
||||
*/
|
||||
static unsigned long get_trampoline_vaddr(void)
|
||||
{
|
||||
struct xol_area *area;
|
||||
unsigned long trampoline_vaddr = -1;
|
||||
|
||||
area = current->mm->uprobes_state.xol_area;
|
||||
smp_read_barrier_depends();
|
||||
if (area)
|
||||
trampoline_vaddr = area->vaddr;
|
||||
|
||||
return trampoline_vaddr;
|
||||
}
|
||||
|
||||
static void prepare_uretprobe(struct uprobe *uprobe, struct pt_regs *regs)
|
||||
{
|
||||
struct return_instance *ri;
|
||||
struct uprobe_task *utask;
|
||||
unsigned long orig_ret_vaddr, trampoline_vaddr;
|
||||
bool chained = false;
|
||||
|
||||
if (!get_xol_area())
|
||||
return;
|
||||
|
||||
utask = get_utask();
|
||||
if (!utask)
|
||||
return;
|
||||
|
||||
if (utask->depth >= MAX_URETPROBE_DEPTH) {
|
||||
printk_ratelimited(KERN_INFO "uprobe: omit uretprobe due to"
|
||||
" nestedness limit pid/tgid=%d/%d\n",
|
||||
current->pid, current->tgid);
|
||||
return;
|
||||
}
|
||||
|
||||
ri = kzalloc(sizeof(struct return_instance), GFP_KERNEL);
|
||||
if (!ri)
|
||||
goto fail;
|
||||
|
||||
trampoline_vaddr = get_trampoline_vaddr();
|
||||
orig_ret_vaddr = arch_uretprobe_hijack_return_addr(trampoline_vaddr, regs);
|
||||
if (orig_ret_vaddr == -1)
|
||||
goto fail;
|
||||
|
||||
/*
|
||||
* We don't want to keep trampoline address in stack, rather keep the
|
||||
* original return address of first caller thru all the consequent
|
||||
* instances. This also makes breakpoint unwrapping easier.
|
||||
*/
|
||||
if (orig_ret_vaddr == trampoline_vaddr) {
|
||||
if (!utask->return_instances) {
|
||||
/*
|
||||
* This situation is not possible. Likely we have an
|
||||
* attack from user-space.
|
||||
*/
|
||||
pr_warn("uprobe: unable to set uretprobe pid/tgid=%d/%d\n",
|
||||
current->pid, current->tgid);
|
||||
goto fail;
|
||||
}
|
||||
|
||||
chained = true;
|
||||
orig_ret_vaddr = utask->return_instances->orig_ret_vaddr;
|
||||
}
|
||||
|
||||
atomic_inc(&uprobe->ref);
|
||||
ri->uprobe = uprobe;
|
||||
ri->func = instruction_pointer(regs);
|
||||
ri->orig_ret_vaddr = orig_ret_vaddr;
|
||||
ri->chained = chained;
|
||||
|
||||
utask->depth++;
|
||||
|
||||
/* add instance to the stack */
|
||||
ri->next = utask->return_instances;
|
||||
utask->return_instances = ri;
|
||||
|
||||
return;
|
||||
|
||||
fail:
|
||||
kfree(ri);
|
||||
}
|
||||
|
||||
/* Prepare to single-step probed instruction out of line. */
|
||||
static int
|
||||
pre_ssout(struct uprobe *uprobe, struct pt_regs *regs, unsigned long bp_vaddr)
|
||||
@ -1431,7 +1552,7 @@ static void mmf_recalc_uprobes(struct mm_struct *mm)
|
||||
clear_bit(MMF_HAS_UPROBES, &mm->flags);
|
||||
}
|
||||
|
||||
static int is_swbp_at_addr(struct mm_struct *mm, unsigned long vaddr)
|
||||
static int is_trap_at_addr(struct mm_struct *mm, unsigned long vaddr)
|
||||
{
|
||||
struct page *page;
|
||||
uprobe_opcode_t opcode;
|
||||
@ -1449,10 +1570,11 @@ static int is_swbp_at_addr(struct mm_struct *mm, unsigned long vaddr)
|
||||
if (result < 0)
|
||||
return result;
|
||||
|
||||
copy_opcode(page, vaddr, &opcode);
|
||||
copy_from_page(page, vaddr, &opcode, UPROBE_SWBP_INSN_SIZE);
|
||||
put_page(page);
|
||||
out:
|
||||
return is_swbp_insn(&opcode);
|
||||
/* This needs to return true for any variant of the trap insn */
|
||||
return is_trap_insn(&opcode);
|
||||
}
|
||||
|
||||
static struct uprobe *find_active_uprobe(unsigned long bp_vaddr, int *is_swbp)
|
||||
@ -1465,14 +1587,14 @@ static struct uprobe *find_active_uprobe(unsigned long bp_vaddr, int *is_swbp)
|
||||
vma = find_vma(mm, bp_vaddr);
|
||||
if (vma && vma->vm_start <= bp_vaddr) {
|
||||
if (valid_vma(vma, false)) {
|
||||
struct inode *inode = vma->vm_file->f_mapping->host;
|
||||
struct inode *inode = file_inode(vma->vm_file);
|
||||
loff_t offset = vaddr_to_offset(vma, bp_vaddr);
|
||||
|
||||
uprobe = find_uprobe(inode, offset);
|
||||
}
|
||||
|
||||
if (!uprobe)
|
||||
*is_swbp = is_swbp_at_addr(mm, bp_vaddr);
|
||||
*is_swbp = is_trap_at_addr(mm, bp_vaddr);
|
||||
} else {
|
||||
*is_swbp = -EFAULT;
|
||||
}
|
||||
@ -1488,16 +1610,27 @@ static void handler_chain(struct uprobe *uprobe, struct pt_regs *regs)
|
||||
{
|
||||
struct uprobe_consumer *uc;
|
||||
int remove = UPROBE_HANDLER_REMOVE;
|
||||
bool need_prep = false; /* prepare return uprobe, when needed */
|
||||
|
||||
down_read(&uprobe->register_rwsem);
|
||||
for (uc = uprobe->consumers; uc; uc = uc->next) {
|
||||
int rc = uc->handler(uc, regs);
|
||||
int rc = 0;
|
||||
|
||||
if (uc->handler) {
|
||||
rc = uc->handler(uc, regs);
|
||||
WARN(rc & ~UPROBE_HANDLER_MASK,
|
||||
"bad rc=0x%x from %pf()\n", rc, uc->handler);
|
||||
}
|
||||
|
||||
if (uc->ret_handler)
|
||||
need_prep = true;
|
||||
|
||||
WARN(rc & ~UPROBE_HANDLER_MASK,
|
||||
"bad rc=0x%x from %pf()\n", rc, uc->handler);
|
||||
remove &= rc;
|
||||
}
|
||||
|
||||
if (need_prep && !remove)
|
||||
prepare_uretprobe(uprobe, regs); /* put bp at return */
|
||||
|
||||
if (remove && uprobe->consumers) {
|
||||
WARN_ON(!uprobe_is_active(uprobe));
|
||||
unapply_uprobe(uprobe, current->mm);
|
||||
@ -1505,6 +1638,64 @@ static void handler_chain(struct uprobe *uprobe, struct pt_regs *regs)
|
||||
up_read(&uprobe->register_rwsem);
|
||||
}
|
||||
|
||||
static void
|
||||
handle_uretprobe_chain(struct return_instance *ri, struct pt_regs *regs)
|
||||
{
|
||||
struct uprobe *uprobe = ri->uprobe;
|
||||
struct uprobe_consumer *uc;
|
||||
|
||||
down_read(&uprobe->register_rwsem);
|
||||
for (uc = uprobe->consumers; uc; uc = uc->next) {
|
||||
if (uc->ret_handler)
|
||||
uc->ret_handler(uc, ri->func, regs);
|
||||
}
|
||||
up_read(&uprobe->register_rwsem);
|
||||
}
|
||||
|
||||
static bool handle_trampoline(struct pt_regs *regs)
|
||||
{
|
||||
struct uprobe_task *utask;
|
||||
struct return_instance *ri, *tmp;
|
||||
bool chained;
|
||||
|
||||
utask = current->utask;
|
||||
if (!utask)
|
||||
return false;
|
||||
|
||||
ri = utask->return_instances;
|
||||
if (!ri)
|
||||
return false;
|
||||
|
||||
/*
|
||||
* TODO: we should throw out return_instance's invalidated by
|
||||
* longjmp(), currently we assume that the probed function always
|
||||
* returns.
|
||||
*/
|
||||
instruction_pointer_set(regs, ri->orig_ret_vaddr);
|
||||
|
||||
for (;;) {
|
||||
handle_uretprobe_chain(ri, regs);
|
||||
|
||||
chained = ri->chained;
|
||||
put_uprobe(ri->uprobe);
|
||||
|
||||
tmp = ri;
|
||||
ri = ri->next;
|
||||
kfree(tmp);
|
||||
|
||||
if (!chained)
|
||||
break;
|
||||
|
||||
utask->depth--;
|
||||
|
||||
BUG_ON(!ri);
|
||||
}
|
||||
|
||||
utask->return_instances = ri;
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
/*
|
||||
* Run handler and ask thread to singlestep.
|
||||
* Ensure all non-fatal signals cannot interrupt thread while it singlesteps.
|
||||
@ -1516,8 +1707,15 @@ static void handle_swbp(struct pt_regs *regs)
|
||||
int uninitialized_var(is_swbp);
|
||||
|
||||
bp_vaddr = uprobe_get_swbp_addr(regs);
|
||||
uprobe = find_active_uprobe(bp_vaddr, &is_swbp);
|
||||
if (bp_vaddr == get_trampoline_vaddr()) {
|
||||
if (handle_trampoline(regs))
|
||||
return;
|
||||
|
||||
pr_warn("uprobe: unable to handle uretprobe pid/tgid=%d/%d\n",
|
||||
current->pid, current->tgid);
|
||||
}
|
||||
|
||||
uprobe = find_active_uprobe(bp_vaddr, &is_swbp);
|
||||
if (!uprobe) {
|
||||
if (is_swbp > 0) {
|
||||
/* No matching uprobe; signal SIGTRAP. */
|
||||
@ -1616,7 +1814,11 @@ void uprobe_notify_resume(struct pt_regs *regs)
|
||||
*/
|
||||
int uprobe_pre_sstep_notifier(struct pt_regs *regs)
|
||||
{
|
||||
if (!current->mm || !test_bit(MMF_HAS_UPROBES, ¤t->mm->flags))
|
||||
if (!current->mm)
|
||||
return 0;
|
||||
|
||||
if (!test_bit(MMF_HAS_UPROBES, ¤t->mm->flags) &&
|
||||
(!current->utask || !current->utask->return_instances))
|
||||
return 0;
|
||||
|
||||
set_thread_flag(TIF_UPROBE);
|
||||
|
||||
@ -103,11 +103,6 @@ struct kretprobe_trace_entry_head {
|
||||
unsigned long ret_ip;
|
||||
};
|
||||
|
||||
struct uprobe_trace_entry_head {
|
||||
struct trace_entry ent;
|
||||
unsigned long ip;
|
||||
};
|
||||
|
||||
/*
|
||||
* trace_flag_type is an enumeration that holds different
|
||||
* states when a trace occurs. These are:
|
||||
|
||||
@ -28,6 +28,18 @@
|
||||
|
||||
#define UPROBE_EVENT_SYSTEM "uprobes"
|
||||
|
||||
struct uprobe_trace_entry_head {
|
||||
struct trace_entry ent;
|
||||
unsigned long vaddr[];
|
||||
};
|
||||
|
||||
#define SIZEOF_TRACE_ENTRY(is_return) \
|
||||
(sizeof(struct uprobe_trace_entry_head) + \
|
||||
sizeof(unsigned long) * (is_return ? 2 : 1))
|
||||
|
||||
#define DATAOF_TRACE_ENTRY(entry, is_return) \
|
||||
((void*)(entry) + SIZEOF_TRACE_ENTRY(is_return))
|
||||
|
||||
struct trace_uprobe_filter {
|
||||
rwlock_t rwlock;
|
||||
int nr_systemwide;
|
||||
@ -64,6 +76,8 @@ static DEFINE_MUTEX(uprobe_lock);
|
||||
static LIST_HEAD(uprobe_list);
|
||||
|
||||
static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs);
|
||||
static int uretprobe_dispatcher(struct uprobe_consumer *con,
|
||||
unsigned long func, struct pt_regs *regs);
|
||||
|
||||
static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter)
|
||||
{
|
||||
@ -77,11 +91,16 @@ static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter)
|
||||
return !filter->nr_systemwide && list_empty(&filter->perf_events);
|
||||
}
|
||||
|
||||
static inline bool is_ret_probe(struct trace_uprobe *tu)
|
||||
{
|
||||
return tu->consumer.ret_handler != NULL;
|
||||
}
|
||||
|
||||
/*
|
||||
* Allocate new trace_uprobe and initialize it (including uprobes).
|
||||
*/
|
||||
static struct trace_uprobe *
|
||||
alloc_trace_uprobe(const char *group, const char *event, int nargs)
|
||||
alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret)
|
||||
{
|
||||
struct trace_uprobe *tu;
|
||||
|
||||
@ -106,6 +125,8 @@ alloc_trace_uprobe(const char *group, const char *event, int nargs)
|
||||
|
||||
INIT_LIST_HEAD(&tu->list);
|
||||
tu->consumer.handler = uprobe_dispatcher;
|
||||
if (is_ret)
|
||||
tu->consumer.ret_handler = uretprobe_dispatcher;
|
||||
init_trace_uprobe_filter(&tu->filter);
|
||||
return tu;
|
||||
|
||||
@ -180,7 +201,7 @@ end:
|
||||
|
||||
/*
|
||||
* Argument syntax:
|
||||
* - Add uprobe: p[:[GRP/]EVENT] PATH:SYMBOL[+offs] [FETCHARGS]
|
||||
* - Add uprobe: p|r[:[GRP/]EVENT] PATH:SYMBOL [FETCHARGS]
|
||||
*
|
||||
* - Remove uprobe: -:[GRP/]EVENT
|
||||
*/
|
||||
@ -192,20 +213,23 @@ static int create_trace_uprobe(int argc, char **argv)
|
||||
char buf[MAX_EVENT_NAME_LEN];
|
||||
struct path path;
|
||||
unsigned long offset;
|
||||
bool is_delete;
|
||||
bool is_delete, is_return;
|
||||
int i, ret;
|
||||
|
||||
inode = NULL;
|
||||
ret = 0;
|
||||
is_delete = false;
|
||||
is_return = false;
|
||||
event = NULL;
|
||||
group = NULL;
|
||||
|
||||
/* argc must be >= 1 */
|
||||
if (argv[0][0] == '-')
|
||||
is_delete = true;
|
||||
else if (argv[0][0] == 'r')
|
||||
is_return = true;
|
||||
else if (argv[0][0] != 'p') {
|
||||
pr_info("Probe definition must be started with 'p' or '-'.\n");
|
||||
pr_info("Probe definition must be started with 'p', 'r' or '-'.\n");
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
@ -303,7 +327,7 @@ static int create_trace_uprobe(int argc, char **argv)
|
||||
kfree(tail);
|
||||
}
|
||||
|
||||
tu = alloc_trace_uprobe(group, event, argc);
|
||||
tu = alloc_trace_uprobe(group, event, argc, is_return);
|
||||
if (IS_ERR(tu)) {
|
||||
pr_info("Failed to allocate trace_uprobe.(%d)\n", (int)PTR_ERR(tu));
|
||||
ret = PTR_ERR(tu);
|
||||
@ -414,9 +438,10 @@ static void probes_seq_stop(struct seq_file *m, void *v)
|
||||
static int probes_seq_show(struct seq_file *m, void *v)
|
||||
{
|
||||
struct trace_uprobe *tu = v;
|
||||
char c = is_ret_probe(tu) ? 'r' : 'p';
|
||||
int i;
|
||||
|
||||
seq_printf(m, "p:%s/%s", tu->call.class->system, tu->call.name);
|
||||
seq_printf(m, "%c:%s/%s", c, tu->call.class->system, tu->call.name);
|
||||
seq_printf(m, " %s:0x%p", tu->filename, (void *)tu->offset);
|
||||
|
||||
for (i = 0; i < tu->nr_args; i++)
|
||||
@ -485,65 +510,81 @@ static const struct file_operations uprobe_profile_ops = {
|
||||
.release = seq_release,
|
||||
};
|
||||
|
||||
/* uprobe handler */
|
||||
static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs)
|
||||
static void uprobe_trace_print(struct trace_uprobe *tu,
|
||||
unsigned long func, struct pt_regs *regs)
|
||||
{
|
||||
struct uprobe_trace_entry_head *entry;
|
||||
struct ring_buffer_event *event;
|
||||
struct ring_buffer *buffer;
|
||||
u8 *data;
|
||||
int size, i, pc;
|
||||
unsigned long irq_flags;
|
||||
void *data;
|
||||
int size, i;
|
||||
struct ftrace_event_call *call = &tu->call;
|
||||
|
||||
local_save_flags(irq_flags);
|
||||
pc = preempt_count();
|
||||
|
||||
size = sizeof(*entry) + tu->size;
|
||||
|
||||
size = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
|
||||
event = trace_current_buffer_lock_reserve(&buffer, call->event.type,
|
||||
size, irq_flags, pc);
|
||||
size + tu->size, 0, 0);
|
||||
if (!event)
|
||||
return 0;
|
||||
return;
|
||||
|
||||
entry = ring_buffer_event_data(event);
|
||||
entry->ip = instruction_pointer(task_pt_regs(current));
|
||||
data = (u8 *)&entry[1];
|
||||
if (is_ret_probe(tu)) {
|
||||
entry->vaddr[0] = func;
|
||||
entry->vaddr[1] = instruction_pointer(regs);
|
||||
data = DATAOF_TRACE_ENTRY(entry, true);
|
||||
} else {
|
||||
entry->vaddr[0] = instruction_pointer(regs);
|
||||
data = DATAOF_TRACE_ENTRY(entry, false);
|
||||
}
|
||||
|
||||
for (i = 0; i < tu->nr_args; i++)
|
||||
call_fetch(&tu->args[i].fetch, regs, data + tu->args[i].offset);
|
||||
|
||||
if (!filter_current_check_discard(buffer, call, entry, event))
|
||||
trace_buffer_unlock_commit(buffer, event, irq_flags, pc);
|
||||
trace_buffer_unlock_commit(buffer, event, 0, 0);
|
||||
}
|
||||
|
||||
/* uprobe handler */
|
||||
static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs)
|
||||
{
|
||||
if (!is_ret_probe(tu))
|
||||
uprobe_trace_print(tu, 0, regs);
|
||||
return 0;
|
||||
}
|
||||
|
||||
static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func,
|
||||
struct pt_regs *regs)
|
||||
{
|
||||
uprobe_trace_print(tu, func, regs);
|
||||
}
|
||||
|
||||
/* Event entry printers */
|
||||
static enum print_line_t
|
||||
print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event)
|
||||
{
|
||||
struct uprobe_trace_entry_head *field;
|
||||
struct uprobe_trace_entry_head *entry;
|
||||
struct trace_seq *s = &iter->seq;
|
||||
struct trace_uprobe *tu;
|
||||
u8 *data;
|
||||
int i;
|
||||
|
||||
field = (struct uprobe_trace_entry_head *)iter->ent;
|
||||
entry = (struct uprobe_trace_entry_head *)iter->ent;
|
||||
tu = container_of(event, struct trace_uprobe, call.event);
|
||||
|
||||
if (!trace_seq_printf(s, "%s: (", tu->call.name))
|
||||
goto partial;
|
||||
if (is_ret_probe(tu)) {
|
||||
if (!trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)", tu->call.name,
|
||||
entry->vaddr[1], entry->vaddr[0]))
|
||||
goto partial;
|
||||
data = DATAOF_TRACE_ENTRY(entry, true);
|
||||
} else {
|
||||
if (!trace_seq_printf(s, "%s: (0x%lx)", tu->call.name,
|
||||
entry->vaddr[0]))
|
||||
goto partial;
|
||||
data = DATAOF_TRACE_ENTRY(entry, false);
|
||||
}
|
||||
|
||||
if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET))
|
||||
goto partial;
|
||||
|
||||
if (!trace_seq_puts(s, ")"))
|
||||
goto partial;
|
||||
|
||||
data = (u8 *)&field[1];
|
||||
for (i = 0; i < tu->nr_args; i++) {
|
||||
if (!tu->args[i].type->print(s, tu->args[i].name,
|
||||
data + tu->args[i].offset, field))
|
||||
data + tu->args[i].offset, entry))
|
||||
goto partial;
|
||||
}
|
||||
|
||||
@ -595,16 +636,23 @@ static void probe_event_disable(struct trace_uprobe *tu, int flag)
|
||||
|
||||
static int uprobe_event_define_fields(struct ftrace_event_call *event_call)
|
||||
{
|
||||
int ret, i;
|
||||
int ret, i, size;
|
||||
struct uprobe_trace_entry_head field;
|
||||
struct trace_uprobe *tu = (struct trace_uprobe *)event_call->data;
|
||||
struct trace_uprobe *tu = event_call->data;
|
||||
|
||||
DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
|
||||
if (is_ret_probe(tu)) {
|
||||
DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0);
|
||||
DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0);
|
||||
size = SIZEOF_TRACE_ENTRY(true);
|
||||
} else {
|
||||
DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0);
|
||||
size = SIZEOF_TRACE_ENTRY(false);
|
||||
}
|
||||
/* Set argument names as fields */
|
||||
for (i = 0; i < tu->nr_args; i++) {
|
||||
ret = trace_define_field(event_call, tu->args[i].type->fmttype,
|
||||
tu->args[i].name,
|
||||
sizeof(field) + tu->args[i].offset,
|
||||
size + tu->args[i].offset,
|
||||
tu->args[i].type->size,
|
||||
tu->args[i].type->is_signed,
|
||||
FILTER_OTHER);
|
||||
@ -622,8 +670,13 @@ static int __set_print_fmt(struct trace_uprobe *tu, char *buf, int len)
|
||||
int i;
|
||||
int pos = 0;
|
||||
|
||||
fmt = "(%lx)";
|
||||
arg = "REC->" FIELD_STRING_IP;
|
||||
if (is_ret_probe(tu)) {
|
||||
fmt = "(%lx <- %lx)";
|
||||
arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;
|
||||
} else {
|
||||
fmt = "(%lx)";
|
||||
arg = "REC->" FIELD_STRING_IP;
|
||||
}
|
||||
|
||||
/* When len=0, we just calculate the needed length */
|
||||
|
||||
@ -752,49 +805,68 @@ static bool uprobe_perf_filter(struct uprobe_consumer *uc,
|
||||
return ret;
|
||||
}
|
||||
|
||||
/* uprobe profile handler */
|
||||
static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs)
|
||||
static void uprobe_perf_print(struct trace_uprobe *tu,
|
||||
unsigned long func, struct pt_regs *regs)
|
||||
{
|
||||
struct ftrace_event_call *call = &tu->call;
|
||||
struct uprobe_trace_entry_head *entry;
|
||||
struct hlist_head *head;
|
||||
u8 *data;
|
||||
int size, __size, i;
|
||||
int rctx;
|
||||
void *data;
|
||||
int size, rctx, i;
|
||||
|
||||
if (!uprobe_perf_filter(&tu->consumer, 0, current->mm))
|
||||
return UPROBE_HANDLER_REMOVE;
|
||||
|
||||
__size = sizeof(*entry) + tu->size;
|
||||
size = ALIGN(__size + sizeof(u32), sizeof(u64));
|
||||
size -= sizeof(u32);
|
||||
size = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
|
||||
size = ALIGN(size + tu->size + sizeof(u32), sizeof(u64)) - sizeof(u32);
|
||||
if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough"))
|
||||
return 0;
|
||||
return;
|
||||
|
||||
preempt_disable();
|
||||
head = this_cpu_ptr(call->perf_events);
|
||||
if (hlist_empty(head))
|
||||
goto out;
|
||||
|
||||
entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx);
|
||||
if (!entry)
|
||||
goto out;
|
||||
|
||||
entry->ip = instruction_pointer(task_pt_regs(current));
|
||||
data = (u8 *)&entry[1];
|
||||
if (is_ret_probe(tu)) {
|
||||
entry->vaddr[0] = func;
|
||||
entry->vaddr[1] = instruction_pointer(regs);
|
||||
data = DATAOF_TRACE_ENTRY(entry, true);
|
||||
} else {
|
||||
entry->vaddr[0] = instruction_pointer(regs);
|
||||
data = DATAOF_TRACE_ENTRY(entry, false);
|
||||
}
|
||||
|
||||
for (i = 0; i < tu->nr_args; i++)
|
||||
call_fetch(&tu->args[i].fetch, regs, data + tu->args[i].offset);
|
||||
|
||||
head = this_cpu_ptr(call->perf_events);
|
||||
perf_trace_buf_submit(entry, size, rctx, entry->ip, 1, regs, head, NULL);
|
||||
|
||||
perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL);
|
||||
out:
|
||||
preempt_enable();
|
||||
}
|
||||
|
||||
/* uprobe profile handler */
|
||||
static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs)
|
||||
{
|
||||
if (!uprobe_perf_filter(&tu->consumer, 0, current->mm))
|
||||
return UPROBE_HANDLER_REMOVE;
|
||||
|
||||
if (!is_ret_probe(tu))
|
||||
uprobe_perf_print(tu, 0, regs);
|
||||
return 0;
|
||||
}
|
||||
|
||||
static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,
|
||||
struct pt_regs *regs)
|
||||
{
|
||||
uprobe_perf_print(tu, func, regs);
|
||||
}
|
||||
#endif /* CONFIG_PERF_EVENTS */
|
||||
|
||||
static
|
||||
int trace_uprobe_register(struct ftrace_event_call *event, enum trace_reg type, void *data)
|
||||
{
|
||||
struct trace_uprobe *tu = (struct trace_uprobe *)event->data;
|
||||
struct trace_uprobe *tu = event->data;
|
||||
|
||||
switch (type) {
|
||||
case TRACE_REG_REGISTER:
|
||||
@ -843,6 +915,23 @@ static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int uretprobe_dispatcher(struct uprobe_consumer *con,
|
||||
unsigned long func, struct pt_regs *regs)
|
||||
{
|
||||
struct trace_uprobe *tu;
|
||||
|
||||
tu = container_of(con, struct trace_uprobe, consumer);
|
||||
|
||||
if (tu->flags & TP_FLAG_TRACE)
|
||||
uretprobe_trace_func(tu, func, regs);
|
||||
|
||||
#ifdef CONFIG_PERF_EVENTS
|
||||
if (tu->flags & TP_FLAG_PROFILE)
|
||||
uretprobe_perf_func(tu, func, regs);
|
||||
#endif
|
||||
return 0;
|
||||
}
|
||||
|
||||
static struct trace_event_functions uprobe_funcs = {
|
||||
.trace = print_uprobe_event
|
||||
};
|
||||
|
||||
Loading…
Reference in New Issue
Block a user