Disclosure of Invention
Because the existing method has the problems, the embodiment of the invention provides a memory leak process tracing method and a memory leak process tracing device.
In a first aspect, an embodiment of the present invention provides a memory leak process tracing method, including:
generating an updated memory operation function according to a native memory operation function, and adding a head and a tail to a first memory distributed by the native memory operation function through the updated memory operation function to obtain a second memory;
if the address of the updated memory operation function is judged to be in the starting and stopping address according to the starting and stopping address of the virtual address of the dynamic library of the pre-acquired executable program and the reserved stack frame, determining that the second memory is traceable;
adding the second memory to a global linked list through the updated memory operation function, or removing the second memory from the global linked list through a memory release function;
and if the global linked list is not empty after the execution of the executable program is finished, determining that the memory leakage exists, and tracing the process of the memory leakage according to the calling relationship of the updated memory operation function.
Optionally, the adding the second memory to the global linked list through the updated memory operation function specifically includes:
and the updated memory operation function acquires the call chain relation of the current function according to the call stack information of the current function, stores the call chain relation in the head of the second memory, and adds the second memory to the global linked list.
Optionally, the method further comprises:
and if the calling times of the calling chain acquired at the next time are greater than the calling times of the calling chain acquired at the previous time, determining that the memory leakage exists, and tracing the process of the memory leakage according to the calling relation of the updated memory operation function.
Optionally, the generating an updated memory operation function according to the native memory operation function specifically includes:
modifying the preloaded environment variable or hook function of the native memory operation function, redefining the link relation of the native memory operation function, or preferentially analyzing the linker according to the target identification under the condition of not changing the logic and calling codes for calling the native memory operation function in the executable program.
Optionally, the information stored in the header includes: the method comprises the following steps of calling information, allocated memory addresses, actually used memory addresses, the total size of allocated memories, the total size of actually used memories and memory out-of-range confirmation information.
In a second aspect, an embodiment of the present invention further provides a memory leak tracing apparatus, including:
the memory updating module is used for generating an updated memory operation function according to a native memory operation function, and adding a head part and a tail part to a first memory distributed by the native memory operation function through the updated memory operation function to obtain a second memory;
a trace-back judging module, configured to determine that the second memory is traceable if it is judged and known that the address of the updated memory operation function is within the start-stop address according to a start-stop address of a virtual address of a dynamic library of a pre-acquired executable program and a reserved stack frame;
the memory operation module is used for adding the second memory into a global linked list through the updated memory operation function or removing the second memory from the global linked list through a memory release function;
and the leakage tracing module is used for determining that the memory leakage exists if the global linked list is not empty after the executable program is executed, and tracing the process of the memory leakage according to the calling relationship of the updated memory operation function.
Optionally, the memory operation module is specifically configured to, by the updated memory operation function, obtain a call chain relationship of the current function according to call stack information of the current function, store the call chain relationship in a head of the second memory, and add the second memory to the global linked list.
Optionally, the apparatus further comprises:
and the leakage judging module is used for determining that the memory leakage exists if the calling frequency of the calling chain acquired at the next time is greater than the calling frequency of the calling chain acquired at the previous time, and tracing the process of the memory leakage according to the calling relation of the updated memory operation function.
Optionally, the memory update module is specifically configured to modify a preloaded environment variable or a hook function of the native memory operation function, redefine a link relationship of the native memory operation function, or preferentially resolve a linker according to a target identifier, without changing a logic and a call code for calling the native memory operation function in the executable program.
Optionally, the information stored in the header includes: the method comprises the following steps of calling information, allocated memory addresses, actually used memory addresses, the total size of allocated memories, the total size of actually used memories and memory out-of-range confirmation information.
In a third aspect, an embodiment of the present invention further provides an electronic device, including:
at least one processor; and
at least one memory communicatively coupled to the processor, wherein:
the memory stores program instructions executable by the processor, which when called by the processor are capable of performing the above-described methods.
In a fourth aspect, an embodiment of the present invention further provides a non-transitory computer-readable storage medium storing a computer program, which causes the computer to execute the above method.
According to the technical scheme, after the second memory traceable and global linked list is determined not to be empty, the memory leakage process is traced back according to the calling relation, the execution process causing the memory leakage is obtained by obtaining the execution path of the updated memory operation function, so that development and testing personnel can clearly see the memory leakage position and the memory leakage reason, and do not need to spend time and energy to analyze the code logic.
Detailed Description
The following further describes embodiments of the present invention with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.
Fig. 1 shows a schematic flow chart of a memory leak process tracing method provided in this embodiment, including:
s101, generating an updated memory operation function according to a native memory operation function, and adding a head and a tail to a first memory distributed by the native memory operation function through the updated memory operation function to obtain a second memory.
The native memory operation function is a memory operation function of the system and is mainly used for memory allocation.
The updated memory operation function is obtained by adding a part of functions to the native memory operation function, where the added functions include adding a head and a tail to a first memory allocated to the native memory operation function, and obtaining a second memory.
The first memory is a memory allocated by a native memory operation function.
And the second memory is obtained by processing the first memory by the updated memory operation function.
The information stored in the header includes: the method comprises the following steps of calling information, allocated memory addresses, actually used memory addresses, the total size of allocated memories, the total size of actually used memories and memory out-of-range confirmation information.
Specifically, in the actual implementation process, the information stored in the header does not only include the above information, and some header information may be added or subtracted according to different application scenarios, for example, the information stored in the header is: calling information, allocated memory addresses and actually used memory addresses; or call information, allocated memory address, actually used memory address, total size of allocated memory, total size of actually used memory, and poison information, wherein the poison information is used to confirm that the memory is out of bounds.
And S102, if the address of the updated memory operation function is judged to be in the starting and stopping address according to the starting and stopping address of the virtual address of the dynamic library of the pre-acquired executable program and the reserved stack frame, determining that the second memory is traceable.
The starting address and the ending address are pre-acquired starting addresses and ending addresses, and are used for judging whether a second memory generated by the updated memory operation function is traceable: and when the address of the updated memory operation function corresponding to the second memory is in the starting and stopping address, determining that the second memory is traceable, otherwise, determining that the second memory is not traceable.
The address of the updated memory operation function includes the addresses of the updated memory operation function and all the upper-level calling functions thereof, the address is a virtual address of the updated memory operation function, and the purpose is to ensure that the addresses of the updated memory operation function and all the upper-level calling functions thereof are within the starting and stopping addresses.
For example, by reading a file under a process corresponding to the executable program, such as a/proc/[ process number ]/maps or maps file, stack information of the executable program and a dynamic library dependent thereon can be obtained, so as to obtain start and stop addresses of virtual addresses of the executable program and the dynamic library in which a stack frame is reserved.
Further, when the second memory is traceable, the process of memory leakage can be traced according to subsequent operations; otherwise, when the second memory is not traceable, the process of memory leak cannot be traced.
S103, adding the second memory into a global linked list through the updated memory operation function, or removing the second memory from the global linked list through a memory release function.
And when the memory in the global linked list is released, removing the corresponding memory from the global linked list.
And S104, if the global linked list is not empty after the executable program is executed, determining that the memory leakage exists, and tracing the process of the memory leakage according to the calling relationship of the updated memory operation function.
Specifically, the global linked list is a linked list for storing memories allocated in the running process of the executable program, and after the memories in the global linked list are released, the corresponding memories are removed from the global linked list, so that after the running of the executable program is finished, all the memories in the global linked list are released under a normal condition, that is, the global linked list is empty. In other words, if the global linked list is not empty after the execution of the executable program is finished, it is determined that there is a memory leak.
The calling relationship of the updated memory operation function is the calling information of the updated memory operation function, when the executable program and the library dependent on the executable program call the updated memory operation function in the execution process, the updated memory operation function obtains the calling chain relationship of the function according to the calling stack information of the current function, namely, the function of the updated memory operation function, the function of calling the function of the updated memory operation function, and the like, for example, the return address information of the function can be obtained through __ build _ return _ address function and the like, so as to obtain the calling relationship of the function, and trace the memory leakage process according to the calling relationship.
In the embodiment, after determining that the second memory traceable and judging that the global linked list is not empty, the process of memory leakage is traced back according to the call relation, and the execution process causing the memory leakage is obtained by obtaining the execution path of the updated memory operation function, so that development and testing personnel can clearly see the position and the reason of the memory leakage without consuming time and energy to analyze the code logic.
Further, on the basis of the above method embodiment, the adding the second memory to the global linked list through the updated memory operation function in S103 specifically includes:
and the updated memory operation function acquires the call chain relation of the current function according to the call stack information of the current function, stores the call chain relation in the head of the second memory, and adds the second memory to the global linked list.
Specifically, in the execution process of the executable program, when the executable program and the library dependent thereon call the memory operation function, the updated memory operation function is called, and the updated memory operation function obtains the call chain relationship of the function according to the call stack information of the current function, that is, the function calling the memory operation function, the function calling the function of the memory operation function, and the like, for example, obtains the return address information of the function through the __ build _ return _ address function and the like, thereby obtaining the call chain of the function, and the information is stored in the head of the allocated memory, and then the memory block is traced back to the global linked list, so as to facilitate the memory leakage process when the memory leakage problem occurs subsequently.
Further, on the basis of the above embodiment of the method, the method further comprises:
and S105, if the calling times of the calling chain acquired at the next time are greater than the calling times of the calling chain acquired at the previous time, determining that the memory leak exists, and tracing the process of the memory leak according to the calling relation of the updated memory operation function.
Specifically, for an executable program (e.g., a background process, a hardware process) having the same runtime as the system, the lifecycle is synchronized with the system, so that the executable program does not end execution in step S104, because the system also ends execution when the executable program ends execution, and the computer cannot perform judgment and subsequent processing. Therefore, the number of times of calling the call chain can be counted, and if the number of times is increased, the call chain is proved to cause memory leakage.
Specifically, the memory information on the linked list is read, and the reading mode may be reading at a specific position of the executable program, or reading at a certain moment of the executable program by sending a signal; and then counting the times of the same call chain in the memory information, if the times are increased in the two counting processes, the memory leakage can occur in the execution process corresponding to the call chain, and further, the memory leakage process can be traced according to the call relation of the updated memory operation function.
For example, as shown in fig. 2, a set of memory operation functions is determined, and a new memory operation function, that is, an updated memory operation function, is realized again according to the native memory operation function, so that the updated memory operation function can record memory allocation information; then hooking an updated memory operation function in the Hook executable program, running the executable program, acquiring the start-stop address of the executable program and the dynamic library code depended on by the executable program, and determining whether the executable program can be traced according to the start-stop address; judging whether the current memory is a memory release function, if so, removing the released memory from the global linked list, otherwise, recording the call information of the current updated memory operation function in the distributed memory, and simultaneously adding the distributed memory to the global linked list; counting the calling times of the updated memory operation function by reading the memory information on the linked list, if the calling times are increased progressively, determining that the memory leakage occurs in the calling chain, and if the memory leakage process can be traced, determining the memory leakage process through the calling relation.
Further, on the basis of the above method embodiment, the generating an updated memory operation function according to a native memory operation function in S101 specifically includes:
modifying the preloaded environment variable or hook function of the native memory operation function, redefining the link relation of the native memory operation function, or preferentially analyzing the linker according to the target identification under the condition of not changing the logic and calling codes for calling the native memory operation function in the executable program.
Specifically, in the process of re-implementing the memory operation function, a native memory operation function, such as a malloc function, may be obtained by dlsym; then, the prototype of the re-implemented memory operation function is consistent with the prototype of the native memory operation function, such as implementing the malloc function void. Adding a head part and a tail part to the memory allocated by the native memory operation function through the acquired memory allocated by the native memory operation function, wherein the head part comprises the relevant information of the memory to be used: the memory starting address, the calling information of the function, the total size of the memory, etc., may be allocated in other ways.
The updated memory operation function can be generated in various ways without changing the logic and calling code of the memory operation function called in the executable program (including library files and the like on which the executable program depends):
for example, a hook method is used to replace the memory operation function in the executable program and the dependent library file thereof, and the hook method includes: modifying an LD _ PRELOAD environment variable; or, modifying a hook function of the native memory operation function, such as __ malloc _ hook, to implement the memory operation function again; or, redefining the link relation of the native memory operation function through the-l link when the executable program is linked to obtain an updated memory operation function; still alternatively, the map _ symbol linker is preferentially resolved __ through the map identifier (target identifier), wherein symbol is the symbol of various memory operation functions, such as malloc, realloc, etc., and then __ map _ malloc is implemented.
The method and the device can locate the position of the memory leak and the process causing the memory leak, not just locate the memory leak point, and enable development and testing personnel to know the position of the memory leak and why the memory leak occurs at a glance without analyzing code logic by the development or testing personnel.
Fig. 3 shows a schematic structural diagram of a memory leak process tracing apparatus provided in this embodiment, where the apparatus includes: a memory update module 301, a trace back determination module 302, a memory operation module 303, and a leakage trace back module 304, wherein:
the memory updating module 301 is configured to generate an updated memory operation function according to a native memory operation function, and add a head and a tail to a first memory allocated by the native memory operation function through the updated memory operation function to obtain a second memory;
the trace-back judging module 302 is configured to determine that the second memory is traceable if it is judged and known that the address of the updated memory operation function is within the start-stop address according to a start-stop address of a virtual address of a dynamic library of a pre-acquired executable program and a reserved stack frame;
the memory operation module 303 is configured to add the second memory to a global linked list through the updated memory operation function, or remove the second memory from the global linked list through a memory release function;
the leakage tracing module 304 is configured to determine that a memory leakage exists if the global linked list is not empty after the executable program is executed, and trace back a process of the memory leakage according to a call relationship of the updated memory operation function.
Specifically, the memory updating module 301 generates an updated memory operation function according to a native memory operation function, and adds a head and a tail to a first memory allocated by the native memory operation function through the updated memory operation function to obtain a second memory; if the tracing back judgment module 302 judges that the address of the updated memory operation function is within the starting and ending address according to the starting and ending address of the virtual address of the dynamic library of the pre-acquired executable program and the reserved stack frame, determining that the second memory can be traced back; the memory operation module 303 adds the second memory to a global linked list through the updated memory operation function, or removes the second memory from the global linked list through a memory release function; if the global linked list is not empty after the execution of the executable program is finished, the leakage tracing module 304 determines that there is memory leakage, and traces back the process of the memory leakage according to the call relationship of the updated memory operation function.
In the embodiment, after determining that the second memory traceable and judging that the global linked list is not empty, the process of memory leakage is traced back according to the call relation, and the execution process causing the memory leakage is obtained by obtaining the execution path of the updated memory operation function, so that development and testing personnel can clearly see the position and the reason of the memory leakage without consuming time and energy to analyze the code logic.
Further, on the basis of the above device embodiment, the memory operation module 303 is specifically configured to obtain, by the updated memory operation function, a call chain relationship of the current function according to the call stack information of the current function, store the call chain relationship in the head of the second memory, and add the second memory to the global linked list.
Further, on the basis of the above embodiment of the apparatus, the apparatus further comprises:
and the leakage judging module is used for determining that the memory leakage exists if the calling frequency of the calling chain acquired at the next time is greater than the calling frequency of the calling chain acquired at the previous time, and tracing the process of the memory leakage according to the calling relation of the updated memory operation function.
Further, on the basis of the above device embodiment, the memory update module 301 is specifically configured to modify the preloaded environment variable or hook function of the native memory operation function, or redefine the link relationship of the native memory operation function, or preferentially resolve the linker according to the target identifier, without changing the logic and calling code for calling the native memory operation function in the executable program.
Further, on the basis of the above apparatus embodiment, the information stored in the header includes: the method comprises the following steps of calling information, allocated memory addresses, actually used memory addresses, the total size of allocated memories, the total size of actually used memories and memory out-of-range confirmation information.
The memory leak process tracing apparatus described in this embodiment may be used to implement the method embodiments, and the principle and the technical effect are similar, which are not described herein again.
Referring to fig. 4, the electronic device includes: a processor (processor)401, a memory (memory)402, and a bus 403;
wherein,
the processor 401 and the memory 402 complete communication with each other through the bus 403;
the processor 401 is configured to call program instructions in the memory 402 to perform the methods provided by the above-described method embodiments.
The present embodiments disclose a computer program product comprising a computer program stored on a non-transitory computer readable storage medium, the computer program comprising program instructions which, when executed by a computer, enable the computer to perform the methods provided by the above-described method embodiments.
The present embodiments provide a non-transitory computer-readable storage medium storing computer instructions that cause the computer to perform the methods provided by the method embodiments described above.
The above-described embodiments of the apparatus are merely illustrative, and the units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.
Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware. With this understanding in mind, the above-described technical solutions may be embodied in the form of a software product, which can be stored in a computer-readable storage medium such as ROM/RAM, magnetic disk, optical disk, etc., and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the methods described in the embodiments or some parts of the embodiments.
It should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.