callstack

问题 In kernel version before 5.2, I use save_stack_trace_tsk to retrieve call stack. But this method is no longer available in Linux kernel 5.2+, what should I use? 回答1: This question seemed so tempting so I did some digging here is my findings. TLDR; stack_trace_save () functions replaced by arch_stack_walk() interfaces * this is part of consolidation plan and remove duplicate code. linux commit 214d8ca6ee854 provide common architecture to walking stack trace. the new interface called arch_stack

问题 I have written the following C code: It simply allocates an array of 1000000 integers and another integer, and sets the first integer of the array to 0 I compiled this using gcc -g test.c -o test -fno-stack-protector It gives a very weird disassembly: Apparently it keeps allocating 4096 bytes on the stack in a loop, and "or"s every 4096th byte with 0 and then once it reaches 3997696 bytes, it then further allocates 2184 bytes. It then proceeds to set the 4000000th byte (which was never

来源： https://stackoverflow.com/questions/62746607/r-how-to-check-that-a-custom-function-is-called-within-a-specific-function-from

来源： https://stackoverflow.com/questions/62746607/r-how-to-check-that-a-custom-function-is-called-within-a-specific-function-from

问题 I know that call and ret will modify the value of esp and that push and pop have a number of variants, but are there other instructions that will affect the stack pointer ? 回答1: The following instructions modify the stack pointer 1 : call enter int n/into/int 3 iret/iretd leave pop push ret sysenter sysexit pusha/pushad popa/popad pushf/pushfd/pushfq popf/popfd/popfq vmlaunch/vmresume eexit I leave to you the burden of telling primary and side effects apart. Keep in mind that any instruction

问题 I'm reading a textbook which shows assembly code based on C code: C code: void echo() { char buf[8]; otherFunction(buf); } assembly code: echo: subq $24, %rsp //Allocate 24 bytes on stack, but why allocate 24 instead of 8 bytes? movq %rsp, %rdi //Compute buf as %rsp call otherFunction I don't understand why stack pointer %rsp is decremented by 24 bytes. I only assign 8 bytes' buffer as char buf[8]; , and there no callee saved registers to push on stack, shouldn't the instruction be subq $8,

问题 I'm reading a textbook which shows assembly code based on C code: C code: void echo() { char buf[8]; otherFunction(buf); } assembly code: echo: subq $24, %rsp //Allocate 24 bytes on stack, but why allocate 24 instead of 8 bytes? movq %rsp, %rdi //Compute buf as %rsp call otherFunction I don't understand why stack pointer %rsp is decremented by 24 bytes. I only assign 8 bytes' buffer as char buf[8]; , and there no callee saved registers to push on stack, shouldn't the instruction be subq $8,

问题 I have recently began learning C++ coming from a C# background. My problem is with the way exceptions get handled. If I have a nullptr somewhere, resulting in reading from a forbidden location, then I get a nice looking callstack in VS like this: However if I throw my own exception, or an assertion fails, then I do not get any clue as of what went wrong. VS just shows an error window: A: This is kind of uncomfortable for me as in C# I would get a stacktrace in both case. Is there a way to

问题 I have recently began learning C++ coming from a C# background. My problem is with the way exceptions get handled. If I have a nullptr somewhere, resulting in reading from a forbidden location, then I get a nice looking callstack in VS like this: However if I throw my own exception, or an assertion fails, then I do not get any clue as of what went wrong. VS just shows an error window: A: This is kind of uncomfortable for me as in C# I would get a stacktrace in both case. Is there a way to

问题 I could test using strncpy() with larger source string then the destination: int main() { char *ptr = malloc(12); strcpy(ptr,"hello world!"); return 0; } Compiling with the flag -fstack-protector and using the -S option I got: .file "malloc.c" .text .globl main .type main, @function main: .LFB2: .cfi_startproc pushq %rbp .cfi_def_cfa_offset 16 .cfi_offset 6, -16 movq %rsp, %rbp .cfi_def_cfa_register 6 subq $32, %rsp movl %edi, -20(%rbp) movq %rsi, -32(%rbp) movq %fs:40, %rax movq %rax, -8(