replace function offset with source code line number in output of "adb dumpsys meminfo --unreachable"

Question

To find memory leaks of the native C code of my app I run the following command

adb shell dumpsys meminfo --unreachable $(adb shell pidof com.mycompany.myapp)

I get the following output

6 bytes unreachable at ee1551b0
   and 654 similar unreachable bytes in 109 allocations
   contents:
   ee1551b0: 31 2e 30 2e 30 00                               1.0.0.
          #00  pc 000421e4  /apex/com.android.runtime/lib/bionic/libc.so (malloc +68)
          #01  pc 00126670  /data/app/~~XX==/com.mycompany.myapp-W6-xx==/lib/x86/mylib.so (myCfunction7 +80)
          #02  pc 0011d2b9  /data/app/~~XX==/com.mycompany.myapp-W6-xx==/lib/x86/mylib.so
          #03  pc 0011d025  /data/app/~~XX==/com.mycompany.myapp-W6-xx==/lib/x86/mylib.so (myCfunction6 +165)
          #04  pc 0011e82c  /data/app/~~XX==/com.mycompany.myapp-W6-xx==/lib/x86/mylib.so (myCfunction5 +892)
          #05  pc 00120ea7  /data/app/~~XX==/com.mycompany.myapp-W6-xx==/lib/x86/mylib.so
          #06  pc 0012091c  /data/app/~~XX==/com.mycompany.myapp-W6-xx==/lib/x86/mylib.so
          #07  pc 00120144  /data/app/~~XX==/com.mycompany.myapp-W6-xx==/lib/x86/mylib.so
          #08  pc 0011eebe  /data/app/~~XX==/com.mycompany.myapp-W6-xx==/lib/x86/mylib.so
          #09  pc 0011e6d4  /data/app/~~XX==/com.mycompany.myapp-W6-xx==/lib/x86/mylib.so (myCfunction4 +548)
          #10  pc 00121924  /data/app/~~XX==/com.mycompany.myapp-W6-xx==/lib/x86/mylib.so (myCfunction3 +68)
          #11  pc 00121743  /data/app/~~XX==/com.mycompany.myapp-W6-xx==/lib/x86/mylib.so (myCfunction2 +99)
          #12  pc 001221c9  /data/app/~~XX==/com.mycompany.myapp-W6-xx==/lib/x86/mylib.so (myCfunction1 +409)
          #13  pc 00121f4d  /data/app/~~XX==/com.mycompany.myapp-W6-xx==/lib/x86/mylib.so (Java_com_mycompany_myapp_myjavaclass_myjavamethod +333)

I'm looking for a simple way to replace offset functions (+333, +409, +99, ...) by line numbers of the source code. I do this kind of stuff by using ndk-stack on tombstone files. Perhaps there is a tool able to decipher the output of 'dumpsys meminfo --unreachable'.

score 0 · Answer 1 · answered Mar 30 '21 at 14:17

I've found a simple solution. I attach the debugger to the process, set a breakpoint and move to the lldb console of android studio. To set a breapoint to a given offset after a function, I enter the command given here https://stackoverflow.com/a/23250892/9459302

For instance b -a (void*()(void, size_t)) myCfunction1 +400

where (void*(*)(void*, size_t)) is the prototype of myCfunction1

replace function offset with source code line number in output of "adb dumpsys meminfo --unreachable"

1 Answers1