How to find the moment of allocation and initialization of some memory area in a binary?

Question

linux

Given: some program, you need to find the moment of initialization of some memory area.
Initially, accessing this address in gdb causes an error:
p/x *0x1234
Cannot access memory at address 0x1234
At some point, memory is allocated and the address becomes read/write:
p/x * 0x1234
0x0
same!)
it is necessary to define this moment.
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What can be done in gdb?
I tried, for example:
1) watch *0x1234 - doesn't work, the debugger freezes
2) make a macro that runs N times, which prints "p/x *0x1234" for each instruction. The macro does not work, it stops right after the error.

Answer 1

I would run the application under strace and look for mmap which return a close address.
Well, or if gdb is required, then a breakpoint to return from mmap to libc.

Answer 2

Try rwatch .

Answer 3

Hang a conditioner break on the exit from malloc (on mmap or whatever your memory allocates)
example here stackoverflow.com/questions/4498965/how-to-set-con...
pay attention to these lines there The breakpoint address may vary with libc versions