Re: Getting the way a SIGSEGV append when catching a SIGSEGV from within

[Richard Weinberger]

On Mon, Mar 27, 2017 at 4:45 PM, none <ytrezq@xxxxxxxxxx> wrote:
> Hello,
>
> Thereâs three way to perform an invalid memory access :
>
> The attempt to execute/jump at an invalid address.
> The attempt to read at an invalid address.
> The attempt to write at an invalid address.
>
> Determining the execute case with rt_sigaction is easy : the last value of
> eip match the value of the address which caused the segfault.
>
> But how to know if the SIGSEGV occurred by a read or by a write attempt ? In
> the same time shouldnât that information belong in the mmu ?

Did you look at the machine specific context of SIGSEGV?
It will give you access to the error code and the trap number.

-- 
Thanks,
//richard