sigaction() support for divide-by-zero exception

[Юрий К]

Hello KOS Team!

I've read here https://support.kaspersky.com/help/KCE/1.1/en-US/posix_uns_ifaces.htm that signals are not fully supported within KOS. But it is not clear on what extent. I can't find within the list the sigaction(). There is a simple app compiled with KOS SDK:

 

#include <stdio.h>

#include <stdlib.h>

#include <strict/posix/signal.h>

 

void signal_me (int signum, siginfo_t *si, void *context);

void signal_me (int signum, siginfo_t *si, void *context)

{

    fprintf(stderr, "divide by zero\n");

}

 

int main(int argc, const char *argv[])

{

    struct sigaction sigact;

 

    sigact.sa_sigaction = signal_me;

    sigact.sa_flags = SA_SIGINFO | SA_RESTART;

    if (sigaction (SIGFPE, &sigact, NULL) != 0) {

        fprintf(stderr,"sigaction returned error %d\n", 123);

    }

 

    int num = 4 / 0;

    // no dependency from vfs_entity when using stderr

    fprintf(stderr,"Hello world: %d!\n", num);

 

    return EXIT_SUCCESS;

}

I try to setup divide-by-zero handler. Is it possible?

Output from KOS:

Unhandled Debug Exception
ESR = 0xf20003e8
EC = 0x3c
Exception class: BRK instruction execution in AArch64 state
    EIID : hello.Hello
    Name : hello.Hello
    Path : Hello
    TID  : 24
    pc   : 0x4100a0
    CPU  : 00

Trap Frame:
    x0 : 0x0000000000000000, x1 : 0x0000000000411d00, x2 : 0x000000000049fcc0, x3 : 0x000000000049fe00
    x4 : 0x0000000000496260, x5 : 0x0000000000000042, x6 : 0x0000000000123f40, x7 : 0x0000000000411594
    x8 : 0x0000000000496b08, x9 : 0x000000000049cad8, x10: 0x0000000000000000, x11: 0x0000000000000201
    x12: 0x0101010101010101, x13: 0x0000000000000030, x14: 0x000000000000003f, x15: 0x0000000000123e78
    x16: 0x000000000046beb0, x17: 0x000000008d757ac4, x18: 0x00000000004100a0, x19: 0x0000000000496260
    x20: 0x0000000000496260, x21: 0x00000000004a0000, x22: 0x0000000000480460, x23: 0x0000000000496a30
    x24: 0x0000000000000000, x25: 0x0000000000000000, x26: 0x0000000000000000, x27: 0x0000000000000000
    x28: 0x0000000000000000, x29: 0x0000000000123f00
    sp: 0xffffc400096e4000, lr: 0x000000000041009c, pc: 0x00000000004100a0
    usr_sp: 0x0000000000123f00, pstate: 0x0000000080000000, mode: User

Stack Data From 0xffffc400096e3ff0
+00 00000000004100a0 0000000000000000
Call Trace (User Mode):
    [<00000000004100a0>] (main+0x48) from [<00000000004115a8>] (__eprol+0x70)
    [<00000000004115a8>] (__eprol+0x70)

Terminating task.
Terminating thread.
[INIT ] System worker finished
[INIT ] System halted...

-----

Do I understand right that signals can't be trapped on KOS at all and that app will exit on exception? Is there any plans of signal trapping support within KOS?

Thanks,

Iurie

[Alexey_Salnikov]

Hello,

A ticket number INC000015134062 is created.
Your request has been sent to kaspersky experts. Please wait for reply.

[Ivan Ponomarev]

Hello!

As it is stated in the documentation https://support.kaspersky.com/help/KCE/1.1/ru-RU/posix_uns_ifaces.htm only SIGTERM signal can be sent, the PID parameter is ignored. Other signals are not supported in KasperskyOS. Adding support for other signals is not planned for now. 

Thanks!