TOOLS/INFO: Validate -m flag

[ovidiusm]

What?

Fix input validation for -m flag in ucx_info, to allow only positive memory size values

Why?

Before:

ucx_info -u a -m -1,host
[1740736432.183591] [rock16:2056552:0]             sys.c:924  UCX  ERROR   shmget(size=0 flags=0xfb0) for user memory failed: Invalid argument, please check shared memory limits by 'ipcs -l'
[1740736432.183613] [rock16:2056552:0]             sys.c:924  UCX  ERROR   shmget(size=0 flags=0x7b0) for user memory failed: Invalid argument, please check shared memory limits by 'ipcs -l'
[1740736432.183621] [rock16:2056552:0]         mm_sysv.c:114  UCX  ERROR   failed to allocate 18446744073709551615 bytes with mm for user memory
[1740736432.183628] [rock16:2056552:0]         uct_mem.c:161  UCX  ERROR   failed to allocate 18446744073709551615 bytes using md sysv for user memory: Out of memory
[1740736445.064992] [rock16:2056552:0]        mm_posix.c:208  UCX  ERROR   Not enough memory to write total of 18446744073709551615 bytes. Please check that /dev/shm or the directory you specified has more available memory.
[1740736448.669457] [rock16:2056552:0]         uct_mem.c:161  UCX  ERROR   failed to allocate 18446744073709551615 bytes using md posix for user memory: Out of memory
#
# UCP memory allocation
#
#  allocated 0 at address 0x7f4ff8200000 with thp, pagesize: 4K
#  registered on: self mlx5_0 mlx5_1 mlx5_2 mlx5_1 knem
#
<Failed to pack rkey: Invalid parameter>
[rock16:2056552:0:2056552]    rcache.inl:89   Assertion `region->refcount > 0' failed

/.autodirect/mtrswgwork/ovidium/ucx/src/ucs/memory/rcache.inl: [ ucs_rcache_region_put_unsafe() ]
      ...
       86 {
       87     ucs_rcache_region_lru_add(rcache, region);
       88
==>    89     ucs_assert(region->refcount > 0);
       90     if (ucs_unlikely(--region->refcount == 0)) {
       91         ucs_mem_region_destroy_internal(rcache, region, 0);
       92     }

==== backtrace (tid:2056552) ====
 0 0x00000000000582d6 ucs_rcache_region_put_unsafe()  /.autodirect/mtrswgwork/ovidium/ucx/src/ucs/memory/rcache.inl:89
 1 0x00000000000582d6 ucp_memh_put_rcache()  /.autodirect/mtrswgwork/ovidium/ucx/src/ucp/core/ucp_mm.c:421
 2 0x00000000000583f7 ucp_memh_cleanup()  /.autodirect/mtrswgwork/ovidium/ucx/src/ucp/core/ucp_mm.c:450
 3 0x000000000005b592 ucp_mem_unmap()  /.autodirect/mtrswgwork/ovidium/ucx/src/ucp/core/ucp_mm.c:1166
 4 0x000000000005cb8e ucp_mem_print_info()  /.autodirect/mtrswgwork/ovidium/ucx/src/ucp/core/ucp_mm.c:1571
 5 0x0000000000403c27 print_ucp_info()  /.autodirect/mtrswgwork/ovidium/ucx/src/tools/info/proto_info.c:382
 6 0x0000000000402ced main()  /.autodirect/mtrswgwork/ovidium/ucx/src/tools/info/ucx_info.c:318
 7 0x000000000003aca3 __libc_start_main()  ???:0
 8 0x0000000000402dfe _start()  ???:0
=================================

ucx_info -u a -m 0,host
#
# UCP memory allocation
#
#  allocated 0 at address (nil) with [rock16:2059140:0:2059140] Caught signal 11 (Segmentation fault: address not mapped to object at address (nil))
==== backtrace (tid:2059140) ====
 0 0x0000000000012ce0 __funlockfile()  :0
 1 0x00000000000ccc95 __strlen_avx2()  :0
 2 0x0000000000087f69 __GI__IO_fputs()  :0
 3 0x000000000005cc26 ucp_mem_print_info()  /.autodirect/mtrswgwork/ovidium/ucx/src/ucp/core/ucp_mm.c:1541
 4 0x0000000000403c27 print_ucp_info()  /.autodirect/mtrswgwork/ovidium/ucx/src/tools/info/proto_info.c:382
 5 0x0000000000402ced main()  /.autodirect/mtrswgwork/ovidium/ucx/src/tools/info/ucx_info.c:318
 6 0x000000000003aca3 __libc_start_main()  ???:0
 7 0x0000000000402dfe _start()  ???:0
=================================

After:

ucx_info -u a -m -1,host
<Memory size must be greater than 0>

ucx_info -u a -m 0,host
<Memory size must be greater than 0>