Checks whether your cpu supports Intel CET or not (Linux).

check_cet_supported.c

#include <stdio.h>
#include <cpuid.h>
#include <stdint.h>

int cpu_supports_cet_shadow_stack() {
    uint32_t eax = 0, ebx = 0, ecx = 0, edx = 0;
    __cpuid_count(7, 0, eax, ebx, ecx, edx);
    return (ecx & (1 << 7)) != 0;
}

int cpu_supports_cet_ibt() {
    uint32_t eax = 0, ebx = 0, ecx = 0, edx = 0;
    __cpuid_count(7, 0, eax, ebx, ecx, edx);
    return (edx & (1 << 20)) != 0;
}

int main() {
    if (cpu_supports_cet_shadow_stack()) {
        puts("CET Shadow Stack is supported");
    }

    if (cpu_supports_cet_ibt()) {
        puts("CET IBT is supported");
    }
}

Partial support on my 5950X (if this applies on AMD CPUs as well that is):

$ cat /proc/cpuinfo
processor	: 0
vendor_id	: AuthenticAMD
cpu family	: 25
model		: 33
model name	: AMD Ryzen 9 5950X 16-Core Processor
stepping	: 0
microcode	: 0xa201016
cpu MHz		: 3400.000
cache size	: 512 KB
physical id	: 0
siblings	: 32
core id		: 0
cpu cores	: 16
apicid		: 0
initial apicid	: 0
fpu		: yes
fpu_exception	: yes
cpuid level	: 16
wp		: yes
flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb rdtscp lm constant_tsc rep_good nopl nonstop_tsc cpuid extd_apicid aperfmperf rapl pni pclmulqdq monitor ssse3 fma cx16 sse4_1 sse4_2 x2apic movbe popcnt aes xsave avx f16c rdrand lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs skinit wdt tce topoext perfctr_core perfctr_nb bpext perfctr_llc mwaitx cpb cat_l3 cdp_l3 hw_pstate ssbd mba ibrs ibpb stibp vmmcall fsgsbase bmi1 avx2 smep bmi2 erms invpcid cqm rdt_a rdseed adx smap clflushopt clwb sha_ni xsaveopt xsavec xgetbv1 xsaves cqm_llc cqm_occup_llc cqm_mbm_total cqm_mbm_local clzero irperf xsaveerptr rdpru wbnoinvd arat npt lbrv svm_lock nrip_save tsc_scale vmcb_clean flushbyasid decodeassists pausefilter pfthreshold avic v_vmsave_vmload vgif v_spec_ctrl umip pku ospke vaes vpclmulqdq rdpid overflow_recov succor smca fsrm
bugs		: sysret_ss_attrs spectre_v1 spectre_v2 spec_store_bypass
bogomips	: 6789.78
TLB size	: 2560 4K pages
clflush size	: 64
cache_alignment	: 64
address sizes	: 48 bits physical, 48 bits virtual
power management: ts ttp tm hwpstate cpb eff_freq_ro [13] [14]

$ gcc cet.c && ./a.out
CET Shadow Stack is supported