I've just built and tried to run rpi_dma_test.c, as told in Raspberry Pi DMA programming in C, but a sudo ./rpi_dma_test immediately ends in a segfault. This is what gdb has to say:

Program received signal SIGSEGV, Segmentation fault.
0x0000005555551c50 in enable_dma ()

I'm using a Pi 3B+ with OS Trixie (64-bit). Of course I made sure that the PHYS_REG_BASE macro is set correctly:

#define PHYS_REG_BASE    0x3F000000  // Pi 2 or 3

I²C, I²S, and SPI are switched on. 1-wire is off. So: What's wrong here?