Hi Alex,
On Mon, May 05, 2025 at 06:02:26PM +0200, Alexandre Ghiti wrote:
On 04/05/2025 12:19, Nam Cao wrote:
When userspace does PR_SET_TAGGED_ADDR_CTRL, but Supm extension is not available, the kernel crashes:
Oops - illegal instruction [#1] [snip] epc : set_tagged_addr_ctrl+0x112/0x15a ra : set_tagged_addr_ctrl+0x74/0x15a epc : ffffffff80011ace ra : ffffffff80011a30 sp : ffffffc60039be10 [snip] status: 0000000200000120 badaddr: 0000000010a79073 cause: 0000000000000002 set_tagged_addr_ctrl+0x112/0x15a __riscv_sys_prctl+0x352/0x73c do_trap_ecall_u+0x17c/0x20c andle_exception+0x150/0x15c
It seems like the csr write is triggering this illegal instruction, can you confirm it is?
Yes, it is the "csr_write(CSR_ENVCFG, envcfg);" in envcfg_update_bits().
If so, I can't find in the specification that an implementation should do that when writing envcfg and I can't reproduce it on qemu. Where did you see this oops?
I can't find it in the spec either. I think it is up to the implementation.
I got this crash on the MangoPI board: https://mangopi.org/mqpro
Best regards, Nam