From: Ammar Faizi <ammarfaizi2@xxxxxxxxxxx> This is an RFC patchset v2. Xin Li reported sysret_rip test fails at: assert(ctx->uc_mcontext.gregs[REG_EFL] == ctx->uc_mcontext.gregs[REG_R11]); in a FRED system. Handle the FRED system scenario too. There are two patches in this series. Comments welcome... Note: This patchset is only tested for 'syscall' sets %rcx=%rip and %r11=%rflags case. I don't have a FRED system to test it. How to test this: $ make -C tools/testing/selftests/x86 $ tools/testing/selftests/x86/sysret_rip_64 Link: https://lore.kernel.org/lkml/5d4ad3e3-034f-c7da-d141-9c001c2343af@xxxxxxxxx Signed-off-by: Ammar Faizi <ammarfaizi2@xxxxxxxxxxx> --- ## Changelog v2: - Use "+r"(rsp) as the right way to avoid redzone problems per Andrew's comment (hpa). (Ref: https://lore.kernel.org/lkml/8f5c24df-514d-5d89-f58f-ec8c3eb1e049@xxxxxxxxx ) --- Ammar Faizi (2): selftests/x86: sysret_rip: Handle syscall in a FRED system selftests/x86: sysret_rip: Add more syscall tests with respect to `%rcx` and `%r11` tools/testing/selftests/x86/sysret_rip.c | 105 ++++++++++++++++++++++- 1 file changed, 104 insertions(+), 1 deletion(-) base-commit: e12ad468c22065a2826b2fc4c11d2113a7975301 -- Ammar Faizi