On Wednesday, July 10th, 2024 at 22:06, Pawan Gupta pawan.kumar.gupta@linux.intel.com wrote:
Fixes: a0e2dab44d22 ("x86/entry_32: Add VERW just before userspace transition") Cc: stable@vger.kernel.org # 5.10+ Reported-by: Robert Gill rtgill82@gmail.com Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218707 Closes: https://lore.kernel.org/all/8c77ccfd-d561-45a1-8ed5-6b75212c7a58@leemhuis.in... Suggested-by: Dave Hansen dave.hansen@linux.intel.com Suggested-by: Brian Gerst brgerst@gmail.com # Use %ss Signed-off-by: Pawan Gupta pawan.kumar.gupta@linux.intel.com
v4:
- Further simplify the patch by using %ss for all VERW calls in 32-bit mode (Brian).
- In NMI exit path move VERW after RESTORE_ALL_NMI that touches GPRs (Dave).
v3: https://lore.kernel.org/r/20240701-fix-dosemu-vm86-v3-1-b1969532c75a@linux.i...
- Simplify CLEAR_CPU_BUFFERS_SAFE by using %ss instead of %ds (Brian).
- Do verw before popf in SYSEXIT path (Jari).
v2: https://lore.kernel.org/r/20240627-fix-dosemu-vm86-v2-1-d5579f698e77@linux.i...
- Safe guard against any other system calls like vm86() that might change %ds (Dave).
v1: https://lore.kernel.org/r/20240426-fix-dosemu-vm86-v1-1-88c826a3f378@linux.i...
Pawan, Your patch looks OK to me.
Greg, I have verified that patch hunks go correct places on kernel.org linux-5.10.221, linux-6.1.97 and linux-6.6.38 kernels. All tests run inside 32-bit VM. The patch fixes show-stopper issues with virtual-8086 mode and dosemu. Once the patch is accepted upstream, it should go to all 5.10+ stable kernels.
-- Jari Ruusu 4096R/8132F189 12D6 4C3A DCDA 0AA4 27BD ACDF F073 3C80 8132 F189