On Thu, Oct 22 2026 at 17:22, H. Peter Anvin wrote:
On October 22, 2026 2:34:08 PM PDT, Thomas Gleixner [off-list ref] wrote:
quoted
-static __always_inline void do_syscall_x32(struct pt_regs *regs, unsigned long nr)
+static __always_inline bool do_syscall_x32(struct pt_regs *regs, unsigned long nr)
{
+ if (!IS_ENABLED(CONFIG_X86_X32_ABI))
+ return false;
+
+ /* Preserve the historic insanity of treating -1 special on x32 */
+ if (nr == ULONG_MAX)
+ return true;
It was never limited to x32...
Tired brain misread the test output:
[RUN] Running tests under ptrace: modifying the default return
[RUN] Checking system calls with msb = 0 (0x0)
[OK] x32 syscalls 0:-64..-2 returned -ENOSYS as expected
[OK] x32 syscall 0:-1 returned MODIFIED_BY_PTRACE as expected
[OK] x64 syscalls 0:-64..-1 returned -ENOSYS as expected
But that's because the "-1" on x32 is actually 0xFFFFFFFF while on x64
it's 0x7FFFFFFF.
The whole mess comes from using -1 as indicator for syscall abort which
is undistinguishable from a syscall(nr=-1).
Bah. Let me restore this nonsense.
Thanks,
tglx