The reason for copying of %r8 to %rcx is quite non-obvious. Add a comment which explains why it is done.
Fix indentation and trailing whitespace while at it. Signed-off-by: Denys Vlasenko <[email protected]> CC: Linus Torvalds <[email protected]> CC: Steven Rostedt <[email protected]> CC: Ingo Molnar <[email protected]> CC: Borislav Petkov <[email protected]> CC: "H. Peter Anvin" <[email protected]> CC: Andy Lutomirski <[email protected]> CC: Oleg Nesterov <[email protected]> CC: Frederic Weisbecker <[email protected]> CC: Alexei Starovoitov <[email protected]> CC: Will Drewry <[email protected]> CC: Kees Cook <[email protected]> CC: [email protected] CC: [email protected] --- This is a resend. arch/x86/ia32/ia32entry.S | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S index 2ca052e..8e72256 100644 --- a/arch/x86/ia32/ia32entry.S +++ b/arch/x86/ia32/ia32entry.S @@ -562,9 +562,17 @@ GLOBAL(\label) ALIGN GLOBAL(stub32_clone) - leaq sys_clone(%rip),%rax + leaq sys_clone(%rip), %rax + /* + * 32-bit clone API is clone(..., int tls_val, int *child_tidptr). + * 64-bit clone API is clone(..., int *child_tidptr, int tls_val). + * Native 64-bit kernel's sys_clone() implements the latter. + * We need to swap args here. But since tls_val is in fact ignored + * by sys_clone(), we can get away with an assignment + * (arg4 = arg5) instead of a full swap: + */ mov %r8, %rcx - jmp ia32_ptregs_common + jmp ia32_ptregs_common ALIGN ia32_ptregs_common: -- 1.8.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
