In 32-bit SYSENTER code, load arg6 into R9 instead of EBP. Jump to SYSCALL code path after we finish setting up pt_regs and clearing FLAGS_NT.
This leaves most of SYSENTER32 code path inaccessible. Signed-off-by: Denys Vlasenko <[email protected]> CC: Ingo Molnar <[email protected]> CC: Linus Torvalds <[email protected]> CC: Krzysztof A. Sobiecki <[email protected]> CC: Steven Rostedt <[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] --- arch/x86/entry/entry_64_compat.S | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S index df102e8..d74745a 100644 --- a/arch/x86/entry/entry_64_compat.S +++ b/arch/x86/entry/entry_64_compat.S @@ -93,7 +93,7 @@ ENTRY(entry_SYSENTER_compat) * 32-bit zero extended */ ASM_STAC -1: movl (%rbp), %ebp +1: movl (%rbp), %r9d _ASM_EXTABLE(1b, ia32_badarg) ASM_CLAC @@ -105,6 +105,7 @@ ENTRY(entry_SYSENTER_compat) testl $X86_EFLAGS_NT, EFLAGS(%rsp) jnz sysenter_fix_flags sysenter_flags_fixed: + jmp sysenter_jumps_here orl $TS_COMPAT, ASM_THREAD_INFO(TI_status, %rsp, SIZEOF_PTREGS) testl $_TIF_WORK_SYSCALL_ENTRY, ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS) @@ -343,6 +344,7 @@ ENTRY(entry_SYSCALL_compat) _ASM_EXTABLE(1b, ia32_badarg) ASM_CLAC +sysenter_jumps_here: orl $TS_COMPAT, ASM_THREAD_INFO(TI_status, %rsp, SIZEOF_PTREGS) testl $_TIF_WORK_SYSCALL_ENTRY, ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS) jnz cstar_tracesys -- 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/
