diff options
Diffstat (limited to 'arch/x86/entry/entry_64_compat.S')
| -rw-r--r-- | arch/x86/entry/entry_64_compat.S | 31 |
1 files changed, 16 insertions, 15 deletions
diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S index 0f974ae01e62..541fdaf64045 100644 --- a/arch/x86/entry/entry_64_compat.S +++ b/arch/x86/entry/entry_64_compat.S @@ -57,29 +57,30 @@ SYM_CODE_START(entry_SYSENTER_compat) movq PER_CPU_VAR(cpu_current_top_of_stack), %rsp - /* - * User tracing code (ptrace or signal handlers) might assume that - * the saved RAX contains a 32-bit number when we're invoking a 32-bit - * syscall. Just in case the high bits are nonzero, zero-extend - * the syscall number. (This could almost certainly be deleted - * with no ill effects.) - */ - movl %eax, %eax - /* Construct struct pt_regs on stack */ pushq $__USER32_DS /* pt_regs->ss */ - pushq %rbp /* pt_regs->sp (stashed in bp) */ + pushq $0 /* pt_regs->sp = 0 (placeholder) */ /* * Push flags. This is nasty. First, interrupts are currently - * off, but we need pt_regs->flags to have IF set. Second, even - * if TF was set when SYSENTER started, it's clear by now. We fix - * that later using TIF_SINGLESTEP. + * off, but we need pt_regs->flags to have IF set. Second, if TS + * was set in usermode, it's still set, and we're singlestepping + * through this code. do_SYSENTER_32() will fix up IF. */ pushfq /* pt_regs->flags (except IF = 0) */ - orl $X86_EFLAGS_IF, (%rsp) /* Fix saved flags */ pushq $__USER32_CS /* pt_regs->cs */ pushq $0 /* pt_regs->ip = 0 (placeholder) */ +SYM_INNER_LABEL(entry_SYSENTER_compat_after_hwframe, SYM_L_GLOBAL) + + /* + * User tracing code (ptrace or signal handlers) might assume that + * the saved RAX contains a 32-bit number when we're invoking a 32-bit + * syscall. Just in case the high bits are nonzero, zero-extend + * the syscall number. (This could almost certainly be deleted + * with no ill effects.) + */ + movl %eax, %eax + pushq %rax /* pt_regs->orig_ax */ pushq %rdi /* pt_regs->di */ pushq %rsi /* pt_regs->si */ @@ -135,7 +136,7 @@ SYM_CODE_START(entry_SYSENTER_compat) .Lsysenter_flags_fixed: movq %rsp, %rdi - call do_fast_syscall_32 + call do_SYSENTER_32 /* XEN PV guests always use IRET path */ ALTERNATIVE "testl %eax, %eax; jz swapgs_restore_regs_and_return_to_usermode", \ "jmp swapgs_restore_regs_and_return_to_usermode", X86_FEATURE_XENPV |