CFI_SIGNAL_FRAME
CFI_DEF_CFA rsp,0
CFI_REGISTER rsp,rbp
- SWAPGS_UNSAFE_STACK
- movq PER_CPU_VAR(cpu_tss + TSS_sp0), %rsp
+
/*
- * No need to follow this irqs on/off section: the syscall
- * disabled irqs, here we enable it straight after entry:
+ * Interrupts are off on entry.
+ * We do not frame this tiny irq-off block with TRACE_IRQS_OFF/ON,
+ * it is too small to ever cause noticeable irq latency.
*/
+ SWAPGS_UNSAFE_STACK
+ movq PER_CPU_VAR(cpu_tss + TSS_sp0), %rsp
ENABLE_INTERRUPTS(CLBR_NONE)
- /* Construct iret frame (ss,rsp,rflags,cs,rip) */
- movl %ebp,%ebp /* zero extension */
- pushq_cfi $__USER32_DS
- /*CFI_REL_OFFSET ss,0*/
- pushq_cfi %rbp
- CFI_REL_OFFSET rsp,0
- pushfq_cfi
- /*CFI_REL_OFFSET rflags,0*/
- movl TI_sysenter_return+THREAD_INFO(%rsp,3*8-KERNEL_STACK_OFFSET),%r10d
- CFI_REGISTER rip,r10
- pushq_cfi $__USER32_CS
- /*CFI_REL_OFFSET cs,0*/
+
+ /* Zero-extending 32-bit regs, do not remove */
+ movl %ebp, %ebp
movl %eax, %eax
- /* Store thread_info->sysenter_return in rip stack slot */
- pushq_cfi %r10
- CFI_REL_OFFSET rip,0
- /* Store orig_ax */
- pushq_cfi %rax
- /* Construct the rest of "struct pt_regs" */
+
+ movl ASM_THREAD_INFO(TI_sysenter_return, %rsp, 0), %r10d
+ CFI_REGISTER rip,r10
+
+ /* Construct struct pt_regs on stack */
+ pushq_cfi $__USER32_DS /* pt_regs->ss */
+ pushq_cfi %rbp /* pt_regs->sp */
+ CFI_REL_OFFSET rsp,0
+ pushfq_cfi /* pt_regs->flags */
+ pushq_cfi $__USER32_CS /* pt_regs->cs */
+ pushq_cfi %r10 /* pt_regs->ip = thread_info->sysenter_return */
+ CFI_REL_OFFSET rip,0
+ pushq_cfi_reg rax /* pt_regs->orig_ax */
+ pushq_cfi_reg rdi /* pt_regs->di */
+ pushq_cfi_reg rsi /* pt_regs->si */
+ pushq_cfi_reg rdx /* pt_regs->dx */
+ pushq_cfi_reg rcx /* pt_regs->cx */
+ pushq_cfi_reg rax /* pt_regs->ax */
cld
- ALLOC_PT_GPREGS_ON_STACK
- SAVE_C_REGS_EXCEPT_R891011
+ sub $(10*8),%rsp /* pt_regs->r8-11,bp,bx,r12-15 not saved */
+ CFI_ADJUST_CFA_OFFSET 10*8
+
/*
* no need to do an access_ok check here because rbp has been
* 32bit zero extended
jnz sysenter_fix_flags
sysenter_flags_fixed:
- orl $TS_COMPAT,TI_status+THREAD_INFO(%rsp,RIP)
- testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags+THREAD_INFO(%rsp,RIP)
+ orl $TS_COMPAT, ASM_THREAD_INFO(TI_status, %rsp, SIZEOF_PTREGS)
+ testl $_TIF_WORK_SYSCALL_ENTRY, ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)
CFI_REMEMBER_STATE
jnz sysenter_tracesys
cmpq $(IA32_NR_syscalls-1),%rax
movq %rax,RAX(%rsp)
DISABLE_INTERRUPTS(CLBR_NONE)
TRACE_IRQS_OFF
- testl $_TIF_ALLWORK_MASK,TI_flags+THREAD_INFO(%rsp,RIP)
+ testl $_TIF_ALLWORK_MASK, ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)
jnz sysexit_audit
sysexit_from_sys_call:
- andl $~TS_COMPAT,TI_status+THREAD_INFO(%rsp,RIP)
- /* clear IF, that popfq doesn't enable interrupts early */
- andl $~0x200,EFLAGS(%rsp)
- movl RIP(%rsp),%edx /* User %eip */
- CFI_REGISTER rip,rdx
+ /*
+ * NB: SYSEXIT is not obviously safe for 64-bit kernels -- an
+ * NMI between STI and SYSEXIT has poorly specified behavior,
+ * and and NMI followed by an IRQ with usergs is fatal. So
+ * we just pretend we're using SYSEXIT but we really use
+ * SYSRETL instead.
+ *
+ * This code path is still called 'sysexit' because it pairs
+ * with 'sysenter' and it uses the SYSENTER calling convention.
+ */
+ andl $~TS_COMPAT,ASM_THREAD_INFO(TI_status, %rsp, SIZEOF_PTREGS)
+ movl RIP(%rsp),%ecx /* User %eip */
+ CFI_REGISTER rip,rcx
RESTORE_RSI_RDI
- /* pop everything except ss,rsp,rflags slots */
- REMOVE_PT_GPREGS_FROM_STACK 3*8
+ xorl %edx,%edx /* avoid info leaks */
xorq %r8,%r8
xorq %r9,%r9
xorq %r10,%r10
- xorq %r11,%r11
- popfq_cfi
+ movl EFLAGS(%rsp),%r11d /* User eflags */
/*CFI_RESTORE rflags*/
- popq_cfi %rcx /* User %esp */
- CFI_REGISTER rsp,rcx
TRACE_IRQS_ON
+
/*
- * 32bit SYSEXIT restores eip from edx, esp from ecx.
- * cs and ss are loaded from MSRs.
+ * SYSRETL works even on Intel CPUs. Use it in preference to SYSEXIT,
+ * since it avoids a dicey window with interrupts enabled.
+ */
+ movl RSP(%rsp),%esp
+
+ /*
+ * USERGS_SYSRET32 does:
+ * gsbase = user's gs base
+ * eip = ecx
+ * rflags = r11
+ * cs = __USER32_CS
+ * ss = __USER_DS
+ *
+ * The prologue set RIP(%rsp) to VDSO32_SYSENTER_RETURN, which does:
+ *
+ * pop %ebp
+ * pop %edx
+ * pop %ecx
+ *
+ * Therefore, we invoke SYSRETL with EDX and R8-R10 zeroed to
+ * avoid info leaks. R11 ends up with VDSO32_SYSENTER_RETURN's
+ * address (already known to user code), and R12-R15 are
+ * callee-saved and therefore don't contain any interesting
+ * kernel data.
*/
- ENABLE_INTERRUPTS_SYSEXIT32
+ USERGS_SYSRET32
CFI_RESTORE_STATE
.endm
.macro auditsys_exit exit
- testl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT),TI_flags+THREAD_INFO(%rsp,RIP)
+ testl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT), ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)
jnz ia32_ret_from_sys_call
TRACE_IRQS_ON
ENABLE_INTERRUPTS(CLBR_NONE)
movl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT),%edi
DISABLE_INTERRUPTS(CLBR_NONE)
TRACE_IRQS_OFF
- testl %edi,TI_flags+THREAD_INFO(%rsp,RIP)
+ testl %edi, ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)
jz \exit
CLEAR_RREGS
jmp int_with_check
sysenter_tracesys:
#ifdef CONFIG_AUDITSYSCALL
- testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT),TI_flags+THREAD_INFO(%rsp,RIP)
+ testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT), ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)
jz sysenter_auditsys
#endif
SAVE_EXTRA_REGS
ENTRY(ia32_cstar_target)
CFI_STARTPROC32 simple
CFI_SIGNAL_FRAME
- CFI_DEF_CFA rsp,KERNEL_STACK_OFFSET
+ CFI_DEF_CFA rsp,0
CFI_REGISTER rip,rcx
/*CFI_REGISTER rflags,r11*/
+
+ /*
+ * Interrupts are off on entry.
+ * We do not frame this tiny irq-off block with TRACE_IRQS_OFF/ON,
+ * it is too small to ever cause noticeable irq latency.
+ */
SWAPGS_UNSAFE_STACK
movl %esp,%r8d
CFI_REGISTER rsp,r8
movq PER_CPU_VAR(kernel_stack),%rsp
- /*
- * No need to follow this irqs on/off section: the syscall
- * disabled irqs and here we enable it straight after entry:
- */
ENABLE_INTERRUPTS(CLBR_NONE)
- ALLOC_PT_GPREGS_ON_STACK 8 /* +8: space for orig_ax */
- SAVE_C_REGS_EXCEPT_RCX_R891011
- movl %eax,%eax /* zero extension */
- movq %rax,ORIG_RAX(%rsp)
- movq %rcx,RIP(%rsp)
- CFI_REL_OFFSET rip,RIP
- movq %rbp,RCX(%rsp) /* this lies slightly to ptrace */
+
+ /* Zero-extending 32-bit regs, do not remove */
+ movl %eax,%eax
+
+ /* Construct struct pt_regs on stack */
+ pushq_cfi $__USER32_DS /* pt_regs->ss */
+ pushq_cfi %r8 /* pt_regs->sp */
+ CFI_REL_OFFSET rsp,0
+ pushq_cfi %r11 /* pt_regs->flags */
+ pushq_cfi $__USER32_CS /* pt_regs->cs */
+ pushq_cfi %rcx /* pt_regs->ip */
+ CFI_REL_OFFSET rip,0
+ pushq_cfi_reg rax /* pt_regs->orig_ax */
+ pushq_cfi_reg rdi /* pt_regs->di */
+ pushq_cfi_reg rsi /* pt_regs->si */
+ pushq_cfi_reg rdx /* pt_regs->dx */
+ pushq_cfi_reg rbp /* pt_regs->cx */
movl %ebp,%ecx
- movq $__USER32_CS,CS(%rsp)
- movq $__USER32_DS,SS(%rsp)
- movq %r11,EFLAGS(%rsp)
- /*CFI_REL_OFFSET rflags,EFLAGS*/
- movq %r8,RSP(%rsp)
- CFI_REL_OFFSET rsp,RSP
- /* iret stack frame is complete now */
+ pushq_cfi_reg rax /* pt_regs->ax */
+ sub $(10*8),%rsp /* pt_regs->r8-11,bp,bx,r12-15 not saved */
+ CFI_ADJUST_CFA_OFFSET 10*8
+
/*
* no need to do an access_ok check here because r8 has been
* 32bit zero extended
1: movl (%r8),%r9d
_ASM_EXTABLE(1b,ia32_badarg)
ASM_CLAC
- orl $TS_COMPAT,TI_status+THREAD_INFO(%rsp,RIP)
- testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags+THREAD_INFO(%rsp,RIP)
+ orl $TS_COMPAT, ASM_THREAD_INFO(TI_status, %rsp, SIZEOF_PTREGS)
+ testl $_TIF_WORK_SYSCALL_ENTRY, ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)
CFI_REMEMBER_STATE
jnz cstar_tracesys
cmpq $IA32_NR_syscalls-1,%rax
movq %rax,RAX(%rsp)
DISABLE_INTERRUPTS(CLBR_NONE)
TRACE_IRQS_OFF
- testl $_TIF_ALLWORK_MASK,TI_flags+THREAD_INFO(%rsp,RIP)
+ testl $_TIF_ALLWORK_MASK, ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)
jnz sysretl_audit
sysretl_from_sys_call:
- andl $~TS_COMPAT,TI_status+THREAD_INFO(%rsp,RIP)
+ andl $~TS_COMPAT, ASM_THREAD_INFO(TI_status, %rsp, SIZEOF_PTREGS)
RESTORE_RSI_RDI_RDX
movl RIP(%rsp),%ecx
CFI_REGISTER rip,rcx
cstar_tracesys:
#ifdef CONFIG_AUDITSYSCALL
- testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT),TI_flags+THREAD_INFO(%rsp,RIP)
+ testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT), ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)
jz cstar_auditsys
#endif
xchgl %r9d,%ebp
ENTRY(ia32_syscall)
CFI_STARTPROC32 simple
CFI_SIGNAL_FRAME
- CFI_DEF_CFA rsp,SS+8-RIP
- /*CFI_REL_OFFSET ss,SS-RIP*/
- CFI_REL_OFFSET rsp,RSP-RIP
- /*CFI_REL_OFFSET rflags,EFLAGS-RIP*/
- /*CFI_REL_OFFSET cs,CS-RIP*/
- CFI_REL_OFFSET rip,RIP-RIP
- PARAVIRT_ADJUST_EXCEPTION_FRAME
- SWAPGS
+ CFI_DEF_CFA rsp,5*8
+ /*CFI_REL_OFFSET ss,4*8 */
+ CFI_REL_OFFSET rsp,3*8
+ /*CFI_REL_OFFSET rflags,2*8 */
+ /*CFI_REL_OFFSET cs,1*8 */
+ CFI_REL_OFFSET rip,0*8
+
/*
- * No need to follow this irqs on/off section: the syscall
- * disabled irqs and here we enable it straight after entry:
+ * Interrupts are off on entry.
+ * We do not frame this tiny irq-off block with TRACE_IRQS_OFF/ON,
+ * it is too small to ever cause noticeable irq latency.
*/
+ PARAVIRT_ADJUST_EXCEPTION_FRAME
+ SWAPGS
ENABLE_INTERRUPTS(CLBR_NONE)
- movl %eax,%eax
- pushq_cfi %rax /* store orig_ax */
+
+ /* Zero-extending 32-bit regs, do not remove */
+ movl %eax,%eax
+
+ /* Construct struct pt_regs on stack (iret frame is already on stack) */
+ pushq_cfi_reg rax /* pt_regs->orig_ax */
+ pushq_cfi_reg rdi /* pt_regs->di */
+ pushq_cfi_reg rsi /* pt_regs->si */
+ pushq_cfi_reg rdx /* pt_regs->dx */
+ pushq_cfi_reg rcx /* pt_regs->cx */
+ pushq_cfi_reg rax /* pt_regs->ax */
cld
- /* note the registers are not zero extended to the sf.
- this could be a problem. */
- ALLOC_PT_GPREGS_ON_STACK
- SAVE_C_REGS_EXCEPT_R891011
- orl $TS_COMPAT,TI_status+THREAD_INFO(%rsp,RIP)
- testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags+THREAD_INFO(%rsp,RIP)
+ sub $(10*8),%rsp /* pt_regs->r8-11,bp,bx,r12-15 not saved */
+ CFI_ADJUST_CFA_OFFSET 10*8
+
+ 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 ia32_tracesys
cmpq $(IA32_NR_syscalls-1),%rax
ja ia32_badsys
projects / deliverable / linux.git / blobdiff