summaryrefslogtreecommitdiff
path: root/arch/x86/ia32
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2015-06-23 00:59:09 (GMT)
committerLinus Torvalds <torvalds@linux-foundation.org>2015-06-23 00:59:09 (GMT)
commitd70b3ef54ceaf1c7c92209f5a662a670d04cbed9 (patch)
tree0f38109c1cabe9e2df028041c1e30f36c803ec5b /arch/x86/ia32
parent650ec5a6bd5df4ab0c9ef38d05b94cd82fb99ad8 (diff)
parent7ef3d7d58d9dc73ee3d4f8f56d0024c8cca8163f (diff)
downloadlinux-d70b3ef54ceaf1c7c92209f5a662a670d04cbed9.tar.xz
Merge branch 'x86-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 core updates from Ingo Molnar: "There were so many changes in the x86/asm, x86/apic and x86/mm topics in this cycle that the topical separation of -tip broke down somewhat - so the result is a more traditional architecture pull request, collected into the 'x86/core' topic. The topics were still maintained separately as far as possible, so bisectability and conceptual separation should still be pretty good - but there were a handful of merge points to avoid excessive dependencies (and conflicts) that would have been poorly tested in the end. The next cycle will hopefully be much more quiet (or at least will have fewer dependencies). The main changes in this cycle were: * x86/apic changes, with related IRQ core changes: (Jiang Liu, Thomas Gleixner) - This is the second and most intrusive part of changes to the x86 interrupt handling - full conversion to hierarchical interrupt domains: [IOAPIC domain] ----- | [MSI domain] --------[Remapping domain] ----- [ Vector domain ] | (optional) | [HPET MSI domain] ----- | | [DMAR domain] ----------------------------- | [Legacy domain] ----------------------------- This now reflects the actual hardware and allowed us to distangle the domain specific code from the underlying parent domain, which can be optional in the case of interrupt remapping. It's a clear separation of functionality and removes quite some duct tape constructs which plugged the remap code between ioapic/msi/hpet and the vector management. - Intel IOMMU IRQ remapping enhancements, to allow direct interrupt injection into guests (Feng Wu) * x86/asm changes: - Tons of cleanups and small speedups, micro-optimizations. This is in preparation to move a good chunk of the low level entry code from assembly to C code (Denys Vlasenko, Andy Lutomirski, Brian Gerst) - Moved all system entry related code to a new home under arch/x86/entry/ (Ingo Molnar) - Removal of the fragile and ugly CFI dwarf debuginfo annotations. Conversion to C will reintroduce many of them - but meanwhile they are only getting in the way, and the upstream kernel does not rely on them (Ingo Molnar) - NOP handling refinements. (Borislav Petkov) * x86/mm changes: - Big PAT and MTRR rework: making the code more robust and preparing to phase out exposing direct MTRR interfaces to drivers - in favor of using PAT driven interfaces (Toshi Kani, Luis R Rodriguez, Borislav Petkov) - New ioremap_wt()/set_memory_wt() interfaces to support Write-Through cached memory mappings. This is especially important for good performance on NVDIMM hardware (Toshi Kani) * x86/ras changes: - Add support for deferred errors on AMD (Aravind Gopalakrishnan) This is an important RAS feature which adds hardware support for poisoned data. That means roughly that the hardware marks data which it has detected as corrupted but wasn't able to correct, as poisoned data and raises an APIC interrupt to signal that in the form of a deferred error. It is the OS's responsibility then to take proper recovery action and thus prolonge system lifetime as far as possible. - Add support for Intel "Local MCE"s: upcoming CPUs will support CPU-local MCE interrupts, as opposed to the traditional system- wide broadcasted MCE interrupts (Ashok Raj) - Misc cleanups (Borislav Petkov) * x86/platform changes: - Intel Atom SoC updates ... and lots of other cleanups, fixlets and other changes - see the shortlog and the Git log for details" * 'x86-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (222 commits) x86/hpet: Use proper hpet device number for MSI allocation x86/hpet: Check for irq==0 when allocating hpet MSI interrupts x86/mm/pat, drivers/infiniband/ipath: Use arch_phys_wc_add() and require PAT disabled x86/mm/pat, drivers/media/ivtv: Use arch_phys_wc_add() and require PAT disabled x86/platform/intel/baytrail: Add comments about why we disabled HPET on Baytrail genirq: Prevent crash in irq_move_irq() genirq: Enhance irq_data_to_desc() to support hierarchy irqdomain iommu, x86: Properly handle posted interrupts for IOMMU hotplug iommu, x86: Provide irq_remapping_cap() interface iommu, x86: Setup Posted-Interrupts capability for Intel iommu iommu, x86: Add cap_pi_support() to detect VT-d PI capability iommu, x86: Avoid migrating VT-d posted interrupts iommu, x86: Save the mode (posted or remapped) of an IRTE iommu, x86: Implement irq_set_vcpu_affinity for intel_ir_chip iommu: dmar: Provide helper to copy shared irte fields iommu: dmar: Extend struct irte for VT-d Posted-Interrupts iommu: Add new member capability to struct irq_remap_ops x86/asm/entry/64: Disentangle error_entry/exit gsbase/ebx/usermode code x86/asm/entry/32: Shorten __audit_syscall_entry() args preparation x86/asm/entry/32: Explain reloading of registers after __audit_syscall_entry() ...
Diffstat (limited to 'arch/x86/ia32')
-rw-r--r--arch/x86/ia32/Makefile2
-rw-r--r--arch/x86/ia32/ia32entry.S611
2 files changed, 1 insertions, 612 deletions
diff --git a/arch/x86/ia32/Makefile b/arch/x86/ia32/Makefile
index bb635c6..cd4339b 100644
--- a/arch/x86/ia32/Makefile
+++ b/arch/x86/ia32/Makefile
@@ -2,7 +2,7 @@
# Makefile for the ia32 kernel emulation subsystem.
#
-obj-$(CONFIG_IA32_EMULATION) := ia32entry.o sys_ia32.o ia32_signal.o
+obj-$(CONFIG_IA32_EMULATION) := sys_ia32.o ia32_signal.o
obj-$(CONFIG_IA32_AOUT) += ia32_aout.o
diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S
deleted file mode 100644
index 72bf268..0000000
--- a/arch/x86/ia32/ia32entry.S
+++ /dev/null
@@ -1,611 +0,0 @@
-/*
- * Compatibility mode system call entry point for x86-64.
- *
- * Copyright 2000-2002 Andi Kleen, SuSE Labs.
- */
-
-#include <asm/dwarf2.h>
-#include <asm/calling.h>
-#include <asm/asm-offsets.h>
-#include <asm/current.h>
-#include <asm/errno.h>
-#include <asm/ia32_unistd.h>
-#include <asm/thread_info.h>
-#include <asm/segment.h>
-#include <asm/irqflags.h>
-#include <asm/asm.h>
-#include <asm/smap.h>
-#include <linux/linkage.h>
-#include <linux/err.h>
-
-/* Avoid __ASSEMBLER__'ifying <linux/audit.h> just for this. */
-#include <linux/elf-em.h>
-#define AUDIT_ARCH_I386 (EM_386|__AUDIT_ARCH_LE)
-#define __AUDIT_ARCH_LE 0x40000000
-
-#ifndef CONFIG_AUDITSYSCALL
-#define sysexit_audit ia32_ret_from_sys_call
-#define sysretl_audit ia32_ret_from_sys_call
-#endif
-
- .section .entry.text, "ax"
-
- /* clobbers %rax */
- .macro CLEAR_RREGS _r9=rax
- xorl %eax,%eax
- movq %rax,R11(%rsp)
- movq %rax,R10(%rsp)
- movq %\_r9,R9(%rsp)
- movq %rax,R8(%rsp)
- .endm
-
- /*
- * Reload arg registers from stack in case ptrace changed them.
- * We don't reload %eax because syscall_trace_enter() returned
- * the %rax value we should see. Instead, we just truncate that
- * value to 32 bits again as we did on entry from user mode.
- * If it's a new value set by user_regset during entry tracing,
- * this matches the normal truncation of the user-mode value.
- * If it's -1 to make us punt the syscall, then (u32)-1 is still
- * an appropriately invalid value.
- */
- .macro LOAD_ARGS32 _r9=0
- .if \_r9
- movl R9(%rsp),%r9d
- .endif
- movl RCX(%rsp),%ecx
- movl RDX(%rsp),%edx
- movl RSI(%rsp),%esi
- movl RDI(%rsp),%edi
- movl %eax,%eax /* zero extension */
- .endm
-
- .macro CFI_STARTPROC32 simple
- CFI_STARTPROC \simple
- CFI_UNDEFINED r8
- CFI_UNDEFINED r9
- CFI_UNDEFINED r10
- CFI_UNDEFINED r11
- CFI_UNDEFINED r12
- CFI_UNDEFINED r13
- CFI_UNDEFINED r14
- CFI_UNDEFINED r15
- .endm
-
-#ifdef CONFIG_PARAVIRT
-ENTRY(native_usergs_sysret32)
- swapgs
- sysretl
-ENDPROC(native_usergs_sysret32)
-
-ENTRY(native_irq_enable_sysexit)
- swapgs
- sti
- sysexit
-ENDPROC(native_irq_enable_sysexit)
-#endif
-
-/*
- * 32bit SYSENTER instruction entry.
- *
- * SYSENTER loads ss, rsp, cs, and rip from previously programmed MSRs.
- * IF and VM in rflags are cleared (IOW: interrupts are off).
- * SYSENTER does not save anything on the stack,
- * and does not save old rip (!!!) and rflags.
- *
- * Arguments:
- * eax system call number
- * ebx arg1
- * ecx arg2
- * edx arg3
- * esi arg4
- * edi arg5
- * ebp user stack
- * 0(%ebp) arg6
- *
- * This is purely a fast path. For anything complicated we use the int 0x80
- * path below. We set up a complete hardware stack frame to share code
- * with the int 0x80 path.
- */
-ENTRY(ia32_sysenter_target)
- CFI_STARTPROC32 simple
- CFI_SIGNAL_FRAME
- CFI_DEF_CFA rsp,0
- CFI_REGISTER rsp,rbp
-
- /*
- * 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)
-
- /* Zero-extending 32-bit regs, do not remove */
- movl %ebp, %ebp
- movl %eax, %eax
-
- 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
- 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
- */
- ASM_STAC
-1: movl (%rbp),%ebp
- _ASM_EXTABLE(1b,ia32_badarg)
- ASM_CLAC
-
- /*
- * Sysenter doesn't filter flags, so we need to clear NT
- * ourselves. To save a few cycles, we can check whether
- * NT was set instead of doing an unconditional popfq.
- */
- testl $X86_EFLAGS_NT,EFLAGS(%rsp)
- jnz sysenter_fix_flags
-sysenter_flags_fixed:
-
- 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
- ja ia32_badsys
-sysenter_do_call:
- /* 32bit syscall -> 64bit C ABI argument conversion */
- movl %edi,%r8d /* arg5 */
- movl %ebp,%r9d /* arg6 */
- xchg %ecx,%esi /* rsi:arg2, rcx:arg4 */
- movl %ebx,%edi /* arg1 */
- movl %edx,%edx /* arg3 (zero extension) */
-sysenter_dispatch:
- call *ia32_sys_call_table(,%rax,8)
- movq %rax,RAX(%rsp)
- DISABLE_INTERRUPTS(CLBR_NONE)
- TRACE_IRQS_OFF
- testl $_TIF_ALLWORK_MASK, ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)
- jnz sysexit_audit
-sysexit_from_sys_call:
- /*
- * 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
- xorl %edx,%edx /* avoid info leaks */
- xorq %r8,%r8
- xorq %r9,%r9
- xorq %r10,%r10
- movl EFLAGS(%rsp),%r11d /* User eflags */
- /*CFI_RESTORE rflags*/
- TRACE_IRQS_ON
-
- /*
- * 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.
- */
- USERGS_SYSRET32
-
- CFI_RESTORE_STATE
-
-#ifdef CONFIG_AUDITSYSCALL
- .macro auditsys_entry_common
- movl %esi,%r8d /* 5th arg: 4th syscall arg */
- movl %ecx,%r9d /*swap with edx*/
- movl %edx,%ecx /* 4th arg: 3rd syscall arg */
- movl %r9d,%edx /* 3rd arg: 2nd syscall arg */
- movl %ebx,%esi /* 2nd arg: 1st syscall arg */
- movl %eax,%edi /* 1st arg: syscall number */
- call __audit_syscall_entry
- movl RAX(%rsp),%eax /* reload syscall number */
- cmpq $(IA32_NR_syscalls-1),%rax
- ja ia32_badsys
- movl %ebx,%edi /* reload 1st syscall arg */
- movl RCX(%rsp),%esi /* reload 2nd syscall arg */
- movl RDX(%rsp),%edx /* reload 3rd syscall arg */
- movl RSI(%rsp),%ecx /* reload 4th syscall arg */
- movl RDI(%rsp),%r8d /* reload 5th syscall arg */
- .endm
-
- .macro auditsys_exit exit
- 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 %eax,%esi /* second arg, syscall return value */
- cmpl $-MAX_ERRNO,%eax /* is it an error ? */
- jbe 1f
- movslq %eax, %rsi /* if error sign extend to 64 bits */
-1: setbe %al /* 1 if error, 0 if not */
- movzbl %al,%edi /* zero-extend that into %edi */
- call __audit_syscall_exit
- movq RAX(%rsp),%rax /* reload syscall return value */
- movl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT),%edi
- DISABLE_INTERRUPTS(CLBR_NONE)
- TRACE_IRQS_OFF
- testl %edi, ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)
- jz \exit
- CLEAR_RREGS
- jmp int_with_check
- .endm
-
-sysenter_auditsys:
- auditsys_entry_common
- movl %ebp,%r9d /* reload 6th syscall arg */
- jmp sysenter_dispatch
-
-sysexit_audit:
- auditsys_exit sysexit_from_sys_call
-#endif
-
-sysenter_fix_flags:
- pushq_cfi $(X86_EFLAGS_IF|X86_EFLAGS_FIXED)
- popfq_cfi
- jmp sysenter_flags_fixed
-
-sysenter_tracesys:
-#ifdef CONFIG_AUDITSYSCALL
- testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT), ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)
- jz sysenter_auditsys
-#endif
- SAVE_EXTRA_REGS
- CLEAR_RREGS
- movq $-ENOSYS,RAX(%rsp)/* ptrace can change this for a bad syscall */
- movq %rsp,%rdi /* &pt_regs -> arg1 */
- call syscall_trace_enter
- LOAD_ARGS32 /* reload args from stack in case ptrace changed it */
- RESTORE_EXTRA_REGS
- cmpq $(IA32_NR_syscalls-1),%rax
- ja int_ret_from_sys_call /* sysenter_tracesys has set RAX(%rsp) */
- jmp sysenter_do_call
- CFI_ENDPROC
-ENDPROC(ia32_sysenter_target)
-
-/*
- * 32bit SYSCALL instruction entry.
- *
- * 32bit SYSCALL saves rip to rcx, clears rflags.RF, then saves rflags to r11,
- * then loads new ss, cs, and rip from previously programmed MSRs.
- * rflags gets masked by a value from another MSR (so CLD and CLAC
- * are not needed). SYSCALL does not save anything on the stack
- * and does not change rsp.
- *
- * Note: rflags saving+masking-with-MSR happens only in Long mode
- * (in legacy 32bit mode, IF, RF and VM bits are cleared and that's it).
- * Don't get confused: rflags saving+masking depends on Long Mode Active bit
- * (EFER.LMA=1), NOT on bitness of userspace where SYSCALL executes
- * or target CS descriptor's L bit (SYSCALL does not read segment descriptors).
- *
- * Arguments:
- * eax system call number
- * ecx return address
- * ebx arg1
- * ebp arg2 (note: not saved in the stack frame, should not be touched)
- * edx arg3
- * esi arg4
- * edi arg5
- * esp user stack
- * 0(%esp) arg6
- *
- * This is purely a fast path. For anything complicated we use the int 0x80
- * path below. We set up a complete hardware stack frame to share code
- * with the int 0x80 path.
- */
-ENTRY(ia32_cstar_target)
- CFI_STARTPROC32 simple
- CFI_SIGNAL_FRAME
- 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
- ENABLE_INTERRUPTS(CLBR_NONE)
-
- /* 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
- 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
- */
- ASM_STAC
-1: movl (%r8),%r9d
- _ASM_EXTABLE(1b,ia32_badarg)
- ASM_CLAC
- 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
- ja ia32_badsys
-cstar_do_call:
- /* 32bit syscall -> 64bit C ABI argument conversion */
- movl %edi,%r8d /* arg5 */
- /* r9 already loaded */ /* arg6 */
- xchg %ecx,%esi /* rsi:arg2, rcx:arg4 */
- movl %ebx,%edi /* arg1 */
- movl %edx,%edx /* arg3 (zero extension) */
-cstar_dispatch:
- call *ia32_sys_call_table(,%rax,8)
- movq %rax,RAX(%rsp)
- DISABLE_INTERRUPTS(CLBR_NONE)
- TRACE_IRQS_OFF
- testl $_TIF_ALLWORK_MASK, ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)
- jnz sysretl_audit
-sysretl_from_sys_call:
- andl $~TS_COMPAT, ASM_THREAD_INFO(TI_status, %rsp, SIZEOF_PTREGS)
- RESTORE_RSI_RDI_RDX
- movl RIP(%rsp),%ecx
- CFI_REGISTER rip,rcx
- movl EFLAGS(%rsp),%r11d
- /*CFI_REGISTER rflags,r11*/
- xorq %r10,%r10
- xorq %r9,%r9
- xorq %r8,%r8
- TRACE_IRQS_ON
- movl RSP(%rsp),%esp
- CFI_RESTORE rsp
- /*
- * 64bit->32bit SYSRET restores eip from ecx,
- * eflags from r11 (but RF and VM bits are forced to 0),
- * cs and ss are loaded from MSRs.
- * (Note: 32bit->32bit SYSRET is different: since r11
- * does not exist, it merely sets eflags.IF=1).
- *
- * NB: On AMD CPUs with the X86_BUG_SYSRET_SS_ATTRS bug, the ss
- * descriptor is not reinitialized. This means that we must
- * avoid SYSRET with SS == NULL, which could happen if we schedule,
- * exit the kernel, and re-enter using an interrupt vector. (All
- * interrupt entries on x86_64 set SS to NULL.) We prevent that
- * from happening by reloading SS in __switch_to.
- */
- USERGS_SYSRET32
-
-#ifdef CONFIG_AUDITSYSCALL
-cstar_auditsys:
- CFI_RESTORE_STATE
- movl %r9d,R9(%rsp) /* register to be clobbered by call */
- auditsys_entry_common
- movl R9(%rsp),%r9d /* reload 6th syscall arg */
- jmp cstar_dispatch
-
-sysretl_audit:
- auditsys_exit sysretl_from_sys_call
-#endif
-
-cstar_tracesys:
-#ifdef CONFIG_AUDITSYSCALL
- testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT), ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)
- jz cstar_auditsys
-#endif
- xchgl %r9d,%ebp
- SAVE_EXTRA_REGS
- CLEAR_RREGS r9
- movq $-ENOSYS,RAX(%rsp) /* ptrace can change this for a bad syscall */
- movq %rsp,%rdi /* &pt_regs -> arg1 */
- call syscall_trace_enter
- LOAD_ARGS32 1 /* reload args from stack in case ptrace changed it */
- RESTORE_EXTRA_REGS
- xchgl %ebp,%r9d
- cmpq $(IA32_NR_syscalls-1),%rax
- ja int_ret_from_sys_call /* cstar_tracesys has set RAX(%rsp) */
- jmp cstar_do_call
-END(ia32_cstar_target)
-
-ia32_badarg:
- ASM_CLAC
- movq $-EFAULT,%rax
- jmp ia32_sysret
- CFI_ENDPROC
-
-/*
- * Emulated IA32 system calls via int 0x80.
- *
- * Arguments:
- * eax system call number
- * ebx arg1
- * ecx arg2
- * edx arg3
- * esi arg4
- * edi arg5
- * ebp arg6 (note: not saved in the stack frame, should not be touched)
- *
- * Notes:
- * Uses the same stack frame as the x86-64 version.
- * All registers except eax must be saved (but ptrace may violate that).
- * Arguments are zero extended. For system calls that want sign extension and
- * take long arguments a wrapper is needed. Most calls can just be called
- * directly.
- * Assumes it is only called from user space and entered with interrupts off.
- */
-
-ENTRY(ia32_syscall)
- CFI_STARTPROC32 simple
- CFI_SIGNAL_FRAME
- 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
-
- /*
- * 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)
-
- /* 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
- 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
-ia32_do_call:
- /* 32bit syscall -> 64bit C ABI argument conversion */
- movl %edi,%r8d /* arg5 */
- movl %ebp,%r9d /* arg6 */
- xchg %ecx,%esi /* rsi:arg2, rcx:arg4 */
- movl %ebx,%edi /* arg1 */
- movl %edx,%edx /* arg3 (zero extension) */
- call *ia32_sys_call_table(,%rax,8) # xxx: rip relative
-ia32_sysret:
- movq %rax,RAX(%rsp)
-ia32_ret_from_sys_call:
- CLEAR_RREGS
- jmp int_ret_from_sys_call
-
-ia32_tracesys:
- SAVE_EXTRA_REGS
- CLEAR_RREGS
- movq $-ENOSYS,RAX(%rsp) /* ptrace can change this for a bad syscall */
- movq %rsp,%rdi /* &pt_regs -> arg1 */
- call syscall_trace_enter
- LOAD_ARGS32 /* reload args from stack in case ptrace changed it */
- RESTORE_EXTRA_REGS
- cmpq $(IA32_NR_syscalls-1),%rax
- ja int_ret_from_sys_call /* ia32_tracesys has set RAX(%rsp) */
- jmp ia32_do_call
-END(ia32_syscall)
-
-ia32_badsys:
- movq $0,ORIG_RAX(%rsp)
- movq $-ENOSYS,%rax
- jmp ia32_sysret
-
- CFI_ENDPROC
-
- .macro PTREGSCALL label, func
- ALIGN
-GLOBAL(\label)
- leaq \func(%rip),%rax
- jmp ia32_ptregs_common
- .endm
-
- CFI_STARTPROC32
-
- PTREGSCALL stub32_rt_sigreturn, sys32_rt_sigreturn
- PTREGSCALL stub32_sigreturn, sys32_sigreturn
- PTREGSCALL stub32_fork, sys_fork
- PTREGSCALL stub32_vfork, sys_vfork
-
- ALIGN
-GLOBAL(stub32_clone)
- leaq sys_clone(%rip),%rax
- mov %r8, %rcx
- jmp ia32_ptregs_common
-
- ALIGN
-ia32_ptregs_common:
- CFI_ENDPROC
- CFI_STARTPROC32 simple
- CFI_SIGNAL_FRAME
- CFI_DEF_CFA rsp,SIZEOF_PTREGS
- CFI_REL_OFFSET rax,RAX
- CFI_REL_OFFSET rcx,RCX
- CFI_REL_OFFSET rdx,RDX
- CFI_REL_OFFSET rsi,RSI
- CFI_REL_OFFSET rdi,RDI
- CFI_REL_OFFSET rip,RIP
-/* CFI_REL_OFFSET cs,CS*/
-/* CFI_REL_OFFSET rflags,EFLAGS*/
- CFI_REL_OFFSET rsp,RSP
-/* CFI_REL_OFFSET ss,SS*/
- SAVE_EXTRA_REGS 8
- call *%rax
- RESTORE_EXTRA_REGS 8
- ret
- CFI_ENDPROC
-END(ia32_ptregs_common)