From aac82d319148c6a84e1bf90b86d3e0ec8bf0ee38 Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Fri, 3 Apr 2015 15:51:54 -0700 Subject: x86, paravirt, xen: Remove the 64-bit ->irq_enable_sysexit() pvop We don't use irq_enable_sysexit on 64-bit kernels any more. Remove all the paravirt and Xen machinery to support it on 64-bit kernels. Tested-by: Boris Ostrovsky Signed-off-by: Andy Lutomirski Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/8a03355698fe5b94194e9e7360f19f91c1b2cf1f.1428100853.git.luto@kernel.org Signed-off-by: Ingo Molnar --- arch/x86/ia32/ia32entry.S | 6 ------ 1 file changed, 6 deletions(-) (limited to 'arch/x86/ia32') diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S index a821b1c..3cdb9ea 100644 --- a/arch/x86/ia32/ia32entry.S +++ b/arch/x86/ia32/ia32entry.S @@ -77,12 +77,6 @@ ENTRY(native_usergs_sysret32) swapgs sysretl ENDPROC(native_usergs_sysret32) - -ENTRY(native_irq_enable_sysexit) - swapgs - sti - sysexit -ENDPROC(native_irq_enable_sysexit) #endif /* -- cgit v1.1 From 3f5159a9221f19b08275b0a6388ab14392ae4eec Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Tue, 21 Apr 2015 18:03:14 +0200 Subject: x86/asm/entry/32: Update -ENOSYS handling to match the 64-bit logic Recently Andy changed the 64-bit syscall logic so that pt_regs->ax is initially set to -ENOSYS, and on syscall exit, it is updated with the actual return value. This simplified the logic there. This patch does the same for 32-bit syscall entry points. The check for %rax being too big is moved to be just before the call instruction which dispatches execution through the syscall table. There is no way to accidentally skip this check now by jumping to a label after it. This allows us to remove redundant checks after ptrace et al. If %rax is too big, we just skip over the (call, write %rax to pt_regs->ax) instruction pair. pt_regs->ax remains set to -ENOSYS, and it gets returned to userspace. Similar to 64-bit code, this eliminates the "ia32_badsys" code path. Run-tested. Signed-off-by: Denys Vlasenko Cc: Alexei Starovoitov Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Frederic Weisbecker Cc: H. Peter Anvin Cc: Kees Cook Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Steven Rostedt Cc: Will Drewry Link: http://lkml.kernel.org/r/1429632194-13445-2-git-send-email-dvlasenk@redhat.com [ Changelog massage. ] Signed-off-by: Ingo Molnar --- arch/x86/ia32/ia32entry.S | 42 ++++++++++++++---------------------------- 1 file changed, 14 insertions(+), 28 deletions(-) (limited to 'arch/x86/ia32') diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S index 3cdb9ea..56fd6dd 100644 --- a/arch/x86/ia32/ia32entry.S +++ b/arch/x86/ia32/ia32entry.S @@ -136,7 +136,7 @@ ENTRY(ia32_sysenter_target) 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 */ + pushq_cfi $-ENOSYS /* pt_regs->ax */ cld sub $(10*8),%rsp /* pt_regs->r8-11,bp,bx,r12-15 not saved */ CFI_ADJUST_CFA_OFFSET 10*8 @@ -163,8 +163,6 @@ sysenter_flags_fixed: 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 */ @@ -173,8 +171,11 @@ sysenter_do_call: movl %ebx,%edi /* arg1 */ movl %edx,%edx /* arg3 (zero extension) */ sysenter_dispatch: + cmpq $(IA32_NR_syscalls-1),%rax + ja 1f call *ia32_sys_call_table(,%rax,8) movq %rax,RAX(%rsp) +1: DISABLE_INTERRUPTS(CLBR_NONE) TRACE_IRQS_OFF testl $_TIF_ALLWORK_MASK, ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS) @@ -241,9 +242,7 @@ sysexit_from_sys_call: 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 ORIG_RAX(%rsp),%eax /* reload syscall number */ movl %ebx,%edi /* reload 1st syscall arg */ movl RCX(%rsp),%esi /* reload 2nd syscall arg */ movl RDX(%rsp),%edx /* reload 3rd syscall arg */ @@ -294,13 +293,10 @@ sysenter_tracesys: #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) @@ -370,7 +366,7 @@ ENTRY(ia32_cstar_target) pushq_cfi_reg rdx /* pt_regs->dx */ pushq_cfi_reg rbp /* pt_regs->cx */ movl %ebp,%ecx - pushq_cfi_reg rax /* pt_regs->ax */ + pushq_cfi $-ENOSYS /* pt_regs->ax */ sub $(10*8),%rsp /* pt_regs->r8-11,bp,bx,r12-15 not saved */ CFI_ADJUST_CFA_OFFSET 10*8 @@ -386,8 +382,6 @@ ENTRY(ia32_cstar_target) 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 */ @@ -396,8 +390,11 @@ cstar_do_call: movl %ebx,%edi /* arg1 */ movl %edx,%edx /* arg3 (zero extension) */ cstar_dispatch: + cmpq $(IA32_NR_syscalls-1),%rax + ja 1f call *ia32_sys_call_table(,%rax,8) movq %rax,RAX(%rsp) +1: DISABLE_INTERRUPTS(CLBR_NONE) TRACE_IRQS_OFF testl $_TIF_ALLWORK_MASK, ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS) @@ -444,14 +441,11 @@ cstar_tracesys: 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) @@ -510,7 +504,7 @@ ENTRY(ia32_syscall) 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 */ + pushq_cfi $-ENOSYS /* pt_regs->ax */ cld sub $(10*8),%rsp /* pt_regs->r8-11,bp,bx,r12-15 not saved */ CFI_ADJUST_CFA_OFFSET 10*8 @@ -518,8 +512,6 @@ ENTRY(ia32_syscall) 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 */ @@ -527,9 +519,12 @@ ia32_do_call: xchg %ecx,%esi /* rsi:arg2, rcx:arg4 */ movl %ebx,%edi /* arg1 */ movl %edx,%edx /* arg3 (zero extension) */ + cmpq $(IA32_NR_syscalls-1),%rax + ja 1f call *ia32_sys_call_table(,%rax,8) # xxx: rip relative ia32_sysret: movq %rax,RAX(%rsp) +1: ia32_ret_from_sys_call: CLEAR_RREGS jmp int_ret_from_sys_call @@ -537,23 +532,14 @@ ia32_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 + CFI_ENDPROC 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) -- cgit v1.1 From 63332a8455d8310b77d38779c6c21a660a8d9feb Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Fri, 24 Apr 2015 17:31:33 +0200 Subject: x86/entry: Stop using PER_CPU_VAR(kernel_stack) PER_CPU_VAR(kernel_stack) is redundant: - On the 64-bit build, we can use PER_CPU_VAR(cpu_tss + TSS_sp0). - On the 32-bit build, we can use PER_CPU_VAR(cpu_current_top_of_stack). PER_CPU_VAR(kernel_stack) will be deleted by a separate change. Signed-off-by: Denys Vlasenko Cc: Alexei Starovoitov Cc: Andrew Morton Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Frederic Weisbecker Cc: H. Peter Anvin Cc: Kees Cook Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Thomas Gleixner Cc: Will Drewry Link: http://lkml.kernel.org/r/1429889495-27850-1-git-send-email-dvlasenk@redhat.com Signed-off-by: Ingo Molnar --- arch/x86/ia32/ia32entry.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86/ia32') diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S index 2ab0f71..1b1330c 100644 --- a/arch/x86/ia32/ia32entry.S +++ b/arch/x86/ia32/ia32entry.S @@ -346,7 +346,7 @@ ENTRY(ia32_cstar_target) SWAPGS_UNSAFE_STACK movl %esp,%r8d CFI_REGISTER rsp,r8 - movq PER_CPU_VAR(kernel_stack),%rsp + movq PER_CPU_VAR(cpu_tss + TSS_sp0),%rsp ENABLE_INTERRUPTS(CLBR_NONE) /* Zero-extending 32-bit regs, do not remove */ -- cgit v1.1 From 3a23208e69679597e767cf3547b1a30dd845d9b5 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Fri, 24 Apr 2015 17:31:35 +0200 Subject: x86/entry: Define 'cpu_current_top_of_stack' for 64-bit code 32-bit code has PER_CPU_VAR(cpu_current_top_of_stack). 64-bit code uses somewhat more obscure: PER_CPU_VAR(cpu_tss + TSS_sp0). Define the 'cpu_current_top_of_stack' macro on CONFIG_X86_64 as well so that the PER_CPU_VAR(cpu_current_top_of_stack) expression can be used in both 32-bit and 64-bit code. Signed-off-by: Denys Vlasenko Cc: Alexei Starovoitov Cc: Andrew Morton Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Frederic Weisbecker Cc: H. Peter Anvin Cc: Kees Cook Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Thomas Gleixner Cc: Will Drewry Link: http://lkml.kernel.org/r/1429889495-27850-3-git-send-email-dvlasenk@redhat.com Signed-off-by: Ingo Molnar --- arch/x86/ia32/ia32entry.S | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/x86/ia32') diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S index 1b1330c..63450a5 100644 --- a/arch/x86/ia32/ia32entry.S +++ b/arch/x86/ia32/ia32entry.S @@ -113,7 +113,7 @@ ENTRY(ia32_sysenter_target) * it is too small to ever cause noticeable irq latency. */ SWAPGS_UNSAFE_STACK - movq PER_CPU_VAR(cpu_tss + TSS_sp0), %rsp + movq PER_CPU_VAR(cpu_current_top_of_stack), %rsp ENABLE_INTERRUPTS(CLBR_NONE) /* Zero-extending 32-bit regs, do not remove */ @@ -346,7 +346,7 @@ ENTRY(ia32_cstar_target) SWAPGS_UNSAFE_STACK movl %esp,%r8d CFI_REGISTER rsp,r8 - movq PER_CPU_VAR(cpu_tss + TSS_sp0),%rsp + movq PER_CPU_VAR(cpu_current_top_of_stack),%rsp ENABLE_INTERRUPTS(CLBR_NONE) /* Zero-extending 32-bit regs, do not remove */ -- cgit v1.1 From 131484c8da97ed600c18dd9d03b661e8ae052df6 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Thu, 28 May 2015 12:21:47 +0200 Subject: x86/debug: Remove perpetually broken, unmaintainable dwarf annotations MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit So the dwarf2 annotations in low level assembly code have become an increasing hindrance: unreadable, messy macros mixed into some of the most security sensitive code paths of the Linux kernel. These debug info annotations don't even buy the upstream kernel anything: dwarf driven stack unwinding has caused problems in the past so it's out of tree, and the upstream kernel only uses the much more robust framepointers based stack unwinding method. In addition to that there's a steady, slow bitrot going on with these annotations, requiring frequent fixups. There's no tooling and no functionality upstream that keeps it correct. So burn down the sick forest, allowing new, healthier growth: 27 files changed, 350 insertions(+), 1101 deletions(-) Someone who has the willingness and time to do this properly can attempt to reintroduce dwarf debuginfo in x86 assembly code plus dwarf unwinding from first principles, with the following conditions: - it should be maximally readable, and maximally low-key to 'ordinary' code reading and maintenance. - find a build time method to insert dwarf annotations automatically in the most common cases, for pop/push instructions that manipulate the stack pointer. This could be done for example via a preprocessing step that just looks for common patterns - plus special annotations for the few cases where we want to depart from the default. We have hundreds of CFI annotations, so automating most of that makes sense. - it should come with build tooling checks that ensure that CFI annotations are sensible. We've seen such efforts from the framepointer side, and there's no reason it couldn't be done on the dwarf side. Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: Frédéric Weisbecker Cc: Jan Beulich Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar --- arch/x86/ia32/ia32entry.S | 133 +++++++++++----------------------------------- 1 file changed, 32 insertions(+), 101 deletions(-) (limited to 'arch/x86/ia32') diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S index 63450a5..2be23c7 100644 --- a/arch/x86/ia32/ia32entry.S +++ b/arch/x86/ia32/ia32entry.S @@ -4,7 +4,6 @@ * Copyright 2000-2002 Andi Kleen, SuSE Labs. */ -#include #include #include #include @@ -60,17 +59,6 @@ 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) @@ -102,11 +90,6 @@ ENDPROC(native_usergs_sysret32) * 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, @@ -121,25 +104,21 @@ ENTRY(ia32_sysenter_target) 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 $-ENOSYS /* pt_regs->ax */ + pushq $__USER32_DS /* pt_regs->ss */ + pushq %rbp /* pt_regs->sp */ + pushfq /* pt_regs->flags */ + pushq $__USER32_CS /* pt_regs->cs */ + pushq %r10 /* pt_regs->ip = thread_info->sysenter_return */ + pushq %rax /* pt_regs->orig_ax */ + pushq %rdi /* pt_regs->di */ + pushq %rsi /* pt_regs->si */ + pushq %rdx /* pt_regs->dx */ + pushq %rcx /* pt_regs->cx */ + pushq $-ENOSYS /* 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 @@ -161,8 +140,8 @@ 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 + sysenter_do_call: /* 32bit syscall -> 64bit C ABI argument conversion */ movl %edi,%r8d /* arg5 */ @@ -193,14 +172,12 @@ sysexit_from_sys_call: */ 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 /* @@ -231,8 +208,6 @@ sysexit_from_sys_call: */ USERGS_SYSRET32 - CFI_RESTORE_STATE - #ifdef CONFIG_AUDITSYSCALL .macro auditsys_entry_common movl %esi,%r8d /* 5th arg: 4th syscall arg */ @@ -282,8 +257,8 @@ sysexit_audit: #endif sysenter_fix_flags: - pushq_cfi $(X86_EFLAGS_IF|X86_EFLAGS_FIXED) - popfq_cfi + pushq $(X86_EFLAGS_IF|X86_EFLAGS_FIXED) + popfq jmp sysenter_flags_fixed sysenter_tracesys: @@ -298,7 +273,6 @@ sysenter_tracesys: LOAD_ARGS32 /* reload args from stack in case ptrace changed it */ RESTORE_EXTRA_REGS jmp sysenter_do_call - CFI_ENDPROC ENDPROC(ia32_sysenter_target) /* @@ -332,12 +306,6 @@ ENDPROC(ia32_sysenter_target) * 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, @@ -345,7 +313,6 @@ ENTRY(ia32_cstar_target) */ SWAPGS_UNSAFE_STACK movl %esp,%r8d - CFI_REGISTER rsp,r8 movq PER_CPU_VAR(cpu_current_top_of_stack),%rsp ENABLE_INTERRUPTS(CLBR_NONE) @@ -353,22 +320,19 @@ ENTRY(ia32_cstar_target) 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 */ + pushq $__USER32_DS /* pt_regs->ss */ + pushq %r8 /* pt_regs->sp */ + pushq %r11 /* pt_regs->flags */ + pushq $__USER32_CS /* pt_regs->cs */ + pushq %rcx /* pt_regs->ip */ + pushq %rax /* pt_regs->orig_ax */ + pushq %rdi /* pt_regs->di */ + pushq %rsi /* pt_regs->si */ + pushq %rdx /* pt_regs->dx */ + pushq %rbp /* pt_regs->cx */ movl %ebp,%ecx - pushq_cfi $-ENOSYS /* pt_regs->ax */ + pushq $-ENOSYS /* 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 @@ -380,8 +344,8 @@ ENTRY(ia32_cstar_target) 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 + cstar_do_call: /* 32bit syscall -> 64bit C ABI argument conversion */ movl %edi,%r8d /* arg5 */ @@ -403,15 +367,12 @@ 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), @@ -430,7 +391,6 @@ sysretl_from_sys_call: #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 */ @@ -460,7 +420,6 @@ ia32_badarg: ASM_CLAC movq $-EFAULT,%rax jmp ia32_sysret - CFI_ENDPROC /* * Emulated IA32 system calls via int 0x80. @@ -484,15 +443,6 @@ ia32_badarg: */ 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, @@ -506,15 +456,14 @@ ENTRY(ia32_syscall) 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 $-ENOSYS /* pt_regs->ax */ + pushq %rax /* pt_regs->orig_ax */ + pushq %rdi /* pt_regs->di */ + pushq %rsi /* pt_regs->si */ + pushq %rdx /* pt_regs->dx */ + pushq %rcx /* pt_regs->cx */ + pushq $-ENOSYS /* 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 $_TIF_WORK_SYSCALL_ENTRY, ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS) @@ -544,7 +493,6 @@ ia32_tracesys: LOAD_ARGS32 /* reload args from stack in case ptrace changed it */ RESTORE_EXTRA_REGS jmp ia32_do_call - CFI_ENDPROC END(ia32_syscall) .macro PTREGSCALL label, func @@ -554,8 +502,6 @@ GLOBAL(\label) jmp ia32_ptregs_common .endm - CFI_STARTPROC32 - PTREGSCALL stub32_rt_sigreturn, sys32_rt_sigreturn PTREGSCALL stub32_sigreturn, sys32_sigreturn PTREGSCALL stub32_fork, sys_fork @@ -569,23 +515,8 @@ GLOBAL(stub32_clone) ALIGN ia32_ptregs_common: - CFI_ENDPROC - CFI_STARTPROC32 simple - CFI_SIGNAL_FRAME - CFI_DEF_CFA rsp,SIZEOF_PTREGS - CFI_REL_OFFSET rax,RAX - CFI_REL_OFFSET rcx,RCX - CFI_REL_OFFSET rdx,RDX - CFI_REL_OFFSET rsi,RSI - CFI_REL_OFFSET rdi,RDI - CFI_REL_OFFSET rip,RIP -/* CFI_REL_OFFSET cs,CS*/ -/* CFI_REL_OFFSET rflags,EFLAGS*/ - CFI_REL_OFFSET rsp,RSP -/* CFI_REL_OFFSET ss,SS*/ SAVE_EXTRA_REGS 8 call *%rax RESTORE_EXTRA_REGS 8 ret - CFI_ENDPROC END(ia32_ptregs_common) -- cgit v1.1 From 19a433f45135656d065bdf1bbe543796b194ba3a Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Wed, 3 Jun 2015 18:00:59 +0200 Subject: x86/asm/entry: Move the compat syscall entry code to arch/x86/entry/ Move the ia32entry.S file over into arch/x86/entry/. Cc: Borislav Petkov Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Thomas Gleixner Cc: Andy Lutomirski Cc: Denys Vlasenko Cc: Brian Gerst Cc: Peter Zijlstra Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar --- arch/x86/ia32/Makefile | 2 +- arch/x86/ia32/ia32entry.S | 522 ---------------------------------------------- 2 files changed, 1 insertion(+), 523 deletions(-) delete mode 100644 arch/x86/ia32/ia32entry.S (limited to 'arch/x86/ia32') diff --git a/arch/x86/ia32/Makefile b/arch/x86/ia32/Makefile index bb635c6..cd4339b 100644 --- a/arch/x86/ia32/Makefile +++ b/arch/x86/ia32/Makefile @@ -2,7 +2,7 @@ # Makefile for the ia32 kernel emulation subsystem. # -obj-$(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 2be23c7..0000000 --- a/arch/x86/ia32/ia32entry.S +++ /dev/null @@ -1,522 +0,0 @@ -/* - * Compatibility mode system call entry point for x86-64. - * - * Copyright 2000-2002 Andi Kleen, SuSE Labs. - */ - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -/* Avoid __ASSEMBLER__'ifying just for this. */ -#include -#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 - - -#ifdef CONFIG_PARAVIRT -ENTRY(native_usergs_sysret32) - swapgs - sysretl -ENDPROC(native_usergs_sysret32) -#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) - /* - * 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_current_top_of_stack), %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 - - /* Construct struct pt_regs on stack */ - pushq $__USER32_DS /* pt_regs->ss */ - pushq %rbp /* pt_regs->sp */ - pushfq /* pt_regs->flags */ - pushq $__USER32_CS /* pt_regs->cs */ - pushq %r10 /* pt_regs->ip = thread_info->sysenter_return */ - pushq %rax /* pt_regs->orig_ax */ - pushq %rdi /* pt_regs->di */ - pushq %rsi /* pt_regs->si */ - pushq %rdx /* pt_regs->dx */ - pushq %rcx /* pt_regs->cx */ - pushq $-ENOSYS /* pt_regs->ax */ - cld - sub $(10*8),%rsp /* pt_regs->r8-11,bp,bx,r12-15 not saved */ - - /* - * 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) - jnz sysenter_tracesys - -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: - cmpq $(IA32_NR_syscalls-1),%rax - ja 1f - call *ia32_sys_call_table(,%rax,8) - movq %rax,RAX(%rsp) -1: - 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 */ - RESTORE_RSI_RDI - xorl %edx,%edx /* avoid info leaks */ - xorq %r8,%r8 - xorq %r9,%r9 - xorq %r10,%r10 - movl EFLAGS(%rsp),%r11d /* User eflags */ - 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 - -#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 ORIG_RAX(%rsp),%eax /* reload syscall number */ - 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 $(X86_EFLAGS_IF|X86_EFLAGS_FIXED) - popfq - 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 %rsp,%rdi /* &pt_regs -> arg1 */ - call syscall_trace_enter - LOAD_ARGS32 /* reload args from stack in case ptrace changed it */ - RESTORE_EXTRA_REGS - jmp sysenter_do_call -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) - /* - * 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 - movq PER_CPU_VAR(cpu_current_top_of_stack),%rsp - ENABLE_INTERRUPTS(CLBR_NONE) - - /* Zero-extending 32-bit regs, do not remove */ - movl %eax,%eax - - /* Construct struct pt_regs on stack */ - pushq $__USER32_DS /* pt_regs->ss */ - pushq %r8 /* pt_regs->sp */ - pushq %r11 /* pt_regs->flags */ - pushq $__USER32_CS /* pt_regs->cs */ - pushq %rcx /* pt_regs->ip */ - pushq %rax /* pt_regs->orig_ax */ - pushq %rdi /* pt_regs->di */ - pushq %rsi /* pt_regs->si */ - pushq %rdx /* pt_regs->dx */ - pushq %rbp /* pt_regs->cx */ - movl %ebp,%ecx - pushq $-ENOSYS /* pt_regs->ax */ - sub $(10*8),%rsp /* pt_regs->r8-11,bp,bx,r12-15 not saved */ - - /* - * 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) - jnz cstar_tracesys - -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: - cmpq $(IA32_NR_syscalls-1),%rax - ja 1f - call *ia32_sys_call_table(,%rax,8) - movq %rax,RAX(%rsp) -1: - 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 - movl EFLAGS(%rsp),%r11d - xorq %r10,%r10 - xorq %r9,%r9 - xorq %r8,%r8 - TRACE_IRQS_ON - movl RSP(%rsp),%esp - /* - * 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: - 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 %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 - jmp cstar_do_call -END(ia32_cstar_target) - -ia32_badarg: - ASM_CLAC - movq $-EFAULT,%rax - jmp ia32_sysret - -/* - * 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) - /* - * 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 %rax /* pt_regs->orig_ax */ - pushq %rdi /* pt_regs->di */ - pushq %rsi /* pt_regs->si */ - pushq %rdx /* pt_regs->dx */ - pushq %rcx /* pt_regs->cx */ - pushq $-ENOSYS /* pt_regs->ax */ - cld - sub $(10*8),%rsp /* pt_regs->r8-11,bp,bx,r12-15 not saved */ - - 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 -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) */ - cmpq $(IA32_NR_syscalls-1),%rax - ja 1f - call *ia32_sys_call_table(,%rax,8) # xxx: rip relative -ia32_sysret: - movq %rax,RAX(%rsp) -1: -ia32_ret_from_sys_call: - CLEAR_RREGS - jmp int_ret_from_sys_call - -ia32_tracesys: - SAVE_EXTRA_REGS - CLEAR_RREGS - movq %rsp,%rdi /* &pt_regs -> arg1 */ - call syscall_trace_enter - LOAD_ARGS32 /* reload args from stack in case ptrace changed it */ - RESTORE_EXTRA_REGS - jmp ia32_do_call -END(ia32_syscall) - - .macro PTREGSCALL label, func - ALIGN -GLOBAL(\label) - leaq \func(%rip),%rax - jmp ia32_ptregs_common - .endm - - 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: - SAVE_EXTRA_REGS 8 - call *%rax - RESTORE_EXTRA_REGS 8 - ret -END(ia32_ptregs_common) -- cgit v1.1