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-rw-r--r--arch/x86/ia32/Makefile1
-rw-r--r--arch/x86/ia32/ia32_signal.c19
-rw-r--r--arch/x86/ia32/ia32entry.S492
-rw-r--r--arch/x86/ia32/nosyscall.c7
-rw-r--r--arch/x86/ia32/sys_ia32.c14
-rw-r--r--arch/x86/ia32/syscall_ia32.c25
6 files changed, 302 insertions, 256 deletions
diff --git a/arch/x86/ia32/Makefile b/arch/x86/ia32/Makefile
index e785b422b766..bb635c641869 100644
--- a/arch/x86/ia32/Makefile
+++ b/arch/x86/ia32/Makefile
@@ -3,7 +3,6 @@
#
obj-$(CONFIG_IA32_EMULATION) := ia32entry.o sys_ia32.o ia32_signal.o
-obj-$(CONFIG_IA32_EMULATION) += nosyscall.o syscall_ia32.o
obj-$(CONFIG_IA32_AOUT) += ia32_aout.o
diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index d0165c9a2932..c81d35e6c7f1 100644
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/ia32/ia32_signal.c
@@ -161,8 +161,7 @@ int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from)
}
static int ia32_restore_sigcontext(struct pt_regs *regs,
- struct sigcontext_ia32 __user *sc,
- unsigned int *pax)
+ struct sigcontext_ia32 __user *sc)
{
unsigned int tmpflags, err = 0;
void __user *buf;
@@ -184,7 +183,7 @@ static int ia32_restore_sigcontext(struct pt_regs *regs,
RELOAD_SEG(es);
COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
- COPY(dx); COPY(cx); COPY(ip);
+ COPY(dx); COPY(cx); COPY(ip); COPY(ax);
/* Don't touch extended registers */
COPY_SEG_CPL3(cs);
@@ -197,12 +196,12 @@ static int ia32_restore_sigcontext(struct pt_regs *regs,
get_user_ex(tmp, &sc->fpstate);
buf = compat_ptr(tmp);
-
- get_user_ex(*pax, &sc->ax);
} get_user_catch(err);
err |= restore_xstate_sig(buf, 1);
+ force_iret();
+
return err;
}
@@ -211,7 +210,6 @@ asmlinkage long sys32_sigreturn(void)
struct pt_regs *regs = current_pt_regs();
struct sigframe_ia32 __user *frame = (struct sigframe_ia32 __user *)(regs->sp-8);
sigset_t set;
- unsigned int ax;
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
@@ -224,9 +222,9 @@ asmlinkage long sys32_sigreturn(void)
set_current_blocked(&set);
- if (ia32_restore_sigcontext(regs, &frame->sc, &ax))
+ if (ia32_restore_sigcontext(regs, &frame->sc))
goto badframe;
- return ax;
+ return regs->ax;
badframe:
signal_fault(regs, frame, "32bit sigreturn");
@@ -238,7 +236,6 @@ asmlinkage long sys32_rt_sigreturn(void)
struct pt_regs *regs = current_pt_regs();
struct rt_sigframe_ia32 __user *frame;
sigset_t set;
- unsigned int ax;
frame = (struct rt_sigframe_ia32 __user *)(regs->sp - 4);
@@ -249,13 +246,13 @@ asmlinkage long sys32_rt_sigreturn(void)
set_current_blocked(&set);
- if (ia32_restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))
+ if (ia32_restore_sigcontext(regs, &frame->uc.uc_mcontext))
goto badframe;
if (compat_restore_altstack(&frame->uc.uc_stack))
goto badframe;
- return ax;
+ return regs->ax;
badframe:
signal_fault(regs, frame, "32bit rt sigreturn");
diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S
index 156ebcab4ada..72bf2680f819 100644
--- a/arch/x86/ia32/ia32entry.S
+++ b/arch/x86/ia32/ia32entry.S
@@ -30,24 +30,13 @@
.section .entry.text, "ax"
- .macro IA32_ARG_FIXUP noebp=0
- movl %edi,%r8d
- .if \noebp
- .else
- movl %ebp,%r9d
- .endif
- xchg %ecx,%esi
- movl %ebx,%edi
- movl %edx,%edx /* zero extension */
- .endm
-
- /* clobbers %eax */
- .macro CLEAR_RREGS offset=0, _r9=rax
+ /* clobbers %rax */
+ .macro CLEAR_RREGS _r9=rax
xorl %eax,%eax
- movq %rax,\offset+R11(%rsp)
- movq %rax,\offset+R10(%rsp)
- movq %\_r9,\offset+R9(%rsp)
- movq %rax,\offset+R8(%rsp)
+ movq %rax,R11(%rsp)
+ movq %rax,R10(%rsp)
+ movq %\_r9,R9(%rsp)
+ movq %rax,R8(%rsp)
.endm
/*
@@ -60,14 +49,14 @@
* If it's -1 to make us punt the syscall, then (u32)-1 is still
* an appropriately invalid value.
*/
- .macro LOAD_ARGS32 offset, _r9=0
+ .macro LOAD_ARGS32 _r9=0
.if \_r9
- movl \offset+16(%rsp),%r9d
+ movl R9(%rsp),%r9d
.endif
- movl \offset+40(%rsp),%ecx
- movl \offset+48(%rsp),%edx
- movl \offset+56(%rsp),%esi
- movl \offset+64(%rsp),%edi
+ movl RCX(%rsp),%ecx
+ movl RDX(%rsp),%edx
+ movl RSI(%rsp),%esi
+ movl RDI(%rsp),%edi
movl %eax,%eax /* zero extension */
.endm
@@ -99,54 +88,69 @@ ENDPROC(native_irq_enable_sysexit)
/*
* 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
- *
- * Interrupts off.
- *
+ * 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. Set up a complete hardware stack frame to share code
+ * 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
- SWAPGS_UNSAFE_STACK
- movq PER_CPU_VAR(kernel_stack), %rsp
- addq $(KERNEL_STACK_OFFSET),%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)
- 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
- pushq_cfi %r10
- CFI_REL_OFFSET rip,0
- pushq_cfi %rax
+
+ 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
- SAVE_ARGS 0,1,0
- /* no need to do an access_ok check here because rbp has been
- 32bit zero extended */
+ 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)
@@ -157,42 +161,80 @@ ENTRY(ia32_sysenter_target)
* ourselves. To save a few cycles, we can check whether
* NT was set instead of doing an unconditional popfq.
*/
- testl $X86_EFLAGS_NT,EFLAGS-ARGOFFSET(%rsp)
+ testl $X86_EFLAGS_NT,EFLAGS(%rsp)
jnz sysenter_fix_flags
sysenter_flags_fixed:
- orl $TS_COMPAT,TI_status+THREAD_INFO(%rsp,RIP-ARGOFFSET)
- testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags+THREAD_INFO(%rsp,RIP-ARGOFFSET)
+ 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:
- IA32_ARG_FIXUP
+ /* 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-ARGOFFSET(%rsp)
+ movq %rax,RAX(%rsp)
DISABLE_INTERRUPTS(CLBR_NONE)
TRACE_IRQS_OFF
- testl $_TIF_ALLWORK_MASK,TI_flags+THREAD_INFO(%rsp,RIP-ARGOFFSET)
+ 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-ARGOFFSET)
- /* clear IF, that popfq doesn't enable interrupts early */
- andl $~0x200,EFLAGS-ARGOFFSET(%rsp)
- movl RIP-ARGOFFSET(%rsp),%edx /* User %eip */
- CFI_REGISTER rip,rdx
- RESTORE_ARGS 0,24,0,0,0,0
+ /*
+ * 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
- 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
- ENABLE_INTERRUPTS_SYSEXIT32
+
+ /*
+ * 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
@@ -205,18 +247,18 @@ 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-ARGOFFSET(%rsp),%eax /* reload syscall number */
+ 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-ARGOFFSET(%rsp),%esi /* reload 2nd syscall arg */
- movl RDX-ARGOFFSET(%rsp),%edx /* reload 3rd syscall arg */
- movl RSI-ARGOFFSET(%rsp),%ecx /* reload 4th syscall arg */
- movl RDI-ARGOFFSET(%rsp),%r8d /* reload 5th 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),TI_flags+THREAD_INFO(%rsp,RIP-ARGOFFSET)
+ 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)
@@ -227,13 +269,13 @@ sysexit_from_sys_call:
1: setbe %al /* 1 if error, 0 if not */
movzbl %al,%edi /* zero-extend that into %edi */
call __audit_syscall_exit
- movq RAX-ARGOFFSET(%rsp),%rax /* reload syscall return value */
+ 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,TI_flags+THREAD_INFO(%rsp,RIP-ARGOFFSET)
+ testl %edi, ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)
jz \exit
- CLEAR_RREGS -ARGOFFSET
+ CLEAR_RREGS
jmp int_with_check
.endm
@@ -253,16 +295,16 @@ sysenter_fix_flags:
sysenter_tracesys:
#ifdef CONFIG_AUDITSYSCALL
- testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT),TI_flags+THREAD_INFO(%rsp,RIP-ARGOFFSET)
+ testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT), ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)
jz sysenter_auditsys
#endif
- SAVE_REST
+ 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 ARGOFFSET /* reload args from stack in case ptrace changed it */
- RESTORE_REST
+ 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
@@ -272,94 +314,135 @@ 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.
- * %ebx Arg1
- * %ecx return EIP
- * %edx Arg3
- * %esi Arg4
- * %edi Arg5
- * %ebp Arg2 [note: not saved in the stack frame, should not be touched]
- * %esp user stack
- * 0(%esp) Arg6
- *
- * Interrupts off.
- *
+ * 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. Set up a complete hardware stack frame to share code
- * with the int 0x80 path.
- */
+ * 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,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)
- SAVE_ARGS 8,0,0
- movl %eax,%eax /* zero extension */
- movq %rax,ORIG_RAX-ARGOFFSET(%rsp)
- movq %rcx,RIP-ARGOFFSET(%rsp)
- CFI_REL_OFFSET rip,RIP-ARGOFFSET
- movq %rbp,RCX-ARGOFFSET(%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-ARGOFFSET(%rsp)
- movq $__USER32_DS,SS-ARGOFFSET(%rsp)
- movq %r11,EFLAGS-ARGOFFSET(%rsp)
- /*CFI_REL_OFFSET rflags,EFLAGS-ARGOFFSET*/
- movq %r8,RSP-ARGOFFSET(%rsp)
- CFI_REL_OFFSET rsp,RSP-ARGOFFSET
- /* no need to do an access_ok check here because r8 has been
- 32bit zero extended */
- /* hardware 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
+ */
ASM_STAC
1: movl (%r8),%r9d
_ASM_EXTABLE(1b,ia32_badarg)
ASM_CLAC
- orl $TS_COMPAT,TI_status+THREAD_INFO(%rsp,RIP-ARGOFFSET)
- testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags+THREAD_INFO(%rsp,RIP-ARGOFFSET)
+ 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:
- IA32_ARG_FIXUP 1
+ /* 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-ARGOFFSET(%rsp)
+ movq %rax,RAX(%rsp)
DISABLE_INTERRUPTS(CLBR_NONE)
TRACE_IRQS_OFF
- testl $_TIF_ALLWORK_MASK,TI_flags+THREAD_INFO(%rsp,RIP-ARGOFFSET)
+ 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-ARGOFFSET)
- RESTORE_ARGS 0,-ARG_SKIP,0,0,0
- movl RIP-ARGOFFSET(%rsp),%ecx
+ 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-ARGOFFSET(%rsp),%r11d
+ movl EFLAGS(%rsp),%r11d
/*CFI_REGISTER rflags,r11*/
xorq %r10,%r10
xorq %r9,%r9
xorq %r8,%r8
TRACE_IRQS_ON
- movl RSP-ARGOFFSET(%rsp),%esp
+ 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-ARGOFFSET(%rsp) /* register to be clobbered by call */
+ movl %r9d,R9(%rsp) /* register to be clobbered by call */
auditsys_entry_common
- movl R9-ARGOFFSET(%rsp),%r9d /* reload 6th syscall arg */
+ movl R9(%rsp),%r9d /* reload 6th syscall arg */
jmp cstar_dispatch
sysretl_audit:
@@ -368,17 +451,17 @@ sysretl_audit:
cstar_tracesys:
#ifdef CONFIG_AUDITSYSCALL
- testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT),TI_flags+THREAD_INFO(%rsp,RIP-ARGOFFSET)
+ testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT), ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)
jz cstar_auditsys
#endif
xchgl %r9d,%ebp
- SAVE_REST
- CLEAR_RREGS 0, r9
+ 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 ARGOFFSET, 1 /* reload args from stack in case ptrace changed it */
- RESTORE_REST
+ 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) */
@@ -391,78 +474,94 @@ ia32_badarg:
jmp ia32_sysret
CFI_ENDPROC
-/*
- * Emulated IA32 system calls via int 0x80.
+/*
+ * 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]
+ * 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)
+ * 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.
- */
+ * 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,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
+
+ /* 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. */
- SAVE_ARGS 0,1,0
- orl $TS_COMPAT,TI_status+THREAD_INFO(%rsp,RIP-ARGOFFSET)
- testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags+THREAD_INFO(%rsp,RIP-ARGOFFSET)
+ 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:
- IA32_ARG_FIXUP
+ /* 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-ARGOFFSET(%rsp)
+ movq %rax,RAX(%rsp)
ia32_ret_from_sys_call:
- CLEAR_RREGS -ARGOFFSET
- jmp int_ret_from_sys_call
+ CLEAR_RREGS
+ jmp int_ret_from_sys_call
-ia32_tracesys:
- SAVE_REST
+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 ARGOFFSET /* reload args from stack in case ptrace changed it */
- RESTORE_REST
+ 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-ARGOFFSET(%rsp)
+ movq $0,ORIG_RAX(%rsp)
movq $-ENOSYS,%rax
jmp ia32_sysret
@@ -479,8 +578,6 @@ GLOBAL(\label)
PTREGSCALL stub32_rt_sigreturn, sys32_rt_sigreturn
PTREGSCALL stub32_sigreturn, sys32_sigreturn
- PTREGSCALL stub32_execve, compat_sys_execve
- PTREGSCALL stub32_execveat, compat_sys_execveat
PTREGSCALL stub32_fork, sys_fork
PTREGSCALL stub32_vfork, sys_vfork
@@ -492,24 +589,23 @@ GLOBAL(stub32_clone)
ALIGN
ia32_ptregs_common:
- popq %r11
CFI_ENDPROC
CFI_STARTPROC32 simple
CFI_SIGNAL_FRAME
- CFI_DEF_CFA rsp,SS+8-ARGOFFSET
- CFI_REL_OFFSET rax,RAX-ARGOFFSET
- CFI_REL_OFFSET rcx,RCX-ARGOFFSET
- CFI_REL_OFFSET rdx,RDX-ARGOFFSET
- CFI_REL_OFFSET rsi,RSI-ARGOFFSET
- CFI_REL_OFFSET rdi,RDI-ARGOFFSET
- CFI_REL_OFFSET rip,RIP-ARGOFFSET
-/* CFI_REL_OFFSET cs,CS-ARGOFFSET*/
-/* CFI_REL_OFFSET rflags,EFLAGS-ARGOFFSET*/
- CFI_REL_OFFSET rsp,RSP-ARGOFFSET
-/* CFI_REL_OFFSET ss,SS-ARGOFFSET*/
- SAVE_REST
+ 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_REST
- jmp ia32_sysret /* misbalances the return cache */
+ RESTORE_EXTRA_REGS 8
+ ret
CFI_ENDPROC
END(ia32_ptregs_common)
diff --git a/arch/x86/ia32/nosyscall.c b/arch/x86/ia32/nosyscall.c
deleted file mode 100644
index 51ecd5b4e787..000000000000
--- a/arch/x86/ia32/nosyscall.c
+++ /dev/null
@@ -1,7 +0,0 @@
-#include <linux/kernel.h>
-#include <linux/errno.h>
-
-long compat_ni_syscall(void)
-{
- return -ENOSYS;
-}
diff --git a/arch/x86/ia32/sys_ia32.c b/arch/x86/ia32/sys_ia32.c
index 8e0ceecdc957..719cd702b0a4 100644
--- a/arch/x86/ia32/sys_ia32.c
+++ b/arch/x86/ia32/sys_ia32.c
@@ -201,20 +201,6 @@ long sys32_fadvise64_64(int fd, __u32 offset_low, __u32 offset_high,
advice);
}
-long sys32_vm86_warning(void)
-{
- struct task_struct *me = current;
- static char lastcomm[sizeof(me->comm)];
-
- if (strncmp(lastcomm, me->comm, sizeof(lastcomm))) {
- compat_printk(KERN_INFO
- "%s: vm86 mode not supported on 64 bit kernel\n",
- me->comm);
- strncpy(lastcomm, me->comm, sizeof(lastcomm));
- }
- return -ENOSYS;
-}
-
asmlinkage ssize_t sys32_readahead(int fd, unsigned off_lo, unsigned off_hi,
size_t count)
{
diff --git a/arch/x86/ia32/syscall_ia32.c b/arch/x86/ia32/syscall_ia32.c
deleted file mode 100644
index 4754ba0f5d9f..000000000000
--- a/arch/x86/ia32/syscall_ia32.c
+++ /dev/null
@@ -1,25 +0,0 @@
-/* System call table for ia32 emulation. */
-
-#include <linux/linkage.h>
-#include <linux/sys.h>
-#include <linux/cache.h>
-#include <asm/asm-offsets.h>
-
-#define __SYSCALL_I386(nr, sym, compat) extern asmlinkage void compat(void) ;
-#include <asm/syscalls_32.h>
-#undef __SYSCALL_I386
-
-#define __SYSCALL_I386(nr, sym, compat) [nr] = compat,
-
-typedef void (*sys_call_ptr_t)(void);
-
-extern void compat_ni_syscall(void);
-
-const sys_call_ptr_t ia32_sys_call_table[__NR_ia32_syscall_max+1] = {
- /*
- * Smells like a compiler bug -- it doesn't work
- * when the & below is removed.
- */
- [0 ... __NR_ia32_syscall_max] = &compat_ni_syscall,
-#include <asm/syscalls_32.h>
-};
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-28 23:29:14 +0300