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sys/i386/i386/sigtramp.s
| Show First 20 Lines • Show All 91 Lines • ▼ Show 20 Lines | osigcode: | ||||
| testl $PSL_VM,SC_PS(%eax) | testl $PSL_VM,SC_PS(%eax) | ||||
| jne 9f | jne 9f | ||||
| mov SC_GS(%eax),%gs /* restore %gs */ | mov SC_GS(%eax),%gs /* restore %gs */ | ||||
| 9: | 9: | ||||
| movl $103,%eax /* 3.x SYS_sigreturn */ | movl $103,%eax /* 3.x SYS_sigreturn */ | ||||
| pushl %eax /* junk to fake return addr. */ | pushl %eax /* junk to fake return addr. */ | ||||
| int $0x80 /* enter kernel with args */ | int $0x80 /* enter kernel with args */ | ||||
| 0: jmp 0b | 0: jmp 0b | ||||
| /* | |||||
| * The lcall $7,$0 handler cannot use the call gate that does an | |||||
| * inter-privilege transition. The reason is that the call gate | |||||
| * does not disable interrupts, and, before the kernel page table is | |||||
| * activated on MMU, we would have a window where the ring 0 code is | |||||
| * executed with the wrong page table and interrupts enabled. | |||||
| * | |||||
| * Instead, set LDT descriptor 0 as code segment, which reflects | |||||
| * the lcall $7,$0 back to ring 3 trampoline. The trampoline sets up | |||||
| * the frame for int $0x80. | |||||
| */ | |||||
| ALIGN_TEXT | |||||
| lcall_tramp: | |||||
| cmpl $SYS_vfork,%eax | |||||
| je 1f | |||||
| pushl %ebp | |||||
| movl %esp,%ebp | |||||
| pushl 0x24(%ebp) /* arg 6 */ | |||||
| pushl 0x20(%ebp) | |||||
| pushl 0x1c(%ebp) | |||||
| pushl 0x18(%ebp) | |||||
| pushl 0x14(%ebp) | |||||
| pushl 0x10(%ebp) /* arg 1 */ | |||||
| subl $4,%esp /* gap */ | |||||
| int $0x80 | |||||
| leavel | |||||
| lretl | |||||
| 1: | |||||
| /* | |||||
| * vfork handling is special and relies on the libc stub saving | |||||
| * the return ip in %ecx. Also, we assume that the call was done | |||||
| * with ucode32 selector in %cs. | |||||
| */ | |||||
| int $0x80 | |||||
| movl $0x33,4(%esp) /* GUCODE32_SEL | SEL_UPL */ | |||||
| movl %ecx,(%esp) | |||||
| lretl | |||||
| #endif /* COMPAT_43 */ | #endif /* COMPAT_43 */ | ||||
| ALIGN_TEXT | ALIGN_TEXT | ||||
| esigcode: | esigcode: | ||||
| .data | .data | ||||
| .globl szsigcode | .globl szsigcode | ||||
| szsigcode: | szsigcode: | ||||
| .long esigcode-sigcode | .long esigcode-sigcode | ||||
| #ifdef COMPAT_FREEBSD4 | #ifdef COMPAT_FREEBSD4 | ||||
| .globl szfreebsd4_sigcode | .globl szfreebsd4_sigcode | ||||
| szfreebsd4_sigcode: | szfreebsd4_sigcode: | ||||
| .long esigcode-freebsd4_sigcode | .long esigcode-freebsd4_sigcode | ||||
| #endif | #endif | ||||
| #ifdef COMPAT_43 | #ifdef COMPAT_43 | ||||
| .globl szosigcode | .globl szosigcode | ||||
| szosigcode: | szosigcode: | ||||
| .long esigcode-osigcode | .long esigcode-osigcode | ||||
| .globl sz_lcall_tramp | |||||
| sz_lcall_tramp: | |||||
| .long esigcode-lcall_tramp | |||||
| #endif | #endif | ||||