1 /*
2 * linux/kernel/signal.c
3 *
4 * (C) 1991 Linus Torvalds
5 */
6
7 #include <linux/sched.h> // 璋冨害绋嬪簭澶存枃浠讹紝瀹氫箟浠诲姟缁撴瀯task_struct銆佸垵濮嬩换鍔�0鐨勬暟鎹紝
// 杩樻湁涓�浜涙湁鍏虫弿杩扮鍙傛暟璁剧疆鍜岃幏鍙栫殑宓屽叆寮忔眹缂栧嚱鏁板畯璇彞銆�
8 #include <linux/kernel.h> // 鍐呮牳澶存枃浠躲�傚惈鏈変竴浜涘唴鏍稿父鐢ㄥ嚱鏁扮殑鍘熷舰瀹氫箟銆�
9 #include <asm/segment.h> // 娈垫搷浣滃ご鏂囦欢銆傚畾涔変簡鏈夊叧娈靛瘎瀛樺櫒鎿嶄綔鐨勫祵鍏ュ紡姹囩紪鍑芥暟銆�
10
11 #include <signal.h> // 淇″彿澶存枃浠躲�傚畾涔変俊鍙风鍙峰父閲忥紝淇″彿缁撴瀯鍙婁俊鍙锋搷浣滃嚱鏁板師鍨嬨��
12 #include <errno.h> // 鍑洪敊鍙峰ご鏂囦欢銆傚畾涔夊嚭閿欏彿绗﹀彿甯搁噺銆�
13
// 鑾峰彇褰撳墠浠诲姟淇″彿灞忚斀浣嶅浘锛堝睆钄界爜鎴栭樆濉炵爜锛夈��sgetmask鍙垎瑙ｄ负signal-get-mask銆備互涓嬬被浼笺��
14 int sys_sgetmask()
15 {
16 return current->blocked;
17 }
18
// 璁剧疆鏂扮殑淇″彿灞忚斀浣嶅浘銆備俊鍙�SIGKILL鍜�SIGSTOP涓嶈兘琚睆钄姐�傝繑鍥炲�兼槸鍘熶俊鍙峰睆钄戒綅鍥俱��
19 int sys_ssetmask(int newmask)
20 {
21 int old=current->blocked;
22
23 current->blocked = newmask & ~(1<<(SIGKILL-1)) & ~(1<<(SIGSTOP-1));
24 return old;
25 }
26
// 妫�娴嬪苟鍙栧緱杩涚▼鏀跺埌鐨勪絾琚睆钄斤紙闃诲锛夌殑淇″彿銆傝繕鏈鐞嗕俊鍙风殑浣嶅浘灏嗚鏀惧叆set涓��
27 int sys_sigpending(sigset_t *set)
28 {
29 /* fill in "set" with signals pending but blocked. */
/* 鐢ㄨ繕鏈鐞嗗苟涓旇闃诲淇″彿鐨勪綅鍥惧～鍏�set鎸囬拡鎵�鎸囦綅缃 */
// 棣栧厛楠岃瘉杩涚▼鎻愪緵鐨勭敤鎴峰瓨鍌ㄧ┖闂村簲鏈�4涓瓧鑺傘�傜劧鍚庢妸杩樻湭澶勭悊骞朵笖琚樆濉炰俊鍙风殑浣嶅浘濉叆
// set鎸囬拡鎵�鎸囦綅缃銆�
30 verify_area(set,4);
31 put_fs_long(current->blocked & current->signal, (unsigned long *)set);
32 return 0;
33 }
34
35 /* atomically swap in the new signal mask, and wait for a signal.
36 *
37 * we need to play some games with syscall restarting. We get help
38 * from the syscall library interface. Note that we need to coordinate
39 * the calling convention with the libc routine.
40 *
41 * "set" is just the sigmask as described in 1003.1-1988, 3.3.7.
42 * It is assumed that sigset_t can be passed as a 32 bit quantity.
43 *
44 * "restart" holds a restart indication. If it's non-zero, then we
45 * install the old mask, and return normally. If it's zero, we store
46 * the current mask in old_mask and block until a signal comes in.
47 */
/* 鑷姩鍦版洿鎹㈡垚鏂扮殑淇″彿灞忚斀鐮侊紝骞剁瓑寰呬俊鍙风殑鍒版潵銆�
*
* 鎴戜滑闇�瑕佸绯荤粺璋冪敤锛�syscall锛夊仛涓�浜涘鐞嗐�傛垜浠細浠庣郴缁熻皟鐢ㄥ簱鎺ュ彛鍙栧緱鏌愪簺淇℃伅銆�
* 娉ㄦ剰锛屾垜浠渶瑕佹妸璋冪敤瑙勫垯涓�libc搴撲腑鐨勫瓙绋嬪簭缁熶竴鑰冭檻銆�
*
* "set" 姝ｆ槸POSIX鏍囧噯1003.1-1988鐨�3.3.7鑺備腑鎵�鎻忚堪鐨勪俊鍙峰睆钄界爜sigmask銆�
* 鍏朵腑璁や负绫诲瀷sigset_t鑳藉浣滀负涓�涓�32浣嶉噺浼犻�掋��
*
* "restart"涓繚鎸佹湁閲嶅惎鎸囩ず鏍囧織銆傚鏋滀负闈�0鍊硷紝閭ｄ箞鎴戜滑灏辫缃師鏉ョ殑灞忚斀鐮侊紝
* 骞朵笖姝ｅ父杩斿洖銆傚鏋滃畠涓�0锛岄偅涔堟垜浠氨鎶婂綋鍓嶇殑灞忚斀鐮佷繚瀛樺湪oldmask涓�
* 骞朵笖闃诲杩涚▼锛岀洿鍒版敹鍒颁换浣曚竴涓俊鍙蜂负姝���
*/
// 璇ョ郴缁熻皟鐢ㄤ复鏃舵妸杩涚▼淇″彿灞忚斀鐮佹浛鎹㈡垚鍙傛暟涓粰瀹氱殑set锛岀劧鍚庢寕璧疯繘绋嬶紝鐩村埌鏀跺埌涓�涓�
// 淇″彿涓烘銆�
// restart鏄竴涓涓柇鐨勭郴缁熻皟鐢ㄩ噸鏂板惎鍔ㄦ爣蹇椼�傚綋绗�1娆¤皟鐢ㄨ绯荤粺璋冪敤鏃讹紝瀹冩槸0銆傚苟涓�
// 鍦ㄨ鍑芥暟涓細鎶婅繘绋嬪師鏉ョ殑闃诲鐮� blocked淇濆瓨璧锋潵锛�old_mask锛夛紝骞惰缃� restart涓洪潪0
// 鍊笺�傚洜姝ゅ綋杩涚▼绗�2娆¤皟鐢ㄨ绯荤粺璋冪敤鏃讹紝瀹冨氨浼氭仮澶嶈繘绋嬪師鏉ヤ繚瀛樺湪old_mask涓殑闃诲鐮併��
48 int sys_sigsuspend(int restart, unsigned long old_mask, unsigned long set)
49 {
// pause()绯荤粺璋冪敤灏嗗鑷磋皟鐢ㄥ畠鐨勮繘绋嬭繘鍏ョ潯鐪犵姸鎬侊紝鐩村埌鏀跺埌涓�涓俊鍙枫�傝淇″彿鎴栬�呬細缁堟
// 杩涚▼鐨勬墽琛岋紝鎴栬�呭鑷磋繘绋嬪幓鎵ц鐩稿簲鐨勪俊鍙锋崟鑾峰嚱鏁般��
50 extern int sys_pause(void);
51
// 濡傛灉restart鏍囧織涓嶄负0锛岃〃绀烘槸閲嶆柊璁╃▼搴忚繍琛岃捣鏉ャ�備簬鏄仮澶嶅墠闈繚瀛樺湪old_mask涓殑
// 鍘熻繘绋嬮樆濉炵爜銆傚苟杩斿洖鐮�-EINTR锛堢郴缁熻皟鐢ㄨ淇″彿涓柇锛夈��
52 if (restart) {
53 /* we're restarting */ /* 鎴戜滑姝ｅ湪閲嶆柊鍚姩绯荤粺璋冪敤 */
54 current->blocked = old_mask;
55 return -EINTR;
56 }
// 鍚﹀垯琛ㄧずrestart鏍囧織鐨勫�兼槸0銆傝〃绀虹1娆¤皟鐢ㄣ�備簬鏄鍏堣缃�restart鏍囧織锛堢疆涓�1锛夛紝
// 淇濆瓨杩涚▼褰撳墠闃诲鐮� blocked 鍒� old_mask涓紝骞舵妸杩涚▼鐨勯樆濉炵爜鏇挎崲鎴� set銆傜劧鍚庤皟鐢�
// pause()璁╄繘绋嬬潯鐪狅紝绛夊緟淇″彿鐨勫埌鏉ャ�傚綋杩涚▼鏀跺埌涓�涓俊鍙锋椂锛�pause() 灏变細杩斿洖锛屽苟涓�
// 杩涚▼浼氬幓鎵ц淇″彿澶勭悊鍑芥暟锛岀劧鍚庢湰璋冪敤杩斿洖 -ERESTARTNOINTR 鐮侀��鍑恒�傝繖涓繑鍥炵爜璇存槑
// 鍦ㄥ鐞嗗畬淇″彿鍚庤姹傝繑鍥炲埌鏈郴缁熻皟鐢ㄤ腑缁х画杩愯锛屽嵆鏈郴缁熻皟鐢ㄤ笉浼氳涓柇銆�
57 /* we're not restarting. do the work */
/* 鎴戜滑涓嶆槸閲嶆柊閲嶆柊杩愯锛岄偅涔堝氨骞叉椿鍚� */
58 *(&restart) = 1;
59 *(&old_mask) = current->blocked;
60 current->blocked = set;
61 (void) sys_pause(); /* return after a signal arrives */
62 return -ERESTARTNOINTR; /* handle the signal, and come back */
63 }
64
// 澶嶅埗sigaction鏁版嵁鍒�fs鏁版嵁娈�to澶勩�傚嵆浠庡唴鏍哥┖闂村鍒跺埌鐢ㄦ埛锛堜换鍔★級鏁版嵁娈典腑銆�
65 static inline void save_old(char * from,char * to)
66 {
67 int i;
68
// 棣栧厛楠岃瘉to澶勭殑鍐呭瓨绌洪棿鏄惁瓒冲澶с�傜劧鍚庢妸涓�涓�sigaction缁撴瀯淇℃伅澶嶅埗鍒�fs娈碉紙鐢ㄦ埛锛�
// 绌洪棿涓�傚畯鍑芥暟put_fs_byte()鍦�include/asm/segment.h涓疄鐜般��
69 verify_area(to, sizeof(struct sigaction));
70 for (i=0 ; i< sizeof(struct sigaction) ; i++) {
71 put_fs_byte(*from,to);
72 from++;
73 to++;
74 }
75 }
76
// 鎶�sigaction鏁版嵁浠�fs鏁版嵁娈�from浣嶇疆澶嶅埗鍒�to澶勩�傚嵆浠庣敤鎴锋暟鎹┖闂村彇鍒板唴鏍告暟鎹涓��
77 static inline void get_new(char * from,char * to)
78 {
79 int i;
80
81 for (i=0 ; i< sizeof(struct sigaction) ; i++)
82 *(to++) = get_fs_byte(from++);
83 }
84
// signal()绯荤粺璋冪敤銆傜被浼间簬sigaction()銆備负鎸囧畾鐨勪俊鍙峰畨瑁呮柊鐨勪俊鍙峰彞鏌�(淇″彿澶勭悊绋嬪簭)銆�
// 淇″彿鍙ユ焺鍙互鏄敤鎴锋寚瀹氱殑鍑芥暟锛屼篃鍙互鏄�SIG_DFL锛堥粯璁ゅ彞鏌勶級鎴�SIG_IGN锛堝拷鐣ワ級銆�
// 鍙傛暟signum --鎸囧畾鐨勪俊鍙凤紱handler -- 鎸囧畾鐨勫彞鏌勶紱restorer 鈥�鎭㈠鍑芥暟鎸囬拡锛岃鍑芥暟鐢�
// Libc 搴撴彁渚涖�傜敤浜庡湪淇″彿澶勭悊绋嬪簭缁撴潫鍚庢仮澶嶇郴缁熻皟鐢ㄨ繑鍥炴椂鍑犱釜瀵勫瓨鍣ㄧ殑鍘熸湁鍊间互鍙婄郴缁�
// 璋冪敤鐨勮繑鍥炲�硷紝灏卞ソ璞＄郴缁熻皟鐢ㄦ病鏈夋墽琛岃繃淇″彿澶勭悊绋嬪簭鑰岀洿鎺ヨ繑鍥炲埌鐢ㄦ埛绋嬪簭涓�鏍枫�� 鍑芥暟
// 杩斿洖鍘熶俊鍙峰彞鏌勩��
85 int sys_signal(int signum, long handler, long restorer)
86 {
87 struct sigaction tmp;
88
// 棣栧厛楠岃瘉淇″彿鍊煎湪鏈夋晥鑼冨洿锛�1--32锛夊唴锛屽苟涓斾笉寰楁槸淇″彿SIGKILL锛堝拰SIGSTOP锛夈�傚洜涓鸿繖
// 涓や釜淇″彿涓嶈兘琚繘绋嬫崟鑾枫��
89 if (signum<1 || signum>32 || signum==SIGKILL || signum==SIGSTOP)
90 return -EINVAL;
// 鐒跺悗鏍规嵁鎻愪緵鐨勫弬鏁扮粍寤�sigaction缁撴瀯鍐呭銆�sa_handler鏄寚瀹氱殑淇″彿澶勭悊鍙ユ焺锛堝嚱鏁帮級銆�
// sa_mask鏄墽琛屼俊鍙峰鐞嗗彞鏌勬椂鐨勪俊鍙峰睆钄界爜銆�sa_flags鏄墽琛屾椂鐨勪竴浜涙爣蹇楃粍鍚堛�傝繖閲岃瀹�
// 璇ヤ俊鍙峰鐞嗗彞鏌勫彧浣跨敤1娆″悗灏辨仮澶嶅埌榛樿鍊硷紝骞跺厑璁镐俊鍙峰湪鑷繁鐨勫鐞嗗彞鏌勪腑鏀跺埌銆�
91 tmp.sa_handler = (void (*)(int)) handler;
92 tmp.sa_mask = 0;
93 tmp.sa_flags = SA_ONESHOT | SA_NOMASK;
94 tmp.sa_restorer = (void (*)(void)) restorer; // 淇濆瓨鎭㈠澶勭悊鍑芥暟鎸囬拡銆�
// 鎺ョ潃鍙栬淇″彿鍘熸潵鐨勫鐞嗗彞鏌勶紝骞惰缃淇″彿鐨�sigaction缁撴瀯銆傛渶鍚庤繑鍥炲師淇″彿鍙ユ焺銆�
95 handler = (long) current->sigaction[signum-1].sa_handler;
96 current->sigaction[signum-1] = tmp;
97 return handler;
98 }
99
// sigaction()绯荤粺璋冪敤銆傛敼鍙樿繘绋嬪湪鏀跺埌涓�涓俊鍙锋椂鐨勬搷浣溿��signum鏄櫎浜�SIGKILL浠ュ鐨�
// 浠讳綍淇″彿銆�[濡傛灉鏂版搷浣滐紙action锛変笉涓虹┖ ]鍒欐柊鎿嶄綔琚畨瑁呫�傚鏋� oldaction鎸囬拡涓嶄负绌猴紝
// 鍒欏師鎿嶄綔琚繚鐣欏埌oldaction銆傛垚鍔熷垯杩斿洖0锛屽惁鍒欎负-EINVAL銆�
100 int sys_sigaction(int signum, const struct sigaction * action,
101 struct sigaction * oldaction)
102 {
103 struct sigaction tmp;
104
// 棣栧厛楠岃瘉淇″彿鍊煎湪鏈夋晥鑼冨洿锛�1--32锛夊唴锛屽苟涓斾笉寰楁槸淇″彿SIGKILL锛堝拰SIGSTOP锛夈�傚洜涓鸿繖
// 涓や釜淇″彿涓嶈兘琚繘绋嬫崟鑾枫��
105 if (signum<1 || signum>32 || signum==SIGKILL || signum==SIGSTOP)
106 return -EINVAL;
// 鍦ㄤ俊鍙风殑sigaction缁撴瀯涓缃柊鐨勬搷浣滐紙鍔ㄤ綔锛夈�傚鏋�oldaction鎸囬拡涓嶄负绌虹殑璇濓紝鍒欏皢
// 鍘熸搷浣滄寚閽堜繚瀛樺埌oldaction鎵�鎸囩殑浣嶇疆銆�
107 tmp = current->sigaction[signum-1];
108 get_new((char *) action,
109 (char *) (signum-1+current->sigaction));
110 if (oldaction)
111 save_old((char *) &tmp,(char *) oldaction);
// 濡傛灉鍏佽淇″彿鍦ㄨ嚜宸辩殑淇″彿鍙ユ焺涓敹鍒帮紝鍒欎护灞忚斀鐮佷负0锛屽惁鍒欒缃睆钄芥湰淇″彿銆�
112 if (current->sigaction[signum-1].sa_flags & SA_NOMASK)
113 current->sigaction[signum-1].sa_mask = 0;
114 else
115 current->sigaction[signum-1].sa_mask |= (1<<(signum-1));
116 return 0;
117 }
118
119 /*
120 * Routine writes a core dump image in the current directory.
121 * Currently not implemented.
122 */
/*
* 鍦ㄥ綋鍓嶇洰褰曚腑浜х敓core dump鏄犲儚鏂囦欢鐨勫瓙绋嬪簭銆傜洰鍓嶈繕娌℃湁瀹炵幇銆�
*/
123 int core_dump(long signr)
124 {
125 return(0); /* We didn't do a dump */
126 }
127
// 绯荤粺璋冪敤鐨勪腑鏂鐞嗙▼搴忎腑鐪熸鐨勪俊鍙烽澶勭悊绋嬪簭锛堝湪kernel/sys_call.s,119琛岋級銆傝繖娈�
// 浠ｇ爜鐨勪富瑕佷綔鐢ㄦ槸灏嗕俊鍙峰鐞嗗彞鏌勬彃鍏ュ埌鐢ㄦ埛绋嬪簭鍫嗘爤涓紝骞跺湪鏈郴缁熻皟鐢ㄧ粨鏉熻繑鍥炲悗绔嬪埢
// 鎵ц淇″彿鍙ユ焺绋嬪簭锛岀劧鍚庣户缁墽琛岀敤鎴风殑绋嬪簭銆�
// 鍑芥暟鐨勫弬鏁版槸杩涘叆绯荤粺璋冪敤澶勭悊绋嬪簭sys_call.s寮�濮嬶紝鐩村埌璋冪敤鏈嚱鏁帮紙sys_call.s
// 绗�125琛岋級鍓嶉�愭鍘嬪叆鍫嗘爤鐨勫�笺�傝繖浜涘�煎寘鎷紙鍦�sys_call.s涓殑浠ｇ爜琛岋級锛�
// 鈶� CPU鎵ц涓柇鎸囦护鍘嬪叆鐨勭敤鎴锋爤鍦板潃ss鍜�esp銆佹爣蹇楀瘎瀛樺櫒eflags鍜岃繑鍥炲湴鍧�cs鍜�eip锛�
// 鈶� 绗�85--91琛屽湪鍒氳繘鍏�system_call鏃跺帇鍏ユ爤鐨勬瀵勫瓨鍣�ds銆�es銆�fs浠ュ強瀵勫瓨鍣�eax
// 锛�orig_eax锛夈��edx銆�ecx鍜�ebx鐨勫�硷紱
// 鈶� 绗�100琛岃皟鐢�sys_call_table鍚庡帇鍏ユ爤涓殑鐩稿簲绯荤粺璋冪敤澶勭悊鍑芥暟鐨勮繑鍥炲�硷紙eax锛夈��
// 鈶� 绗�124琛屽帇鍏ユ爤涓殑褰撳墠澶勭悊鐨勪俊鍙峰�硷紙signr锛夈��
128 int do_signal(long signr,long eax,long ebx, long ecx, long edx, long orig_eax,
129 long fs, long es, long ds,
130 long eip, long cs, long eflags,
131 unsigned long * esp, long ss)
132 {
133 unsigned long sa_handler;
134 long old_eip=eip;
135 struct sigaction * sa = current->sigaction + signr - 1;
136 int longs; // 鍗� current->sigaction[signr-1]銆�
137
138 unsigned long * tmp_esp;
139
// 浠ヤ笅鏄皟璇曡鍙ャ�傚綋瀹氫箟浜�notdef鏃朵細鎵撳嵃鐩稿叧淇℃伅銆�
140 #ifdef notdef
141 printk("pid: %d, signr: %x, eax=%d, oeax = %d, int=%d\n",
142 current->pid, signr, eax, orig_eax,
143 sa->sa_flags & SA_INTERRUPT);
144 #endif
// 濡傛灉涓嶆槸绯荤粺璋冪敤鑰屾槸鍏跺畠涓柇鎵ц杩囩▼涓皟鐢ㄥ埌鏈嚱鏁版椂锛� roig_eax 鍊间负 -1銆� 鍙傝
// sys_call.s 绗�144琛� 绛夎鍙ャ�傚洜姝ゅ綋 orig_eax涓嶇瓑浜� -1 鏃讹紝璇存槑鏄湪鏌愪釜绯荤粺璋冪敤鐨�
// 鏈�鍚庤皟鐢ㄤ簡鏈嚱鏁般�傚湪 kernel/exit.c 鐨� waitpid() 鍑芥暟涓紝濡傛灉鏀跺埌浜�SIGCHLD 淇″彿锛�
// 鎴栬�呭湪璇荤閬撳嚱鏁�fs/pipe.c涓閬撳綋鍓嶈鏁版嵁浣嗘病鏈夎鍒颁换浣曟暟鎹瓑鎯呭喌涓嬶紝杩涚▼鏀跺埌
// 浜嗕换浣曚竴涓潪闃诲鐨勪俊鍙凤紝鍒欓兘浼氫互 -ERESTARTSYS 杩斿洖鍊艰繑鍥炪�傚畠琛ㄧず杩涚▼鍙互琚腑鏂紝
// 浣嗘槸鍦ㄧ户缁墽琛屽悗浼氶噸鏂板惎鍔ㄧ郴缁熻皟鐢ㄣ�傝繑鍥炵爜-ERESTARTNOINTR璇存槑鍦ㄥ鐞嗗畬淇″彿鍚庤姹�
// 杩斿洖鍒板師绯荤粺璋冪敤涓户缁繍琛岋紝鍗崇郴缁熻皟鐢ㄤ笉浼氳涓柇銆傚弬瑙佸墠闈㈢62琛屻��
// 鍥犳涓嬮潰璇彞璇存槑濡傛灉鏄湪绯荤粺璋冪敤涓皟鐢ㄧ殑鏈嚱鏁帮紝骞朵笖鐩稿簲绯荤粺璋冪敤鐨勮繑鍥炵爜 eax绛変簬
// -ERESTARTSYS鎴� -ERESTARTNOINTR鏃惰繘琛屼笅闈㈢殑澶勭悊锛堝疄闄呬笂杩樻病鏈夌湡姝ｅ洖鍒扮敤鎴风▼搴忎腑锛夈��
145 if ((orig_eax != -1) &&
146 ((eax == -ERESTARTSYS) || (eax == -ERESTARTNOINTR))) {
// 濡傛灉绯荤粺璋冪敤杩斿洖鐮佹槸 -ERESTARTSYS锛堥噸鏂板惎鍔ㄧ郴缁熻皟鐢級锛屽苟涓� sigaction 涓惈鏈夋爣蹇�
// SA_INTERRUPT锛堢郴缁熻皟鐢ㄨ淇″彿涓柇鍚庝笉閲嶆柊鍚姩绯荤粺璋冪敤锛夋垨鑰呬俊鍙峰�煎皬浜� SIGCONT鎴栬��
// 淇″彿鍊煎ぇ浜�SIGTTOU锛堝嵆淇″彿涓嶆槸SIGCONT銆�SIGSTOP銆�SIGTSTP銆�SIGTTIN 鎴�SIGTTOU锛夛紝鍒�
// 淇敼绯荤粺璋冪敤鐨勮繑鍥炲�间负eax = -EINTR锛屽嵆琚俊鍙蜂腑鏂殑绯荤粺璋冪敤銆�
147 if ((eax == -ERESTARTSYS) && ((sa->sa_flags & SA_INTERRUPT) ||
148 signr < SIGCONT || signr > SIGTTOU))
149 *(&eax) = -EINTR;
150 else {
// 鍚﹀垯灏辨仮澶嶈繘绋嬪瘎瀛樺櫒eax鍦ㄨ皟鐢ㄧ郴缁熻皟鐢ㄤ箣鍓嶇殑鍊硷紝骞朵笖鎶婂師绋嬪簭鎸囦护鎸囬拡鍥炶皟2瀛楄妭銆傚嵆
// 褰撹繑鍥炵敤鎴风▼搴忔椂锛岃绋嬪簭閲嶆柊鍚姩鎵ц琚俊鍙蜂腑鏂殑绯荤粺璋冪敤銆�
151 *(&eax) = orig_eax;
152 *(&eip) = old_eip -= 2;
153 }
154 }
// 濡傛灉淇″彿鍙ユ焺涓�SIG_IGN锛�1锛岄粯璁ゅ拷鐣ュ彞鏌勶級鍒欎笉瀵逛俊鍙疯繘琛屽鐞嗚�岀洿鎺ヨ繑鍥炪��
155 sa_handler = (unsigned long) sa->sa_handler;
156 if (sa_handler==1)
157 return(1); /* Ignore, see if there are more signals... */
// 濡傛灉鍙ユ焺涓�SIG_DFL锛�0锛岄粯璁ゅ鐞嗭級锛屽垯鏍规嵁鍏蜂綋鐨勪俊鍙疯繘琛屽垎鍒鐞嗐��
158 if (!sa_handler) {
159 switch (signr) {
// 濡傛灉淇″彿鏄互涓嬩袱涓垯涔熷拷鐣ヤ箣锛屽苟杩斿洖銆�
160 case SIGCONT:
161 case SIGCHLD:
162 return(1); /* Ignore, ... */
163
// 濡傛灉淇″彿鏄互涓�4绉嶄俊鍙蜂箣涓�锛屽垯鎶婂綋鍓嶈繘绋嬬姸鎬佺疆涓哄仠姝㈢姸鎬�TASK_STOPPED銆傝嫢褰撳墠杩涚▼
// 鐖惰繘绋嬪SIGCHLD淇″彿鐨� sigaction澶勭悊鏍囧織 SA_NOCLDSTOP 锛堝嵆褰撳瓙杩涚▼鍋滄鎵ц鎴栧張缁�
// 缁墽琛屾椂涓嶈浜х敓SIGCHLD淇″彿锛夋病鏈夌疆浣嶏紝閭ｄ箞灏辩粰鐖惰繘绋嬪彂閫�SIGCHLD淇″彿銆�
164 case SIGSTOP:
165 case SIGTSTP:
166 case SIGTTIN:
167 case SIGTTOU:
168 current->state = TASK_STOPPED;
169 current->exit_code = signr;
170 if (!(current->p_pptr->sigaction[SIGCHLD-1].sa_flags &
171 SA_NOCLDSTOP))
172 current->p_pptr->signal |= (1<<(SIGCHLD-1));
173 return(1); /* Reschedule another event */
174
// 濡傛灉淇″彿鏄互涓�6绉嶄俊鍙蜂箣涓�锛岄偅涔堣嫢淇″彿浜х敓浜�core dump锛屽垯浠ラ��鍑虹爜涓�signr|0x80
// 璋冪敤do_exit()閫�鍑恒�傚惁鍒欓��鍑虹爜灏辨槸淇″彿鍊笺��do_exit()鐨勫弬鏁版槸杩斿洖鐮佸拰绋嬪簭鎻愪緵鐨勯��鍑�
// 鐘舵�佷俊鎭�傚彲浣滀负wait()鎴�waitpid()鍑芥暟鐨勭姸鎬佷俊鎭�傚弬瑙�sys/wait.h鏂囦欢绗�13-18琛屻��
// wait()鎴�waitpid()鍒╃敤杩欎簺瀹忓氨鍙互鍙栧緱瀛愯繘绋嬬殑閫�鍑虹姸鎬佺爜鎴栧瓙杩涚▼缁堟鐨勫師鍥狅紙淇″彿锛夈��
175 case SIGQUIT:
176 case SIGILL:
177 case SIGTRAP:
178 case SIGIOT:
179 case SIGFPE:
180 case SIGSEGV:
181 if (core_dump(signr))
182 do_exit(signr|0x80);
183 /* fall through */
184 default:
185 do_exit(signr);
186 }
187 }
188 /*
189 * OK, we're invoking a handler
190 */
/*
* OK锛岀幇鍦ㄦ垜浠噯澶囧淇″彿鍙ユ焺璋冪敤鐨勮缃�
*/
// 濡傛灉璇ヤ俊鍙峰彞鏌勫彧闇�琚皟鐢ㄤ竴娆★紝鍒欏皢璇ュ彞鏌勭疆绌恒�傛敞鎰忥紝璇ヤ俊鍙峰彞鏌勫湪鍓嶉潰宸茬粡淇濆瓨鍦�
// sa_handler鎸囬拡涓��
// 鍦ㄧ郴缁熻皟鐢ㄨ繘鍏ュ唴鏍告椂锛岀敤鎴风▼搴忚繑鍥炲湴鍧�锛�eip銆�cs锛夎淇濆瓨鍦ㄥ唴鏍告�佹爤涓�備笅闈㈣繖娈典唬
// 鐮佷慨鏀瑰唴鏍告�佸爢鏍堜笂鐢ㄦ埛璋冪敤绯荤粺璋冪敤鏃剁殑浠ｇ爜鎸囬拡 eip 涓烘寚鍚戜俊鍙峰鐞嗗彞鏌勶紝鍚屾椂涔熷皢
// sa_restorer銆�signr銆佽繘绋嬪睆钄界爜(濡傛灉SA_NOMASK娌＄疆浣�)銆�eax銆�ecx銆�edx浣滀负鍙傛暟浠ュ強
// 鍘熻皟鐢ㄧ郴缁熻皟鐢ㄧ殑绋嬪簭杩斿洖鎸囬拡鍙婃爣蹇楀瘎瀛樺櫒鍊煎帇鍏ョ敤鎴峰爢鏍堛�� 鍥犳鍦ㄦ湰娆＄郴缁熻皟鐢ㄤ腑鏂�
// 杩斿洖鐢ㄦ埛绋嬪簭鏃朵細棣栧厛鎵ц鐢ㄦ埛鐨勪俊鍙峰彞鏌勭▼搴忥紝鐒跺悗鍐嶇户缁墽琛岀敤鎴风▼搴忋��
191 if (sa->sa_flags & SA_ONESHOT)
192 sa->sa_handler = NULL;
// 灏嗗唴鏍告�佹爤涓婄敤鎴疯皟鐢ㄧ郴缁熻皟鐢ㄤ笅涓�鏉′唬鐮佹寚浠ゆ寚閽�eip鎸囧悜璇ヤ俊鍙峰鐞嗗彞鏌勩�傜敱浜�C鍑芥暟
// 鏄紶鍊煎嚱鏁帮紝鍥犳缁�eip璧嬪�兼椂闇�瑕佷娇鐢� "*(&eip)" 鐨勫舰寮忋�傚彟澶栵紝濡傛灉鍏佽淇″彿鑷繁鐨�
// 澶勭悊鍙ユ焺鏀跺埌淇″彿鑷繁锛屽垯涔熼渶瑕佸皢杩涚▼鐨勯樆濉炵爜鍘嬪叆鍫嗘爤銆�
// 杩欓噷璇锋敞鎰忥紝浣跨敤濡備笅鏂瑰紡锛堢193琛岋級瀵规櫘閫�C鍑芥暟鍙傛暟杩涜淇敼鏄笉璧蜂綔鐢ㄧ殑銆傚洜涓哄綋
// 鍑芥暟杩斿洖鏃跺爢鏍堜笂鐨勫弬鏁板皢浼氳璋冪敤鑰呬涪寮冦�傝繖閲屼箣鎵�浠ュ彲浠ヤ娇鐢ㄨ繖绉嶆柟寮忥紝鏄洜涓鸿鍑芥暟
// 鏄粠姹囩紪绋嬪簭涓璋冪敤鐨勶紝骞朵笖鍦ㄥ嚱鏁拌繑鍥炲悗姹囩紪绋嬪簭骞舵病鏈夋妸璋冪敤do_signal()鏃剁殑鎵�鏈�
// 鍙傛暟閮戒涪寮冦��eip绛変粛鐒跺湪鍫嗘爤涓��
// sigaction缁撴瀯鐨�sa_mask瀛楁缁欏嚭浜嗗湪褰撳墠淇″彿鍙ユ焺锛堜俊鍙锋弿杩扮锛夌▼搴忔墽琛屾湡闂村簲璇ヨ
// 灞忚斀鐨勪俊鍙烽泦銆傚悓鏃讹紝寮曡捣鏈俊鍙峰彞鏌勬墽琛岀殑淇″彿涔熶細琚睆钄姐�� 涓嶈繃鑻�sa_flags涓娇鐢ㄤ簡
// SA_NOMASK鏍囧織锛岄偅涔堝紩璧锋湰淇″彿鍙ユ焺鎵ц鐨勪俊鍙峰皢涓嶄細琚睆钄芥帀銆傚鏋滃厑璁镐俊鍙疯嚜宸辩殑澶�
// 鐞嗗彞鏌勭▼搴忔敹鍒颁俊鍙疯嚜宸憋紝鍒欎篃闇�瑕佸皢杩涚▼鐨勪俊鍙烽樆濉炵爜鍘嬪叆鍫嗘爤銆�
193 *(&eip) = sa_handler;
194 longs = (sa->sa_flags & SA_NOMASK)?7:8;
// 灏嗗師璋冪敤绋嬪簭鐨勭敤鎴峰爢鏍堟寚閽堝悜涓嬫墿灞�7锛堟垨8锛変釜闀垮瓧锛堢敤鏉ュ瓨鏀捐皟鐢ㄤ俊鍙峰彞鏌勭殑鍙傛暟绛夛級锛�
// 骞舵鏌ュ唴瀛樹娇鐢ㄦ儏鍐碉紙渚嬪濡傛灉鍐呭瓨瓒呯晫鍒欏垎閰嶆柊椤电瓑锛夈��
195 *(&esp) -= longs;
196 verify_area(esp,longs*4);
// 鍦ㄧ敤鎴峰爢鏍堜腑浠庝笅鍒颁笂瀛樻斁sa_restorer銆佷俊鍙�signr銆佸睆钄界爜blocked锛堝鏋�SA_NOMASK
// 缃綅锛夈��eax銆�ecx銆�edx銆�eflags鍜岀敤鎴风▼搴忓師浠ｇ爜鎸囬拡銆�
197 tmp_esp=esp;
198 put_fs_long((long) sa->sa_restorer,tmp_esp++);
199 put_fs_long(signr,tmp_esp++);
200 if (!(sa->sa_flags & SA_NOMASK))
201 put_fs_long(current->blocked,tmp_esp++);
202 put_fs_long(eax,tmp_esp++);
203 put_fs_long(ecx,tmp_esp++);
204 put_fs_long(edx,tmp_esp++);
205 put_fs_long(eflags,tmp_esp++);
206 put_fs_long(old_eip,tmp_esp++);
207 current->blocked |= sa->sa_mask; // 杩涚▼闃诲鐮�(灞忚斀鐮�)娣讳笂sa_mask涓殑鐮佷綅銆�
208 return(0); /* Continue, execute handler */
209 }
210