【Linux之父17年前写的这段代码，你见过吗？】
Linux之父托瓦尔兹是一个拥有十足个性的程序员。
1991年秋，托沃兹公开了Linux源代码，不求名利。
他看过去跟像是一个独行侠，他承认过自己不善交际，48岁的他仍然热爱编程。
大部分程序员网友对他印象比较深刻的就是，他曾因为Nvidia不支持Linux直接开骂“f*ck you”。
近日，这为被誉为“活着的传奇”的程序员又开始发飙了，展现了他的暴脾气。
托瓦尔兹在一封邮件中写到：“这一些纯粹都是垃圾。Intel到底还想不想把事情搞好?有没有人能找他们说说，告诉他们都TMD疯了!拜托了，如果有Intel工程师看到，和你们的主管谈谈吧。”
0、为什么托瓦尔兹会对Intel感到暴怒?
其实，托沃兹一直以来都将大部分精力都放在了开发Linux上。
这次Intel的漏洞，让他也得花费大量时间和精力，和社区一同修复解决。
可以说，托瓦尔兹简直是为Linux系统而生。他的暴脾气也是有资本的，看完他的代码你会觉得这个人简直就是天才！
1、托瓦尔兹1991年公开的Linux源代码曝光
90年代，他并没有把将Linux打造成商业系统，有人问他：会不会觉得遗憾?
他说，“如果当初没有公开Linux源代码，那才会感到遗憾;如果当初让Linux走商业化道路，那么不会发展到今天这个地步;因此，对当初的决定感到很高兴。”
有程序员网友曝出了托瓦尔兹1991年公开的Linux源代码，这引起了W3Cschool的注意，下面直接贴代码。(由于篇幅所限，可以点击以下“了解更多”查看)。
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/ system_call.s contains the system-call low-level handling routines. This also contains the timer-interrupt handler, as some of the code is the same. The hd-interrupt is also here. NOTE: This code handles signal-recognition, which happens every time after a timer-interrupt and after each system call. Ordinary interrupts don't handle signal-recognition, as that would clutter them up totally unnecessarily. Stack layout in 'ret_from_system_call': 0(%esp) - %eax 4(%esp) - %ebx 8(%esp) - %ecx C(%esp) - %edx 10(%esp) - %fs 14(%esp) - %es 18(%esp) - %ds 1C(%esp) - %eip 20(%esp) - %cs 24(%esp) - %eflags 28(%esp) - %oldesp 2C(%esp) - %oldss / SIG_CHLD = 17 EAX = 0x00 EBX = 0x04 ECX = 0x08 EDX = 0x0C FS = 0x10 ES = 0x14 DS = 0x18 EIP = 0x1C CS = 0x20 EFLAGS = 0x24 OLDESP = 0x28 OLDSS = 0x2C state = 0 # these are offsets into the task-struct. counter = 4 priority = 8 signal = 12 restorer = 16 # address of info-restorer sig_fn = 20 # table of 32 signal addresses nr_system_calls = 67 .globl _system_call,_sys_fork,_timer_interrupt,_hd_interrupt,_sys_execve .align 2 bad_sys_call: movl $-1,%eax iret .align 2 reschedule: pushl $ret_from_sys_call jmp _schedule .align 2 _system_call: cmpl $nr_system_calls-1,%eax ja bad_sys_call push %ds push %es push %fs pushl %edx pushl %ecx # push %ebx,%ecx,%edx as parameters pushl %ebx # to the system call movl $0x10,%edx # set up ds,es to kernel space mov %dx,%ds mov %dx,%es movl $0x17,%edx # fs points to local data space mov %dx,%fs call _sys_call_table(,%eax,4) pushl %eax movl _current,%eax cmpl $0,state(%eax) # state jne reschedule cmpl $0,counter(%eax) # counter je reschedule ret_from_sys_call: movl _current,%eax # task[0] cannot have signals cmpl _task,%eax je 3f movl CS(%esp),%ebx # was old code segment supervisor testl $3,%ebx # mode? If so - don't check signals je 3f cmpw $0x17,OLDSS(%esp) # was stack segment = 0x17 ? jne 3f 2: movl signal(%eax),%ebx # signals (bitmap, 32 signals) bsfl %ebx,%ecx # %ecx is signal nr, return if none je 3f btrl %ecx,%ebx # clear it movl %ebx,signal(%eax) movl sig_fn(%eax,%ecx,4),%ebx # %ebx is signal handler address cmpl $1,%ebx jb default_signal # 0 is default signal handler - exit je 2b # 1 is ignore - find next signal movl $0,sig_fn(%eax,%ecx,4) # reset signal handler address incl %ecx xchgl %ebx,EIP(%esp) # put new return address on stack subl $28,OLDESP(%esp) movl OLDESP(%esp),%edx # push old return address on stack pushl %eax # but first check that it's ok. pushl %ecx pushl $28 pushl %edx call _verify_area popl %edx addl $4,%esp popl %ecx popl %eax movl restorer(%eax),%eax movl %eax,%fs:(%edx) # flag/reg restorer movl %ecx,%fs:4(%edx) # signal nr movl EAX(%esp),%eax movl %eax,%fs:8(%edx) # old eax movl ECX(%esp),%eax movl %eax,%fs:12(%edx) # old ecx movl EDX(%esp),%eax movl %eax,%fs:16(%edx) # old edx movl EFLAGS(%esp),%eax movl %eax,%fs:20(%edx) # old eflags movl %ebx,%fs:24(%edx) # old return addr 3: popl %eax popl %ebx popl %ecx popl %edx pop %fs pop %es pop %ds iret default_signal: incl %ecx cmpl $SIG_CHLD,%ecx je 2b pushl %ecx call _do_exit # remember to set bit 7 when dumping core addl $4,%esp jmp 3b .align 2 _timer_interrupt: push %ds # save ds,es and put kernel data space push %es # into them. %fs is used by _system_call push %fs pushl %edx # we save %eax,%ecx,%edx as gcc doesn't pushl %ecx # save those across function calls. %ebx pushl %ebx # is saved as we use that in ret_sys_call pushl %eax movl $0x10,%eax mov %ax,%ds mov %ax,%es movl $0x17,%eax mov %ax,%fs incl _jiffies movb $0x20,%al # EOI to interrupt controller #1 outb %al,$0x20 movl CS(%esp),%eax andl $3,%eax # %eax is CPL (0 or 3, 0=supervisor) pushl %eax call _do_timer # 'do_timer(long CPL)' does everything from addl $4,%esp # task switching to accounting ... jmp ret_from_sys_call .align 2 _sys_execve: lea EIP(%esp),%eax pushl %eax call _do_execve addl $4,%esp ret .align 2 _sys_fork: call _find_empty_process testl %eax,%eax js 1f push %gs pushl %esi pushl %edi pushl %ebp pushl %eax call _copy_process addl $20,%esp 1: ret _hd_interrupt: pushl %eax pushl %ecx pushl %edx push %ds push %es push %fs movl $0x10,%eax mov %ax,%ds mov %ax,%es movl $0x17,%eax mov %ax,%fs movb $0x20,%al outb %al,$0x20 # EOI to interrupt controller #1 jmp 1f # give port chance to breathe 1: jmp 1f 1: outb %al,$0xA0 # same to controller #2 movl _do_hd,%eax testl %eax,%eax jne 1f movl $_unexpected_hd_interrupt,%eax 1: call %eax # "interesting" way of handling intr. pop %fs pop %es pop %ds popl %edx popl %ecx popl %eax iret |
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