Imbus/xv6-riscv-kernel
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Separate system call path from trap path. Passes usertests on 1 and 2 cpus.

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This commit is contained in:
Frans Kaashoek 2018-10-09 14:28:54 -04:00
parent f241e67d91
commit 54e6f829e4
8 changed files with 106 additions and 88 deletions
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26
proc.c
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@ -17,10 +17,8 @@ static struct proc *initproc;
int nextpid = 1;
extern void forkret(void);
// we can return two ways out of the kernel and
// for new processes we can choose either way
// for returning out of the kernel
extern void sysexit(void);
extern void trapret(void);
static void wakeup1(void *chan);
@ -102,16 +100,16 @@ found:
}
sp = p->kstack + KSTACKSIZE;
// Leave room for trap frame.
sp -= sizeof *p->tf;
// Leave room for syscall frame.
sp -= sizeof *p->sf;
if ((uint64) sp % 16)
panic("misaligned sp");
p->tf = (struct trapframe*)sp;
p->sf = (struct sysframe*)sp;
// Set up new context to start executing at forkret,
// which returns to trapret.
// which returns to sysexit.
sp -= sizeof(uint64);
*(uint64*)sp = (uint64)sysexit;
@ -138,12 +136,10 @@ userinit(void)
panic("userinit: out of memory?");
inituvm(p->pgdir, _binary_initcode_start, (uint64)_binary_initcode_size);
p->sz = PGSIZE;
memset(p->tf, 0, sizeof(*p->tf));
p->tf->cs = SEG_UCODE | DPL_USER;
p->tf->ss = SEG_UDATA | DPL_USER;
p->tf->r11 = FL_IF;
p->tf->rsp = PGSIZE;
p->tf->rcx = 0; // beginning of initcode.S
memset(p->sf, 0, sizeof(*p->sf));
p->sf->r11 = FL_IF;
p->sf->rsp = PGSIZE;
p->sf->rcx = 0; // beginning of initcode.S
safestrcpy(p->name, "initcode", sizeof(p->name));
p->cwd = namei("/");
@ -204,10 +200,10 @@ fork(void)
}
np->sz = curproc->sz;
np->parent = curproc;
*np->tf = *curproc->tf;
*np->sf = *curproc->sf;
// Clear %eax so that fork returns 0 in the child.
np->tf->rax = 0;
np->sf->rax = 0;
for(i = 0; i < NOFILE; i++)
if(curproc->ofile[i])