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author | Frans Kaashoek <[email protected]> | 2012-08-22 20:20:17 -0400 |
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committer | Frans Kaashoek <[email protected]> | 2012-08-22 20:20:17 -0400 |
commit | 432acbaf9e8817e16026bfcaaa8bca0ba7c8a6f8 (patch) | |
tree | 0b107cc92179b5b936d36174ff5af87e8fd3eec8 | |
parent | 4ce832ddd280a4cea36e16115ddeaea74213314e (diff) | |
parent | 9d59eb015141697da616a4b98ac27cf4269cd780 (diff) | |
download | xv6-labs-432acbaf9e8817e16026bfcaaa8bca0ba7c8a6f8.tar.gz xv6-labs-432acbaf9e8817e16026bfcaaa8bca0ba7c8a6f8.tar.bz2 xv6-labs-432acbaf9e8817e16026bfcaaa8bca0ba7c8a6f8.zip |
Merge branch 'master' of git+ssh://amsterdam.csail.mit.edu/home/am0/6.828/xv6
-rw-r--r-- | bio.c | 4 | ||||
-rw-r--r-- | defs.h | 4 | ||||
-rw-r--r-- | file.c | 8 | ||||
-rw-r--r-- | log.c | 1 | ||||
-rw-r--r-- | syscall.c | 18 | ||||
-rw-r--r-- | sysfile.c | 10 |
6 files changed, 28 insertions, 17 deletions
@@ -79,9 +79,9 @@ bget(uint dev, uint sector) } } - // Not cached; recycle some existing buffer. + // Not cached; recycle some non-busy and clean buffer. for(b = bcache.head.prev; b != &bcache.head; b = b->prev){ - if((b->flags & B_BUSY) == 0){ + if((b->flags & B_BUSY) == 0 && (b->flags & B_DIRTY) == 0){ b->dev = dev; b->sector = sector; b->flags = B_BUSY; @@ -142,8 +142,8 @@ char* strncpy(char*, const char*, int); int argint(int, int*); int argptr(int, char**, int); int argstr(int, char**); -int fetchint(struct proc*, uint, int*); -int fetchstr(struct proc*, uint, char**); +int fetchint(uint, int*); +int fetchstr(uint, char**); void syscall(void); // timer.c @@ -1,3 +1,7 @@ +// +// File descriptors +// + #include "types.h" #include "defs.h" #include "param.h" @@ -87,7 +91,7 @@ filestat(struct file *f, struct stat *st) return -1; } -// Read from file f. Addr is kernel address. +// Read from file f. int fileread(struct file *f, char *addr, int n) { @@ -108,7 +112,7 @@ fileread(struct file *f, char *addr, int n) } //PAGEBREAK! -// Write to file f. Addr is kernel address. +// Write to file f. int filewrite(struct file *f, char *addr, int n) { @@ -177,6 +177,7 @@ log_write(struct buf *b) brelse(lbuf); if (i == log.lh.n) log.lh.n++; + b->flags |= B_DIRTY; // XXX prevent eviction } //PAGEBREAK! @@ -13,28 +13,28 @@ // library system call function. The saved user %esp points // to a saved program counter, and then the first argument. -// Fetch the int at addr from process p. +// Fetch the int at addr from the current process. int -fetchint(struct proc *p, uint addr, int *ip) +fetchint(uint addr, int *ip) { - if(addr >= p->sz || addr+4 > p->sz) + if(addr >= proc->sz || addr+4 > proc->sz) return -1; *ip = *(int*)(addr); return 0; } -// Fetch the nul-terminated string at addr from process p. +// Fetch the nul-terminated string at addr from the current process. // Doesn't actually copy the string - just sets *pp to point at it. // Returns length of string, not including nul. int -fetchstr(struct proc *p, uint addr, char **pp) +fetchstr(uint addr, char **pp) { char *s, *ep; - if(addr >= p->sz) + if(addr >= proc->sz) return -1; *pp = (char*)addr; - ep = (char*)p->sz; + ep = (char*)proc->sz; for(s = *pp; s < ep; s++) if(*s == 0) return s - *pp; @@ -45,7 +45,7 @@ fetchstr(struct proc *p, uint addr, char **pp) int argint(int n, int *ip) { - return fetchint(proc, proc->tf->esp + 4 + 4*n, ip); + return fetchint(proc->tf->esp + 4 + 4*n, ip); } // Fetch the nth word-sized system call argument as a pointer @@ -74,7 +74,7 @@ argstr(int n, char **pp) int addr; if(argint(n, &addr) < 0) return -1; - return fetchstr(proc, addr, pp); + return fetchstr(addr, pp); } extern int sys_chdir(void); @@ -1,3 +1,9 @@ +// +// File-system system calls. +// Mostly argument checking, since we don't trust +// user code, and calls into file.c and fs.c. +// + #include "types.h" #include "defs.h" #include "param.h" @@ -382,13 +388,13 @@ sys_exec(void) for(i=0;; i++){ if(i >= NELEM(argv)) return -1; - if(fetchint(proc, uargv+4*i, (int*)&uarg) < 0) + if(fetchint(uargv+4*i, (int*)&uarg) < 0) return -1; if(uarg == 0){ argv[i] = 0; break; } - if(fetchstr(proc, uarg, &argv[i]) < 0) + if(fetchstr(uarg, &argv[i]) < 0) return -1; } return exec(path, argv); |