diff options
Diffstat (limited to 'pk/syscall.c')
| -rw-r--r-- | pk/syscall.c | 234 |
1 files changed, 177 insertions, 57 deletions
diff --git a/pk/syscall.c b/pk/syscall.c index e6916a2..bfc95ec 100644 --- a/pk/syscall.c +++ b/pk/syscall.c @@ -3,9 +3,11 @@ #include "syscall.h" #include "pk.h" #include "file.h" +#include "bits.h" #include "frontend.h" #include "mmap.h" #include "boot.h" +#include "usermem.h" #include <string.h> #include <errno.h> @@ -13,6 +15,8 @@ typedef long (*syscall_t)(long, long, long, long, long, long, long); #define CLOCK_FREQ 1000000000 +#define MAX_BUF 512 + void sys_exit(int code) { if (current.cycle0) { @@ -33,10 +37,25 @@ ssize_t sys_read(int fd, char* buf, size_t n) { ssize_t r = -EBADF; file_t* f = file_get(fd); + char kbuf[MAX_BUF]; + + if (f) { + for (size_t total = 0; ; ) { + size_t cur = MIN(n - total, MAX_BUF); + r = file_read(f, kbuf, cur); + if (r < 0) + break; + + memcpy_to_user(buf, kbuf, r); + + total += r; + buf += r; + if (r < cur || total == n) { + r = total; + break; + } + } - if (f) - { - r = file_read(f, buf, n); file_decref(f); } @@ -47,10 +66,26 @@ ssize_t sys_pread(int fd, char* buf, size_t n, off_t offset) { ssize_t r = -EBADF; file_t* f = file_get(fd); + char kbuf[MAX_BUF]; + + if (f) { + for (size_t total = 0; ; ) { + size_t cur = MIN(n - total, MAX_BUF); + r = file_pread(f, kbuf, cur, offset); + if (r < 0) + break; + + memcpy_to_user(buf, kbuf, r); + + total += r; + buf += r; + offset += r; + if (r < cur || total == n) { + r = total; + break; + } + } - if (f) - { - r = file_pread(f, buf, n, offset); file_decref(f); } @@ -61,10 +96,26 @@ ssize_t sys_write(int fd, const char* buf, size_t n) { ssize_t r = -EBADF; file_t* f = file_get(fd); + char kbuf[MAX_BUF]; + + if (f) { + for (size_t total = 0; ; ) { + size_t cur = MIN(n - total, MAX_BUF); + memcpy_from_user(kbuf, buf, cur); + + r = file_write(f, kbuf, cur); + + if (r < 0) + break; + + total += r; + buf += r; + if (r < cur || total == n) { + r = total; + break; + } + } - if (f) - { - r = file_write(f, buf, n); file_decref(f); } @@ -85,7 +136,11 @@ int sys_openat(int dirfd, const char* name, int flags, int mode) { int kfd = at_kfd(dirfd); if (kfd != -1) { - file_t* file = file_openat(kfd, name, flags, mode); + char kname[MAX_BUF]; + if (!strcpy_from_user(kname, name, MAX_BUF)) + return -ENAMETOOLONG; + + file_t* file = file_openat(kfd, kname, flags, mode); if (IS_ERR_VALUE(file)) return PTR_ERR(file); @@ -114,13 +169,19 @@ int sys_close(int fd) } int sys_renameat(int old_fd, const char *old_path, int new_fd, const char *new_path) { + int old_kfd = at_kfd(old_fd); int new_kfd = at_kfd(new_fd); if(old_kfd != -1 && new_kfd != -1) { - size_t old_size = strlen(old_path)+1; - size_t new_size = strlen(new_path)+1; - return frontend_syscall(SYS_renameat, old_kfd, va2pa(old_path), old_size, - new_kfd, va2pa(new_path), new_size, 0); + char kold_path[MAX_BUF], knew_path[MAX_BUF]; + if (!strcpy_from_user(kold_path, old_path, MAX_BUF) || !strcpy_from_user(knew_path, new_path, MAX_BUF)) + return -ENAMETOOLONG; + + size_t old_size = strlen(kold_path)+1; + size_t new_size = strlen(knew_path)+1; + + return frontend_syscall(SYS_renameat, old_kfd, kva2pa(kold_path), old_size, + new_kfd, kva2pa(knew_path), new_size, 0); } return -EBADF; } @@ -133,8 +194,8 @@ int sys_fstat(int fd, void* st) if (f) { struct frontend_stat buf; - r = frontend_syscall(SYS_fstat, f->kfd, va2pa(&buf), 0, 0, 0, 0, 0); - memcpy(st, &buf, sizeof(buf)); + r = frontend_syscall(SYS_fstat, f->kfd, kva2pa(&buf), 0, 0, 0, 0, 0); + memcpy_to_user(st, &buf, sizeof(buf)); file_decref(f); } @@ -215,8 +276,14 @@ ssize_t sys_lseek(int fd, size_t ptr, int dir) long sys_lstat(const char* name, void* st) { struct frontend_stat buf; - size_t name_size = strlen(name)+1; - long ret = frontend_syscall(SYS_lstat, va2pa(name), name_size, va2pa(&buf), 0, 0, 0, 0); + + char kname[MAX_BUF]; + if (!strcpy_from_user(kname, name, MAX_BUF)) + return -ENAMETOOLONG; + + size_t name_size = strlen(kname)+1; + + long ret = frontend_syscall(SYS_lstat, kva2pa(kname), name_size, kva2pa(&buf), 0, 0, 0, 0); memcpy(st, &buf, sizeof(buf)); return ret; } @@ -226,9 +293,15 @@ long sys_fstatat(int dirfd, const char* name, void* st, int flags) int kfd = at_kfd(dirfd); if (kfd != -1) { struct frontend_stat buf; - size_t name_size = strlen(name)+1; - long ret = frontend_syscall(SYS_fstatat, kfd, va2pa(name), name_size, va2pa(&buf), flags, 0, 0); - memcpy(st, &buf, sizeof(buf)); + + char kname[MAX_BUF]; + if (!strcpy_from_user(kname, name, MAX_BUF)) + return -ENAMETOOLONG; + + size_t name_size = strlen(kname)+1; + + long ret = frontend_syscall(SYS_fstatat, kfd, kva2pa(kname), name_size, kva2pa(&buf), flags, 0, 0); + memcpy_to_user(st, &buf, sizeof(buf)); return ret; } return -EBADF; @@ -262,8 +335,13 @@ long sys_faccessat(int dirfd, const char *name, int mode) { int kfd = at_kfd(dirfd); if (kfd != -1) { - size_t name_size = strlen(name)+1; - return frontend_syscall(SYS_faccessat, kfd, va2pa(name), name_size, mode, 0, 0, 0); + char kname[MAX_BUF]; + if (!strcpy_from_user(kname, name, MAX_BUF)) + return -ENAMETOOLONG; + + size_t name_size = strlen(kname)+1; + + return frontend_syscall(SYS_faccessat, kfd, kva2pa(kname), name_size, mode, 0, 0, 0); } return -EBADF; } @@ -278,10 +356,16 @@ long sys_linkat(int old_dirfd, const char* old_name, int new_dirfd, const char* int old_kfd = at_kfd(old_dirfd); int new_kfd = at_kfd(new_dirfd); if (old_kfd != -1 && new_kfd != -1) { - size_t old_size = strlen(old_name)+1; - size_t new_size = strlen(new_name)+1; - return frontend_syscall(SYS_linkat, old_kfd, va2pa(old_name), old_size, - new_kfd, va2pa(new_name), new_size, + + char kold_name[MAX_BUF], knew_name[MAX_BUF]; + if (!strcpy_from_user(kold_name, old_name, MAX_BUF) || !strcpy_from_user(knew_name, new_name, MAX_BUF)) + return -ENAMETOOLONG; + + size_t old_size = strlen(kold_name)+1; + size_t new_size = strlen(knew_name)+1; + + return frontend_syscall(SYS_linkat, old_kfd, kva2pa(kold_name), old_size, + new_kfd, kva2pa(knew_name), new_size, flags); } return -EBADF; @@ -296,8 +380,13 @@ long sys_unlinkat(int dirfd, const char* name, int flags) { int kfd = at_kfd(dirfd); if (kfd != -1) { - size_t name_size = strlen(name)+1; - return frontend_syscall(SYS_unlinkat, kfd, va2pa(name), name_size, flags, 0, 0, 0); + char kname[MAX_BUF]; + if (!strcpy_from_user(kname, name, MAX_BUF)) + return -ENAMETOOLONG; + + size_t name_size = strlen(kname)+1; + + return frontend_syscall(SYS_unlinkat, kfd, kva2pa(kname), name_size, flags, 0, 0, 0); } return -EBADF; } @@ -311,8 +400,13 @@ long sys_mkdirat(int dirfd, const char* name, int mode) { int kfd = at_kfd(dirfd); if (kfd != -1) { - size_t name_size = strlen(name)+1; - return frontend_syscall(SYS_mkdirat, kfd, va2pa(name), name_size, mode, 0, 0, 0); + char kname[MAX_BUF]; + if (!strcpy_from_user(kname, name, MAX_BUF)) + return -ENAMETOOLONG; + + size_t name_size = strlen(kname)+1; + + return frontend_syscall(SYS_mkdirat, kfd, kva2pa(kname), name_size, mode, 0, 0, 0); } return -EBADF; } @@ -322,10 +416,13 @@ long sys_mkdir(const char* name, int mode) return sys_mkdirat(AT_FDCWD, name, mode); } -long sys_getcwd(const char* buf, size_t size) +long sys_getcwd(char* buf, size_t size) { - populate_mapping(buf, size, PROT_WRITE); - return frontend_syscall(SYS_getcwd, va2pa(buf), size, 0, 0, 0, 0, 0); + char kbuf[MAX_BUF]; + long ret = frontend_syscall(SYS_getcwd, kva2pa(kbuf), MIN(size, MAX_BUF), 0, 0, 0, 0, 0); + if (ret == 0) + memcpy_to_user(buf, kbuf, strlen(kbuf) + 1); + return ret; } size_t sys_brk(size_t pos) @@ -335,13 +432,19 @@ size_t sys_brk(size_t pos) int sys_uname(void* buf) { - const int sz = 65; - strcpy(buf + 0*sz, "Proxy Kernel"); - strcpy(buf + 1*sz, ""); - strcpy(buf + 2*sz, "4.15.0"); - strcpy(buf + 3*sz, ""); - strcpy(buf + 4*sz, ""); - strcpy(buf + 5*sz, ""); + const int sz = 65, sz_total = sz * 6; + char kbuf[sz_total]; + memset(kbuf, 0, sz_total); + + strcpy(kbuf + 0*sz, "Proxy Kernel"); + strcpy(kbuf + 1*sz, ""); + strcpy(kbuf + 2*sz, "4.15.0"); + strcpy(kbuf + 3*sz, ""); + strcpy(kbuf + 4*sz, ""); + strcpy(kbuf + 5*sz, ""); + + memcpy_to_user(buf, kbuf, sz_total); + return 0; } @@ -382,17 +485,19 @@ uintptr_t sys_mprotect(uintptr_t addr, size_t length, int prot) int sys_rt_sigaction(int sig, const void* act, void* oact, size_t sssz) { - if (oact) - memset(oact, 0, sizeof(long) * 3); + if (oact) { + long koact[3] = {0}; + memcpy_to_user(oact, koact, sizeof(koact)); + } return 0; } long sys_time(long* loc) { - uint64_t t = rdcycle64() / CLOCK_FREQ; + long t = (long)(rdcycle64() / CLOCK_FREQ); if (loc) - *loc = t; + memcpy_to_user(loc, &t, sizeof(t)); return t; } @@ -400,10 +505,11 @@ int sys_times(long* loc) { uint64_t t = rdcycle64(); kassert(CLOCK_FREQ % 1000000 == 0); - loc[0] = t / (CLOCK_FREQ / 1000000); - loc[1] = 0; - loc[2] = 0; - loc[3] = 0; + + long kloc[4] = {0}; + kloc[0] = t / (CLOCK_FREQ / 1000000); + + memcpy_to_user(loc, kloc, sizeof(kloc)); return 0; } @@ -411,8 +517,12 @@ int sys_times(long* loc) int sys_gettimeofday(long* loc) { uint64_t t = rdcycle64(); - loc[0] = t / CLOCK_FREQ; - loc[1] = (t % CLOCK_FREQ) / (CLOCK_FREQ / 1000000); + + long kloc[2]; + kloc[0] = t / CLOCK_FREQ; + kloc[1] = (t % CLOCK_FREQ) / (CLOCK_FREQ / 1000000); + + memcpy_to_user(loc, kloc, sizeof(kloc)); return 0; } @@ -420,8 +530,12 @@ int sys_gettimeofday(long* loc) long sys_clock_gettime(int clk_id, long *loc) { uint64_t t = rdcycle64(); - loc[0] = t / CLOCK_FREQ; - loc[1] = (t % CLOCK_FREQ) / (CLOCK_FREQ / 1000000000); + + long kloc[2]; + kloc[0] = t / CLOCK_FREQ; + kloc[1] = (t % CLOCK_FREQ) / (CLOCK_FREQ / 1000000000); + + memcpy_to_user(loc, kloc, sizeof(kloc)); return 0; } @@ -429,9 +543,11 @@ long sys_clock_gettime(int clk_id, long *loc) ssize_t sys_writev(int fd, const long* iov, int cnt) { ssize_t ret = 0; - for (int i = 0; i < cnt; i++) - { - ssize_t r = sys_write(fd, (void*)iov[2*i], iov[2*i+1]); + for (int i = 0; i < cnt; i++) { + long kiov[2]; + memcpy_from_user(kiov, iov + 2*i, 2*sizeof(long)); + + ssize_t r = sys_write(fd, (void*)kiov[0], kiov[1]); if (r < 0) return r; ret += r; @@ -441,7 +557,11 @@ ssize_t sys_writev(int fd, const long* iov, int cnt) int sys_chdir(const char *path) { - return frontend_syscall(SYS_chdir, va2pa(path), 0, 0, 0, 0, 0, 0); + char kbuf[MAX_BUF]; + if (!strcpy_from_user(kbuf, path, MAX_BUF)) + return -ENAMETOOLONG; + + return frontend_syscall(SYS_chdir, kva2pa(kbuf), 0, 0, 0, 0, 0, 0); } int sys_getdents(int fd, void* dirbuf, int count) |