diff options
Diffstat (limited to 'src/kernel')
| -rw-r--r-- | src/kernel/mem/virt.c | 21 | ||||
| -rw-r--r-- | src/kernel/proc.c | 3 | ||||
| -rw-r--r-- | src/kernel/util.h | 10 | ||||
| -rw-r--r-- | src/kernel/vfs/request.c | 7 |
4 files changed, 22 insertions, 19 deletions
diff --git a/src/kernel/mem/virt.c b/src/kernel/mem/virt.c index a9450c7..1fa5a10 100644 --- a/src/kernel/mem/virt.c +++ b/src/kernel/mem/virt.c @@ -28,9 +28,9 @@ bool virt_iter_next(struct virt_iter *iter) { if (partial <= 0) return false; if (iter->_pages) { // if iterating over virtual memory - // don't read past the page - if (((uintptr_t)iter->_virt & PAGE_MASK) + partial > PAGE_SIZE) - partial = PAGE_SIZE - ((uintptr_t)iter->_virt & PAGE_MASK); + // don't cross page boundaries + size_t to_page = PAGE_SIZE - ((uintptr_t)iter->_virt & PAGE_MASK); + partial = min(partial, to_page); iter->frag = pagedir_virt2phys(iter->_pages, iter->_virt, iter->_user, iter->_writeable); @@ -56,7 +56,7 @@ bool virt_cpy( struct pagedir *src_pages, const void __user *src, size_t length) { struct virt_iter dest_iter, src_iter; - size_t min; + size_t cur_len; virt_iter_new(&dest_iter, dest, length, dest_pages, true, true); virt_iter_new( &src_iter, (userptr_t)src, length, src_pages, true, false); @@ -69,14 +69,13 @@ bool virt_cpy( if ( src_iter.frag_len <= 0) if (!virt_iter_next( &src_iter)) break; - min = src_iter.frag_len < dest_iter.frag_len - ? src_iter.frag_len : dest_iter.frag_len; - memcpy(dest_iter.frag, src_iter.frag, min); + cur_len = min(src_iter.frag_len, dest_iter.frag_len); + memcpy(dest_iter.frag, src_iter.frag, cur_len); - dest_iter.frag_len -= min; - dest_iter.frag += min; - src_iter.frag_len -= min; - src_iter.frag += min; + dest_iter.frag_len -= cur_len; + dest_iter.frag += cur_len; + src_iter.frag_len -= cur_len; + src_iter.frag += cur_len; } return !(dest_iter.error || src_iter.error); diff --git a/src/kernel/proc.c b/src/kernel/proc.c index 94fc419..13ce759 100644 --- a/src/kernel/proc.c +++ b/src/kernel/proc.c @@ -115,8 +115,7 @@ int process_try2collect(struct process *dead) { dead->state = PS_DEADER; parent->state = PS_RUNNING; - len = parent->death_msg.len < dead->death_msg.len - ? parent->death_msg.len : dead->death_msg.len; + len = min(parent->death_msg.len, dead->death_msg.len); res = virt_cpy( parent->pages, parent->death_msg.buf, dead->pages, dead->death_msg.buf, len); diff --git a/src/kernel/util.h b/src/kernel/util.h index b50810d..839aa49 100644 --- a/src/kernel/util.h +++ b/src/kernel/util.h @@ -8,3 +8,13 @@ void *memcpy(void *dest, const void *src, size_t n); void *memset(void *s, int c, size_t n); int memcmp(const void *s1, const void *s2, size_t n); + +// see https://gcc.gnu.org/onlinedocs/gcc/Typeof.html +#define min(a,b) ({ \ + typeof (a) _a = (a); \ + typeof (b) _b = (b); \ + _a < _b ? _a : _b; }) +#define max(a,b) ({ \ + typeof (a) _a = (a); \ + typeof (b) _b = (b); \ + _a > _b ? _a : _b; }) diff --git a/src/kernel/vfs/request.c b/src/kernel/vfs/request.c index fcd6c47..9826982 100644 --- a/src/kernel/vfs/request.c +++ b/src/kernel/vfs/request.c @@ -47,12 +47,7 @@ _Noreturn void vfs_request_pass2handler(struct vfs_request *req) { handler->state = PS_RUNNING; handler->handled_req = req; - len = handler->awaited_req.max_len; - if (len > req->input.len) { - // input bigger than buffer - // TODO what should be done during e.g. open() calls? truncating doesn't seem right - len = req->input.len; - } + len = min(req->input.len, handler->awaited_req.max_len); if (req->input.kern) { if (!virt_cpy_to(handler->pages, |