diff options
| -rw-r--r-- | bsd-user/mmap.c | 38 |
1 files changed, 36 insertions, 2 deletions
diff --git a/bsd-user/mmap.c b/bsd-user/mmap.c index f3a4f17..775e905 100644 --- a/bsd-user/mmap.c +++ b/bsd-user/mmap.c @@ -129,6 +129,40 @@ error: } /* + * Perform a pread on behalf of target_mmap. We can reach EOF, we can be + * interrupted by signals, and in general there's no good error return path. + * If @zero, zero the rest of the block at EOF. + * Return true on success. + */ +static bool mmap_pread(int fd, void *p, size_t len, off_t offset, bool zero) +{ + while (1) { + ssize_t r = pread(fd, p, len, offset); + + if (likely(r == len)) { + /* Complete */ + return true; + } + if (r == 0) { + /* EOF */ + if (zero) { + memset(p, 0, len); + } + return true; + } + if (r > 0) { + /* Short read */ + p += r; + len -= r; + offset += r; + } else if (errno != EINTR) { + /* Error */ + return false; + } + } +} + +/* * map an incomplete host page * * mmap_frag can be called with a valid fd, if flags doesn't contain one of @@ -190,7 +224,7 @@ static int mmap_frag(abi_ulong real_start, mprotect(host_start, qemu_host_page_size, prot1 | PROT_WRITE); /* read the corresponding file data */ - if (pread(fd, g2h_untagged(start), end - start, offset) == -1) { + if (!mmap_pread(fd, g2h_untagged(start), end - start, offset, true)) { return -1; } @@ -565,7 +599,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot, -1, 0); if (retaddr == -1) goto fail; - if (pread(fd, g2h_untagged(start), len, offset) == -1) { + if (!mmap_pread(fd, g2h_untagged(start), len, offset, false)) { goto fail; } if (!(prot & PROT_WRITE)) { |