Message ID | 20230708054249.10245-2-deller@gmx.de |
---|---|
State | New |
Headers | show |
Series | linux-user: Fix fcntl64() and accept4() for 32-bit targets | expand |
On 7/8/23 06:42, Helge Deller wrote: > When running a 32-bit guest on a 64-bit host, fcntl[64](F_GETFL) should > return with the TARGET_O_LARGEFILE flag set, because all 64-bit hosts > support large files unconditionally. > > But on 64-bit hosts, O_LARGEFILE has the value 0, so the flag > translation can't be done with the fcntl_flags_tbl[]. Instead add the > TARGET_O_LARGEFILE flag afterwards. > > Note that for 64-bit guests the compiler will optimize away this code, > since TARGET_O_LARGEFILE is zero. > > Signed-off-by: Helge Deller<deller@gmx.de> > --- > linux-user/syscall.c | 4 ++++ > 1 file changed, 4 insertions(+) Reviewed-by: Richard Henderson <richard.henderson@linaro.org> r~
diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 08162cc966..10f05b1e55 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -7132,6 +7132,10 @@ static abi_long do_fcntl(int fd, int cmd, abi_ulong arg) ret = get_errno(safe_fcntl(fd, host_cmd, arg)); if (ret >= 0) { ret = host_to_target_bitmask(ret, fcntl_flags_tbl); + /* tell 32-bit guests it uses largefile on 64-bit hosts: */ + if (O_LARGEFILE == 0 && HOST_LONG_BITS == 64) { + ret |= TARGET_O_LARGEFILE; + } } break;
When running a 32-bit guest on a 64-bit host, fcntl[64](F_GETFL) should return with the TARGET_O_LARGEFILE flag set, because all 64-bit hosts support large files unconditionally. But on 64-bit hosts, O_LARGEFILE has the value 0, so the flag translation can't be done with the fcntl_flags_tbl[]. Instead add the TARGET_O_LARGEFILE flag afterwards. Note that for 64-bit guests the compiler will optimize away this code, since TARGET_O_LARGEFILE is zero. Signed-off-by: Helge Deller <deller@gmx.de> --- linux-user/syscall.c | 4 ++++ 1 file changed, 4 insertions(+) -- 2.41.0