Messages in this thread | | | From | David Laight <> | Subject | RE: [PATCH v2 1/4] tools/nolibc: sys.h: add __syscall() and __sysret() helpers | Date | Thu, 8 Jun 2023 14:35:49 +0000 |
| |
From: Zhangjin Wu > Sent: 06 June 2023 09:10 > > most of the library routines share the same code model, let's add two > helpers to simplify the coding and shrink the code lines too. > ... > +/* Syscall return helper, set errno as -ret when ret < 0 */ > +static inline __attribute__((always_inline)) long __sysret(long ret) > +{ > + if (ret < 0) { > + SET_ERRNO(-ret); > + ret = -1; > + } > + return ret; > +}
If that right? I thought that that only the first few (1024?) negative values got used as errno values.
Do all Linux architectures even use negatives for error? I thought at least some used the carry flag. (It is the historic method of indicating a system call failure.)
David
- Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
| |