kernel: syscalls now have to explicitly save the return value

thus they can opt out of doing that

so the calls which might return immediately but can return later don't
have to both regs_savereturn and return to the caller.
and because of that, the return values of a lot of VFS things have just
got way saner

1 files changed, 2 insertions, 1 deletions

diff --git a/src/kernel/arch/i386/registers.h b/src/kernel/arch/i386/registers.h
index 8bd090d..9f481d3 100644
--- a/src/kernel/arch/i386/registers.h
+++ b/src/kernel/arch/i386/registers.h
@@ -14,7 +14,8 @@ struct registers {
 } __attribute__((__packed__));
 
 // saves a return value according to the SysV ABI
-static inline void regs_savereturn(struct registers *regs, uint64_t value) {
+static inline uint64_t regs_savereturn(struct registers *regs, uint64_t value) {
 	regs->eax = value;
 	regs->edx = value >> 32;
+	return value;
 }