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Where Do the Bytes Go?
where do the bytes go? Or perhaps more precisely, how do they get there? What happens when you call write? trap The write function in libc sets things up and makes the system call, which probably enters somewhere in locore.s like Xsyscall_meltdown, but eventually we end up in syscall in arch/amd64/amd64/trap.c. Or we might be in svc_handler in arch/arm64/arm64/syscall.c.
The write function in libc sets things up and makes the system call, which probably enters somewhere in locore.s like Xsyscall_meltdown, but eventually we end up in syscall in arch/amd64/amd64/trap.c. There’s a full page of code just checking for debug flags and trace points and stack validity and also pledge and pins. There’s quite a bit going on here, but the short version is we’re setting up a reasonable transfer size, and getting a buffer from the cache for the correct disk location.
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