Resolve /proc/thread-self/* in syscall interception code. #101
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When intercepting system calls that use filepaths as arguments, those paths may be regular paths or may be paths under /proc (e.g., "/proc/self/fd/<num>", "/proc/self/task/<tid>/fd/<num>", or "/proc/thread-self/fd/<num>"). Sysbox was dealing properly with the first two but not with the last one (i.e., "/proc/thread-self/*"). This went unnoticed until a recent change in the OCI runc (commit 8e8b136c4923ac33567c4cb775c6c8a17749fd02) where it's now using "/proc/thread-self/<path>" in mount system calls it issues. When that new OCI runc ran inside a Sysbox container, it failed with an error such as: "error mounting "proc" to rootfs at "/proc": mount src=proc, dst=/proc, dstFd=/proc/thread-self/fd/8, flags=0xe: no such file or directory: unknown." See nestybox/sysbox#879 for further info. This commit fixes this by updating Sysbox to deal properly with syscalls that have "/proc/thread-self/*" in their arguments. Signed-off-by: Cesar Talledo <cesar.talledo@docker.com>
rodnymolina
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Dec 5, 2024
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When intercepting system calls that use filepaths as arguments, those paths may be regular paths or may be paths under /proc (e.g., "/proc/self/fd/", "/proc/self/task//fd/", or "/proc/thread-self/fd/"). Sysbox was dealing properly with the first two but not with the last one (i.e., "/proc/thread-self/*").
This went unnoticed until a recent change in the OCI runc (commit 8e8b136c4923ac33567c4cb775c6c8a17749fd02) where it's now using "/proc/thread-self/" in mount system calls it issues. When that new OCI runc ran inside a Sysbox container, it failed with an error such as:
"error mounting "proc" to rootfs at "/proc": mount src=proc, dst=/proc, dstFd=/proc/thread-self/fd/8, flags=0xe: no such file or directory: unknown."
See nestybox/sysbox#879 for further info.
This commit fixes this by updating Sysbox to deal properly with syscalls that have "/proc/thread-self/*" in their arguments.