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Bruno Meneguele authored
The commit 625d3449 ("Revert "kernel/printk: add kmsg SEEK_CUR handling"") reverted a change done to the return value in case a SEEK_CUR operation was performed for kmsg buffer based on the fact that different userspace apps were handling the new return value (-ESPIPE) in different ways, breaking them. At the same time -ESPIPE was the wrong decision because kmsg /does support/ seek() but doesn't follow the "normal" behavior userspace is used to. Because of that and also considering the time -EINVAL has been used, it was decided to keep this way to avoid more userspace breakage. This patch adds an official statement to the kmsg documentation pointing to the current return value for SEEK_CUR, -EINVAL, thus userspace libraries and apps can refer to it for a definitive guide on what to expect. Signed-off-by:
Bruno Meneguele <bmeneg@redhat.com> Reviewed-by:
Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by:
Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20200710174423.10480-1-bmeneg@redhat.com
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