lkl: remove string functions duplicate implementation #590
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Looks like a nice cleanup. One concern: lkl_ops is set at run-time, so we could have a "posix" host call lkl_init() with e.g. lkl_host_operations.memset = NULL.
It looks as though the main reason for using run-time ops instead of build-time is for overloading the print() hook, so perhaps we could switch the API to use build-time ops and provide print() hooks elsewhere? Another (simpler) option would be to fail lkl_init() if any of the mem ops are NULL alongside CONFIG_LKL_HOST_MEM*=y.
Good catch!
The original intent was to have LKL distributed as a shared library and allow external applications to override run-time ops. In practice, because we lack support for modules the former is not yet achievable. On one hand having runtime host ops gives more flexibility to applications, on the other hand built-time host ops would probably give a nice performance boost.
Yes, this is a good option while we discuss more built-in vs run-time host ops. I'll send another version to add these checks. |
arch/lkl/kernel/init.c
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| @@ -6,6 +6,25 @@ int lkl_init(struct lkl_host_operations *ops) | |||
| { | |||
| lkl_ops = ops; | |||
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Please put this after the config checks. I don't think lkl_ops should be initialized on failure...
(edit: kasan_init() failure should probably leave it unset too, but that can be done separately)
| return -1; | ||
| } | ||
| #endif | ||
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coding-style.rst encourages avoiding #ifdef CONFIG_... outside of header files. How about something like:
if ((IS_ENABLED(CONFIG_LKL_HOST_MEMCPY) && !ops->memcpy)
|| (IS_ENABLED(CONFIG_LKL_HOST_MEMSET) && !ops->memset)
|| (IS_ENABLED(CONFIG_LKL_HOST_MEMMOVE) && !ops->memmove)) {
lkl_printf("unexpected NULL lkl_host_ops memory I/O call\n");
return -1;
}
The compiler should still be able to optimize it out for non-posix hosts.
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arch/lkl/kernel/init.c
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| @@ -4,6 +4,15 @@ | |||
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| int lkl_init(struct lkl_host_operations *ops) | |||
| { | |||
| int ret; | |||
Now that we have the ability to set kernel config options per host built we can avoid duplicating the implementation for string functions that may be provided by the host (e.g. memcpy, memset). Signed-off-by: Octavian Purdila <[email protected]>
Check lkl_init for failures. Print the log buffer in case of failures, to make debugging easier. Signed-off-by: Octavian Purdila <[email protected]>
Now that we have the ability to set kernel config options per host built we can avoid duplicating the implementation for string functions that may be provided by the host (e.g. memcpy, memset).
Fixes: #582