kernel/linux.git/tools/include/nolibc/stdlib.h, branch v6.12.80

tools/nolibc: implement strtol() and friends

2024-06-29T07:44:55+00:00

The implementation always works on uintmax_t values. This is inefficient when only 32bit are needed. However for all functions this only happens for strtol() on 32bit platforms. Signed-off-by: Thomas Weißschuh Acked-by: Willy Tarreau Link: https://lore.kernel.org/r/20240425-nolibc-strtol-v1-2-bfeef7846902@weissschuh.net

tools/nolibc/stdlib: fix memory error in realloc()

2024-04-10T21:19:00+00:00

Pass user_p_len to memcpy() instead of heap->len to prevent realloc() from copying an extra sizeof(heap) bytes from beyond the allocated region. Signed-off-by: Brennan Xavier McManus Cc: stable@vger.kernel.org Reviewed-by: Ammar Faizi Fixes: 0e0ff638400be8f497a35b51a4751fd823f6bd6a ("tools/nolibc/stdlib: Implement `malloc()`, `calloc()`, `realloc()` and `free()`") Signed-off-by: Willy Tarreau Signed-off-by: Thomas Weißschuh

tools/nolibc: completely remove optional environ support

2023-08-23T02:40:22+00:00

In commit 52e423f5b93e ("tools/nolibc: export environ as a weak symbol on i386") and friends the asm startup logic was extended to directly populate the "environ" array. This makes it impossible for "environ" to be dropped by the linker. Therefore also drop the other logic to handle non-present "environ". Also add a testcase to validate the initialization of environ. Signed-off-by: Thomas Weißschuh Signed-off-by: Willy Tarreau

tools/nolibc: use inline syntax

2023-06-09T18:46:07+00:00

When building in strict C89 mode the "inline" keyword is unknown. While "__inline__" is non-standard it is used by the kernel headers themselves. So the used compilers would have to support it or the users shim it with a #define. Signed-off-by: Thomas Weißschuh Signed-off-by: Willy Tarreau Signed-off-by: Paul E. McKenney

nolibc/stdlib: Implement `getauxval(3)` function

2023-01-10T21:33:56+00:00

Previous commits save the address of the auxiliary vector into a global variable @_auxv. This commit creates a new function 'getauxval()' as a helper function to get the auxv value based on the given key. The behavior of this function is identic with the function documented in 'man 3 getauxval'. This function is also needed to implement 'getpagesize()' function that we will wire up in the next patches. Signed-off-by: Ammar Faizi Signed-off-by: Willy Tarreau Signed-off-by: Paul E. McKenney

tools/nolibc: fix missing includes causing build issues at -O0

2023-01-09T17:36:05+00:00

After the nolibc includes were split to facilitate portability from standard libcs, programs that include only what they need may miss some symbols which are needed by libgcc. This is the case for raise() which is needed by the divide by zero code in some architectures for example. Regardless, being able to include only the apparently needed files is convenient. Instead of trying to move all exported definitions to a single file, since this can change over time, this patch takes another approach consisting in including the nolibc header at the end of all standard include files. This way their types and functions are already known at the moment of inclusion, and including any single one of them is sufficient to bring all the required ones. Signed-off-by: Willy Tarreau Signed-off-by: Paul E. McKenney

tools/nolibc/stdlib: Support overflow checking for older compiler versions

2022-06-20T16:43:19+00:00

Previously, we used __builtin_mul_overflow() to check for overflow in the multiplication operation in the calloc() function. However, older compiler versions don't support this built-in. This patch changes the overflow checking mechanism to make it work on any compiler version by using a division method to check for overflow. No functional change intended. While in there, remove the unused variable `void *orig`. Link: https://lore.kernel.org/lkml/20220330024114.GA18892@1wt.eu Suggested-by: Willy Tarreau Cc: Alviro Iskandar Setiawan Signed-off-by: Ammar Faizi Acked-by: Willy Tarreau Reviewed-by: Alviro Iskandar Setiawan Signed-off-by: Paul E. McKenney

tools/nolibc/stdlib: Implement `malloc()`, `calloc()`, `realloc()` and `free()`

2022-04-21T00:05:46+00:00

Implement basic dynamic allocator functions. These functions are currently only available on architectures that have nolibc mmap() syscall implemented. These are not a super-fast memory allocator, but at least they can satisfy basic needs for having heap without libc. Cc: David Laight Acked-by: Willy Tarreau Signed-off-by: Ammar Faizi Signed-off-by: Paul E. McKenney

tools/nolibc/stdlib: only reference the external environ when inlined

2022-04-21T00:05:46+00:00

When building with gcc at -O0 we're seeing link errors due to the "environ" variable being referenced by getenv(). The problem is that at -O0 gcc will not inline getenv() and will not drop the external reference. One solution would be to locally declare the variable as weak, but then it would appear in all programs even those not using it, and would be confusing to users of getenv() who would forget to set environ to envp. An alternate approach used in this patch consists in always inlining the outer part of getenv() that references this extern so that it's always dropped when not used. The biggest part of the function was now moved to a new function called _getenv() that's still not inlined by default. Reported-by: Ammar Faizi Signed-off-by: Willy Tarreau Tested-by: Ammar Faizi Signed-off-by: Paul E. McKenney

tools/nolibc/stdlib: add a simple getenv() implementation

2022-04-21T00:05:45+00:00

This implementation relies on an extern definition of the environ variable, that the caller must declare and initialize from envp. Signed-off-by: Willy Tarreau Signed-off-by: Paul E. McKenney

kernel/linux.git/tools/include/nolibc/stdlib.h, branch v6.12.80

tools/nolibc: implement strtol() and friends

tools/nolibc/stdlib: fix memory error in realloc()

tools/nolibc: completely remove optional environ support

tools/nolibc: use __inline__ syntax

nolibc/stdlib: Implement `getauxval(3)` function

tools/nolibc: fix missing includes causing build issues at -O0

tools/nolibc/stdlib: Support overflow checking for older compiler versions

tools/nolibc/stdlib: Implement `malloc()`, `calloc()`, `realloc()` and `free()`

tools/nolibc/stdlib: only reference the external environ when inlined

tools/nolibc/stdlib: add a simple getenv() implementation

tools/nolibc: use inline syntax