diff options
Diffstat (limited to 'include/setjmp.h')
| -rw-r--r-- | include/setjmp.h | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/include/setjmp.h b/include/setjmp.h index 37d3a8af85d..32dd48803e9 100644 --- a/include/setjmp.h +++ b/include/setjmp.h @@ -3,12 +3,27 @@ #ifndef _SETJMP_H_ #define _SETJMP_H_ 1 +/** + * DOC: Overview + * + * The long jump API allows to perform nonlocal gotos, that is jump from one + * function to another typically further down in the stack, while properly + * restoring the stack's state (unwinding). The two functions needed to do this + * are setjmp() and longjmp(). + * + * In addition to these two standard POSIX.1-2001/C89 functions, a third one is + * present in U-Boot: initjmp(). It is an extension which allows to implement + * user-mode threads. + */ + #ifdef CONFIG_HAVE_SETJMP #include <asm/setjmp.h> #else struct jmp_buf_data { }; #endif +#include <linux/compiler_attributes.h> +#include <stddef.h> /** * typedef jmp_buf - information needed to restore a calling environment @@ -37,4 +52,21 @@ int setjmp(jmp_buf env); */ void longjmp(jmp_buf env, int val); +/** + * initjmp() - prepare for a long jump to a given function with a given stack + * + * This function sets up a jump buffer for later use with longjmp(). It allows + * to branch to a specific function with a specific stack. Please note that + * @func MUST NOT return. It shall typically restore the main stack and resume + * execution by doing a long jump to a jump buffer initialized by setjmp() + * before the long jump. initjmp() allows to implement multithreading. + * + * @env: jump buffer + * @func: function to be called on longjmp(), MUST NOT RETURN + * @stack_base: the stack to be used by @func (lower address) + * @stack_sz: the stack size in bytes + */ +int initjmp(jmp_buf env, void __noreturn (*func)(void), void *stack_base, + size_t stack_sz); + #endif /* _SETJMP_H_ */ |