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Diffstat (limited to 'src/basic/util.h')
-rw-r--r-- | src/basic/util.h | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/src/basic/util.h b/src/basic/util.h new file mode 100644 index 0000000..68ae3b5 --- /dev/null +++ b/src/basic/util.h @@ -0,0 +1,80 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +#pragma once + +#include <stdint.h> + +#include "macro.h" + +extern int saved_argc; +extern char **saved_argv; + +static inline void save_argc_argv(int argc, char **argv) { + + /* Protect against CVE-2021-4034 style attacks */ + assert_se(argc > 0); + assert_se(argv); + assert_se(argv[0]); + + saved_argc = argc; + saved_argv = argv; +} + +bool kexec_loaded(void); + +int prot_from_flags(int flags) _const_; + +bool in_initrd(void); +void in_initrd_force(bool value); + +/* Note: log2(0) == log2(1) == 0 here and below. */ + +#define CONST_LOG2ULL(x) ((x) > 1 ? (unsigned) __builtin_clzll(x) ^ 63U : 0) +#define NONCONST_LOG2ULL(x) ({ \ + unsigned long long _x = (x); \ + _x > 1 ? (unsigned) __builtin_clzll(_x) ^ 63U : 0; \ + }) +#define LOG2ULL(x) __builtin_choose_expr(__builtin_constant_p(x), CONST_LOG2ULL(x), NONCONST_LOG2ULL(x)) + +static inline unsigned log2u64(uint64_t x) { +#if __SIZEOF_LONG_LONG__ == 8 + return LOG2ULL(x); +#else +# error "Wut?" +#endif +} + +static inline unsigned u32ctz(uint32_t n) { +#if __SIZEOF_INT__ == 4 + return n != 0 ? __builtin_ctz(n) : 32; +#else +# error "Wut?" +#endif +} + +#define CONST_LOG2U(x) ((x) > 1 ? __SIZEOF_INT__ * 8 - __builtin_clz(x) - 1 : 0) +#define NONCONST_LOG2U(x) ({ \ + unsigned _x = (x); \ + _x > 1 ? __SIZEOF_INT__ * 8 - __builtin_clz(_x) - 1 : 0; \ + }) +#define LOG2U(x) __builtin_choose_expr(__builtin_constant_p(x), CONST_LOG2U(x), NONCONST_LOG2U(x)) + +static inline unsigned log2i(int x) { + return LOG2U(x); +} + +static inline unsigned log2u(unsigned x) { + return LOG2U(x); +} + +static inline unsigned log2u_round_up(unsigned x) { + if (x <= 1) + return 0; + + return log2u(x - 1) + 1; +} + +int container_get_leader(const char *machine, pid_t *pid); + +int version(void); + +void disable_coredumps(void); |