diff options
| author | Lennart Poettering <lennart@poettering.net> | 2021-10-13 12:05:54 +0200 |
|---|---|---|
| committer | Lennart Poettering <lennart@poettering.net> | 2021-10-14 15:57:52 +0200 |
| commit | 9e1a759903a3ff9943334d25de19b06afc40c11e (patch) | |
| tree | aa197bafb029b50dc9002127601165b6bb5a09a1 /src/basic/alloc-util.h | |
| parent | a69f1dd9ca2a8eb20bf75083a4199c8791d55bf8 (diff) | |
| download | systemd-9e1a759903a3ff9943334d25de19b06afc40c11e.tar.gz | |
alloc-util: introduce new helper alloca_safe()
This is like alloca(), but does two things:
1. Verifies the allocation is smaller than ALLOCA_MAX
2. Ensures we allocate at least one byte
This was previously done manually in all invocations. This adds a handy
helper that does that implicitly.
Diffstat (limited to 'src/basic/alloc-util.h')
| -rw-r--r-- | src/basic/alloc-util.h | 25 |
1 files changed, 13 insertions, 12 deletions
diff --git a/src/basic/alloc-util.h b/src/basic/alloc-util.h index e587fe79e7..ef25ff3a36 100644 --- a/src/basic/alloc-util.h +++ b/src/basic/alloc-util.h @@ -22,20 +22,25 @@ typedef void (*free_func_t)(void *p); #define new0(t, n) ((t*) calloc((n) ?: 1, sizeof(t))) +#define alloca_safe(n) \ + ({ \ + size_t _nn_ = n; \ + assert(_nn_ <= ALLOCA_MAX); \ + alloca(_nn_ == 0 ? 1 : _nn_); \ + }) \ + #define newa(t, n) \ ({ \ size_t _n_ = n; \ assert(!size_multiply_overflow(sizeof(t), _n_)); \ - assert(sizeof(t)*_n_ <= ALLOCA_MAX); \ - (t*) alloca((sizeof(t)*_n_) ?: 1); \ + (t*) alloca_safe(sizeof(t)*_n_); \ }) #define newa0(t, n) \ ({ \ size_t _n_ = n; \ assert(!size_multiply_overflow(sizeof(t), _n_)); \ - assert(sizeof(t)*_n_ <= ALLOCA_MAX); \ - (t*) alloca0((sizeof(t)*_n_) ?: 1); \ + (t*) alloca0((sizeof(t)*_n_)); \ }) #define newdup(t, p, n) ((t*) memdup_multiply(p, sizeof(t), (n))) @@ -67,8 +72,7 @@ void* memdup_suffix0(const void *p, size_t l); /* We can't use _alloc_() here, s ({ \ void *_q_; \ size_t _l_ = l; \ - assert(_l_ <= ALLOCA_MAX); \ - _q_ = alloca(_l_ ?: 1); \ + _q_ = alloca_safe(_l_); \ memcpy_safe(_q_, p, _l_); \ }) @@ -76,8 +80,7 @@ void* memdup_suffix0(const void *p, size_t l); /* We can't use _alloc_() here, s ({ \ void *_q_; \ size_t _l_ = l; \ - assert(_l_ <= ALLOCA_MAX); \ - _q_ = alloca(_l_ + 1); \ + _q_ = alloca_safe(_l_ + 1); \ ((uint8_t*) _q_)[_l_] = 0; \ memcpy_safe(_q_, p, _l_); \ }) @@ -144,8 +147,7 @@ void* greedy_realloc0(void **p, size_t need, size_t size); ({ \ char *_new_; \ size_t _len_ = n; \ - assert(_len_ <= ALLOCA_MAX); \ - _new_ = alloca(_len_ ?: 1); \ + _new_ = alloca_safe(_len_); \ (void *) memset(_new_, 0, _len_); \ }) @@ -155,8 +157,7 @@ void* greedy_realloc0(void **p, size_t need, size_t size); void *_ptr_; \ size_t _mask_ = (align) - 1; \ size_t _size_ = size; \ - assert(_size_ <= ALLOCA_MAX); \ - _ptr_ = alloca((_size_ + _mask_) ?: 1); \ + _ptr_ = alloca_safe(_size_ + _mask_); \ (void*)(((uintptr_t)_ptr_ + _mask_) & ~_mask_); \ }) |