If defined, this function must return
the size and base address of an eight-byte aligned heap extension
block.
Syntax
extern size_t __user_heap_extend(int var0, void **base, size_t requested_size);
Usage
There is no default implementation of this function. If you
define this function, it must have the following characteristics:
- The returned size is one of the following:
- In AArch32 state, a multiple of 8 bytes of at least the
requested size.
- In AArch64 state, a multiple of 16 bytes of at least the
requested size.
- 0, denoting that the request cannot be honored.
- The returned base address is aligned on:
- In AArch32 state, an 8-byte boundary.
- In AArch64 state, a 16-byte boundary.
- Size is measured in bytes.
- The function is subject only to Procedure Call Standard
for the ARM®
Architecture (AAPCS) constraints.
- The first argument is always zero on entry and can be ignored. The base is
returned in the register holding this argument.
Returns
This function places a pointer to a block of at least the
requested size in *base and
returns the size of the block. 0 is returned
if no such block can be returned, in which case the value stored at *base is
never used.
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