Re: [PATCH v2 3/5] alloca.3: clarify reasoning for no error return in BUGS

Alejandro Colomar (man-pages)
2021-09-15T19:42:33Z

Hi, наб!

On 9/14/21 2:41 PM, наб wrote:
> A stack lasts from some high point until it runs off the back
> of the pages allocated, making detecting errors impossible,
> save for actually trying to access said unallocated page
>
> Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
> ---
> man3/alloca.3 | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/man3/alloca.3 b/man3/alloca.3
> index 71348e609..20761b079 100644
> --- a/man3/alloca.3
> +++ b/man3/alloca.3
> @@ -163,10 +163,11 @@ The inlined code often consists of a single instruction adjusting
> the stack pointer, and does not check for stack overflow.
> Thus, there is no NULL error return.
> .SH BUGS
> -There is no error indication if the stack frame cannot be extended.
> -(However, after a failed allocation, the program is likely to receive a
> +Due to the nature of the stack, it is impossible to check if the allocation
> +would overflow the space available, and, hence, neither is indicating an error.

I'm not sure this use of neither (without a preceding "not") is valid
English. Is it?

Cheers,

Alex

> +(However, the program is likely to receive a
> .B SIGSEGV
> -signal if it attempts to access the unallocated space.)
> +signal if it attempts to access unavailable space.)
> .PP
> On many systems
> .BR alloca ()
>

--
Alejandro Colomar
Linux man-pages comaintainer; https://www.kernel.org/doc/man-pages/