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Date: Tue, 5 Apr 2022 06:43:59 +0200
From: Markus Wichmann <nullplan@....net>
To: musl@...ts.openwall.com
Cc: Colin Cross <ccross@...gle.com>
Subject: Re: [PATCH] dl_iterate_phdr: return empty string for the name
 of the main program

On Mon, Apr 04, 2022 at 08:18:59PM -0700, Colin Cross wrote:
> diff --git a/ldso/dynlink.c b/ldso/dynlink.c
> index fd0d38e9..d2e22a0b 100644
> --- a/ldso/dynlink.c
> +++ b/ldso/dynlink.c
> @@ -2323,12 +2323,15 @@ no_redir:
>
>  int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void *data), void *data)
>  {
> +	static const char* empty_string = "";
>  	struct dso *current;
>  	struct dl_phdr_info info;
>  	int ret = 0;
>  	for(current = head; current;) {
>  		info.dlpi_addr      = (uintptr_t)current->base;
> -		info.dlpi_name      = current->name;
> +                /* glibc uses an empty string for the main program */
> +		info.dlpi_name      = (current == head) ? empty_string :
> +			current->name;
>  		info.dlpi_phdr      = current->phdr;
>  		info.dlpi_phnum     = current->phnum;
>  		info.dlpi_adds      = gencnt;
> --
> 2.35.1.1094.g7c7d902a7c-goog
>

Any particular reason you chose to create an object for the empty
string, instead of just using an empty string? I.e. why not just

info.dlpi_name = current==head? "" : current->name;

Ciao,
Markus

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