[PATCH 18/19] arm64:ilp32: add vdso-ilp32 and use for signal return

Andreas Schwab
2016-06-20T14:54:17Z

Yury Norov <ynorov@caviumnetworks.com> writes:

> diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
> index 2a0de6f..e48ea34 100644
> --- a/arch/arm64/kernel/vdso.c
> +++ b/arch/arm64/kernel/vdso.c
> @@ -40,6 +40,12 @@ extern char vdso_start, vdso_end;
> static unsigned long vdso_pages;
> static struct page **vdso_pagelist;
>
> +#ifdef CONFIG_ARM64_ILP32
> +extern char vdso_ilp32_start, vdso_ilp32_end;
> +static unsigned long vdso_ilp32_pages;
> +static struct page **vdso_ilp32_pagelist;
> +#endif
> +
> /*
> * The vDSO data page.
> */
> @@ -110,24 +116,29 @@ int aarch32_setup_vectors_page(struct linux_binprm *bprm, int uses_interp)
> }
> #endif /* CONFIG_AARCH32_EL0 */
>
> -static struct vm_special_mapping vdso_spec[2];
> -
> -static int __init vdso_init(void)
> +static int __init vdso_init_common(char *vdso_start, char *vdso_end,

Using the same name for the parameter as for the global variable is
dangerous ....

> + unsigned long *vdso_pagesp,
> + struct page ***vdso_pagelistp,
> + struct vm_special_mapping* vdso_spec)
> {
> int i;
> + unsigned long vdso_pages;
> + struct page **vdso_pagelist;
>
> - if (memcmp(&vdso_start, "\177ELF", 4)) {
> + if (memcmp(vdso_start, "\177ELF", 4)) {

... because forgetting to remove & can be fatal, and your compiler may
not even warn you.

Andreas.

--
Andreas Schwab, SUSE Labs, schwab at suse.de
GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE 1748 E4D4 88E3 0EEA B9D7
"And now for something completely different."