On 20.11.2023 23:49, Andrew Cooper wrote: > GCC complains: > > In file included from arch/arm/efi/boot.c:700: > arch/arm/efi/efi-boot.h: In function 'efi_arch_handle_cmdline': > arch/arm/efi/efi-boot.h:482:16: error: assignment discards 'const' > qualifier from pointer target type [-Werror=discarded-qualifiers] > 482 | name.s = "xen"; > | ^ > > There's no easy option. .rodata is really read-only, so the fact Xen doesn't > crash means these strings aren't written to.
And the consuming sites confirm this being the case. Hence ... > Lie to the compiler using a union. ... to at least slightly limit the lying, how about ... > --- a/xen/arch/arm/efi/efi-boot.h > +++ b/xen/arch/arm/efi/efi-boot.h > @@ -479,7 +479,7 @@ static void __init efi_arch_handle_cmdline(CHAR16 > *image_name, > w2s(&name); > } > else > - name.s = "xen"; > + name.cs = "xen"; /* TODO, find a better way of doing this. */ > > prop_len = 0; > prop_len += snprintf(buf + prop_len, ... you also switch to using name.cs down below here and ... > --- a/xen/arch/x86/efi/efi-boot.h > +++ b/xen/arch/x86/efi/efi-boot.h > @@ -324,7 +324,8 @@ static void __init efi_arch_handle_cmdline(CHAR16 > *image_name, > w2s(&name); > } > else > - name.s = "xen"; > + name.cs = "xen"; /* TODO, find a better way of doing this. */ > + > place_string(&mbi.cmdline, name.s); ... here? An alternative would be to introduce 'char xen[4] = "xen";' in both cases, and use them instead of plain string literals. Jan
