Re: linux-next: manual merge of the akpm-current tree with the powerpc tree

Stephen Rothwell
2021-04-15T09:58:20Z

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Hi all,

On Thu, 15 Apr 2021 19:44:17 +1000 Stephen Rothwell <sfr@canb.auug.org.au> wrote:
>
> Today's linux-next merge of the akpm-current tree got a conflict in:
>
> arch/powerpc/kernel/module.c
>
> between commit:
>
> 2ec13df16704 ("powerpc/modules: Load modules closer to kernel text")
>
> from the powerpc tree and commit:
>
> 4930ba789f8d ("powerpc/64s/radix: enable huge vmalloc mappings")
>
> from the akpm-current tree.
>
> I fixed it up (I think - see below) and can carry the fix as
> necessary. This is now fixed as far as linux-next is concerned, but any
> non trivial conflicts should be mentioned to your upstream maintainer
> when your tree is submitted for merging. You may also want to consider
> cooperating with the maintainer of the conflicting tree to minimise any
> particularly complex conflicts.
>
> --
> Cheers,
> Stephen Rothwell
>
> diff --cc arch/powerpc/kernel/module.c
> index fab84024650c,cdb2d88c54e7..000000000000
> --- a/arch/powerpc/kernel/module.c
> +++ b/arch/powerpc/kernel/module.c
> @@@ -88,29 -88,26 +89,42 @@@ int module_finalize(const Elf_Ehdr *hdr
> return 0;
> }
>
> - #ifdef MODULES_VADDR
> -void *module_alloc(unsigned long size)
> +static __always_inline void *
> +__module_alloc(unsigned long size, unsigned long start, unsigned long end)
> {
> - unsigned long start = VMALLOC_START;
> - unsigned long end = VMALLOC_END;
> -
> -#ifdef MODULES_VADDR
> - BUILD_BUG_ON(TASK_SIZE > MODULES_VADDR);
> - start = MODULES_VADDR;
> - end = MODULES_END;
> -#endif
> -
> + /*
> + * Don't do huge page allocations for modules yet until more testing
> + * is done. STRICT_MODULE_RWX may require extra work to support this
> + * too.
> + */
> +
> return __vmalloc_node_range(size, 1, start, end, GFP_KERNEL,
> - PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS, NUMA_NO_NODE,
> + PAGE_KERNEL_EXEC,
> + VM_NO_HUGE_VMAP | VM_FLUSH_RESET_PERMS,
> + NUMA_NO_NODE,
> __builtin_return_address(0));
> }
> +
> ++
> +void *module_alloc(unsigned long size)
> +{
> ++ unsigned long start = VMALLOC_START;
> ++ unsigned long end = VMALLOC_END;
> + unsigned long limit = (unsigned long)_etext - SZ_32M;
> + void *ptr = NULL;
> +
> ++#ifdef MODULES_VADDR
> + BUILD_BUG_ON(TASK_SIZE > MODULES_VADDR);
> ++ start = MODULES_VADDR;
> ++ end = MODULES_END;
> +
> + /* First try within 32M limit from _etext to avoid branch trampolines */
> + if (MODULES_VADDR < PAGE_OFFSET && MODULES_END > limit)
> - ptr = __module_alloc(size, limit, MODULES_END);
> ++ ptr = __module_alloc(size, limit, end);
> +
> + if (!ptr)
> - ptr = __module_alloc(size, MODULES_VADDR, MODULES_END);
> ++#endif
> ++ ptr = __module_alloc(size, start, end);
> +
> + return ptr;
> +}
> - #endif

Unfortunately, it also needs this:

From: Stephen Rothwell <sfr@canb.auug.org.au>
Date: Thu, 15 Apr 2021 19:53:58 +1000
Subject: [PATCH] merge fix up for powerpc merge fix

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
---
arch/powerpc/kernel/module.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/arch/powerpc/kernel/module.c b/arch/powerpc/kernel/module.c
index d8ab1ad2eb05..c060f99afd4d 100644
--- a/arch/powerpc/kernel/module.c
+++ b/arch/powerpc/kernel/module.c
@@ -110,7 +110,9 @@ void *module_alloc(unsigned long size)
{
unsigned long start = VMALLOC_START;
unsigned long end = VMALLOC_END;
+#ifdef MODULES_VADDR
unsigned long limit = (unsigned long)_etext - SZ_32M;
+#endif
void *ptr = NULL;

#ifdef MODULES_VADDR
--
2.30.2