Re: [PATCH v2 10/22] coredump: make the dump helper return bool

[R Nageswara Sastry <rnsastry@linux.ibm.com>]

On 20.08.2026 4:39 AM, Christian Brauner wrote:
> The various dump helpers return one and zero. Every caller just does a
> boolean test. Convert them to return an actual bool.
>
> While at it, drop the externs.
>
> No functional changes.
>
> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
Tested-by: R Nageswara Sastry <rnsastry@linux.ibm.com>

System: ppc64le LPAR (IBM POWER), Linux 7.3-rc2
> ---
>   fs/coredump.c            | 63 ++++++++++++++++++++++++------------------------
>   include/linux/coredump.h | 14 +++++------
>   2 files changed, 39 insertions(+), 38 deletions(-)
>
> diff --git a/fs/coredump.c b/fs/coredump.c
> index cd36a72be445..d837819031ff 100644
> --- a/fs/coredump.c
> +++ b/fs/coredump.c
> @@ -1215,41 +1215,41 @@ void vfs_coredump(const kernel_siginfo_t *siginfo)
>    * do on a core-file: use only these functions to write out all the
>    * necessary info.
>    */
> -static int __dump_emit(struct coredump_params *cprm, const void *addr, int nr)
> +static bool __dump_emit(struct coredump_params *cprm, const void *addr, int nr)
>   {
>   	struct file *file = cprm->file;
>   	loff_t pos = file->f_pos;
>   	ssize_t n;
>   
>   	if (cprm->written + nr > cprm->limit)
> -		return 0;
> +		return false;
>   	if (dump_interrupted())
> -		return 0;
> +		return false;
>   	n = __kernel_write(file, addr, nr, &pos);
>   	if (n != nr)
> -		return 0;
> +		return false;
>   	file->f_pos = pos;
>   	cprm->written += n;
>   	cprm->pos += n;
>   
> -	return 1;
> +	return true;
>   }
>   
> -static int __dump_skip(struct coredump_params *cprm, size_t nr)
> +static bool __dump_skip(struct coredump_params *cprm, size_t nr)
>   {
>   	static char zeroes[PAGE_SIZE];
>   	struct file *file = cprm->file;
>   
>   	if (file->f_mode & FMODE_LSEEK) {
>   		if (dump_interrupted() || vfs_llseek(file, nr, SEEK_CUR) < 0)
> -			return 0;
> +			return false;
>   		cprm->pos += nr;
> -		return 1;
> +		return true;
>   	}
>   
>   	while (nr > PAGE_SIZE) {
>   		if (!__dump_emit(cprm, zeroes, PAGE_SIZE))
> -			return 0;
> +			return false;
>   		nr -= PAGE_SIZE;
>   	}
>   
> @@ -1257,20 +1257,20 @@ static int __dump_skip(struct coredump_params *cprm, size_t nr)
>   }
>   
>   /* Flush the accumulated hole before writing data. */
> -static int dump_flush_skip(struct coredump_params *cprm)
> +static bool dump_flush_skip(struct coredump_params *cprm)
>   {
>   	if (cprm->to_skip) {
>   		if (!__dump_skip(cprm, cprm->to_skip))
> -			return 0;
> +			return false;
>   		cprm->to_skip = 0;
>   	}
> -	return 1;
> +	return true;
>   }
>   
> -int dump_emit(struct coredump_params *cprm, const void *addr, int nr)
> +bool dump_emit(struct coredump_params *cprm, const void *addr, int nr)
>   {
>   	if (!dump_flush_skip(cprm))
> -		return 0;
> +		return false;
>   	return __dump_emit(cprm, addr, nr);
>   }
>   EXPORT_SYMBOL(dump_emit);
> @@ -1290,7 +1290,7 @@ void dump_skip(struct coredump_params *cprm, size_t nr)
>   EXPORT_SYMBOL(dump_skip);
>   
>   #ifdef CONFIG_ELF_CORE
> -static int dump_emit_page(struct coredump_params *cprm, struct page *page)
> +static bool dump_emit_page(struct coredump_params *cprm, struct page *page)
>   {
>   	struct bio_vec bvec;
>   	struct iov_iter iter;
> @@ -1299,25 +1299,25 @@ static int dump_emit_page(struct coredump_params *cprm, struct page *page)
>   	ssize_t n;
>   
>   	if (!page)
> -		return 0;
> +		return false;
>   
>   	if (!dump_flush_skip(cprm))
> -		return 0;
> +		return false;
>   	if (cprm->written + PAGE_SIZE > cprm->limit)
> -		return 0;
> +		return false;
>   	if (dump_interrupted())
> -		return 0;
> +		return false;
>   	pos = file->f_pos;
>   	bvec_set_page(&bvec, page, PAGE_SIZE, 0);
>   	iov_iter_bvec(&iter, ITER_SOURCE, &bvec, 1, PAGE_SIZE);
>   	n = __kernel_write_iter(cprm->file, &iter, &pos);
>   	if (n != PAGE_SIZE)
> -		return 0;
> +		return false;
>   	file->f_pos = pos;
>   	cprm->written += PAGE_SIZE;
>   	cprm->pos += PAGE_SIZE;
>   
> -	return 1;
> +	return true;
>   }
>   
>   /*
> @@ -1349,18 +1349,19 @@ static inline struct page *dump_page_copy(struct page *src, struct page *dst)
>   }
>   #endif
>   
> -int dump_user_range(struct coredump_params *cprm, unsigned long start,
> -		    unsigned long len)
> +bool dump_user_range(struct coredump_params *cprm, unsigned long start,
> +		     unsigned long len)
>   {
>   	unsigned long addr;
>   	struct page *dump_page;
> -	int locked, ret;
> +	int locked;
> +	bool ret;
>   
>   	dump_page = dump_page_alloc();
>   	if (!dump_page)
> -		return 0;
> +		return false;
>   
> -	ret = 0;
> +	ret = false;
>   	locked = 0;
>   	for (addr = start; addr < start + len; addr += PAGE_SIZE) {
>   		struct page *page;
> @@ -1384,7 +1385,7 @@ int dump_user_range(struct coredump_params *cprm, unsigned long start,
>   				mmap_read_unlock(current->mm);
>   				locked = 0;
>   			}
> -			int stop = !dump_emit_page(cprm, dump_page_copy(page, dump_page));
> +			bool stop = !dump_emit_page(cprm, dump_page_copy(page, dump_page));
>   			put_page(page);
>   			if (stop)
>   				goto out;
> @@ -1403,7 +1404,7 @@ int dump_user_range(struct coredump_params *cprm, unsigned long start,
>   		}
>   		cond_resched();
>   	}
> -	ret = 1;
> +	ret = true;
>   out:
>   	if (locked)
>   		mmap_read_unlock(current->mm);
> @@ -1413,14 +1414,14 @@ int dump_user_range(struct coredump_params *cprm, unsigned long start,
>   }
>   #endif
>   
> -int dump_align(struct coredump_params *cprm, int align)
> +bool dump_align(struct coredump_params *cprm, int align)
>   {
>   	unsigned mod = (cprm->pos + cprm->to_skip) & (align - 1);
>   	if (align & (align - 1))
> -		return 0;
> +		return false;
>   	if (mod)
>   		cprm->to_skip += align - mod;
> -	return 1;
> +	return true;
>   }
>   EXPORT_SYMBOL(dump_align);
>   
> diff --git a/include/linux/coredump.h b/include/linux/coredump.h
> index dc7a05b1bb0a..943bddfb22bf 100644
> --- a/include/linux/coredump.h
> +++ b/include/linux/coredump.h
> @@ -43,13 +43,13 @@ extern unsigned int core_file_note_size_limit;
>    * These are the only things you should do on a core-file: use only these
>    * functions to write out all the necessary info.
>    */
> -extern void dump_skip_to(struct coredump_params *cprm, unsigned long to);
> -extern void dump_skip(struct coredump_params *cprm, size_t nr);
> -extern int dump_emit(struct coredump_params *cprm, const void *addr, int nr);
> -extern int dump_align(struct coredump_params *cprm, int align);
> -int dump_user_range(struct coredump_params *cprm, unsigned long start,
> -		    unsigned long len);
> -extern void vfs_coredump(const kernel_siginfo_t *siginfo);
> +void dump_skip_to(struct coredump_params *cprm, unsigned long to);
> +void dump_skip(struct coredump_params *cprm, size_t nr);
> +bool dump_emit(struct coredump_params *cprm, const void *addr, int nr);
> +bool dump_align(struct coredump_params *cprm, int align);
> +bool dump_user_range(struct coredump_params *cprm, unsigned long start,
> +		     unsigned long len);
> +void vfs_coredump(const kernel_siginfo_t *siginfo);
>   
>   /*
>    * Logging for the coredump code, ratelimited.
>
-- 
Thanks and Regards
R.Nageswara Sastry