Re: [PATCH v8 1/6] selftests/mm: make file helpers return errors

[Lance Yang]

On Mon, Aug 31, 2026 at 09:50:56AM +0530, Sarthak Sharma wrote:
[...]
>diff --git a/tools/testing/selftests/mm/vm_util.h 
>b/tools/testing/selftests/mm/vm_util.h
>index 9a49af88702e..62f6f5b42649 100644
>--- a/tools/testing/selftests/mm/vm_util.h
>+++ b/tools/testing/selftests/mm/vm_util.h
>@@ -166,11 +166,11 @@ int unpoison_memory(unsigned long pfn);
> #define PAGEMAP_PRESENT(ent)  (((ent) & (1ull << 63)) != 0)
> #define PAGEMAP_PFN(ent)      ((ent) & ((1ull << 55) - 1))
> 
>-void write_file(const char *path, const char *buf, size_t buflen);
>+int write_file(const char *path, const char *buf, size_t buflen);
> int read_file(const char *path, char *buf, size_t buflen);
>-unsigned long read_num(const char *path);
>-void write_num(const char *path, unsigned long num);
>-void write_num_ignore_einval(const char *path, unsigned long num);
>+int read_num(const char *path, unsigned long *num);
>+int write_num(const char *path, unsigned long num);
>+int write_num_ignore_einval(const char *path, unsigned long num);

Ouch ...

Looks like this conversion misses hugetlb-soft-offline.c ...

TEST_GEN_FILES += hugetlb-soft-offline

int main(int argc, char **argv)
{
...
        orig_enable_soft_offline = read_num(ENABLE_SOFT_OFFLINE_PATH);
...
}

And the compiler isn't happy:

tools/testing/selftests/mm/hugetlb-soft-offline.c:199:36:
error: too few arguments to function 'read_num'
  199 |  orig_enable_soft_offline = read_num(ENABLE_SOFT_OFFLINE_PATH);
tools/lib/mm/file_utils.h:9:5: note: declared here
    9 | int read_num(const char *path, unsigned long *num);

Cheers, Lance

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