There are codepaths that currently use something like WARN() where CHECK_DATA_CORRUPTION() would be more appropriate, but it is not possible to gracefully bail out when corruption has been detected.
CHECK_DATA_CORRUPTION() is currently deliberately unusable in such cases. While it would be nice for users of CHECK_DATA_CORRUPTION() to bail out on corruption, that shouldn't be a hard requirement for CHECK_DATA_CORRUPTION(). So remove the __must_check requirement so that CHECK_DATA_CORRUPTION() can be used in codepaths where bailing out is infeasible. Signed-off-by: Jann Horn <[email protected]> --- I think this should probably go through Kees' hardening tree? This patch is inspired by me looking at file_ref_inc() and thinking that that really should be using CHECK_DATA_CORRUPTION(). --- include/linux/bug.h | 31 +++++++++++++++---------------- 1 file changed, 15 insertions(+), 16 deletions(-) diff --git a/include/linux/bug.h b/include/linux/bug.h index 17a4933c611b..e8d1febd8ae4 100644 --- a/include/linux/bug.h +++ b/include/linux/bug.h @@ -89,22 +89,21 @@ static inline void mem_dump_obj(void *object) {} /* * Since detected data corruption should stop operation on the affected - * structures. Return value must be checked and sanely acted on by caller. + * structures. Return value should be checked and sanely acted on by caller if + * possible. */ -static inline __must_check bool check_data_corruption(bool v) { return v; } -#define CHECK_DATA_CORRUPTION(condition, addr, fmt, ...) \ - check_data_corruption(({ \ - bool corruption = unlikely(condition); \ - if (corruption) { \ - if (addr) \ - mem_dump_obj(addr); \ - if (IS_ENABLED(CONFIG_BUG_ON_DATA_CORRUPTION)) { \ - pr_err(fmt, ##__VA_ARGS__); \ - BUG(); \ - } else \ - WARN(1, fmt, ##__VA_ARGS__); \ - } \ - corruption; \ - })) +#define CHECK_DATA_CORRUPTION(condition, addr, fmt, ...) ({ \ + bool corruption = unlikely(condition); \ + if (corruption) { \ + if (addr) \ + mem_dump_obj(addr); \ + if (IS_ENABLED(CONFIG_BUG_ON_DATA_CORRUPTION)) { \ + pr_err(fmt, ##__VA_ARGS__); \ + BUG(); \ + } else \ + WARN(1, fmt, ##__VA_ARGS__); \ + } \ + corruption; \ +}) #endif /* _LINUX_BUG_H */ --- base-commit: 3d6d817622b0a9721e3cc404df3469171582be13 change-id: 20260812-data-corruption-mustcheck-c1a8f76d6e24 Best regards, -- Jann Horn <[email protected]>
