| Message ID | 20221202010410.gonna.444-kees@kernel.org |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] crypto/caam: Avoid GCC constprop bug warning | expand |
diff --git a/drivers/crypto/caam/desc_constr.h b/drivers/crypto/caam/desc_constr.h index 62ce6421bb3f..d9da4173af9d 100644 --- a/drivers/crypto/caam/desc_constr.h +++ b/drivers/crypto/caam/desc_constr.h @@ -163,7 +163,8 @@ static inline void append_data(u32 * const desc, const void *data, int len) { u32 *offset = desc_end(desc); - if (len) /* avoid sparse warning: memcpy with byte count of 0 */ + /* Avoid GCC warning: memcpy with NULL dest (but byte count of 0). */ + if (data && len) memcpy(offset, data, len); (*desc) = cpu_to_caam32(caam32_to_cpu(*desc) +
GCC 12 appears to perform constant propagation incompletely(?) and can no longer notice that "len" is always 0 when "data" is NULL. Expand the check to avoid warnings about memcpy() having a NULL argument: ... from drivers/crypto/caam/key_gen.c:8: drivers/crypto/caam/desc_constr.h: In function 'append_data.constprop': include/linux/fortify-string.h:48:33: warning: argument 2 null where non-null expected [-Wnonnull] 48 | #define __underlying_memcpy __builtin_memcpy | ^ include/linux/fortify-string.h:438:9: note: in expansion of macro '__underlying_memcpy' 438 | __underlying_##op(p, q, __fortify_size); \ | ^~~~~~~~~~~~~ The NULL was being propagated from: append_fifo_load_as_imm(desc, NULL, 0, LDST_CLASS_2_CCB | FIFOLD_TYPE_MSG | FIFOLD_TYPE_LAST2); ... static inline void append_##cmd##_as_imm(u32 * const desc, const void *data, \ unsigned int len, u32 options) \ { \ PRINT_POS; \ append_cmd_data(desc, data, len, CMD_##op | options); \ } ... APPEND_CMD_PTR_TO_IMM(fifo_load, FIFO_LOAD); ... static inline void append_cmd_data(u32 * const desc, const void *data, int len, u32 command) { append_cmd(desc, command | IMMEDIATE | len); append_data(desc, data, len); } Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: "Horia Geantă" <horia.geanta@nxp.com> Cc: Pankaj Gupta <pankaj.gupta@nxp.com> Cc: Gaurav Jain <gaurav.jain@nxp.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: linux-crypto@vger.kernel.org Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/lkml/202210290446.qBayTfzl-lkp@intel.com Tested-by: Anders Roxell <anders.roxell@linaro.org> Signed-off-by: Kees Cook <keescook@chromium.org> --- v1: https://lore.kernel.org/lkml/20221028210527.never.934-kees@kernel.org/ v2: update comment (anders) Note that this is about GCC, not sparse (any more). --- drivers/crypto/caam/desc_constr.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)