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    crypto: ccp - Reduce maximum stack usage · 72c8117a
    Arnd Bergmann 提交于
    Each of the operations in ccp_run_cmd() needs several hundred
    bytes of kernel stack. Depending on the inlining, these may
    need separate stack slots that add up to more than the warning
    limit, as shown in this clang based build:
    
    drivers/crypto/ccp/ccp-ops.c:871:12: error: stack frame size of 1164 bytes in function 'ccp_run_aes_cmd' [-Werror,-Wframe-larger-than=]
    static int ccp_run_aes_cmd(struct ccp_cmd_queue *cmd_q, struct ccp_cmd *cmd)
    
    The problem may also happen when there is no warning, e.g. in the
    ccp_run_cmd()->ccp_run_aes_cmd()->ccp_run_aes_gcm_cmd() call chain with
    over 2000 bytes.
    
    Mark each individual function as 'noinline_for_stack' to prevent
    this from happening, and move the calls to the two special cases for aes
    into the top-level function. This will keep the actual combined stack
    usage to the mimimum: 828 bytes for ccp_run_aes_gcm_cmd() and
    at most 524 bytes for each of the other cases.
    
    Fixes: 63b94509 ("crypto: ccp - CCP device driver and interface support")
    Signed-off-by: NArnd Bergmann <arnd@arndb.de>
    Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
    72c8117a
ccp-ops.c 60.6 KB