scsi: lpfc: reduce stack size with CONFIG_GCC_PLUGIN_STRUCTLEAK_VERBOSE

The lpfc_debug_dump_all_queues() function repeatedly calls into
lpfc_debug_dump_qe() which has a temporary 128 byte buffer.  This was fine
before the introduction of CONFIG_GCC_PLUGIN_STRUCTLEAK_VERBOSE because
each instance could occupy the same stack slot. However, now they each get
their own copy, which leads to a huge increase in stack usage as seen from
the compiler warning:

drivers/scsi/lpfc/lpfc_debugfs.c: In function 'lpfc_debug_dump_all_queues':
drivers/scsi/lpfc/lpfc_debugfs.c:6474:1: error: the frame size of 1712 bytes is larger than 100 bytes [-Werror=frame-larger-than=]

Avoid this by not marking lpfc_debug_dump_qe() as inline so the compiler
can choose to emit a static version of this function when it's needed or
otherwise silently drop it. As an added benefit, not inlining multiple
copies of this function means we save several kilobytes of .text section,
reducing the file size from 47kb to 43.

It is somewhat unusual to have a function that is static but not inline in
a header file, but this does not cause problems here because it is only
used by other inline functions. It would however seem reasonable to move
all the lpfc_debug_dump_* functions into lpfc_debugfs.c and not mark them
inline as a later cleanup.

Fixes: 81a56f6dcd ("gcc-plugins: structleak: Generalize to all variable types")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Arnd Bergmann 2019-06-28 14:37:47 +02:00 committed by Martin K. Petersen
parent 4bc022145c
commit 057959c6e3

View File

@ -330,7 +330,7 @@ enum {
* This function dumps an entry indexed by @idx from a queue specified by the
* queue descriptor @q.
**/
static inline void
static void
lpfc_debug_dump_qe(struct lpfc_queue *q, uint32_t idx)
{
char line_buf[LPFC_LBUF_SZ];