On 7/12/19 6:15 PM, KyleMahlkuch wrote:
> Power and x86 have different page sizes so rather than allocate the
> buffer based on number of pages we should allocate space by using
> max_sectors. There is also code in lpfc_scsi.c to be sure we don't
> write past the end of this buffer.
>
> Signed-off-by: KyleMahlkuch <kmahl...@linux.vnet.ibm.com>
> ---
> drivers/scsi/lpfc/lpfc_init.c | 41 +++++++----------------------------------
> drivers/scsi/lpfc/lpfc_scsi.c | 14 ++++++++++++--
> 2 files changed, 19 insertions(+), 36 deletions(-)
>
> diff --git a/drivers/scsi/lpfc/lpfc_init.c b/drivers/scsi/lpfc/lpfc_init.c
> index eaaef68..59b52a0 100644
> --- a/drivers/scsi/lpfc/lpfc_init.c
> +++ b/drivers/scsi/lpfc/lpfc_init.c
> @@ -39,6 +39,7 @@
> #include <linux/msi.h>
> #include <linux/irq.h>
> #include <linux/bitops.h>
> +#include <linux/vmalloc.h>
>
> #include <scsi/scsi.h>
> #include <scsi/scsi_device.h>
> @@ -7549,7 +7550,6 @@ struct lpfc_rpi_hdr *
> uint32_t old_mask;
> uint32_t old_guard;
>
> - int pagecnt = 10;
> if (phba->cfg_prot_mask && phba->cfg_prot_guard) {
> lpfc_printf_log(phba, KERN_INFO, LOG_INIT,
> "1478 Registering BlockGuard with the "
> @@ -7588,23 +7588,9 @@ struct lpfc_rpi_hdr *
> }
>
> if (!_dump_buf_data) {
> - while (pagecnt) {
> - spin_lock_init(&_dump_buf_lock);
> - _dump_buf_data =
> - (char *) __get_free_pages(GFP_KERNEL, pagecnt);
> - if (_dump_buf_data) {
> - lpfc_printf_log(phba, KERN_ERR, LOG_BG,
> - "9043 BLKGRD: allocated %d pages for "
> - "_dump_buf_data at 0x%p\n",
> - (1 << pagecnt), _dump_buf_data);
> - _dump_buf_data_order = pagecnt;
> - memset(_dump_buf_data, 0,
> - ((1 << PAGE_SHIFT) << pagecnt));
> - break;
> - } else
> - --pagecnt;
> - }
> - if (!_dump_buf_data_order)
> + _dump_buf_data = (char *) vmalloc(shost->hostt->max_sectors *
> 512);
> + _dump_buf_data_order = get_order(shost->hostt->max_sectors *
> 512);
> + if (!_dump_buf_data)
> lpfc_printf_log(phba, KERN_ERR, LOG_BG,
> "9044 BLKGRD: ERROR unable to allocate "
> "memory for hexdump\n");
> @@ -7613,22 +7599,9 @@ struct lpfc_rpi_hdr *
> "9045 BLKGRD: already allocated _dump_buf_data=0x%p"
> "\n", _dump_buf_data);
> if (!_dump_buf_dif) {
> - while (pagecnt) {
> - _dump_buf_dif =
> - (char *) __get_free_pages(GFP_KERNEL, pagecnt);
> - if (_dump_buf_dif) {
> - lpfc_printf_log(phba, KERN_ERR, LOG_BG,
> - "9046 BLKGRD: allocated %d pages for "
> - "_dump_buf_dif at 0x%p\n",
> - (1 << pagecnt), _dump_buf_dif);
> - _dump_buf_dif_order = pagecnt;
> - memset(_dump_buf_dif, 0,
> - ((1 << PAGE_SHIFT) << pagecnt));
> - break;
> - } else
> - --pagecnt;
> - }
> - if (!_dump_buf_dif_order)
> + _dump_buf_dif = (char *) vmalloc(shost->hostt->max_sectors *
> 512);
> + _dump_buf_dif_order = get_order(shost->hostt->max_sectors *
> 512);
> + if (!_dump_buf_dif)
> lpfc_printf_log(phba, KERN_ERR, LOG_BG,
> "9047 BLKGRD: ERROR unable to allocate "
> "memory for hexdump\n");
> diff --git a/drivers/scsi/lpfc/lpfc_scsi.c b/drivers/scsi/lpfc/lpfc_scsi.c
> index ba996fb..719612d 100644
> --- a/drivers/scsi/lpfc/lpfc_scsi.c
> +++ b/drivers/scsi/lpfc/lpfc_scsi.c
> @@ -92,7 +92,7 @@ struct scsi_dif_tuple {
> static void
> lpfc_debug_save_data(struct lpfc_hba *phba, struct scsi_cmnd *cmnd)
> {
> - void *src, *dst;
> + void *src, *dst, *end;
> struct scatterlist *sgde = scsi_sglist(cmnd);
>
> if (!_dump_buf_data) {
> @@ -110,7 +110,12 @@ struct scsi_dif_tuple {
> }
>
> dst = (void *) _dump_buf_data;
> + end = ((char *) dst) + ((1 << PAGE_SHIFT) << _dump_buf_data_order);
> while (sgde) {
> + if (dst + sgde->length >= end) {
> + printk(KERN_ERR "overflow buffer\n");
> + break;
> + }
> src = sg_virt(sgde);
> memcpy(dst, src, sgde->length);
> dst += sgde->length;
> @@ -121,7 +126,7 @@ struct scsi_dif_tuple {
> static void
> lpfc_debug_save_dif(struct lpfc_hba *phba, struct scsi_cmnd *cmnd)
> {
> - void *src, *dst;
> + void *src, *dst, *end;
> struct scatterlist *sgde = scsi_prot_sglist(cmnd);
>
> if (!_dump_buf_dif) {
> @@ -138,7 +143,12 @@ struct scsi_dif_tuple {
> }
>
> dst = _dump_buf_dif;
> + end = ((char *) dst) + ((1 << PAGE_SHIFT) << _dump_buf_dif_order);
> while (sgde) {
> + if (dst + sgde->length >= end) {
> + printk(KERN_ERR "overflow buffer\n");
> + break;
> + }
> src = sg_virt(sgde);
> memcpy(dst, src, sgde->length);
> dst += sgde->length;
>
Not sure this is correct.
vmalloc() is not equivalent to __get_pages().
I would rather start off with the fixed buffer size (say, 40k), and
calculate the values like pagecnt etc from there.
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
h...@suse.de +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: Felix Imendörffer, Mary Higgins, Sri Rasiah
HRB 21284 (AG Nürnberg)
