From d194139c18edb7dae45e159a24f2aa72091033b8 Mon Sep 17 00:00:00 2001 From: Marcin Slusarz Date: Sun, 16 Nov 2008 19:06:37 +0100 Subject: [PATCH] cdrom: reduce stack usage of mmc_ioctl_dvd_read_struct 1. kmalloc 192 bytes in dvd_read_bca (which is inlined into dvd_read_struct) 2. Pass struct packet_command to all dvd_read_* functions. Checkstack output: Before: mmc_ioctl_dvd_read_struct: 280 After: mmc_ioctl_dvd_read_struct: 56 Signed-off-by: Marcin Slusarz Cc: Bartlomiej Zolnierkiewicz Cc: Andrew Morton Cc: Jens Axboe Signed-off-by: Jens Axboe --- drivers/cdrom/cdrom.c | 139 +++++++++++++++++++++++------------------- 1 file changed, 77 insertions(+), 62 deletions(-) diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c index b927aa24424..cceace61ef2 100644 --- a/drivers/cdrom/cdrom.c +++ b/drivers/cdrom/cdrom.c @@ -1712,29 +1712,30 @@ static int dvd_do_auth(struct cdrom_device_info *cdi, dvd_authinfo *ai) return 0; } -static int dvd_read_physical(struct cdrom_device_info *cdi, dvd_struct *s) +static int dvd_read_physical(struct cdrom_device_info *cdi, dvd_struct *s, + struct packet_command *cgc) { unsigned char buf[21], *base; struct dvd_layer *layer; - struct packet_command cgc; struct cdrom_device_ops *cdo = cdi->ops; int ret, layer_num = s->physical.layer_num; if (layer_num >= DVD_LAYERS) return -EINVAL; - init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ); - cgc.cmd[0] = GPCMD_READ_DVD_STRUCTURE; - cgc.cmd[6] = layer_num; - cgc.cmd[7] = s->type; - cgc.cmd[9] = cgc.buflen & 0xff; + init_cdrom_command(cgc, buf, sizeof(buf), CGC_DATA_READ); + cgc->cmd[0] = GPCMD_READ_DVD_STRUCTURE; + cgc->cmd[6] = layer_num; + cgc->cmd[7] = s->type; + cgc->cmd[9] = cgc->buflen & 0xff; /* * refrain from reporting errors on non-existing layers (mainly) */ - cgc.quiet = 1; + cgc->quiet = 1; - if ((ret = cdo->generic_packet(cdi, &cgc))) + ret = cdo->generic_packet(cdi, cgc); + if (ret) return ret; base = &buf[4]; @@ -1762,21 +1763,22 @@ static int dvd_read_physical(struct cdrom_device_info *cdi, dvd_struct *s) return 0; } -static int dvd_read_copyright(struct cdrom_device_info *cdi, dvd_struct *s) +static int dvd_read_copyright(struct cdrom_device_info *cdi, dvd_struct *s, + struct packet_command *cgc) { int ret; u_char buf[8]; - struct packet_command cgc; struct cdrom_device_ops *cdo = cdi->ops; - init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ); - cgc.cmd[0] = GPCMD_READ_DVD_STRUCTURE; - cgc.cmd[6] = s->copyright.layer_num; - cgc.cmd[7] = s->type; - cgc.cmd[8] = cgc.buflen >> 8; - cgc.cmd[9] = cgc.buflen & 0xff; + init_cdrom_command(cgc, buf, sizeof(buf), CGC_DATA_READ); + cgc->cmd[0] = GPCMD_READ_DVD_STRUCTURE; + cgc->cmd[6] = s->copyright.layer_num; + cgc->cmd[7] = s->type; + cgc->cmd[8] = cgc->buflen >> 8; + cgc->cmd[9] = cgc->buflen & 0xff; - if ((ret = cdo->generic_packet(cdi, &cgc))) + ret = cdo->generic_packet(cdi, cgc); + if (ret) return ret; s->copyright.cpst = buf[4]; @@ -1785,79 +1787,89 @@ static int dvd_read_copyright(struct cdrom_device_info *cdi, dvd_struct *s) return 0; } -static int dvd_read_disckey(struct cdrom_device_info *cdi, dvd_struct *s) +static int dvd_read_disckey(struct cdrom_device_info *cdi, dvd_struct *s, + struct packet_command *cgc) { int ret, size; u_char *buf; - struct packet_command cgc; struct cdrom_device_ops *cdo = cdi->ops; size = sizeof(s->disckey.value) + 4; - if ((buf = kmalloc(size, GFP_KERNEL)) == NULL) + buf = kmalloc(size, GFP_KERNEL); + if (!buf) return -ENOMEM; - init_cdrom_command(&cgc, buf, size, CGC_DATA_READ); - cgc.cmd[0] = GPCMD_READ_DVD_STRUCTURE; - cgc.cmd[7] = s->type; - cgc.cmd[8] = size >> 8; - cgc.cmd[9] = size & 0xff; - cgc.cmd[10] = s->disckey.agid << 6; + init_cdrom_command(cgc, buf, size, CGC_DATA_READ); + cgc->cmd[0] = GPCMD_READ_DVD_STRUCTURE; + cgc->cmd[7] = s->type; + cgc->cmd[8] = size >> 8; + cgc->cmd[9] = size & 0xff; + cgc->cmd[10] = s->disckey.agid << 6; - if (!(ret = cdo->generic_packet(cdi, &cgc))) + ret = cdo->generic_packet(cdi, cgc); + if (!ret) memcpy(s->disckey.value, &buf[4], sizeof(s->disckey.value)); kfree(buf); return ret; } -static int dvd_read_bca(struct cdrom_device_info *cdi, dvd_struct *s) +static int dvd_read_bca(struct cdrom_device_info *cdi, dvd_struct *s, + struct packet_command *cgc) { - int ret; - u_char buf[4 + 188]; - struct packet_command cgc; + int ret, size = 4 + 188; + u_char *buf; struct cdrom_device_ops *cdo = cdi->ops; - init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ); - cgc.cmd[0] = GPCMD_READ_DVD_STRUCTURE; - cgc.cmd[7] = s->type; - cgc.cmd[9] = cgc.buflen & 0xff; + buf = kmalloc(size, GFP_KERNEL); + if (!buf) + return -ENOMEM; - if ((ret = cdo->generic_packet(cdi, &cgc))) - return ret; + init_cdrom_command(cgc, buf, size, CGC_DATA_READ); + cgc->cmd[0] = GPCMD_READ_DVD_STRUCTURE; + cgc->cmd[7] = s->type; + cgc->cmd[9] = cgc->buflen & 0xff; + + ret = cdo->generic_packet(cdi, cgc); + if (ret) + goto out; s->bca.len = buf[0] << 8 | buf[1]; if (s->bca.len < 12 || s->bca.len > 188) { cdinfo(CD_WARNING, "Received invalid BCA length (%d)\n", s->bca.len); - return -EIO; + ret = -EIO; + goto out; } memcpy(s->bca.value, &buf[4], s->bca.len); - - return 0; + ret = 0; +out: + kfree(buf); + return ret; } -static int dvd_read_manufact(struct cdrom_device_info *cdi, dvd_struct *s) +static int dvd_read_manufact(struct cdrom_device_info *cdi, dvd_struct *s, + struct packet_command *cgc) { int ret = 0, size; u_char *buf; - struct packet_command cgc; struct cdrom_device_ops *cdo = cdi->ops; size = sizeof(s->manufact.value) + 4; - if ((buf = kmalloc(size, GFP_KERNEL)) == NULL) + buf = kmalloc(size, GFP_KERNEL); + if (!buf) return -ENOMEM; - init_cdrom_command(&cgc, buf, size, CGC_DATA_READ); - cgc.cmd[0] = GPCMD_READ_DVD_STRUCTURE; - cgc.cmd[7] = s->type; - cgc.cmd[8] = size >> 8; - cgc.cmd[9] = size & 0xff; + init_cdrom_command(cgc, buf, size, CGC_DATA_READ); + cgc->cmd[0] = GPCMD_READ_DVD_STRUCTURE; + cgc->cmd[7] = s->type; + cgc->cmd[8] = size >> 8; + cgc->cmd[9] = size & 0xff; - if ((ret = cdo->generic_packet(cdi, &cgc))) { - kfree(buf); - return ret; - } + ret = cdo->generic_packet(cdi, cgc); + if (ret) + goto out; s->manufact.len = buf[0] << 8 | buf[1]; if (s->manufact.len < 0 || s->manufact.len > 2048) { @@ -1868,27 +1880,29 @@ static int dvd_read_manufact(struct cdrom_device_info *cdi, dvd_struct *s) memcpy(s->manufact.value, &buf[4], s->manufact.len); } +out: kfree(buf); return ret; } -static int dvd_read_struct(struct cdrom_device_info *cdi, dvd_struct *s) +static int dvd_read_struct(struct cdrom_device_info *cdi, dvd_struct *s, + struct packet_command *cgc) { switch (s->type) { case DVD_STRUCT_PHYSICAL: - return dvd_read_physical(cdi, s); + return dvd_read_physical(cdi, s, cgc); case DVD_STRUCT_COPYRIGHT: - return dvd_read_copyright(cdi, s); + return dvd_read_copyright(cdi, s, cgc); case DVD_STRUCT_DISCKEY: - return dvd_read_disckey(cdi, s); + return dvd_read_disckey(cdi, s, cgc); case DVD_STRUCT_BCA: - return dvd_read_bca(cdi, s); + return dvd_read_bca(cdi, s, cgc); case DVD_STRUCT_MANUFACT: - return dvd_read_manufact(cdi, s); + return dvd_read_manufact(cdi, s, cgc); default: cdinfo(CD_WARNING, ": Invalid DVD structure read requested (%d)\n", @@ -3027,7 +3041,8 @@ static noinline int mmc_ioctl_cdrom_pause_resume(struct cdrom_device_info *cdi, } static noinline int mmc_ioctl_dvd_read_struct(struct cdrom_device_info *cdi, - void __user *arg) + void __user *arg, + struct packet_command *cgc) { int ret; dvd_struct *s; @@ -3046,7 +3061,7 @@ static noinline int mmc_ioctl_dvd_read_struct(struct cdrom_device_info *cdi, return -EFAULT; } - ret = dvd_read_struct(cdi, s); + ret = dvd_read_struct(cdi, s, cgc); if (ret) goto out; @@ -3132,7 +3147,7 @@ static int mmc_ioctl(struct cdrom_device_info *cdi, unsigned int cmd, case CDROMRESUME: return mmc_ioctl_cdrom_pause_resume(cdi, &cgc, cmd); case DVD_READ_STRUCT: - return mmc_ioctl_dvd_read_struct(cdi, userptr); + return mmc_ioctl_dvd_read_struct(cdi, userptr, &cgc); case DVD_AUTH: return mmc_ioctl_dvd_auth(cdi, userptr); case CDROM_NEXT_WRITABLE: -- 2.41.1