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From: Ralf Baechle <ralf@linux-mips.org>
To: linux-scsi@vger.kernel.org
Subject: [SCSI] Avoid ld errors messages by marking sd_major noinline.
Date: Sat, 4 Mar 2006 17:16:09 +0000	[thread overview]
Message-ID: <20060304171609.GA23288@linux-mips.org> (raw)

Gcc may compile sd_major() using a jump table which it will put into
.rodata.  If also inline sd_major's function body into exit_sd() and
CONFIG_BLK_DEV_SD has been set to y ld is going to discard exit_sd's
code later at link time.  It won't discard the jump table if was put
into another section than .exit.data and so the remaining refernces
to sd_major's function body will result in about 100 lines of non-fatal
linker error messages.  This is avoided by marking sd_major noinline.

Observed on MIPS with GCC 4.0.2 and 4.1.0 but not 3.4.5 and seems
possible on other architectures such as i386.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 9d98723..f1af700 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -158,8 +158,16 @@ static struct scsi_driver sd_template = 
  * for major1, ... 
  * As we stay compatible with our numbering scheme, we can reuse 
  * the well-know SCSI majors 8, 65--71, 136--143.
+ *
+ * Gcc may compile sd_major() using a jump table which it will put into
+ * .rodata.  If also inline sd_major's function body into exit_sd() and
+ * CONFIG_BLK_DEV_SD has been set to y ld is going to discard exit_sd's
+ * code later at link time.  It won't discard the jump table if was put
+ * into another section than .exit.data and so the remaining refernces to
+ * sd_major's function body will result in about 100 lines of non-fatal
+ * linker error messages.  This is avoided by marking sd_major noinline.
  */
-static int sd_major(int major_idx)
+static noinline int sd_major(int major_idx)
 {
 	switch (major_idx) {
 	case 0:

             reply	other threads:[~2006-03-04 17:16 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-03-04 17:16 Ralf Baechle [this message]
  -- strict thread matches above, loose matches on Subject: below --
2006-03-04 17:12 [SCSI] Avoid ld errors messages by marking sd_major noinline Ralf Baechle
2006-03-04 17:15 ` Ralf Baechle

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