Patch "mISDN: avoid arch specific __builtin_return_address call" has been added to the 3.18-stable tree

Patch "mISDN: avoid arch specific __builtin_return_address call" has been added to the 3.18-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    mISDN: avoid arch specific __builtin_return_address call

to the 3.18-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     misdn-avoid-arch-specific-__builtin_return_address-call.patch
and it can be found in the queue-3.18 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 3e7a8716e20b759eec0ad88145255bb33174f0c8 Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd@arndb.de>
Date: Tue, 13 Jan 2015 17:10:58 +0100
Subject: mISDN: avoid arch specific __builtin_return_address call

From: Arnd Bergmann <arnd@arndb.de>

commit 3e7a8716e20b759eec0ad88145255bb33174f0c8 upstream.

Not all architectures are able to call __builtin_return_address().
On ARM, the mISDN code produces this warning:

hardware/mISDN/w6692.c: In function 'w6692_dctrl':
hardware/mISDN/w6692.c:1181:75: warning: unsupported argument to '__builtin_return_address'
  pr_debug("%s: %s dev(%d) open from %p\n", card->name, __func__,
                                                                           ^
hardware/mISDN/mISDNipac.c: In function 'open_dchannel':
hardware/mISDN/mISDNipac.c:759:75: warning: unsupported argument to '__builtin_return_address'
  pr_debug("%s: %s dev(%d) open from %p\n", isac->name, __func__,
                                                                           ^

In a lot of cases, this is relatively easy to work around by
passing the value of __builtin_return_address(0) from the
callers into the functions that want it. One exception is
the indirect 'open' function call in struct isac_hw. While it
would be possible to fix this as well, this patch only addresses
the other callers properly and lets this one return the direct
parent function, which should be good enough.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/isdn/hardware/mISDN/mISDNipac.c |   12 +++++++++---
 drivers/isdn/hardware/mISDN/w6692.c     |    6 +++---
 2 files changed, 12 insertions(+), 6 deletions(-)

--- a/drivers/isdn/hardware/mISDN/mISDNipac.c
+++ b/drivers/isdn/hardware/mISDN/mISDNipac.c
@@ -754,10 +754,10 @@ dbusy_timer_handler(struct isac_hw *isac
 }
 
 static int
-open_dchannel(struct isac_hw *isac, struct channel_req *rq)
+open_dchannel_caller(struct isac_hw *isac, struct channel_req *rq, void *caller)
 {
 	pr_debug("%s: %s dev(%d) open from %p\n", isac->name, __func__,
-		 isac->dch.dev.id, __builtin_return_address(1));
+		 isac->dch.dev.id, caller);
 	if (rq->protocol != ISDN_P_TE_S0)
 		return -EINVAL;
 	if (rq->adr.channel == 1)
@@ -771,6 +771,12 @@ open_dchannel(struct isac_hw *isac, stru
 	return 0;
 }
 
+static int
+open_dchannel(struct isac_hw *isac, struct channel_req *rq)
+{
+	return open_dchannel_caller(isac, rq, __builtin_return_address(0));
+}
+
 static const char *ISACVer[] =
 {"2086/2186 V1.1", "2085 B1", "2085 B2",
  "2085 V2.3"};
@@ -1548,7 +1554,7 @@ ipac_dctrl(struct mISDNchannel *ch, u32
 	case OPEN_CHANNEL:
 		rq = arg;
 		if (rq->protocol == ISDN_P_TE_S0)
-			err = open_dchannel(isac, rq);
+			err = open_dchannel_caller(isac, rq, __builtin_return_address(0));
 		else
 			err = open_bchannel(ipac, rq);
 		if (err)
--- a/drivers/isdn/hardware/mISDN/w6692.c
+++ b/drivers/isdn/hardware/mISDN/w6692.c
@@ -1176,10 +1176,10 @@ w6692_l1callback(struct dchannel *dch, u
 }
 
 static int
-open_dchannel(struct w6692_hw *card, struct channel_req *rq)
+open_dchannel(struct w6692_hw *card, struct channel_req *rq, void *caller)
 {
 	pr_debug("%s: %s dev(%d) open from %p\n", card->name, __func__,
-		 card->dch.dev.id, __builtin_return_address(1));
+		 card->dch.dev.id, caller);
 	if (rq->protocol != ISDN_P_TE_S0)
 		return -EINVAL;
 	if (rq->adr.channel == 1)
@@ -1207,7 +1207,7 @@ w6692_dctrl(struct mISDNchannel *ch, u32
 	case OPEN_CHANNEL:
 		rq = arg;
 		if (rq->protocol == ISDN_P_TE_S0)
-			err = open_dchannel(card, rq);
+			err = open_dchannel(card, rq, __builtin_return_address(0));
 		else
 			err = open_bchannel(card, rq);
 		if (err)


Patches currently in stable-queue which might be from arnd@arndb.de are

queue-3.18/ib-iser-fix-sparse-warnings.patch
queue-3.18/cred-userns-define-current_user_ns-as-a-function.patch
queue-3.18/pci-xilinx-fix-harmless-format-string-warning.patch
queue-3.18/arm64-build-vdso-without-libgcov.patch
queue-3.18/arm64-provide-a-namespace-to-ncaps.patch
queue-3.18/alsa-ppc-awacs-shut-up-maybe-uninitialized-warning.patch
queue-3.18/net-tg3-avoid-uninitialized-variable-warning.patch
queue-3.18/tty-isicom-fix-big-endian-compile-warning.patch
queue-3.18/mtd-avoid-stack-overflow-in-mtd-cfi-code.patch
queue-3.18/ib-qib-rename-bits_per_page-to-rvt_bits_per_page.patch
queue-3.18/ips-remove-pointless-warning.patch
queue-3.18/powerpc-ptrace-fix-out-of-bounds-array-access-warning.patch
queue-3.18/staging-imx-drm-fix-indentation-warning.patch
queue-3.18/mlx5-avoid-build-warnings-on-32-bit.patch
queue-3.18/mm-cma-silence-warnings-due-to-max-usage.patch
queue-3.18/misdn-avoid-arch-specific-__builtin_return_address-call.patch
queue-3.18/staging-bcm-add-32-bit-host-dependency.patch
queue-3.18/staging-vt6655-fix-overly-large-stack-usage.patch
queue-3.18/drbd-avoid-redefinition-of-bits_per_page.patch
queue-3.18/infiniband-mlx5-avoid-a-compile-time-warning.patch
queue-3.18/arm-cns3xxx-shut-up-frame-size-warning.patch
queue-3.18/ib-ehca-fix-maybe-uninitialized-warnings.patch