procd: improve early console handling
authorGabor Juhos <juhosg@openwrt.org>
Fri, 19 Jul 2013 17:12:44 +0000 (17:12 +0000)
committerGabor Juhos <juhosg@openwrt.org>
Fri, 19 Jul 2013 17:12:44 +0000 (17:12 +0000)
The malta target is broken since procd is used
as init. The initramfs image boots fine, however
the console is not working.

Improve the early console handling to fix the
problem.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
SVN-Revision: 37451

package/system/procd/Makefile
package/system/procd/patches/0001-early-keep-stdio-files-open.patch [new file with mode: 0644]
package/system/procd/patches/0002-early-remove-superfluous-close-of-stdio-file-descrip.patch [new file with mode: 0644]

index 014e01caf9895de289b991f04328b25cc266f92d..0c5a34cbb9ac84ae6ed85c11803da4d05f1ac72c 100644 (file)
@@ -2,7 +2,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=procd
 PKG_VERSION:=2013-07-14
-PKG_RELEASE=$(PKG_SOURCE_VERSION)
+PKG_RELEASE=$(PKG_SOURCE_VERSION)-1
 
 PKG_SOURCE_PROTO:=git
 PKG_SOURCE_URL:=git://nbd.name/luci2/procd.git
diff --git a/package/system/procd/patches/0001-early-keep-stdio-files-open.patch b/package/system/procd/patches/0001-early-keep-stdio-files-open.patch
new file mode 100644 (file)
index 0000000..74cca07
--- /dev/null
@@ -0,0 +1,49 @@
+From 13ebb50d2789de7bd47cebe57e3f6eba58fdcc7e Mon Sep 17 00:00:00 2001
+From: Gabor Juhos <juhosg@openwrt.org>
+Date: Fri, 19 Jul 2013 08:43:35 +0200
+Subject: [PATCH 1/2] early: keep stdio files open
+
+At the end of the 'early_console' function, the
+file descriptor is closed unconditionally. This
+'close' call closes the stdio files if the fd
+returned by the 'open(dev/console)' call equals
+with any of the STD{IN,OUT,ERR}_FILENO values.
+When this happens, all subsequent accesses to
+the stdio files will fail and early console
+access won't work.
+
+To avoid this, don't close the file descriptor if
+that equals with any of the STD*_FILENO values.
+
+Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
+---
+Note:
+
+The issue happens if Linux is unable to open the
+initial console before calling init. In this case,
+the 'open(dev/console)' call in the 'early_console'
+function returns with zero.
+---
+ early.c |    6 +++++-
+ 1 file changed, 5 insertions(+), 1 deletion(-)
+
+diff --git a/early.c b/early.c
+index 27d0929..204623b 100644
+--- a/early.c
++++ b/early.c
+@@ -65,7 +65,11 @@ static void early_console(const char *dev)
+       dup2(dd, STDIN_FILENO);
+       dup2(dd, STDOUT_FILENO);
+       dup2(dd, STDERR_FILENO);
+-      close(dd);
++
++      if (dd != STDIN_FILENO &&
++          dd != STDOUT_FILENO &&
++          dd != STDERR_FILENO)
++              close(dd);
+ }
+ static void early_env(void)
+-- 
+1.7.10
+
diff --git a/package/system/procd/patches/0002-early-remove-superfluous-close-of-stdio-file-descrip.patch b/package/system/procd/patches/0002-early-remove-superfluous-close-of-stdio-file-descrip.patch
new file mode 100644 (file)
index 0000000..0969832
--- /dev/null
@@ -0,0 +1,40 @@
+From 1edd25cfa0a26dac1ca5d49bce479ebdea336437 Mon Sep 17 00:00:00 2001
+From: Gabor Juhos <juhosg@openwrt.org>
+Date: Fri, 19 Jul 2013 08:21:17 +0200
+Subject: [PATCH 2/2] early: remove superfluous close of stdio file
+ descriptors
+
+'man dup2' says:
+
+  dup2() makes newfd be the copy of oldfd, closing newfd first if
+  necessary, but note the following:
+
+  *  If oldfd is not a valid file descriptor, then the call fails,
+     and newfd is not closed.
+
+  *  If oldfd is a valid file descriptor, and newfd has the same
+     value as oldfd, then dup2() does nothing, and returns newfd.
+
+Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
+---
+ early.c |    4 ----
+ 1 file changed, 4 deletions(-)
+
+diff --git a/early.c b/early.c
+index 204623b..f9e3277 100644
+--- a/early.c
++++ b/early.c
+@@ -53,10 +53,6 @@ static void early_console(const char *dev)
+               mkdev("*console", 0600);
+       dd = open(dev, O_RDWR);
+-      close(STDIN_FILENO);
+-      close(STDOUT_FILENO);
+-      close(STDERR_FILENO);
+-
+       if (dd < 0) {
+               ERROR("Failed to open %s\n", dev);
+               return;
+-- 
+1.7.10
+