From: Alexander Graf <agraf@suse.de>
To: qemu-devel Developers <qemu-devel@nongnu.org>
Cc: riku.voipio@iki.fi, Reinhard Max <max@suse.de>
Subject: [Qemu-devel] [PATCH] linux-user: add binfmt wrapper for argv[0] handling
Date: Fri, 30 Sep 2011 19:46:28 +0200 [thread overview]
Message-ID: <1317404788-30244-1-git-send-email-agraf@suse.de> (raw)
When using qemu's linux-user binaries through binfmt, argv[0] gets lost
along the execution because qemu only gets passed in the full file name
to the executable while argv[0] can be something completely different.
This breaks in some subtile situations, such as the grep and make test
suites.
This patch adds a wrapper binary called qemu-$TARGET-binfmt that can be
used with binfmt's P flag which passes the full path _and_ argv[0] to
the binfmt handler.
The binary would be smart enough to be versatile and only exist in the
system once, creating the qemu binary path names from its own argv[0].
However, this seemed like it didn't fit the make system too well, so
we're currently creating a new binary for each target archictecture.
CC: Reinhard Max <max@suse.de>
Signed-off-by: Alexander Graf <agraf@suse.de>
---
Makefile.target | 8 ++++++++
linux-user/binfmt.c | 42 ++++++++++++++++++++++++++++++++++++++++++
scripts/qemu-binfmt-conf.sh | 34 +++++++++++++++++-----------------
3 files changed, 67 insertions(+), 17 deletions(-)
create mode 100644 linux-user/binfmt.c
diff --git a/Makefile.target b/Makefile.target
index 88d2f1f..33f9630 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -33,6 +33,10 @@ endif
PROGS=$(QEMU_PROG)
STPFILES=
+ifdef CONFIG_LINUX_USER
+PROGS+=$(QEMU_PROG)-binfmt
+endif
+
ifndef CONFIG_HAIKU
LIBS+=-lm
endif
@@ -128,6 +132,8 @@ obj-y += $(addprefix ../libuser/, $(user-obj-y))
obj-y += $(addprefix ../libdis-user/, $(libdis-y))
obj-y += $(libobj-y)
+obj-binfmt-y += binfmt.o
+
endif #CONFIG_LINUX_USER
#########################################################
@@ -400,6 +406,8 @@ obj-$(CONFIG_GDBSTUB_XML) += gdbstub-xml.o
$(QEMU_PROG): $(obj-y) $(obj-$(TARGET_BASE_ARCH)-y)
$(call LINK,$^)
+$(QEMU_PROG)-binfmt: $(obj-binfmt-y)
+ $(call LINK,$^)
gdbstub-xml.c: $(TARGET_XML_FILES) $(SRC_PATH)/scripts/feature_to_c.sh
$(call quiet-command,rm -f $@ && $(SHELL) $(SRC_PATH)/scripts/feature_to_c.sh $@ $(TARGET_XML_FILES)," GEN $(TARGET_DIR)$@")
diff --git a/linux-user/binfmt.c b/linux-user/binfmt.c
new file mode 100644
index 0000000..cd1f513
--- /dev/null
+++ b/linux-user/binfmt.c
@@ -0,0 +1,42 @@
+#include <stdio.h>
+#include <stdarg.h>
+#include <unistd.h>
+#include <libgen.h>
+#include <string.h>
+#include <stdlib.h>
+
+
+int main(int argc, char **argv, char **envp)
+{
+ char *binfmt;
+ char **new_argv;
+
+ /*
+ * Check if our file name ends with -binfmt
+ */
+ binfmt = argv[0] + strlen(argv[0]) - strlen("-binfmt");
+ if (strcmp(binfmt, "-binfmt")) {
+ fprintf(stderr, "%s: Invalid executable name\n", argv[0]);
+ exit(1);
+ }
+ if (argc < 3) {
+ fprintf(stderr, "%s: Please use me through binfmt with P flag\n",
+ argv[0]);
+ exit(1);
+ }
+
+ binfmt[0] = '\0';
+ /* Now argv[0] is the real qemu binary name */
+
+ new_argv = (char **)malloc((argc + 2) * sizeof(*new_argv));
+ if (argc > 3) {
+ memcpy(&new_argv[4], &argv[3], (argc - 3) * sizeof(*new_argv));
+ }
+ new_argv[0] = argv[0];
+ new_argv[1] = (char *)"-0";
+ new_argv[2] = argv[2];
+ new_argv[3] = argv[1];
+ new_argv[argc + 1] = NULL;
+
+ return execve(new_argv[0], new_argv, envp);
+}
diff --git a/scripts/qemu-binfmt-conf.sh b/scripts/qemu-binfmt-conf.sh
index 83a44d8..c164569 100644
--- a/scripts/qemu-binfmt-conf.sh
+++ b/scripts/qemu-binfmt-conf.sh
@@ -31,38 +31,38 @@ esac
# register the interpreter for each cpu except for the native one
if [ $cpu != "i386" ] ; then
- echo ':i386:M::\x7fELF\x01\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x03\x00:\xff\xff\xff\xff\xff\xfe\xfe\xff\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff:/usr/local/bin/qemu-i386:' > /proc/sys/fs/binfmt_misc/register
- echo ':i486:M::\x7fELF\x01\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x06\x00:\xff\xff\xff\xff\xff\xfe\xfe\xff\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff:/usr/local/bin/qemu-i386:' > /proc/sys/fs/binfmt_misc/register
+ echo ':i386:M::\x7fELF\x01\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x03\x00:\xff\xff\xff\xff\xff\xfe\xfe\xff\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff:/usr/local/bin/qemu-i386-binfmt:P' > /proc/sys/fs/binfmt_misc/register
+ echo ':i486:M::\x7fELF\x01\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x06\x00:\xff\xff\xff\xff\xff\xfe\xfe\xff\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff:/usr/local/bin/qemu-i386-binfmt:P' > /proc/sys/fs/binfmt_misc/register
fi
if [ $cpu != "alpha" ] ; then
- echo ':alpha:M::\x7fELF\x02\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x26\x90:\xff\xff\xff\xff\xff\xfe\xfe\xff\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff:/usr/local/bin/qemu-alpha:' > /proc/sys/fs/binfmt_misc/register
+ echo ':alpha:M::\x7fELF\x02\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x26\x90:\xff\xff\xff\xff\xff\xfe\xfe\xff\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff:/usr/local/bin/qemu-alpha-binfmt:P' > /proc/sys/fs/binfmt_misc/register
fi
if [ $cpu != "arm" ] ; then
- echo ':arm:M::\x7fELF\x01\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x28\x00:\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff:/usr/local/bin/qemu-arm:' > /proc/sys/fs/binfmt_misc/register
- echo ':armeb:M::\x7fELF\x01\x02\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x28:\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff:/usr/local/bin/qemu-armeb:' > /proc/sys/fs/binfmt_misc/register
+ echo ':arm:M::\x7fELF\x01\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x28\x00:\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff:/usr/local/bin/qemu-arm-binfmt:P' > /proc/sys/fs/binfmt_misc/register
+ echo ':armeb:M::\x7fELF\x01\x02\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x28:\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff:/usr/local/bin/qemu-armeb-binfmt:P' > /proc/sys/fs/binfmt_misc/register
fi
if [ $cpu != "sparc" ] ; then
- echo ':sparc:M::\x7fELF\x01\x02\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x02:\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff:/usr/local/bin/qemu-sparc:' > /proc/sys/fs/binfmt_misc/register
+ echo ':sparc:M::\x7fELF\x01\x02\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x02:\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff:/usr/local/bin/qemu-sparc-binfmt:P' > /proc/sys/fs/binfmt_misc/register
fi
if [ $cpu != "ppc" ] ; then
- echo ':ppc:M::\x7fELF\x01\x02\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x14:\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff:/usr/local/bin/qemu-ppc:' > /proc/sys/fs/binfmt_misc/register
+ echo ':ppc:M::\x7fELF\x01\x02\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x14:\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff:/usr/local/bin/qemu-ppc-binfmt:P' > /proc/sys/fs/binfmt_misc/register
fi
if [ $cpu != "m68k" ] ; then
echo 'Please check cpu value and header information for m68k!'
- echo ':m68k:M::\x7fELF\x01\x02\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x04:\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff:/usr/local/bin/qemu-m68k:' > /proc/sys/fs/binfmt_misc/register
+ echo ':m68k:M::\x7fELF\x01\x02\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x04:\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff:/usr/local/bin/qemu-m68k-binfmt:P' > /proc/sys/fs/binfmt_misc/register
fi
if [ $cpu != "mips" ] ; then
# FIXME: We could use the other endianness on a MIPS host.
- echo ':mips:M::\x7fELF\x01\x02\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x08:\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff:/usr/local/bin/qemu-mips:' > /proc/sys/fs/binfmt_misc/register
- echo ':mipsel:M::\x7fELF\x01\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x08\x00:\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff:/usr/local/bin/qemu-mipsel:' > /proc/sys/fs/binfmt_misc/register
- echo ':mipsn32:M::\x7fELF\x01\x02\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x08:\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff:/usr/local/bin/qemu-mipsn32:' > /proc/sys/fs/binfmt_misc/register
- echo ':mipsn32el:M::\x7fELF\x01\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x08\x00:\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff:/usr/local/bin/qemu-mipsn32el:' > /proc/sys/fs/binfmt_misc/register
- echo ':mips64:M::\x7fELF\x02\x02\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x08:\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff:/usr/local/bin/qemu-mips64:' > /proc/sys/fs/binfmt_misc/register
- echo ':mips64el:M::\x7fELF\x02\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x08\x00:\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff:/usr/local/bin/qemu-mips64el:' > /proc/sys/fs/binfmt_misc/register
+ echo ':mips:M::\x7fELF\x01\x02\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x08:\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff:/usr/local/bin/qemu-mips-binfmt:P' > /proc/sys/fs/binfmt_misc/register
+ echo ':mipsel:M::\x7fELF\x01\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x08\x00:\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff:/usr/local/bin/qemu-mipsel-binfmt:P' > /proc/sys/fs/binfmt_misc/register
+ echo ':mipsn32:M::\x7fELF\x01\x02\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x08:\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff:/usr/local/bin/qemu-mipsn32-binfmt:P' > /proc/sys/fs/binfmt_misc/register
+ echo ':mipsn32el:M::\x7fELF\x01\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x08\x00:\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff:/usr/local/bin/qemu-mipsn32el-binfmt:P' > /proc/sys/fs/binfmt_misc/register
+ echo ':mips64:M::\x7fELF\x02\x02\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x08:\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff:/usr/local/bin/qemu-mips64-binfmt:P' > /proc/sys/fs/binfmt_misc/register
+ echo ':mips64el:M::\x7fELF\x02\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x08\x00:\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff:/usr/local/bin/qemu-mips64el-binfmt:P' > /proc/sys/fs/binfmt_misc/register
fi
if [ $cpu != "sh" ] ; then
- echo ':sh4:M::\x7fELF\x01\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x2a\x00:\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff:/usr/local/bin/qemu-sh4:' > /proc/sys/fs/binfmt_misc/register
- echo ':sh4eb:M::\x7fELF\x01\x02\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x2a:\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff:/usr/local/bin/qemu-sh4eb:' > /proc/sys/fs/binfmt_misc/register
+ echo ':sh4:M::\x7fELF\x01\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x2a\x00:\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff:/usr/local/bin/qemu-sh4-binfmt:P' > /proc/sys/fs/binfmt_misc/register
+ echo ':sh4eb:M::\x7fELF\x01\x02\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x2a:\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff:/usr/local/bin/qemu-sh4eb-binfmt:P' > /proc/sys/fs/binfmt_misc/register
if [ $cpu != "s390x" ] ; then
- echo ':s390x:M::\x7fELF\x02\x02\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x16:\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff:/usr/local/bin/qemu-s390x:' > /proc/sys/fs/binfmt_misc/register
+ echo ':s390x:M::\x7fELF\x02\x02\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x16:\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff:/usr/local/bin/qemu-s390x-binfmt:P' > /proc/sys/fs/binfmt_misc/register
fi
--
1.7.3.4
next reply other threads:[~2011-09-30 17:43 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-30 17:46 Alexander Graf [this message]
2011-10-29 18:08 ` [Qemu-devel] [PATCH] linux-user: add binfmt wrapper for argv[0] handling Alexander Graf
2011-10-31 19:16 ` Riku Voipio
2011-10-31 23:55 ` Alexander Graf
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