Patchwork [13/14] linux-user: Build vdso for x64.

login
register
mail settings
Submitter Richard Henderson
Date April 4, 2010, 6:38 p.m.
Message ID <bc6fee537b4281a7e18be0b3a31add32dbfc4114.1272483393.git.rth@twiddle.net>
Download mbox | patch
Permalink /patch/51243/
State New
Headers show

Comments

Richard Henderson - April 4, 2010, 6:38 p.m.
... Well, sortof.  The Makefile bits are broken.
Patch to load the vdso into the running program to follow.

Signed-off-by: Richard Henderson <rth@twiddle.net>
---
 Makefile                  |    3 +-
 pc-bios/Makefile          |    5 ++
 pc-bios/vdso-linux-x64.S  |  102 +++++++++++++++++++++++++++++++++++++++++++++
 pc-bios/vdso-linux-x64.ld |   81 +++++++++++++++++++++++++++++++++++
 pc-bios/vdso-linux-x64.so |  Bin 0 -> 7515 bytes
 5 files changed, 190 insertions(+), 1 deletions(-)
 create mode 100644 pc-bios/vdso-linux-x64.S
 create mode 100644 pc-bios/vdso-linux-x64.ld
 create mode 100755 pc-bios/vdso-linux-x64.so

diff --git a/pc-bios/vdso-linux-x64.so b/pc-bios/vdso-linux-x64.so
new file mode 100755
index 0000000000000000000000000000000000000000..5ebf5959f9dac5065428148e7625f58c722e1cca
GIT binary patch
literal 7515
zcmeHMO>Z1U5Uus%*iM{y6Cwl{#0nW7EEvfVLXjZIcKj8xI3d_l!ezYij=dJ%U9iWI
z%^?^OD>4#Nj&MZWI6#g*@TnkV@(Xf7Z~z1s6b@K90872;dYhfeh7%G(Oxr!L>s3`x
zcTM-~sQUG>!gyOIBP>~YRwC&>#|)Wb$7F~@a#Z%{H7ENOMed0>XrOb2c-p!qcA6eE
zeD78^vQ9%3$wvhI+O=-n8;N(|CvA==(hoGodBw()L^o+QFg?c!AJlga>!k(uIa-LY
zMLGRLSVH?_^GhP_iS#=Vd5cEa74n?#Z-3Tn&}`fM5et-CCNrj2EDn2}TFw~mGrZsM
z_qywE*2ejV$>uIMO@7Yw=Ju~ZR<csIb-@APIXx=fBDOyH+#nuOK9}GhHv1%x#}4~s
zKa<KIlwa!#u`-|%?DN(?`b8Pkit!|QuD8f2y`&LHBalWQjX)ZKGy-V^(g>sxNF$I&
zAdNs8fiwdDs|X;S(WMo63*>s3&(UU7n9pH82KF6Vf#8t0fXy3+^O=!AHo&0|a2IF3
zc~!3WUcG#B^T!9?KVE%n;H&=rtLKBt*~@kD{R^d)nm@Nxn|s+`2*Pl&5|A{pHeV{P
zH*s^Xtjf}2b#?6txO)0OD1{SKGiUuH-cx!%jHvk!Ove7+`|OwfNFhC>mANg9y-oGI
zs~={WUP8VF1+f5!c}`5t$n~E(zYGQjCO+st_x8J=e$+R<aq`<tZ}#cD*^Fvu&uDvE
zaaysYxTMH_Gq0VI%vvtf+uhNLTnu=O1p#Ev2qO3=wcgU2<O|B()XH3sHvjWw`+J>2
zPy4l=M=nKk*`AHdgI`Z>*2Au?oyY1uB3m7ko4aBA7e9Az9T@!lns_Vgm9ThTF<f?7
zW~;PbEmjui#M6daDHg+`cnj54uUuRyJ3d@?%!OciWwBO`34TeuYAp=J3(Efda<LNl
z<&xS{5-$wa!f4R{z@=CFz@EW+Lt(y-h;@R({m8YEb99vdMQ)Y*l=)ZU4YPwkZ0OHC
z?BmMe7Q8?6oJ88GNmS@h#Qwv+=lz*4CLVQe4L$v^&rptN-PK$#{h41T4#7wZ_4IeF
z+k1Q`fnz?J$ow<yEu0i(R9p3?`!nB6JY<%<e-d9%J#yFNXR(pB5IO&3{GFBBX#?+7
z`X}@KeKa&=+(^%B19PJP-SYjkPx@maH~W8Q<0sD2(J&eRi{{Vu$vigkSi+y{mh?ew
zaP5%;9<%)RrDjsw$>-NR_GZ(a2c49&!01avP&t0CYy1Yby8n&nB`xx%>!xu{-oK$}
z(a7p(8~eCPpVg<u{n<q8IPN@WfIh3gO59Iz`}W3pOq}1-*avaGL%6Qvd}m|5#`&(s
z`BR+V+c;l}^ZSJBCeGhJ-yn}TX7qd`86TV*f#>^&_IYizI&blmZ*@+Beb?$72EV1P
z&QD&l{*&i33&tnURjSqx*E!df_@n2hhMzxiT>Oc`sgdD=e`<XE#j$CBdU&KT=1cs$
X=k`~OeHQ)A7f?*40=|k`eoXxZDW(!W

literal 0
HcmV?d00001

Patch

diff --git a/Makefile b/Makefile
index 18e7368..c6d1de5 100644
--- a/Makefile
+++ b/Makefile
@@ -180,7 +180,8 @@  pxe-e1000.bin \
 pxe-ne2k_pci.bin pxe-pcnet.bin \
 pxe-rtl8139.bin pxe-virtio.bin \
 bamboo.dtb petalogix-s3adsp1800.dtb \
-multiboot.bin linuxboot.bin
+multiboot.bin linuxboot.bin \
+vdso-linux-x64.so
 else
 BLOBS=
 endif
diff --git a/pc-bios/Makefile b/pc-bios/Makefile
index 315288d..70e2485 100644
--- a/pc-bios/Makefile
+++ b/pc-bios/Makefile
@@ -15,5 +15,10 @@  all: $(TARGETS)
 %.dtb: %.dts
 	dtc -I dts -O dtb -o $@ $<
 
+vdso-linux-x64.so: vdso-linux-x64.o vdso-linux-x64.ld
+	$(CC) -nostdlib -shared -Wl,-T,vdso-linux-x64.ld \
+	  -Wl,-h,linux-vdso.so.1 -Wl,--hash-style=both \
+	  vdso-linux-x64.o -o $@
+
 clean:
 	rm -f $(TARGETS) *.o *~
diff --git a/pc-bios/vdso-linux-x64.S b/pc-bios/vdso-linux-x64.S
new file mode 100644
index 0000000..e7784c9
--- /dev/null
+++ b/pc-bios/vdso-linux-x64.S
@@ -0,0 +1,102 @@ 
+/*
+ *  x86-64 linux replacement vdso.
+ *
+ *  Copyright (c) 2010 Fabrice Bellard
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <asm/unistd.h>
+
+	.globl	__vdso_clock_gettime
+	.type	__vdso_clock_gettime, @function
+	.balign	16
+	.cfi_startproc
+__vdso_clock_gettime:
+	mov	$__NR_clock_gettime, %eax
+	syscall
+	ret
+	.cfi_endproc
+	.size	__vdso_clock_gettime, . - __vdso_clock_gettime
+
+clock_gettime = __vdso_clock_gettime
+	.weak	clock_gettime
+
+
+	.globl	__vdso_gettimeofday
+	.type	__vdso_gettimeofday, @function
+	.balign	16
+	.cfi_startproc
+__vdso_gettimeofday:
+	mov	$__NR_gettimeofday, %eax
+	syscall
+	ret
+	.cfi_endproc
+	.size	__vdso_gettimeofday, . - __vdso_gettimeofday
+
+gettimeofday = __vdso_gettimeofday
+	.weak	gettimeofday
+
+
+	.globl	__vdso_getcpu
+	.type	__vdso_getcpu, @function
+	.balign	16
+	.cfi_startproc
+__vdso_getcpu:
+	/* ??? There is no syscall number for this allocated on x64.
+	   We can handle this several ways:
+
+	   (1) Invent a syscall number for use within qemu.
+               It should be easy enough to pick a number that
+               is well out of the way of the kernel numbers.
+
+           (2) Force the emulated cpu to support the rdtscp insn,
+	       and initialize the TSC_AUX value the appropriate value.
+
+	   (3) Pretend that we're always running on cpu 0.
+
+	   This last is the one that's implemented here, with the
+	   tiny bit of extra code to support rdtscp in place.  */
+
+	xor	%ecx, %ecx		/* rdtscp w/ tsc_aux = 0 */
+
+	/* if (cpu != NULL) *cpu = (ecx & 0xfff); */
+	test	%rdi, %rdi
+	jz	1f
+	mov	%ecx, %eax
+	and	$0xfff, %eax
+	mov	%eax, (%rdi)
+
+	/* if (node != NULL) *node = (ecx >> 12); */
+1:	test	%rsi, %rsi
+	jz	2f
+	shr	$12, %ecx
+	mov	%ecx, (%rsi)
+
+2:	xor	%eax, %eax
+	ret
+	.cfi_endproc
+	.size	__vdso_getcpu, . - __vdso_getcpu
+
+getcpu = __vdso_getcpu
+	.weak	getcpu
+
+/* ??? Perhaps add elf notes.  E.g.
+
+   #include <linux/elfnote.h>
+   ELFNOTE_START(Linux, 0, "a")
+	.long LINUX_VERSION_CODE
+   ELFNOTE_END
+
+   but what version number would we set for QEMU?  */
diff --git a/pc-bios/vdso-linux-x64.ld b/pc-bios/vdso-linux-x64.ld
new file mode 100644
index 0000000..d57d0e7
--- /dev/null
+++ b/pc-bios/vdso-linux-x64.ld
@@ -0,0 +1,81 @@ 
+/*
+ * Linker script for linux x64 replacement vdso.
+ *
+ *  Copyright (c) 2010 Fabrice Bellard
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+VERSION {
+	LINUX_2.6 {
+	global:
+		clock_gettime;
+		__vdso_clock_gettime;
+		gettimeofday;
+		__vdso_gettimeofday;
+		getcpu;
+		__vdso_getcpu;
+	local: *;
+	};
+}
+
+PHDRS {
+	phdr		PT_PHDR		FLAGS(4) PHDRS;
+	data		PT_LOAD		FLAGS(6) FILEHDR PHDRS;
+	text		PT_LOAD		FLAGS(5);
+	dynamic		PT_DYNAMIC	FLAGS(4);
+	note		PT_NOTE		FLAGS(4);
+	/* ??? Various versions of ld don't know PT_GNU_EH_FRAME. */
+	eh_frame_hdr	0x6474e550;
+}
+
+SECTIONS {
+	/* ??? We can't really prelink to any address without knowing
+	   something about the virtual memory space of the host, since
+	   that leaks over into the available memory space of the guest.  */
+	. = SIZEOF_HEADERS;
+
+	/* The following, including the FILEHDRS and PHDRS, are modified
+	   when we relocate the binary.  We want them to be initially
+	   writable for the relocation; we'll force them read-only after.  */
+	.dynamic	: { *(.dynamic) }	:data :dynamic
+	.dynsym		: { *(.dynsym) }	:data
+	.data		: {
+		/* There ought not be any real read-write data.
+		   But since we manipulated the segment layout,
+		   we have to put these sections somewhere.  */
+		*(.data*)
+		*(.sdata*)
+		*(.got.plt) *(.got)
+		*(.gnu.linkonce.d.*)
+		*(.bss*)
+		*(.dynbss*)
+		*(.gnu.linkonce.b.*)
+	}
+
+	. += 4096;
+	.hash		: { *(.hash) }		:text
+	.gnu.hash	: { *(.gnu.hash) }
+	.dynstr		: { *(.dynstr) }
+	.gnu.version	: { *(.gnu.version) }
+	.gnu.version_d	: { *(.gnu.version_d) }
+	.gnu.version_r	: { *(.gnu.version_r) }
+	.note		: { *(.note*) }		:text :note
+	.eh_frame_hdr	: { *(.eh_frame_hdr) }	:text :eh_frame_hdr
+	.eh_frame	: { *(.eh_frame) }	:text
+	.rodata		: { *(.rodata) }
+
+	. = ALIGN(0x100);
+	.text		: { *(.text*) }		:text	=0x90909090
+}