@@ -154,6 +154,9 @@ static uint32_t get_elf_hwcap(void)
#define ELF_CLASS ELFCLASS64
#define ELF_ARCH EM_X86_64
+#define HAVE_VDSO 1
+#include "vdso.c.inc"
+
static inline void init_thread(struct target_pt_regs *regs, struct image_info *infop)
{
regs->rax = 0;
new file mode 100644
@@ -0,0 +1,3 @@
+vdso.so: vdso.S vdso.ld Makefile.vdso
+ $(CC) -nostdlib -shared -Wl,-T,vdso.ld -Wl,--build-id=none \
+ -Wl,-h,linux-vdso.so.1 -Wl,--hash-style=both vdso.S -o $@
@@ -3,3 +3,9 @@ syscall_nr_generators += {
arguments: [ meson.current_source_dir() / 'syscallhdr.sh', '@INPUT@', '@OUTPUT@', '@EXTRA_ARGS@' ],
output: '@BASENAME@_nr.h')
}
+
+gen = [
+ gen_vdso.process('vdso.so')
+]
+
+linux_user_ss.add(when: 'TARGET_X86_64', if_true: gen)
new file mode 100644
@@ -0,0 +1,122 @@
+/*
+ * x86-64 linux replacement vdso.
+ *
+ * Copyright 2021 Linaro, Ltd.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#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_clock_getres
+ .type __vdso_clock_getres, @function
+ .balign 16
+ .cfi_startproc
+__vdso_clock_getres:
+ mov $__NR_clock_getres, %eax
+ syscall
+ ret
+ .cfi_endproc
+ .size __vdso_clock_getres, . - __vdso_clock_getres
+
+clock_getres = __vdso_clock_getres
+ .weak clock_getres
+
+ .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_time
+ .type __vdso_time, @function
+ .balign 16
+ .cfi_startproc
+__vdso_time:
+ mov $__NR_time, %eax
+ syscall
+ ret
+ .cfi_endproc
+ .size __vdso_time, . - __vdso_time
+
+time = __vdso_time
+ .weak time
+
+
+ .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?
+ */
new file mode 100644
@@ -0,0 +1,74 @@
+/*
+ * Linker script for linux x86-64 replacement vdso.
+ *
+ * Copyright 2021 Linaro, Ltd.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+VERSION {
+ LINUX_2.6 {
+ global:
+ clock_gettime;
+ __vdso_clock_gettime;
+ gettimeofday;
+ __vdso_gettimeofday;
+ getcpu;
+ __vdso_getcpu;
+ time;
+ __vdso_time;
+ clock_getres;
+ __vdso_clock_getres;
+
+ 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);
+ eh_frame_hdr PT_GNU_EH_FRAME;
+ note PT_NOTE FLAGS(4);
+}
+
+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. */
+ .note : { *(.note*) } :data :note
+ .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.*)
+ }
+
+ .rodata : { *(.rodata*) }
+ .hash : { *(.hash) }
+ .gnu.hash : { *(.gnu.hash) }
+ .dynstr : { *(.dynstr) }
+ .gnu.version : { *(.gnu.version) }
+ .gnu.version_d : { *(.gnu.version_d) }
+ .gnu.version_r : { *(.gnu.version_r) }
+ .eh_frame_hdr : { *(.eh_frame_hdr) } :data :eh_frame_hdr
+ .eh_frame : { *(.eh_frame) } :data
+
+ . = ALIGN(4096);
+ .text : { *(.text*) } :text =0x90909090
+}
new file mode 100755
Building the vdso itself is not actually wired up to anything, since we require a cross-compiler. Just check in that file for now. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> --- linux-user/elfload.c | 3 + linux-user/x86_64/Makefile.vdso | 3 + linux-user/x86_64/meson.build | 6 ++ linux-user/x86_64/vdso.S | 122 ++++++++++++++++++++++++++++++++ linux-user/x86_64/vdso.ld | 74 +++++++++++++++++++ linux-user/x86_64/vdso.so | Bin 0 -> 5912 bytes 6 files changed, 208 insertions(+) create mode 100644 linux-user/x86_64/Makefile.vdso create mode 100644 linux-user/x86_64/vdso.S create mode 100644 linux-user/x86_64/vdso.ld create mode 100755 linux-user/x86_64/vdso.so GIT binary patch literal 5912 zcmeHL&ud&&6h4#5G>PWNw2COv8bm7;9TF)LD3qy9;>5Ng1_DtiuhYzHCzzShnU^w= zQbCLwDVjwW#YJgxFIg5hDiyK*1ybnF3T~t>3@+61eDlsXyt#d~g5c_%<jr^Qch5QR z-gDm@=DY7qADih(rG%E2L(=YLLndznmmZ>rNM0somwpb*kfKPhUU?gKao$oB`^^tD zV((?&WWo`m*nAMz9<n}p;t5MgB;TVv=DB6_aWP!9I@mbpIe$ASAuen4aq)nT!HDpM z0oiU7_xa%chRtuukU6%~A@SQ^tr}XtTi>Q71#@Igx3FNf2SSj#;e&>c8vfA=^Zj7) ze_G$d<&O2g;6yC${|40ODXhl!o%PzU{2t}U9R3OO&pP}g=I`<o=I`b?Wd7q$o@w)U zc|1Otk2}w@^1J2NmO_`kqCNQMEkEWBdsQ#2*X6P8gL+|~vG=TlHf2CB?3>=bZP;tf zr!VXZV!4fIV+<E^Z627+%=mJZ{>XKH@zz`N{pj}1?5CF(J{d2+e{|!gp^x{zd$D=> z++&{|seZKo+kN}CPx+Ol4_e}RXG@Kmx4c?ge#1NC2f<3kzl*H<4RYpEJ6$TSlZ(da z`0|@;vbs`TYd(+EIsKoIW3zLMOWq5)7j=F;v41+Cma@OAU;Z-mu=XF<i|-WH*rVe+ zYoDhv2E+cqQlsgEc$ZPzJ6gzjkXp!+LRPV<IHq_(aa{3=B8+)bZ!buynN5uj_VwdC z2HT2zU(#IMD{$j_U39o9<+dCSbH3nktIB<-9G?~KCYDqnsX$VJqyk9=k_sdhNGgz2 z;9phX+K=islDR(e<a=%ZYqy>LNvD6KyFYQGu+a(zHotqOHKHn_uduNbWWN4+aC3O# ztLy6ePnOo-;MCz!zqI~3r+)3`(?T8G&G&Zna5tan=;CgEm&EDWv??X);BNo^j{fiF z2c!U@;8;4M|2PEA0ZrnrSAWK<-JKtLBTnz)H-DUtd{+559Sr?~Jg(k7X#TFgoHgF{ z&sm-^h!-_#nRRU=zpH~^GTzO9Lisp-jPnWbZXWTbUYk37eD;WH#Fyt5z3GBCvvBzM zv{#r~h=@T`pK+qngruuaBT_V0v$nOU<QnUhpm<6#sE1f)tF&G%R#uiJrw#Rz+?ncH zu3T)CLnf$)%vrzQSgBRJI$lX~e%U)+FIIf7TvAW=Bp3M2Kx^?|ZB!FL*F)#S_}mfo zQEVF@U+$-EuRN`zDsS~o42|z2aV!##CgXXo1bvI#jOTkxoC?!+#u?vh{Bw#sdiKP4 zo_7)PT*Eld_>dLB`2g0=ah{J6c^*c8TMoN=3M$fy+@IeUM6Q$hT|BDsI7=hX?-k;t z-HA1F=l{BnV@`~}*SVvm>747ZUv}d8Jw-f6M??4is1NSX^ThT+27K)S!FwDvJ~!l| zb0-HpX^weY7|ybW^y2+lSDZib+0|ypuIve$=Q~W;aQAPw(sA*7?Hs##pZLE4>E9DK literal 0 HcmV?d00001