@@ -317,12 +317,12 @@ static void elf_core_copy_regs(target_elf_gregset_t *regs, const CPUX86State *en
#define DLINFO_ARCH_ITEMS 1
#define ARCH_DLINFO NEW_AUX_ENT(AT_SYSINFO, vdso_info->entry);
+#endif /* TARGET_X86_64 */
+
#include "vdso.c.inc"
#define vdso_image_info() &vdso_image_info
-#endif /* TARGET_X86_64 */
-
#define USE_ELF_CORE_DUMP
#define ELF_EXEC_PAGESIZE 4096
new file mode 100644
@@ -0,0 +1,5 @@
+CROSS_CC ?= $(CC)
+
+vdso.so: vdso.S vdso.ld Makefile.vdso
+ $(CROSS_CC) -nostdlib -shared -Wl,-T,vdso.ld -Wl,--build-id=sha1 \
+ -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 | 4 +- linux-user/x86_64/Makefile.vdso | 5 ++ 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 -> 6008 bytes 6 files changed, 209 insertions(+), 2 deletions(-) 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 6008 zcmeHL&1+m$6hD*6bW%;4w2CP4BTB81(jh6O1S%zMlQ_{f#6U1z)R$>ynhDL!#F>{e zBc*~EB_e)+D;LFL*V5(etQ1Pyzn}<i#QFh6bYXCzj^{V;{Khx8PhALZoHM!k-TS-e z+>dkbd%SaAn>;?%6^jWaE{CPr8VHzi>!?3K4UusflWqFHUv?;pbZZ&6ZWm{5Xkw4) zfrjm0$=yWILlj#N?3!KHCQm$N0}{!1DUWs5Z9Ogqn^pzu=Q?Na_*vME*?L?&pnVV` zbRj^L_ia2EcSA{q2we#9K`n7D&&|xsOK11)tzA92?}KkI-@3ef_h>r#@}PF9=L1<V zr2TCes{H(WqXZnX4qLvgS)0DE!!auN1t4X^`wbs9{IwB`7dT(!H*1@@{Alg3xDd1Z zuL0-wl<4a1e()TJmEWcOki$P_`U4LCkm<YpsOh`o95($CXPimXcX?b3tjAqvUiqE! zQ$wLmp4S%i$8CJ98}gzS?APUS4SKcUoN@N_gH~m`7MvT;9A}O7B(*?b%VR_xeJB`f z^T1eQDkqnykFhSyfBA~s8octwz(*J7-W$ok`NGCGeeXX0`iIqv=O6jxSn=)Q>wETG zIh`vkywwoTJD07LyrtFB(phgg=ld&#+&yGDS0QIAr8C(~ja=A9`<K?%Wp$;vUfqYG zQ~Eb5$ERoJ7rgzcgSx)1$e(to#O!zJvmg5K+&!v=&lL99rTts$pT^M#!TCU9gYiRn z=Hc5L>d0Be+lpDm?-Z+wzbL+=*rN{qSP{Z;Vz16gtU3@I>`nII-GF1o+-qvXvjR7w zW!2#(l*>CD)|_>?Rpl0y<6Y5aM>-zpc%b8fjt4p(=y;&xfsP0M=N_nktq$l<T<d@0 zjix8+cbxX3)4ti>9=(~~X!zSVZ#>=T*XSUb-q`XJpMT%GxnuO|HC6pPiR-sD<KnPh zT)(;*pSSaIVZ7STcMId*c0SRHf7|(OtvI-yPfAq$8pjtoKJ*=lYb3>dK)5Tek=0tH z{-5z4^$}ylBKE7F?JD<<kN6@gzQs3wRNVNC@=<Xw;uVbJ#<zz|-;F1yjd%4^HqH=& z6&1!VHLYWOH|{-ZygU9W<)h+Z<Riel<A^tLa^}d1>0=rbYM#WKOnXyvM@~$7>4~{e z@MqCxR1j%_qZ^NgLeIz;wHbR#s!}WXnbV4XIlw$?#gd<sRJK;k6jqj+71fp0a&bMC z&s6dO<Cg>GT&`SMDHYoqURF}MymzLYDdfC-RyEm@l%K2m>XCmhNFpKLXa0uIA#t}e zMYq#_QrpM}AU^=%^Gei9-4y1TcrWal$guVz@4)%_ToZ>v_NdaH`6$Hoc*JPW=bt#C zeGsmX_T0yQ?c36v744ZPBjWjhxb^`n@~rjIo_RGQ^Jvt!?XW3WUn4X>-#bL^lk;;P zBJw`S!Li+XKiPX{%w~fBp~L+fEsI*gnrP4W7!kRRu+VShidqTV^L<A=Pens_{;JvY zel!yx(6tMK_d!^AZ^(t`CI?(J#Rc0~pK{2Ra(?<1c`N!>t1YST3aS@cOi*#pZ>Q2x M_6IFb{!jLQ0P{>E*#H0l literal 0 HcmV?d00001