diff mbox series

[v6,10/19] linux-user/x86_64: Add vdso

Message ID 20230930021529.987950-11-richard.henderson@linaro.org
State Superseded
Headers show
Series linux-user: Implement VDSOs | expand

Commit Message

Richard Henderson Sept. 30, 2023, 2:15 a.m. UTC 
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 linux-user/elfload.c            |   4 +-
 linux-user/x86_64/Makefile.vdso |  11 +++++
 linux-user/x86_64/meson.build   |   4 ++
 linux-user/x86_64/vdso.S        |  78 ++++++++++++++++++++++++++++++++
 linux-user/x86_64/vdso.ld       |  73 ++++++++++++++++++++++++++++++
 linux-user/x86_64/vdso.so       | Bin 0 -> 2968 bytes
 6 files changed, 168 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 2968
zcmcgtO=w(I6uvKUOl$t7l}J=nY6?Lgol-PVEvcEL6HP)om@-1c>vZO|6VjQnGcRQ#
zQlk(xE{v3}x(Eh$E+iYFJ0pdXxDr=E=&lLvMs(4vwBz~aoiCl-j=CuHBzL}hzkANP
z=iPhmJs%H_3^h28p){If=E2CAex2B8q6WA=6OrF`(`KF&`Uz?MI&EW@IwS5;J<v5S
zm3;u8M8ZDNbcEvu0jxKter?<dUgx>q_-2rSodh0=h5M8yR&|8~q9xUzjR(|@2weye
zz8a;S7@IIXlUIKD#o1b1+rN5odUE>L=z;rh$dv40C`m=ye*;62d-p2^;2j+^>^@b*
z{zK-lF(OZeV2X;(id~9-RYHGjYX7&6)!h7{<L?-V+C6T-xxH+fO-w(S=h!R!)55=J
z@z1ONh{Zpn`Zga`ecR75)jw_d8B~3nM_M2rJI<`|o#xMqz%F@5M$pfwf5Z(rDGlFi
z^EmbvX*g$?a37>=_DaLK@yv17h==zIwme4kF^2|U3rG4QL%vz2K73uCxOLI|+`aN!
z$F-%z;-Tzk@6K<ve)YnqSIbKuJ^SrI{>$E*Jv}RD{ao_%it)TlnNq<^Unr!fz4Lw$
zOy&HC$f92&rz(YWnba(~S{s>9e=uV%Oyy_Fufeq||4}nCJT{T^4!f^Qd<}K~WJ1Kz
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vr;^|o8ppUAv<ink<oeuK)I;vAba!M!1G>D!gdKbRPND1BpVH#|fA;?X5$6$T

literal 0
HcmV?d00001

Comments

Philippe Mathieu-Daudé Oct. 5, 2023, 4:44 p.m. UTC | #1 
On 30/9/23 04:15, Richard Henderson wrote:
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   linux-user/elfload.c            |   4 +-
>   linux-user/x86_64/Makefile.vdso |  11 +++++
>   linux-user/x86_64/meson.build   |   4 ++
>   linux-user/x86_64/vdso.S        |  78 ++++++++++++++++++++++++++++++++
>   linux-user/x86_64/vdso.ld       |  73 ++++++++++++++++++++++++++++++
>   linux-user/x86_64/vdso.so       | Bin 0 -> 2968 bytes
>   6 files changed, 168 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

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

> diff --git a/linux-user/elfload.c b/linux-user/elfload.c
> index 314ae7cacf..1e1fdce656 100644
> --- a/linux-user/elfload.c
> +++ b/linux-user/elfload.c
> @@ -318,10 +318,10 @@ static void elf_core_copy_regs(target_elf_gregset_t *regs, const CPUX86State *en
>           }                                               \
>       } while (0)
>   
> -#define VDSO_HEADER "vdso.c.inc"
> -
>   #endif /* TARGET_X86_64 */
>   
> +#define VDSO_HEADER "vdso.c.inc"
> +
>   #define USE_ELF_CORE_DUMP
>   #define ELF_EXEC_PAGESIZE       4096
>   
> diff --git a/linux-user/x86_64/Makefile.vdso b/linux-user/x86_64/Makefile.vdso
> new file mode 100644
> index 0000000000..26552b66db
> --- /dev/null
> +++ b/linux-user/x86_64/Makefile.vdso
> @@ -0,0 +1,11 @@
> +include $(BUILD_DIR)/tests/tcg/x86_64-linux-user/config-target.mak
> +
> +SUBDIR = $(SRC_PATH)/linux-user/x86_64
> +VPATH += $(SUBDIR)
> +
> +all: $(SUBDIR)/vdso.so
> +
> +$(SUBDIR)/vdso.so: vdso.S vdso.ld
> +	$(CC) -o $@ -nostdlib -shared -Wl,-h,linux-vdso.so.1 \
> +	  -Wl,--build-id=sha1 -Wl,--hash-style=both \
> +	  -Wl,-T,$(SUBDIR)/vdso.ld $<
> diff --git a/linux-user/x86_64/meson.build b/linux-user/x86_64/meson.build
> index 203af9a60c..8c60da7a60 100644
> --- a/linux-user/x86_64/meson.build
> +++ b/linux-user/x86_64/meson.build
> @@ -3,3 +3,7 @@ syscall_nr_generators += {
>                         arguments: [ meson.current_source_dir() / 'syscallhdr.sh', '@INPUT@', '@OUTPUT@', '@EXTRA_ARGS@' ],
>                         output: '@BASENAME@_nr.h')
>   }
> +
> +vdso_inc = gen_vdso.process('vdso.so')
> +
> +linux_user_ss.add(when: 'TARGET_X86_64', if_true: vdso_inc)
> diff --git a/linux-user/x86_64/vdso.S b/linux-user/x86_64/vdso.S
> new file mode 100644
> index 0000000000..47d16c00ab
> --- /dev/null
> +++ b/linux-user/x86_64/vdso.S
> @@ -0,0 +1,78 @@
> +/*
> + * x86-64 linux replacement vdso.
> + *
> + * Copyright 2023 Linaro, Ltd.
> + *
> + * SPDX-License-Identifier: GPL-2.0-or-later
> + */
> +
> +#include <asm/unistd.h>
> +
> +.macro endf name
> +	.globl	\name
> +	.type	\name, @function
> +	.size	\name, . - \name
> +.endm
> +
> +.macro weakalias name
> +\name	= __vdso_\name
> +	.weak	\name
> +.endm
> +
> +.macro vdso_syscall name, nr
> +__vdso_\name:
> +	mov	$\nr, %eax
> +	syscall
> +	ret
> +endf	__vdso_\name
> +weakalias \name
> +.endm
> +
> +	.cfi_startproc
> +
> +vdso_syscall clock_gettime, __NR_clock_gettime
> +vdso_syscall clock_getres, __NR_clock_getres
> +vdso_syscall gettimeofday, __NR_gettimeofday
> +vdso_syscall time, __NR_time
> +
> +__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
> +endf	__vdso_getcpu
> +
> +weakalias getcpu
> +
> +	.cfi_endproc
> +
> +/* TODO: Add elf note for LINUX_VERSION_CODE */
> diff --git a/linux-user/x86_64/vdso.ld b/linux-user/x86_64/vdso.ld
> new file mode 100644
> index 0000000000..ca6001cc3c
> --- /dev/null
> +++ b/linux-user/x86_64/vdso.ld
> @@ -0,0 +1,73 @@
> +/*
> + * Linker script for linux x86-64 replacement vdso.
> + *
> + * Copyright 2023 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;
> +        load            PT_LOAD         FLAGS(7) FILEHDR PHDRS; /* FLAGS=RWX */
> +        dynamic         PT_DYNAMIC      FLAGS(4);
> +        eh_frame_hdr    PT_GNU_EH_FRAME;
> +        note            PT_NOTE         FLAGS(4);
> +}
> +
> +SECTIONS {
> +        . = 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*) }         :load :note
> +        .dynamic        : { *(.dynamic) }       :load :dynamic
> +        .dynsym         : { *(.dynsym) }        :load
> +        .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) }  :load :eh_frame_hdr
> +        .eh_frame       : { *(.eh_frame) }      :load
> +
> +        .text           : { *(.text*) }         :load   =0x90909090
> +}
> diff --git a/linux-user/x86_64/vdso.so b/linux-user/x86_64/vdso.so
> new file mode 100755
> index 0000000000000000000000000000000000000000..c873d6ea580b393825506d2ffbddcf9827d89e14
> GIT binary patch
> literal 2968
> zcmcgtO=w(I6uvKUOl$t7l}J=nY6?Lgol-PVEvcEL6HP)om@-1c>vZO|6VjQnGcRQ#
> zQlk(xE{v3}x(Eh$E+iYFJ0pdXxDr=E=&lLvMs(4vwBz~aoiCl-j=CuHBzL}hzkANP
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> zm3;u8M8ZDNbcEvu0jxKter?<dUgx>q_-2rSodh0=h5M8yR&|8~q9xUzjR(|@2weye
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> z^EmbvX*g$?a37>=_DaLK@yv17h==zIwme4kF^2|U3rG4QL%vz2K73uCxOLI|+`aN!
> z$F-%z;-Tzk@6K<ve)YnqSIbKuJ^SrI{>$E*Jv}RD{ao_%it)TlnNq<^Unr!fz4Lw$
> zOy&HC$f92&rz(YWnba(~S{s>9e=uV%Oyy_Fufeq||4}nCJT{T^4!f^Qd<}K~WJ1Kz
> zzvUl)Z^gZPP8#nNzOg~(w`aa@<o(9^K%DNzqu`(ulXgfNgnG`03FDMIobHyUJzt9w
> zo+0?gnY<+pa{adav`21S-&8!KxE^A3Jw9Iv_AacwQfZf+Z;H=v2a%udwk)(oS8s^Q
> ze+lApB>FjYY9u^!IW^5APGzK1@7^HK>gD4>;p^R}arI;0o1?04=jpKWw!W)=?0Yt=
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> zbIC83rV9C8121D-KkJ<<rgFZQ&4?yP#tr;(AUpEt(k(9Vj<7ELTixSId}la*Nji9E
> z@a{mEzeGvus<3|XJhjXlyz_X^xc;1Wh%eUIqf2|%IlLE07230&5^>idjF0yGj>9sy
> zEwzyLtiMFu4~T6avc|lrbF^o@CbB+LUq6S#>RVK)S)cWo$nWI(T!)Byg4)h8>pihg
> zSHk{7hu^QXIU^m!MEjk0M(-crN9uFmIL=%4U1~>sm5Pe?`en6ee(>HC`S#L{y??u6
> vr;^|o8ppUAv<ink<oeuK)I;vAba!M!1G>D!gdKbRPND1BpVH#|fA;?X5$6$T
> 
> literal 0
> HcmV?d00001
>
diff mbox series

Patch

diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index 314ae7cacf..1e1fdce656 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -318,10 +318,10 @@  static void elf_core_copy_regs(target_elf_gregset_t *regs, const CPUX86State *en
         }                                               \
     } while (0)
 
-#define VDSO_HEADER "vdso.c.inc"
-
 #endif /* TARGET_X86_64 */
 
+#define VDSO_HEADER "vdso.c.inc"
+
 #define USE_ELF_CORE_DUMP
 #define ELF_EXEC_PAGESIZE       4096
 
diff --git a/linux-user/x86_64/Makefile.vdso b/linux-user/x86_64/Makefile.vdso
new file mode 100644
index 0000000000..26552b66db
--- /dev/null
+++ b/linux-user/x86_64/Makefile.vdso
@@ -0,0 +1,11 @@ 
+include $(BUILD_DIR)/tests/tcg/x86_64-linux-user/config-target.mak
+
+SUBDIR = $(SRC_PATH)/linux-user/x86_64
+VPATH += $(SUBDIR)
+
+all: $(SUBDIR)/vdso.so
+
+$(SUBDIR)/vdso.so: vdso.S vdso.ld
+	$(CC) -o $@ -nostdlib -shared -Wl,-h,linux-vdso.so.1 \
+	  -Wl,--build-id=sha1 -Wl,--hash-style=both \
+	  -Wl,-T,$(SUBDIR)/vdso.ld $<
diff --git a/linux-user/x86_64/meson.build b/linux-user/x86_64/meson.build
index 203af9a60c..8c60da7a60 100644
--- a/linux-user/x86_64/meson.build
+++ b/linux-user/x86_64/meson.build
@@ -3,3 +3,7 @@  syscall_nr_generators += {
                       arguments: [ meson.current_source_dir() / 'syscallhdr.sh', '@INPUT@', '@OUTPUT@', '@EXTRA_ARGS@' ],
                       output: '@BASENAME@_nr.h')
 }
+
+vdso_inc = gen_vdso.process('vdso.so')
+
+linux_user_ss.add(when: 'TARGET_X86_64', if_true: vdso_inc)
diff --git a/linux-user/x86_64/vdso.S b/linux-user/x86_64/vdso.S
new file mode 100644
index 0000000000..47d16c00ab
--- /dev/null
+++ b/linux-user/x86_64/vdso.S
@@ -0,0 +1,78 @@ 
+/*
+ * x86-64 linux replacement vdso.
+ *
+ * Copyright 2023 Linaro, Ltd.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include <asm/unistd.h>
+
+.macro endf name
+	.globl	\name
+	.type	\name, @function
+	.size	\name, . - \name
+.endm
+
+.macro weakalias name
+\name	= __vdso_\name
+	.weak	\name
+.endm
+
+.macro vdso_syscall name, nr
+__vdso_\name:
+	mov	$\nr, %eax
+	syscall
+	ret
+endf	__vdso_\name
+weakalias \name
+.endm
+
+	.cfi_startproc
+
+vdso_syscall clock_gettime, __NR_clock_gettime
+vdso_syscall clock_getres, __NR_clock_getres
+vdso_syscall gettimeofday, __NR_gettimeofday
+vdso_syscall time, __NR_time
+
+__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
+endf	__vdso_getcpu
+
+weakalias getcpu
+
+	.cfi_endproc
+
+/* TODO: Add elf note for LINUX_VERSION_CODE */
diff --git a/linux-user/x86_64/vdso.ld b/linux-user/x86_64/vdso.ld
new file mode 100644
index 0000000000..ca6001cc3c
--- /dev/null
+++ b/linux-user/x86_64/vdso.ld
@@ -0,0 +1,73 @@ 
+/*
+ * Linker script for linux x86-64 replacement vdso.
+ *
+ * Copyright 2023 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;
+        load            PT_LOAD         FLAGS(7) FILEHDR PHDRS; /* FLAGS=RWX */
+        dynamic         PT_DYNAMIC      FLAGS(4);
+        eh_frame_hdr    PT_GNU_EH_FRAME;
+        note            PT_NOTE         FLAGS(4);
+}
+
+SECTIONS {
+        . = 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*) }         :load :note
+        .dynamic        : { *(.dynamic) }       :load :dynamic
+        .dynsym         : { *(.dynsym) }        :load
+        .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) }  :load :eh_frame_hdr
+        .eh_frame       : { *(.eh_frame) }      :load
+
+        .text           : { *(.text*) }         :load   =0x90909090
+}
diff --git a/linux-user/x86_64/vdso.so b/linux-user/x86_64/vdso.so
new file mode 100755
index 0000000000000000000000000000000000000000..c873d6ea580b393825506d2ffbddcf9827d89e14