[PATCH 00/16] selftests: vDSO: parse_vdso: Make compatible with nolibc

[PATCH 00/16] selftests: vDSO: parse_vdso: Make compatible with nolibc

[Thomas Weißschuh]

For testing the functionality of the vDSO, it is necessary to build
userspace programs for multiple different architectures.
It is additional work to acquire matching userspace cross-compilers with
full C libraries and then building root images out of those.
The kernel tree already contains nolibc, a small, header-only C library.
By using it, it is possible to build userspace programs without any
additional dependencies.
For example the kernel.org crosstools or multi-target clang can be used
to build test programs for a multitude of architectures.
While nolibc is very limited, it is enough for many selftests.
With some minor adjustments it is possible to make parse_vdso.c
compatible with nolibc.
As an example, vdso_standalone_test_x86 is now built from the same C
code as the regular vdso_test_gettimeofday, while still being completely
standalone.

This should probably go through the kselftest tree.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
Thomas Weißschuh (16):
      MAINTAINERS: Add vDSO selftests
      elf, uapi: Add definition for STN_UNDEF
      elf, uapi: Add definition for DT_GNU_HASH
      elf, uapi: Add definitions for VER_FLG_BASE and VER_FLG_WEAK
      elf, uapi: Add type ElfXX_Versym
      elf, uapi: Add types ElfXX_Verdef and ElfXX_Veraux
      tools/include: Add uapi/linux/elf.h
      selftests: Add headers target
      selftests: vDSO: vdso_standalone_test_x86: Use vdso_init_form_sysinfo_ehdr
      selftests: vDSO: parse_vdso: Drop vdso_init_from_auxv()
      selftests: vDSO: parse_vdso: Use UAPI headers instead of libc headers
      selftests: vDSO: parse_vdso: Test __SIZEOF_LONG__ instead of ULONG_MAX
      selftests: vDSO: parse_vdso: Make compatible with nolibc
      selftests: vDSO: vdso_test_gettimeofday: Clean up includes
      selftests: vDSO: vdso_test_gettimeofday: Make compatible with nolibc
      selftests: vDSO: vdso_standalone_test_x86: Switch to nolibc

 MAINTAINERS                                        |   1 +
 include/uapi/linux/elf.h                           |  38 ++
 tools/include/uapi/linux/elf.h                     | 524 +++++++++++++++++++++
 tools/testing/selftests/lib.mk                     |   5 +-
 tools/testing/selftests/vDSO/Makefile              |  11 +-
 tools/testing/selftests/vDSO/parse_vdso.c          |  21 +-
 tools/testing/selftests/vDSO/parse_vdso.h          |   1 -
 .../selftests/vDSO/vdso_standalone_test_x86.c      | 143 +-----
 .../selftests/vDSO/vdso_test_gettimeofday.c        |   4 +-
 9 files changed, 584 insertions(+), 164 deletions(-)
---
base-commit: 2014c95afecee3e76ca4a56956a936e23283f05b
change-id: 20241017-parse_vdso-nolibc-e069baa7ff48

Best regards,
-- 
Thomas Weißschuh <thomas.weissschuh@linutronix.de>

[PATCH 01/16] MAINTAINERS: Add vDSO selftests

[Thomas Weißschuh]

These currently have no maintainer besides the default kselftest ones.
Add the general vDSO maintainers, too.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
 MAINTAINERS | 1 +
 1 file changed, 1 insertion(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 896a307fa06545e2861abe46ea7029f9b4d3628e..959c8a86844eb1e5c6218e8fdbde6c3ebf68e25d 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9777,6 +9777,7 @@ F:	include/asm-generic/vdso/vsyscall.h
 F:	include/vdso/
 F:	kernel/time/vsyscall.c
 F:	lib/vdso/
+F:	tools/testing/selftests/vDSO/
 
 GENWQE (IBM Generic Workqueue Card)
 M:	Frank Haverkamp <haver@linux.ibm.com>

-- 
2.48.1

[PATCH 02/16] elf, uapi: Add definition for STN_UNDEF

[Thomas Weißschuh]

The definition is used by tools/testing/selftests/vDSO/parse_vdso.c.
To be able to build the vDSO selftests without a libc dependency,
add the definition to the kernels own UAPI headers.

Link: https://refspecs.linuxfoundation.org/elf/gabi4+/ch4.symtab.html
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
 include/uapi/linux/elf.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/uapi/linux/elf.h b/include/uapi/linux/elf.h
index b44069d29cecc0f9de90ee66bfffd2137f4275a8..448695c7364042b10682acc8223eb6053ad039dd 100644
--- a/include/uapi/linux/elf.h
+++ b/include/uapi/linux/elf.h
@@ -125,6 +125,8 @@ typedef __s64	Elf64_Sxword;
 #define STB_GLOBAL 1
 #define STB_WEAK   2
 
+#define STN_UNDEF 0
+
 #define STT_NOTYPE  0
 #define STT_OBJECT  1
 #define STT_FUNC    2

-- 
2.48.1

Re: [PATCH 02/16] elf, uapi: Add definition for STN_UNDEF

[Kees Cook]

On Mon, Feb 03, 2025 at 10:05:03AM +0100, Thomas Weißschuh wrote:
> The definition is used by tools/testing/selftests/vDSO/parse_vdso.c.
> To be able to build the vDSO selftests without a libc dependency,
> add the definition to the kernels own UAPI headers.
> 
> Link: https://refspecs.linuxfoundation.org/elf/gabi4+/ch4.symtab.html
> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>

Reviewed-by: Kees Cook <kees@kernel.org>

-- 
Kees Cook

[PATCH 03/16] elf, uapi: Add definition for DT_GNU_HASH

[Thomas Weißschuh]

The definition is used by tools/testing/selftests/vDSO/parse_vdso.c.
To be able to build the vDSO selftests without a libc dependency,
add the define to the kernels own UAPI headers.

Link: https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/libc-ddefs.html
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
 include/uapi/linux/elf.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/uapi/linux/elf.h b/include/uapi/linux/elf.h
index 448695c7364042b10682acc8223eb6053ad039dd..c5383cc7bb13c931fea083de5243c4006f795006 100644
--- a/include/uapi/linux/elf.h
+++ b/include/uapi/linux/elf.h
@@ -107,6 +107,7 @@ typedef __s64	Elf64_Sxword;
 #define DT_VALRNGLO	0x6ffffd00
 #define DT_VALRNGHI	0x6ffffdff
 #define DT_ADDRRNGLO	0x6ffffe00
+#define DT_GNU_HASH	0x6ffffef5
 #define DT_ADDRRNGHI	0x6ffffeff
 #define DT_VERSYM	0x6ffffff0
 #define DT_RELACOUNT	0x6ffffff9

-- 
2.48.1

Re: [PATCH 03/16] elf, uapi: Add definition for DT_GNU_HASH

[Kees Cook]

On Mon, Feb 03, 2025 at 10:05:04AM +0100, Thomas Weißschuh wrote:
> The definition is used by tools/testing/selftests/vDSO/parse_vdso.c.
> To be able to build the vDSO selftests without a libc dependency,
> add the define to the kernels own UAPI headers.
> 
> Link: https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/libc-ddefs.html
> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>

Reviewed-by: Kees Cook <kees@kernel.org>

-- 
Kees Cook

[PATCH 04/16] elf, uapi: Add definitions for VER_FLG_BASE and VER_FLG_WEAK

[Thomas Weißschuh]

The definitions are used by tools/testing/selftests/vDSO/parse_vdso.c.
To be able to build the vDSO selftests without a libc dependency,
add the definitions to the kernels own UAPI headers.

Link: https://docs.oracle.com/cd/E19683-01/816-1386/chapter6-80869/index.html
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
 include/uapi/linux/elf.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/include/uapi/linux/elf.h b/include/uapi/linux/elf.h
index c5383cc7bb13c931fea083de5243c4006f795006..d040f12ff1c0ae3dde5c371c81d6089118fbe8ed 100644
--- a/include/uapi/linux/elf.h
+++ b/include/uapi/linux/elf.h
@@ -136,6 +136,9 @@ typedef __s64	Elf64_Sxword;
 #define STT_COMMON  5
 #define STT_TLS     6
 
+#define VER_FLG_BASE 0x1
+#define VER_FLG_WEAK 0x2
+
 #define ELF_ST_BIND(x)		((x) >> 4)
 #define ELF_ST_TYPE(x)		((x) & 0xf)
 #define ELF32_ST_BIND(x)	ELF_ST_BIND(x)

-- 
2.48.1

Re: [PATCH 04/16] elf, uapi: Add definitions for VER_FLG_BASE and VER_FLG_WEAK

[Kees Cook]

On Mon, Feb 03, 2025 at 10:05:05AM +0100, Thomas Weißschuh wrote:
> The definitions are used by tools/testing/selftests/vDSO/parse_vdso.c.
> To be able to build the vDSO selftests without a libc dependency,
> add the definitions to the kernels own UAPI headers.

For all the UAPI changes, where are the defines "normally" found? i.e.
how does adding these to UAPI not break something that already has them?
Or have these never been defined before? I'm confused about how removing
the libc dependency exposes the lack of these defines. Are they defined
in a non-exported libc header somewhere?

-Kees

-- 
Kees Cook

Re: [PATCH 04/16] elf, uapi: Add definitions for VER_FLG_BASE and VER_FLG_WEAK

[Thomas Weißschuh]

On Tue, Feb 04, 2025 at 07:10:00AM -0800, Kees Cook wrote:
> On Mon, Feb 03, 2025 at 10:05:05AM +0100, Thomas Weißschuh wrote:
> > The definitions are used by tools/testing/selftests/vDSO/parse_vdso.c.
> > To be able to build the vDSO selftests without a libc dependency,
> > add the definitions to the kernels own UAPI headers.
> 
> For all the UAPI changes, where are the defines "normally" found? i.e.
> how does adding these to UAPI not break something that already has them?
> Or have these never been defined before? I'm confused about how removing
> the libc dependency exposes the lack of these defines. Are they defined
> in a non-exported libc header somewhere?

They are normally defined directly in libc <elf.h>, which does not use
UAPI headers. Libc elf.h and Linux UAPI elf.h can not be used at the
same time because they define the same symbols.
In theory some user of UAPI elf.h could have defined these new symbols
on their own without ifdef guards. However UAPI elf.h is regularly
updated with new symbols.

Re: [PATCH 04/16] elf, uapi: Add definitions for VER_FLG_BASE and VER_FLG_WEAK

[Kees Cook]

On Tue, Feb 04, 2025 at 04:17:03PM +0100, Thomas Weißschuh wrote:
> On Tue, Feb 04, 2025 at 07:10:00AM -0800, Kees Cook wrote:
> > On Mon, Feb 03, 2025 at 10:05:05AM +0100, Thomas Weißschuh wrote:
> > > The definitions are used by tools/testing/selftests/vDSO/parse_vdso.c.
> > > To be able to build the vDSO selftests without a libc dependency,
> > > add the definitions to the kernels own UAPI headers.
> > 
> > For all the UAPI changes, where are the defines "normally" found? i.e.
> > how does adding these to UAPI not break something that already has them?
> > Or have these never been defined before? I'm confused about how removing
> > the libc dependency exposes the lack of these defines. Are they defined
> > in a non-exported libc header somewhere?
> 
> They are normally defined directly in libc <elf.h>, which does not use
> UAPI headers. Libc elf.h and Linux UAPI elf.h can not be used at the
> same time because they define the same symbols.
> In theory some user of UAPI elf.h could have defined these new symbols
> on their own without ifdef guards. However UAPI elf.h is regularly
> updated with new symbols.

Okay, great. As long as the collision risk is low, I'm fine with all the
UAPI additions. Thanks for doing this!

-- 
Kees Cook

Re: [PATCH 04/16] elf, uapi: Add definitions for VER_FLG_BASE and VER_FLG_WEAK

[Kees Cook]

On Mon, Feb 03, 2025 at 10:05:05AM +0100, Thomas Weißschuh wrote:
> The definitions are used by tools/testing/selftests/vDSO/parse_vdso.c.
> To be able to build the vDSO selftests without a libc dependency,
> add the definitions to the kernels own UAPI headers.
> 
> Link: https://docs.oracle.com/cd/E19683-01/816-1386/chapter6-80869/index.html
> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>

Reviewed-by: Kees Cook <kees@kernel.org>

-- 
Kees Cook

[PATCH 05/16] elf, uapi: Add type ElfXX_Versym

[Thomas Weißschuh]

The types are used by tools/testing/selftests/vDSO/parse_vdso.c.
To be able to build the vDSO selftests without a libc dependency,
add the types to the kernels own UAPI headers.

As documented by elf(5).

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
 include/uapi/linux/elf.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/uapi/linux/elf.h b/include/uapi/linux/elf.h
index d040f12ff1c0ae3dde5c371c81d6089118fbe8ed..8846fe03ca5b836c96aad1be6d8fb9daf3d4b1d9 100644
--- a/include/uapi/linux/elf.h
+++ b/include/uapi/linux/elf.h
@@ -11,6 +11,7 @@ typedef __u16	Elf32_Half;
 typedef __u32	Elf32_Off;
 typedef __s32	Elf32_Sword;
 typedef __u32	Elf32_Word;
+typedef __u16	Elf32_Versym;
 
 /* 64-bit ELF base types. */
 typedef __u64	Elf64_Addr;
@@ -21,6 +22,7 @@ typedef __s32	Elf64_Sword;
 typedef __u32	Elf64_Word;
 typedef __u64	Elf64_Xword;
 typedef __s64	Elf64_Sxword;
+typedef __u16	Elf64_Versym;
 
 /* These constants are for the segment types stored in the image headers */
 #define PT_NULL    0

-- 
2.48.1

Re: [PATCH 05/16] elf, uapi: Add type ElfXX_Versym

[Kees Cook]

On Mon, Feb 03, 2025 at 10:05:06AM +0100, Thomas Weißschuh wrote:
> The types are used by tools/testing/selftests/vDSO/parse_vdso.c.
> To be able to build the vDSO selftests without a libc dependency,
> add the types to the kernels own UAPI headers.
> 
> As documented by elf(5).
> 
> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>

Reviewed-by: Kees Cook <kees@kernel.org>

-- 
Kees Cook

[PATCH 06/16] elf, uapi: Add types ElfXX_Verdef and ElfXX_Veraux

[Thomas Weißschuh]

The types are used by tools/testing/selftests/vDSO/parse_vdso.c.
To be able to build the vDSO selftests without a libc dependency,
add the types to the kernels own UAPI headers.

Link: https://refspecs.linuxfoundation.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/symversion.html#VERDEFEXTS
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
 include/uapi/linux/elf.h | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/include/uapi/linux/elf.h b/include/uapi/linux/elf.h
index 8846fe03ca5b836c96aad1be6d8fb9daf3d4b1d9..49f9f90458d8ca8e7b8f823d32be0a719ff827b3 100644
--- a/include/uapi/linux/elf.h
+++ b/include/uapi/linux/elf.h
@@ -491,4 +491,34 @@ typedef struct elf64_note {
 /* Bits for GNU_PROPERTY_AARCH64_FEATURE_1_BTI */
 #define GNU_PROPERTY_AARCH64_FEATURE_1_BTI	(1U << 0)
 
+typedef struct {
+  Elf32_Half	vd_version;
+  Elf32_Half	vd_flags;
+  Elf32_Half	vd_ndx;
+  Elf32_Half	vd_cnt;
+  Elf32_Word	vd_hash;
+  Elf32_Word	vd_aux;
+  Elf32_Word	vd_next;
+} Elf32_Verdef;
+
+typedef struct {
+  Elf64_Half	vd_version;
+  Elf64_Half	vd_flags;
+  Elf64_Half	vd_ndx;
+  Elf64_Half	vd_cnt;
+  Elf64_Word	vd_hash;
+  Elf64_Word	vd_aux;
+  Elf64_Word	vd_next;
+} Elf64_Verdef;
+
+typedef struct {
+  Elf32_Word    vda_name;
+  Elf32_Word    vda_next;
+} Elf32_Verdaux;
+
+typedef struct {
+  Elf64_Word    vda_name;
+  Elf64_Word    vda_next;
+} Elf64_Verdaux;
+
 #endif /* _UAPI_LINUX_ELF_H */

-- 
2.48.1

Re: [PATCH 06/16] elf, uapi: Add types ElfXX_Verdef and ElfXX_Veraux

[Kees Cook]

On Mon, Feb 03, 2025 at 10:05:07AM +0100, Thomas Weißschuh wrote:
> The types are used by tools/testing/selftests/vDSO/parse_vdso.c.
> To be able to build the vDSO selftests without a libc dependency,
> add the types to the kernels own UAPI headers.
> 
> Link: https://refspecs.linuxfoundation.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/symversion.html#VERDEFEXTS
> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>

Reviewed-by: Kees Cook <kees@kernel.org>

-- 
Kees Cook

[PATCH 07/16] tools/include: Add uapi/linux/elf.h

[Thomas Weißschuh]

It will be used by the vDSO selftests.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
 tools/include/uapi/linux/elf.h | 524 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 524 insertions(+)

diff --git a/tools/include/uapi/linux/elf.h b/tools/include/uapi/linux/elf.h
new file mode 100644
index 0000000000000000000000000000000000000000..3d0935a11613bbcf8c381188de3a10bafd6cc29f
--- /dev/null
+++ b/tools/include/uapi/linux/elf.h
@@ -0,0 +1,524 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _LINUX_ELF_H
+#define _LINUX_ELF_H
+
+#include <linux/types.h>
+#include <linux/elf-em.h>
+
+/* 32-bit ELF base types. */
+typedef __u32	Elf32_Addr;
+typedef __u16	Elf32_Half;
+typedef __u32	Elf32_Off;
+typedef __s32	Elf32_Sword;
+typedef __u32	Elf32_Word;
+typedef __u16	Elf32_Versym;
+
+/* 64-bit ELF base types. */
+typedef __u64	Elf64_Addr;
+typedef __u16	Elf64_Half;
+typedef __s16	Elf64_SHalf;
+typedef __u64	Elf64_Off;
+typedef __s32	Elf64_Sword;
+typedef __u32	Elf64_Word;
+typedef __u64	Elf64_Xword;
+typedef __s64	Elf64_Sxword;
+typedef __u16	Elf64_Versym;
+
+/* These constants are for the segment types stored in the image headers */
+#define PT_NULL    0
+#define PT_LOAD    1
+#define PT_DYNAMIC 2
+#define PT_INTERP  3
+#define PT_NOTE    4
+#define PT_SHLIB   5
+#define PT_PHDR    6
+#define PT_TLS     7               /* Thread local storage segment */
+#define PT_LOOS    0x60000000      /* OS-specific */
+#define PT_HIOS    0x6fffffff      /* OS-specific */
+#define PT_LOPROC  0x70000000
+#define PT_HIPROC  0x7fffffff
+#define PT_GNU_EH_FRAME	(PT_LOOS + 0x474e550)
+#define PT_GNU_STACK	(PT_LOOS + 0x474e551)
+#define PT_GNU_RELRO	(PT_LOOS + 0x474e552)
+#define PT_GNU_PROPERTY	(PT_LOOS + 0x474e553)
+
+
+/* ARM MTE memory tag segment type */
+#define PT_AARCH64_MEMTAG_MTE	(PT_LOPROC + 0x2)
+
+/*
+ * Extended Numbering
+ *
+ * If the real number of program header table entries is larger than
+ * or equal to PN_XNUM(0xffff), it is set to sh_info field of the
+ * section header at index 0, and PN_XNUM is set to e_phnum
+ * field. Otherwise, the section header at index 0 is zero
+ * initialized, if it exists.
+ *
+ * Specifications are available in:
+ *
+ * - Oracle: Linker and Libraries.
+ *   Part No: 817–1984–19, August 2011.
+ *   https://docs.oracle.com/cd/E18752_01/pdf/817-1984.pdf
+ *
+ * - System V ABI AMD64 Architecture Processor Supplement
+ *   Draft Version 0.99.4,
+ *   January 13, 2010.
+ *   http://www.cs.washington.edu/education/courses/cse351/12wi/supp-docs/abi.pdf
+ */
+#define PN_XNUM 0xffff
+
+/* These constants define the different elf file types */
+#define ET_NONE   0
+#define ET_REL    1
+#define ET_EXEC   2
+#define ET_DYN    3
+#define ET_CORE   4
+#define ET_LOPROC 0xff00
+#define ET_HIPROC 0xffff
+
+/* This is the info that is needed to parse the dynamic section of the file */
+#define DT_NULL		0
+#define DT_NEEDED	1
+#define DT_PLTRELSZ	2
+#define DT_PLTGOT	3
+#define DT_HASH		4
+#define DT_STRTAB	5
+#define DT_SYMTAB	6
+#define DT_RELA		7
+#define DT_RELASZ	8
+#define DT_RELAENT	9
+#define DT_STRSZ	10
+#define DT_SYMENT	11
+#define DT_INIT		12
+#define DT_FINI		13
+#define DT_SONAME	14
+#define DT_RPATH	15
+#define DT_SYMBOLIC	16
+#define DT_REL	        17
+#define DT_RELSZ	18
+#define DT_RELENT	19
+#define DT_PLTREL	20
+#define DT_DEBUG	21
+#define DT_TEXTREL	22
+#define DT_JMPREL	23
+#define DT_ENCODING	32
+#define OLD_DT_LOOS	0x60000000
+#define DT_LOOS		0x6000000d
+#define DT_HIOS		0x6ffff000
+#define DT_VALRNGLO	0x6ffffd00
+#define DT_VALRNGHI	0x6ffffdff
+#define DT_ADDRRNGLO	0x6ffffe00
+#define DT_GNU_HASH	0x6ffffef5
+#define DT_ADDRRNGHI	0x6ffffeff
+#define DT_VERSYM	0x6ffffff0
+#define DT_RELACOUNT	0x6ffffff9
+#define DT_RELCOUNT	0x6ffffffa
+#define DT_FLAGS_1	0x6ffffffb
+#define DT_VERDEF	0x6ffffffc
+#define	DT_VERDEFNUM	0x6ffffffd
+#define DT_VERNEED	0x6ffffffe
+#define	DT_VERNEEDNUM	0x6fffffff
+#define OLD_DT_HIOS     0x6fffffff
+#define DT_LOPROC	0x70000000
+#define DT_HIPROC	0x7fffffff
+
+/* This info is needed when parsing the symbol table */
+#define STB_LOCAL  0
+#define STB_GLOBAL 1
+#define STB_WEAK   2
+
+#define STN_UNDEF 0
+
+#define STT_NOTYPE  0
+#define STT_OBJECT  1
+#define STT_FUNC    2
+#define STT_SECTION 3
+#define STT_FILE    4
+#define STT_COMMON  5
+#define STT_TLS     6
+
+#define VER_FLG_BASE 0x1
+#define VER_FLG_WEAK 0x2
+
+#define ELF_ST_BIND(x)		((x) >> 4)
+#define ELF_ST_TYPE(x)		((x) & 0xf)
+#define ELF32_ST_BIND(x)	ELF_ST_BIND(x)
+#define ELF32_ST_TYPE(x)	ELF_ST_TYPE(x)
+#define ELF64_ST_BIND(x)	ELF_ST_BIND(x)
+#define ELF64_ST_TYPE(x)	ELF_ST_TYPE(x)
+
+typedef struct {
+  Elf32_Sword d_tag;
+  union {
+    Elf32_Sword	d_val;
+    Elf32_Addr	d_ptr;
+  } d_un;
+} Elf32_Dyn;
+
+typedef struct {
+  Elf64_Sxword d_tag;		/* entry tag value */
+  union {
+    Elf64_Xword d_val;
+    Elf64_Addr d_ptr;
+  } d_un;
+} Elf64_Dyn;
+
+/* The following are used with relocations */
+#define ELF32_R_SYM(x) ((x) >> 8)
+#define ELF32_R_TYPE(x) ((x) & 0xff)
+
+#define ELF64_R_SYM(i)			((i) >> 32)
+#define ELF64_R_TYPE(i)			((i) & 0xffffffff)
+
+typedef struct elf32_rel {
+  Elf32_Addr	r_offset;
+  Elf32_Word	r_info;
+} Elf32_Rel;
+
+typedef struct elf64_rel {
+  Elf64_Addr r_offset;	/* Location at which to apply the action */
+  Elf64_Xword r_info;	/* index and type of relocation */
+} Elf64_Rel;
+
+typedef struct elf32_rela {
+  Elf32_Addr	r_offset;
+  Elf32_Word	r_info;
+  Elf32_Sword	r_addend;
+} Elf32_Rela;
+
+typedef struct elf64_rela {
+  Elf64_Addr r_offset;	/* Location at which to apply the action */
+  Elf64_Xword r_info;	/* index and type of relocation */
+  Elf64_Sxword r_addend;	/* Constant addend used to compute value */
+} Elf64_Rela;
+
+typedef struct elf32_sym {
+  Elf32_Word	st_name;
+  Elf32_Addr	st_value;
+  Elf32_Word	st_size;
+  unsigned char	st_info;
+  unsigned char	st_other;
+  Elf32_Half	st_shndx;
+} Elf32_Sym;
+
+typedef struct elf64_sym {
+  Elf64_Word st_name;		/* Symbol name, index in string tbl */
+  unsigned char	st_info;	/* Type and binding attributes */
+  unsigned char	st_other;	/* No defined meaning, 0 */
+  Elf64_Half st_shndx;		/* Associated section index */
+  Elf64_Addr st_value;		/* Value of the symbol */
+  Elf64_Xword st_size;		/* Associated symbol size */
+} Elf64_Sym;
+
+
+#define EI_NIDENT	16
+
+typedef struct elf32_hdr {
+  unsigned char	e_ident[EI_NIDENT];
+  Elf32_Half	e_type;
+  Elf32_Half	e_machine;
+  Elf32_Word	e_version;
+  Elf32_Addr	e_entry;  /* Entry point */
+  Elf32_Off	e_phoff;
+  Elf32_Off	e_shoff;
+  Elf32_Word	e_flags;
+  Elf32_Half	e_ehsize;
+  Elf32_Half	e_phentsize;
+  Elf32_Half	e_phnum;
+  Elf32_Half	e_shentsize;
+  Elf32_Half	e_shnum;
+  Elf32_Half	e_shstrndx;
+} Elf32_Ehdr;
+
+typedef struct elf64_hdr {
+  unsigned char	e_ident[EI_NIDENT];	/* ELF "magic number" */
+  Elf64_Half e_type;
+  Elf64_Half e_machine;
+  Elf64_Word e_version;
+  Elf64_Addr e_entry;		/* Entry point virtual address */
+  Elf64_Off e_phoff;		/* Program header table file offset */
+  Elf64_Off e_shoff;		/* Section header table file offset */
+  Elf64_Word e_flags;
+  Elf64_Half e_ehsize;
+  Elf64_Half e_phentsize;
+  Elf64_Half e_phnum;
+  Elf64_Half e_shentsize;
+  Elf64_Half e_shnum;
+  Elf64_Half e_shstrndx;
+} Elf64_Ehdr;
+
+/* These constants define the permissions on sections in the program
+   header, p_flags. */
+#define PF_R		0x4
+#define PF_W		0x2
+#define PF_X		0x1
+
+typedef struct elf32_phdr {
+  Elf32_Word	p_type;
+  Elf32_Off	p_offset;
+  Elf32_Addr	p_vaddr;
+  Elf32_Addr	p_paddr;
+  Elf32_Word	p_filesz;
+  Elf32_Word	p_memsz;
+  Elf32_Word	p_flags;
+  Elf32_Word	p_align;
+} Elf32_Phdr;
+
+typedef struct elf64_phdr {
+  Elf64_Word p_type;
+  Elf64_Word p_flags;
+  Elf64_Off p_offset;		/* Segment file offset */
+  Elf64_Addr p_vaddr;		/* Segment virtual address */
+  Elf64_Addr p_paddr;		/* Segment physical address */
+  Elf64_Xword p_filesz;		/* Segment size in file */
+  Elf64_Xword p_memsz;		/* Segment size in memory */
+  Elf64_Xword p_align;		/* Segment alignment, file & memory */
+} Elf64_Phdr;
+
+/* sh_type */
+#define SHT_NULL	0
+#define SHT_PROGBITS	1
+#define SHT_SYMTAB	2
+#define SHT_STRTAB	3
+#define SHT_RELA	4
+#define SHT_HASH	5
+#define SHT_DYNAMIC	6
+#define SHT_NOTE	7
+#define SHT_NOBITS	8
+#define SHT_REL		9
+#define SHT_SHLIB	10
+#define SHT_DYNSYM	11
+#define SHT_NUM		12
+#define SHT_LOPROC	0x70000000
+#define SHT_HIPROC	0x7fffffff
+#define SHT_LOUSER	0x80000000
+#define SHT_HIUSER	0xffffffff
+
+/* sh_flags */
+#define SHF_WRITE		0x1
+#define SHF_ALLOC		0x2
+#define SHF_EXECINSTR		0x4
+#define SHF_RELA_LIVEPATCH	0x00100000
+#define SHF_RO_AFTER_INIT	0x00200000
+#define SHF_MASKPROC		0xf0000000
+
+/* special section indexes */
+#define SHN_UNDEF	0
+#define SHN_LORESERVE	0xff00
+#define SHN_LOPROC	0xff00
+#define SHN_HIPROC	0xff1f
+#define SHN_LIVEPATCH	0xff20
+#define SHN_ABS		0xfff1
+#define SHN_COMMON	0xfff2
+#define SHN_HIRESERVE	0xffff
+ 
+typedef struct elf32_shdr {
+  Elf32_Word	sh_name;
+  Elf32_Word	sh_type;
+  Elf32_Word	sh_flags;
+  Elf32_Addr	sh_addr;
+  Elf32_Off	sh_offset;
+  Elf32_Word	sh_size;
+  Elf32_Word	sh_link;
+  Elf32_Word	sh_info;
+  Elf32_Word	sh_addralign;
+  Elf32_Word	sh_entsize;
+} Elf32_Shdr;
+
+typedef struct elf64_shdr {
+  Elf64_Word sh_name;		/* Section name, index in string tbl */
+  Elf64_Word sh_type;		/* Type of section */
+  Elf64_Xword sh_flags;		/* Miscellaneous section attributes */
+  Elf64_Addr sh_addr;		/* Section virtual addr at execution */
+  Elf64_Off sh_offset;		/* Section file offset */
+  Elf64_Xword sh_size;		/* Size of section in bytes */
+  Elf64_Word sh_link;		/* Index of another section */
+  Elf64_Word sh_info;		/* Additional section information */
+  Elf64_Xword sh_addralign;	/* Section alignment */
+  Elf64_Xword sh_entsize;	/* Entry size if section holds table */
+} Elf64_Shdr;
+
+#define	EI_MAG0		0		/* e_ident[] indexes */
+#define	EI_MAG1		1
+#define	EI_MAG2		2
+#define	EI_MAG3		3
+#define	EI_CLASS	4
+#define	EI_DATA		5
+#define	EI_VERSION	6
+#define	EI_OSABI	7
+#define	EI_PAD		8
+
+#define	ELFMAG0		0x7f		/* EI_MAG */
+#define	ELFMAG1		'E'
+#define	ELFMAG2		'L'
+#define	ELFMAG3		'F'
+#define	ELFMAG		"\177ELF"
+#define	SELFMAG		4
+
+#define	ELFCLASSNONE	0		/* EI_CLASS */
+#define	ELFCLASS32	1
+#define	ELFCLASS64	2
+#define	ELFCLASSNUM	3
+
+#define ELFDATANONE	0		/* e_ident[EI_DATA] */
+#define ELFDATA2LSB	1
+#define ELFDATA2MSB	2
+
+#define EV_NONE		0		/* e_version, EI_VERSION */
+#define EV_CURRENT	1
+#define EV_NUM		2
+
+#define ELFOSABI_NONE	0
+#define ELFOSABI_LINUX	3
+
+#ifndef ELF_OSABI
+#define ELF_OSABI ELFOSABI_NONE
+#endif
+
+/*
+ * Notes used in ET_CORE. Architectures export some of the arch register sets
+ * using the corresponding note types via the PTRACE_GETREGSET and
+ * PTRACE_SETREGSET requests.
+ * The note name for these types is "LINUX", except NT_PRFPREG that is named
+ * "CORE".
+ */
+#define NT_PRSTATUS	1
+#define NT_PRFPREG	2
+#define NT_PRPSINFO	3
+#define NT_TASKSTRUCT	4
+#define NT_AUXV		6
+/*
+ * Note to userspace developers: size of NT_SIGINFO note may increase
+ * in the future to accomodate more fields, don't assume it is fixed!
+ */
+#define NT_SIGINFO      0x53494749
+#define NT_FILE         0x46494c45
+#define NT_PRXFPREG     0x46e62b7f      /* copied from gdb5.1/include/elf/common.h */
+#define NT_PPC_VMX	0x100		/* PowerPC Altivec/VMX registers */
+#define NT_PPC_SPE	0x101		/* PowerPC SPE/EVR registers */
+#define NT_PPC_VSX	0x102		/* PowerPC VSX registers */
+#define NT_PPC_TAR	0x103		/* Target Address Register */
+#define NT_PPC_PPR	0x104		/* Program Priority Register */
+#define NT_PPC_DSCR	0x105		/* Data Stream Control Register */
+#define NT_PPC_EBB	0x106		/* Event Based Branch Registers */
+#define NT_PPC_PMU	0x107		/* Performance Monitor Registers */
+#define NT_PPC_TM_CGPR	0x108		/* TM checkpointed GPR Registers */
+#define NT_PPC_TM_CFPR	0x109		/* TM checkpointed FPR Registers */
+#define NT_PPC_TM_CVMX	0x10a		/* TM checkpointed VMX Registers */
+#define NT_PPC_TM_CVSX	0x10b		/* TM checkpointed VSX Registers */
+#define NT_PPC_TM_SPR	0x10c		/* TM Special Purpose Registers */
+#define NT_PPC_TM_CTAR	0x10d		/* TM checkpointed Target Address Register */
+#define NT_PPC_TM_CPPR	0x10e		/* TM checkpointed Program Priority Register */
+#define NT_PPC_TM_CDSCR	0x10f		/* TM checkpointed Data Stream Control Register */
+#define NT_PPC_PKEY	0x110		/* Memory Protection Keys registers */
+#define NT_PPC_DEXCR	0x111		/* PowerPC DEXCR registers */
+#define NT_PPC_HASHKEYR	0x112		/* PowerPC HASHKEYR register */
+#define NT_386_TLS	0x200		/* i386 TLS slots (struct user_desc) */
+#define NT_386_IOPERM	0x201		/* x86 io permission bitmap (1=deny) */
+#define NT_X86_XSTATE	0x202		/* x86 extended state using xsave */
+/* Old binutils treats 0x203 as a CET state */
+#define NT_X86_SHSTK	0x204		/* x86 SHSTK state */
+#define NT_X86_XSAVE_LAYOUT	0x205	/* XSAVE layout description */
+#define NT_S390_HIGH_GPRS	0x300	/* s390 upper register halves */
+#define NT_S390_TIMER	0x301		/* s390 timer register */
+#define NT_S390_TODCMP	0x302		/* s390 TOD clock comparator register */
+#define NT_S390_TODPREG	0x303		/* s390 TOD programmable register */
+#define NT_S390_CTRS	0x304		/* s390 control registers */
+#define NT_S390_PREFIX	0x305		/* s390 prefix register */
+#define NT_S390_LAST_BREAK	0x306	/* s390 breaking event address */
+#define NT_S390_SYSTEM_CALL	0x307	/* s390 system call restart data */
+#define NT_S390_TDB	0x308		/* s390 transaction diagnostic block */
+#define NT_S390_VXRS_LOW	0x309	/* s390 vector registers 0-15 upper half */
+#define NT_S390_VXRS_HIGH	0x30a	/* s390 vector registers 16-31 */
+#define NT_S390_GS_CB	0x30b		/* s390 guarded storage registers */
+#define NT_S390_GS_BC	0x30c		/* s390 guarded storage broadcast control block */
+#define NT_S390_RI_CB	0x30d		/* s390 runtime instrumentation */
+#define NT_S390_PV_CPU_DATA	0x30e	/* s390 protvirt cpu dump data */
+#define NT_ARM_VFP	0x400		/* ARM VFP/NEON registers */
+#define NT_ARM_TLS	0x401		/* ARM TLS register */
+#define NT_ARM_HW_BREAK	0x402		/* ARM hardware breakpoint registers */
+#define NT_ARM_HW_WATCH	0x403		/* ARM hardware watchpoint registers */
+#define NT_ARM_SYSTEM_CALL	0x404	/* ARM system call number */
+#define NT_ARM_SVE	0x405		/* ARM Scalable Vector Extension registers */
+#define NT_ARM_PAC_MASK		0x406	/* ARM pointer authentication code masks */
+#define NT_ARM_PACA_KEYS	0x407	/* ARM pointer authentication address keys */
+#define NT_ARM_PACG_KEYS	0x408	/* ARM pointer authentication generic key */
+#define NT_ARM_TAGGED_ADDR_CTRL	0x409	/* arm64 tagged address control (prctl()) */
+#define NT_ARM_PAC_ENABLED_KEYS	0x40a	/* arm64 ptr auth enabled keys (prctl()) */
+#define NT_ARM_SSVE	0x40b		/* ARM Streaming SVE registers */
+#define NT_ARM_ZA	0x40c		/* ARM SME ZA registers */
+#define NT_ARM_ZT	0x40d		/* ARM SME ZT registers */
+#define NT_ARM_FPMR	0x40e		/* ARM floating point mode register */
+#define NT_ARM_POE	0x40f		/* ARM POE registers */
+#define NT_ARM_GCS	0x410		/* ARM GCS state */
+#define NT_ARC_V2	0x600		/* ARCv2 accumulator/extra registers */
+#define NT_VMCOREDD	0x700		/* Vmcore Device Dump Note */
+#define NT_MIPS_DSP	0x800		/* MIPS DSP ASE registers */
+#define NT_MIPS_FP_MODE	0x801		/* MIPS floating-point mode */
+#define NT_MIPS_MSA	0x802		/* MIPS SIMD registers */
+#define NT_RISCV_CSR	0x900		/* RISC-V Control and Status Registers */
+#define NT_RISCV_VECTOR	0x901		/* RISC-V vector registers */
+#define NT_RISCV_TAGGED_ADDR_CTRL 0x902	/* RISC-V tagged address control (prctl()) */
+#define NT_LOONGARCH_CPUCFG	0xa00	/* LoongArch CPU config registers */
+#define NT_LOONGARCH_CSR	0xa01	/* LoongArch control and status registers */
+#define NT_LOONGARCH_LSX	0xa02	/* LoongArch Loongson SIMD Extension registers */
+#define NT_LOONGARCH_LASX	0xa03	/* LoongArch Loongson Advanced SIMD Extension registers */
+#define NT_LOONGARCH_LBT	0xa04	/* LoongArch Loongson Binary Translation registers */
+#define NT_LOONGARCH_HW_BREAK	0xa05   /* LoongArch hardware breakpoint registers */
+#define NT_LOONGARCH_HW_WATCH	0xa06   /* LoongArch hardware watchpoint registers */
+
+/* Note types with note name "GNU" */
+#define NT_GNU_PROPERTY_TYPE_0	5
+
+/* Note header in a PT_NOTE section */
+typedef struct elf32_note {
+  Elf32_Word	n_namesz;	/* Name size */
+  Elf32_Word	n_descsz;	/* Content size */
+  Elf32_Word	n_type;		/* Content type */
+} Elf32_Nhdr;
+
+/* Note header in a PT_NOTE section */
+typedef struct elf64_note {
+  Elf64_Word n_namesz;	/* Name size */
+  Elf64_Word n_descsz;	/* Content size */
+  Elf64_Word n_type;	/* Content type */
+} Elf64_Nhdr;
+
+/* .note.gnu.property types for EM_AARCH64: */
+#define GNU_PROPERTY_AARCH64_FEATURE_1_AND	0xc0000000
+
+/* Bits for GNU_PROPERTY_AARCH64_FEATURE_1_BTI */
+#define GNU_PROPERTY_AARCH64_FEATURE_1_BTI	(1U << 0)
+
+typedef struct {
+  Elf32_Half	vd_version;
+  Elf32_Half	vd_flags;
+  Elf32_Half	vd_ndx;
+  Elf32_Half	vd_cnt;
+  Elf32_Word	vd_hash;
+  Elf32_Word	vd_aux;
+  Elf32_Word	vd_next;
+} Elf32_Verdef;
+
+typedef struct {
+  Elf64_Half	vd_version;
+  Elf64_Half	vd_flags;
+  Elf64_Half	vd_ndx;
+  Elf64_Half	vd_cnt;
+  Elf64_Word	vd_hash;
+  Elf64_Word	vd_aux;
+  Elf64_Word	vd_next;
+} Elf64_Verdef;
+
+typedef struct {
+  Elf32_Word    vda_name;
+  Elf32_Word    vda_next;
+} Elf32_Verdaux;
+
+typedef struct {
+  Elf64_Word    vda_name;
+  Elf64_Word    vda_next;
+} Elf64_Verdaux;
+
+#endif /* _LINUX_ELF_H */

-- 
2.48.1

[PATCH 08/16] selftests: Add headers target

[Thomas Weißschuh]

Some selftests need access to a full UAPI headers tree, for example when
building with nolibc which heavily relies on UAPI headers.
A reference to such a tree is available in the KHDR_INCLUDES variable,
but there is currently no way to populate such a tree automatically.

Provide a target that the tests can depend on to get access to usable
UAPI headers.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
 tools/testing/selftests/lib.mk | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/lib.mk b/tools/testing/selftests/lib.mk
index d6edcfcb5be832ddee4c3d34b5ad221e9295f878..5303900339292e618dee4fd7ff8a7c2fa3209a68 100644
--- a/tools/testing/selftests/lib.mk
+++ b/tools/testing/selftests/lib.mk
@@ -228,4 +228,7 @@ $(OUTPUT)/%:%.S
 	$(LINK.S) $^ $(LDLIBS) -o $@
 endif
 
-.PHONY: run_tests all clean install emit_tests gen_mods_dir clean_mods_dir
+headers:
+	$(Q)$(MAKE) -C $(top_srcdir) headers
+
+.PHONY: run_tests all clean install emit_tests gen_mods_dir clean_mods_dir headers

-- 
2.48.1

[PATCH 09/16] selftests: vDSO: vdso_standalone_test_x86: Use vdso_init_form_sysinfo_ehdr

[Thomas Weißschuh]

vdso_standalone_test_x86 is the only user of vdso_init_from_auxv().
Instead of combining the parsing the aux vector with the parsing of the
vDSO, split them apart into getauxval() and the regular
vdso_init_from_sysinfo_ehdr().

The implementation of getauxval() is taken from
tools/include/nolibc/stdlib.h.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>

---
All of this code will be deleted later again.
---
 .../selftests/vDSO/vdso_standalone_test_x86.c      | 27 +++++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/vDSO/vdso_standalone_test_x86.c b/tools/testing/selftests/vDSO/vdso_standalone_test_x86.c
index 644915862af8883131e5defd336f1bd80736fc0f..500608f89c66b5747e3d845ebc54e4c3a35b6ccd 100644
--- a/tools/testing/selftests/vDSO/vdso_standalone_test_x86.c
+++ b/tools/testing/selftests/vDSO/vdso_standalone_test_x86.c
@@ -15,6 +15,7 @@
 #include <sys/time.h>
 #include <unistd.h>
 #include <stdint.h>
+#include <linux/auxvec.h>
 
 #include "parse_vdso.h"
 
@@ -84,6 +85,30 @@ void to_base10(char *lastdig, time_t n)
 	}
 }
 
+unsigned long getauxval(const unsigned long *auxv, unsigned long type)
+{
+	unsigned long ret;
+
+	if (!auxv)
+		return 0;
+
+	while (1) {
+		if (!auxv[0] && !auxv[1]) {
+			ret = 0;
+			break;
+		}
+
+		if (auxv[0] == type) {
+			ret = auxv[1];
+			break;
+		}
+
+		auxv += 2;
+	}
+
+	return ret;
+}
+
 void c_main(void **stack)
 {
 	/* Parse the stack */
@@ -96,7 +121,7 @@ void c_main(void **stack)
 	stack++;
 
 	/* Now we're pointing at auxv.  Initialize the vDSO parser. */
-	vdso_init_from_auxv((void *)stack);
+	vdso_init_from_sysinfo_ehdr(getauxval((unsigned long *)stack, AT_SYSINFO_EHDR));
 
 	/* Find gettimeofday. */
 	typedef long (*gtod_t)(struct timeval *tv, struct timezone *tz);

-- 
2.48.1

[PATCH 10/16] selftests: vDSO: parse_vdso: Drop vdso_init_from_auxv()

[Thomas Weißschuh]

There are no users left.

Also remove the usage of ElfXX_auxv_t, which is not formally
standardized.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
 tools/testing/selftests/vDSO/parse_vdso.c | 14 --------------
 tools/testing/selftests/vDSO/parse_vdso.h |  1 -
 2 files changed, 15 deletions(-)

diff --git a/tools/testing/selftests/vDSO/parse_vdso.c b/tools/testing/selftests/vDSO/parse_vdso.c
index 2fe5e983cb22f1ed066d0310a54f6aef2ed77ed8..3638fe605e80ca41b29d43c6ac452964eef35d56 100644
--- a/tools/testing/selftests/vDSO/parse_vdso.c
+++ b/tools/testing/selftests/vDSO/parse_vdso.c
@@ -297,17 +297,3 @@ void *vdso_sym(const char *version, const char *name)
 
 	return 0;
 }
-
-void vdso_init_from_auxv(void *auxv)
-{
-	ELF(auxv_t) *elf_auxv = auxv;
-	for (int i = 0; elf_auxv[i].a_type != AT_NULL; i++)
-	{
-		if (elf_auxv[i].a_type == AT_SYSINFO_EHDR) {
-			vdso_init_from_sysinfo_ehdr(elf_auxv[i].a_un.a_val);
-			return;
-		}
-	}
-
-	vdso_info.valid = false;
-}
diff --git a/tools/testing/selftests/vDSO/parse_vdso.h b/tools/testing/selftests/vDSO/parse_vdso.h
index de0453067d7cd0d8b63f7d3738842f60370db813..09d068ed11f97f0c5c8f4e7b341f08fa261c9735 100644
--- a/tools/testing/selftests/vDSO/parse_vdso.h
+++ b/tools/testing/selftests/vDSO/parse_vdso.h
@@ -26,6 +26,5 @@
  */
 void *vdso_sym(const char *version, const char *name);
 void vdso_init_from_sysinfo_ehdr(uintptr_t base);
-void vdso_init_from_auxv(void *auxv);
 
 #endif

-- 
2.48.1

[PATCH 11/16] selftests: vDSO: parse_vdso: Use UAPI headers instead of libc headers

[Thomas Weißschuh]

To allow the usage of parse_vdso.c together with a limited libc like
nolibc, use the kernels own elf.h and auxvec.h headers.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
 tools/testing/selftests/vDSO/Makefile     | 3 +++
 tools/testing/selftests/vDSO/parse_vdso.c | 3 ++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/vDSO/Makefile b/tools/testing/selftests/vDSO/Makefile
index 1cf14a8da43803249f72fe1b09689c8834806986..bc8ca186fb877dc11740c37f1e07e45e84c2ae92 100644
--- a/tools/testing/selftests/vDSO/Makefile
+++ b/tools/testing/selftests/vDSO/Makefile
@@ -19,6 +19,9 @@ LDLIBS += -lgcc_s
 endif
 
 include ../lib.mk
+
+CFLAGS += $(TOOLS_INCLUDES)
+
 $(OUTPUT)/vdso_test_gettimeofday: parse_vdso.c vdso_test_gettimeofday.c
 $(OUTPUT)/vdso_test_getcpu: parse_vdso.c vdso_test_getcpu.c
 $(OUTPUT)/vdso_test_abi: parse_vdso.c vdso_test_abi.c
diff --git a/tools/testing/selftests/vDSO/parse_vdso.c b/tools/testing/selftests/vDSO/parse_vdso.c
index 3638fe605e80ca41b29d43c6ac452964eef35d56..200c534cc70e2c2381fce3be5c0ebe4cb5675e84 100644
--- a/tools/testing/selftests/vDSO/parse_vdso.c
+++ b/tools/testing/selftests/vDSO/parse_vdso.c
@@ -19,7 +19,8 @@
 #include <stdint.h>
 #include <string.h>
 #include <limits.h>
-#include <elf.h>
+#include <linux/auxvec.h>
+#include <linux/elf.h>
 
 #include "parse_vdso.h"
 

-- 
2.48.1

[PATCH 12/16] selftests: vDSO: parse_vdso: Test __SIZEOF_LONG__ instead of ULONG_MAX

[Thomas Weißschuh]

According to limits.h(2) ULONG_MAX is only guaranteed to expand to an
expression, not a symbolic constant which can be evaluated by the
preprocessor.
Specifically the definition of ULONG_MAX from nolibc can no be evaluated
by the preprocessor. To provide compatibility with nolibc, check with
__SIZEOF_LONG__ instead, with is provided directly by the preprocessor
and therefore always a symbolic constant.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
 tools/testing/selftests/vDSO/parse_vdso.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/vDSO/parse_vdso.c b/tools/testing/selftests/vDSO/parse_vdso.c
index 200c534cc70e2c2381fce3be5c0ebe4cb5675e84..902b8f9984a1f70049d46bcd4f199df24f507dcb 100644
--- a/tools/testing/selftests/vDSO/parse_vdso.c
+++ b/tools/testing/selftests/vDSO/parse_vdso.c
@@ -26,7 +26,7 @@
 
 /* And here's the code. */
 #ifndef ELF_BITS
-# if ULONG_MAX > 0xffffffffUL
+# if __SIZEOF_LONG__ >= 8
 #  define ELF_BITS 64
 # else
 #  define ELF_BITS 32

-- 
2.48.1

[PATCH 13/16] selftests: vDSO: parse_vdso: Make compatible with nolibc

[Thomas Weißschuh]

nolibc does not provide this header, instead its definitions are
available unconditionally.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
 tools/testing/selftests/vDSO/parse_vdso.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/testing/selftests/vDSO/parse_vdso.c b/tools/testing/selftests/vDSO/parse_vdso.c
index 902b8f9984a1f70049d46bcd4f199df24f507dcb..6ea1d7cca6a3da910097630e8237a3a6daa0cd06 100644
--- a/tools/testing/selftests/vDSO/parse_vdso.c
+++ b/tools/testing/selftests/vDSO/parse_vdso.c
@@ -18,7 +18,9 @@
 #include <stdbool.h>
 #include <stdint.h>
 #include <string.h>
+#ifndef NOLIBC
 #include <limits.h>
+#endif
 #include <linux/auxvec.h>
 #include <linux/elf.h>
 

-- 
2.48.1

Re: [PATCH 13/16] selftests: vDSO: parse_vdso: Make compatible with nolibc

[Willy Tarreau]

On Mon, Feb 03, 2025 at 10:05:14AM +0100, Thomas Weißschuh wrote:
> nolibc does not provide this header, instead its definitions are
> available unconditionally.

Please think about reminding which one you're talking about so that a
simple "git log" shows what header you're talking about (limits.h)
without requiring to also see the patch itself.

BTW, I think that limits.h is common enough that we could probably
provide it as well with nolibc to ease porting (and the current patch
is a good example of this). Maybe it could simply start by including
stdint.h to provide the various limits we rely on. I remember that in
the early days of nolibc-test we had to exclude it as well for nolibc.

What do you think? The less we need to patch programs to insert #ifndef
NOLIBC, the better.

Cheers,
Willy

Re: [PATCH 13/16] selftests: vDSO: parse_vdso: Make compatible with nolibc

[Thomas Weißschuh]

On Sat, Feb 22, 2025 at 11:24:26AM +0100, Willy Tarreau wrote:
> On Mon, Feb 03, 2025 at 10:05:14AM +0100, Thomas Weißschuh wrote:
> > nolibc does not provide this header, instead its definitions are
> > available unconditionally.
> 
> Please think about reminding which one you're talking about so that a
> simple "git log" shows what header you're talking about (limits.h)
> without requiring to also see the patch itself.

Ack.

> BTW, I think that limits.h is common enough that we could probably
> provide it as well with nolibc to ease porting (and the current patch
> is a good example of this). Maybe it could simply start by including
> stdint.h to provide the various limits we rely on. I remember that in
> the early days of nolibc-test we had to exclude it as well for nolibc.
>
> What do you think? The less we need to patch programs to insert #ifndef
> NOLIBC, the better.

Sounds good, I'll do that for v2.
Given that any nolibc header always also includes the global nolibc.h,
I think limits.h can directly include nolibc.h.
 
> Cheers,
> Willy

[PATCH 14/16] selftests: vDSO: vdso_test_gettimeofday: Clean up includes

[Thomas Weißschuh]

Some unnecessary headers are included, remove them.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
 tools/testing/selftests/vDSO/vdso_test_gettimeofday.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/tools/testing/selftests/vDSO/vdso_test_gettimeofday.c b/tools/testing/selftests/vDSO/vdso_test_gettimeofday.c
index e31b18ffae338c1576449b54ca7f84d9816d2ecb..636a56ccf8e4e7943ca446fe3fad6897598ca77f 100644
--- a/tools/testing/selftests/vDSO/vdso_test_gettimeofday.c
+++ b/tools/testing/selftests/vDSO/vdso_test_gettimeofday.c
@@ -10,8 +10,6 @@
  * Tested on x86, 32-bit and 64-bit.  It may work on other architectures, too.
  */
 
-#include <stdint.h>
-#include <elf.h>
 #include <stdio.h>
 #include <sys/auxv.h>
 #include <sys/time.h>

-- 
2.48.1

[PATCH 15/16] selftests: vDSO: vdso_test_gettimeofday: Make compatible with nolibc

[Thomas Weißschuh]

nolibc does not provide these headers, instead those definitions are
available unconditionally.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
 tools/testing/selftests/vDSO/vdso_test_gettimeofday.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/testing/selftests/vDSO/vdso_test_gettimeofday.c b/tools/testing/selftests/vDSO/vdso_test_gettimeofday.c
index 636a56ccf8e4e7943ca446fe3fad6897598ca77f..9ce795b806f0992b83cef78c7e16fac0e54750da 100644
--- a/tools/testing/selftests/vDSO/vdso_test_gettimeofday.c
+++ b/tools/testing/selftests/vDSO/vdso_test_gettimeofday.c
@@ -11,8 +11,10 @@
  */
 
 #include <stdio.h>
+#ifndef NOLIBC
 #include <sys/auxv.h>
 #include <sys/time.h>
+#endif
 
 #include "../kselftest.h"
 #include "parse_vdso.h"

-- 
2.48.1

[PATCH 16/16] selftests: vDSO: vdso_standalone_test_x86: Switch to nolibc

[Thomas Weißschuh]

vdso_standalone_test_x86 provides its own ASM syscall wrappers and
_start() implementation. The in-tree nolibc library already provides
this functionality for multiple architectures. By making use of nolibc,
the standalone testcase can be built from the exact same codebase as the
non-standalone version.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
 tools/testing/selftests/vDSO/Makefile              |   8 +-
 .../selftests/vDSO/vdso_standalone_test_x86.c      | 168 +--------------------
 2 files changed, 7 insertions(+), 169 deletions(-)

diff --git a/tools/testing/selftests/vDSO/Makefile b/tools/testing/selftests/vDSO/Makefile
index bc8ca186fb877dc11740c37f1e07e45e84c2ae92..12a0614b9fd4983deffe5d6a7cfa06ba8d92a516 100644
--- a/tools/testing/selftests/vDSO/Makefile
+++ b/tools/testing/selftests/vDSO/Makefile
@@ -22,13 +22,17 @@ include ../lib.mk
 
 CFLAGS += $(TOOLS_INCLUDES)
 
+CFLAGS_NOLIBC := -nostdlib -nostdinc -ffreestanding -fno-asynchronous-unwind-tables \
+		 -fno-stack-protector -include $(top_srcdir)/tools/include/nolibc/nolibc.h \
+		 -I$(top_srcdir)/tools/include/nolibc/ $(KHDR_INCLUDES)
+
 $(OUTPUT)/vdso_test_gettimeofday: parse_vdso.c vdso_test_gettimeofday.c
 $(OUTPUT)/vdso_test_getcpu: parse_vdso.c vdso_test_getcpu.c
 $(OUTPUT)/vdso_test_abi: parse_vdso.c vdso_test_abi.c
 $(OUTPUT)/vdso_test_clock_getres: vdso_test_clock_getres.c
 
-$(OUTPUT)/vdso_standalone_test_x86: vdso_standalone_test_x86.c parse_vdso.c
-$(OUTPUT)/vdso_standalone_test_x86: CFLAGS +=-nostdlib -fno-asynchronous-unwind-tables -fno-stack-protector
+$(OUTPUT)/vdso_standalone_test_x86: vdso_standalone_test_x86.c parse_vdso.c | headers
+$(OUTPUT)/vdso_standalone_test_x86: CFLAGS:=$(CFLAGS_NOLIBC) $(CFLAGS)
 
 $(OUTPUT)/vdso_test_correctness: vdso_test_correctness.c
 $(OUTPUT)/vdso_test_correctness: LDFLAGS += -ldl
diff --git a/tools/testing/selftests/vDSO/vdso_standalone_test_x86.c b/tools/testing/selftests/vDSO/vdso_standalone_test_x86.c
deleted file mode 100644
index 500608f89c66b5747e3d845ebc54e4c3a35b6ccd..0000000000000000000000000000000000000000
--- a/tools/testing/selftests/vDSO/vdso_standalone_test_x86.c
+++ /dev/null
@@ -1,167 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * vdso_test.c: Sample code to test parse_vdso.c on x86
- * Copyright (c) 2011-2014 Andy Lutomirski
- *
- * You can amuse yourself by compiling with:
- * gcc -std=gnu99 -nostdlib
- *     -Os -fno-asynchronous-unwind-tables -flto -lgcc_s
- *      vdso_standalone_test_x86.c parse_vdso.c
- * to generate a small binary.  On x86_64, you can omit -lgcc_s
- * if you want the binary to be completely standalone.
- */
-
-#include <sys/syscall.h>
-#include <sys/time.h>
-#include <unistd.h>
-#include <stdint.h>
-#include <linux/auxvec.h>
-
-#include "parse_vdso.h"
-
-/* We need some libc functions... */
-int strcmp(const char *a, const char *b)
-{
-	/* This implementation is buggy: it never returns -1. */
-	while (*a || *b) {
-		if (*a != *b)
-			return 1;
-		if (*a == 0 || *b == 0)
-			return 1;
-		a++;
-		b++;
-	}
-
-	return 0;
-}
-
-/*
- * The clang build needs this, although gcc does not.
- * Stolen from lib/string.c.
- */
-void *memcpy(void *dest, const void *src, size_t count)
-{
-	char *tmp = dest;
-	const char *s = src;
-
-	while (count--)
-		*tmp++ = *s++;
-	return dest;
-}
-
-/* ...and two syscalls.  This is x86-specific. */
-static inline long x86_syscall3(long nr, long a0, long a1, long a2)
-{
-	long ret;
-#ifdef __x86_64__
-	asm volatile ("syscall" : "=a" (ret) : "a" (nr),
-		      "D" (a0), "S" (a1), "d" (a2) :
-		      "cc", "memory", "rcx",
-		      "r8", "r9", "r10", "r11" );
-#else
-	asm volatile ("int $0x80" : "=a" (ret) : "a" (nr),
-		      "b" (a0), "c" (a1), "d" (a2) :
-		      "cc", "memory" );
-#endif
-	return ret;
-}
-
-static inline long linux_write(int fd, const void *data, size_t len)
-{
-	return x86_syscall3(__NR_write, fd, (long)data, (long)len);
-}
-
-static inline void linux_exit(int code)
-{
-	x86_syscall3(__NR_exit, code, 0, 0);
-}
-
-void to_base10(char *lastdig, time_t n)
-{
-	while (n) {
-		*lastdig = (n % 10) + '0';
-		n /= 10;
-		lastdig--;
-	}
-}
-
-unsigned long getauxval(const unsigned long *auxv, unsigned long type)
-{
-	unsigned long ret;
-
-	if (!auxv)
-		return 0;
-
-	while (1) {
-		if (!auxv[0] && !auxv[1]) {
-			ret = 0;
-			break;
-		}
-
-		if (auxv[0] == type) {
-			ret = auxv[1];
-			break;
-		}
-
-		auxv += 2;
-	}
-
-	return ret;
-}
-
-void c_main(void **stack)
-{
-	/* Parse the stack */
-	long argc = (long)*stack;
-	stack += argc + 2;
-
-	/* Now we're pointing at the environment.  Skip it. */
-	while(*stack)
-		stack++;
-	stack++;
-
-	/* Now we're pointing at auxv.  Initialize the vDSO parser. */
-	vdso_init_from_sysinfo_ehdr(getauxval((unsigned long *)stack, AT_SYSINFO_EHDR));
-
-	/* Find gettimeofday. */
-	typedef long (*gtod_t)(struct timeval *tv, struct timezone *tz);
-	gtod_t gtod = (gtod_t)vdso_sym("LINUX_2.6", "__vdso_gettimeofday");
-
-	if (!gtod)
-		linux_exit(1);
-
-	struct timeval tv;
-	long ret = gtod(&tv, 0);
-
-	if (ret == 0) {
-		char buf[] = "The time is                     .000000\n";
-		to_base10(buf + 31, tv.tv_sec);
-		to_base10(buf + 38, tv.tv_usec);
-		linux_write(1, buf, sizeof(buf) - 1);
-	} else {
-		linux_exit(ret);
-	}
-
-	linux_exit(0);
-}
-
-/*
- * This is the real entry point.  It passes the initial stack into
- * the C entry point.
- */
-asm (
-	".text\n"
-	".global _start\n"
-	".type _start,@function\n"
-	"_start:\n\t"
-#ifdef __x86_64__
-	"mov %rsp,%rdi\n\t"
-	"and $-16,%rsp\n\t"
-	"sub $8,%rsp\n\t"
-	"jmp c_main"
-#else
-	"push %esp\n\t"
-	"call c_main\n\t"
-	"int $3"
-#endif
-	);
diff --git a/tools/testing/selftests/vDSO/vdso_standalone_test_x86.c b/tools/testing/selftests/vDSO/vdso_standalone_test_x86.c
new file mode 120000
index 0000000000000000000000000000000000000000..4d3d96f1e440c965474681a6f35375a60b3921be
--- /dev/null
+++ b/tools/testing/selftests/vDSO/vdso_standalone_test_x86.c
@@ -0,0 +1 @@
+vdso_test_gettimeofday.c
\ No newline at end of file

-- 
2.48.1

Re: [PATCH 00/16] selftests: vDSO: parse_vdso: Make compatible with nolibc

[Christophe Leroy]

Le 03/02/2025 à 10:05, Thomas Weißschuh a écrit :
> For testing the functionality of the vDSO, it is necessary to build
> userspace programs for multiple different architectures.
> It is additional work to acquire matching userspace cross-compilers with
> full C libraries and then building root images out of those.
> The kernel tree already contains nolibc, a small, header-only C library.
> By using it, it is possible to build userspace programs without any
> additional dependencies.
> For example the kernel.org crosstools or multi-target clang can be used
> to build test programs for a multitude of architectures.
> While nolibc is very limited, it is enough for many selftests.
> With some minor adjustments it is possible to make parse_vdso.c
> compatible with nolibc.
> As an example, vdso_standalone_test_x86 is now built from the same C
> code as the regular vdso_test_gettimeofday, while still being completely
> standalone.
> 
> This should probably go through the kselftest tree.

Not sure what are the expectations with this series.

I gave it a try with vdso_test_gettimeofday and get the following:

$ powerpc64-linux-gcc -nostdlib -nostdinc -ffreestanding 
-fno-asynchronous-unwind-tables -fno-stack-protector -include 
/home/chleroy/linux-powerpc/tools/testing/selftests/../../../tools/include/nolibc/nolibc.h 
-I/home/chleroy/linux-powerpc/tools/testing/selftests/../../../tools/include/nolibc/ 
-isystem 
/home/chleroy/linux-powerpc/tools/testing/selftests/../../../usr/include 
-std=gnu99 -O2 -D_GNU_SOURCE= -isystem 
/home/chleroy/linux-powerpc/tools/testing/selftests/../../../tools/include/uapi 
    vdso_test_gettimeofday.c parse_vdso.c  -o 
/home/chleroy/linux-powerpc/tools/testing/selftests/vDSO/vdso_test_gettimeofday

make: Entering directory 
'/home/chleroy/linux-powerpc/tools/testing/selftests/vDSO'
powerpc64-linux-gcc -nostdlib -nostdinc -ffreestanding 
-fno-asynchronous-unwind-tables -fno-stack-protector -include 
/home/chleroy/linux-powerpc/tools/testing/selftests/../../../tools/include/nolibc/nolibc.h 
-I/home/chleroy/linux-powerpc/tools/testing/selftests/../../../tools/include/nolibc/ 
-isystem 
/home/chleroy/linux-powerpc/tools/testing/selftests/../../../usr/include 
-std=gnu99 -O2 -D_GNU_SOURCE= -isystem 
/home/chleroy/linux-powerpc/tools/testing/selftests/../../../tools/include/uapi 
    vdso_test_gettimeofday.c parse_vdso.c  -o 
/home/chleroy/linux-powerpc/tools/testing/selftests/vDSO/vdso_test_gettimeofday
parse_vdso.c:38:34: error: unknown type name 'Elf64_Versym'
    38 | #define ELF_BITS_XFORM2(bits, x) Elf##bits##_##x
       |                                  ^~~
parse_vdso.c:39:33: note: in expansion of macro 'ELF_BITS_XFORM2'
    39 | #define ELF_BITS_XFORM(bits, x) ELF_BITS_XFORM2(bits, x)
       |                                 ^~~~~~~~~~~~~~~
parse_vdso.c:40:16: note: in expansion of macro 'ELF_BITS_XFORM'
    40 | #define ELF(x) ELF_BITS_XFORM(ELF_BITS, x)
       |                ^~~~~~~~~~~~~~
parse_vdso.c:63:9: note: in expansion of macro 'ELF'
    63 |         ELF(Versym) *versym;
       |         ^~~
parse_vdso.c:38:34: error: unknown type name 'Elf64_Verdef'
    38 | #define ELF_BITS_XFORM2(bits, x) Elf##bits##_##x
       |                                  ^~~
parse_vdso.c:39:33: note: in expansion of macro 'ELF_BITS_XFORM2'
    39 | #define ELF_BITS_XFORM(bits, x) ELF_BITS_XFORM2(bits, x)
       |                                 ^~~~~~~~~~~~~~~
parse_vdso.c:40:16: note: in expansion of macro 'ELF_BITS_XFORM'
    40 | #define ELF(x) ELF_BITS_XFORM(ELF_BITS, x)
       |                ^~~~~~~~~~~~~~
parse_vdso.c:64:9: note: in expansion of macro 'ELF'
    64 |         ELF(Verdef) *verdef;
       |         ^~~
parse_vdso.c: In function 'vdso_init_from_sysinfo_ehdr':
parse_vdso.c:38:34: error: 'Elf64_Versym' undeclared (first use in this 
function); did you mean 'Elf64_Sym'?
    38 | #define ELF_BITS_XFORM2(bits, x) Elf##bits##_##x
       |                                  ^~~
parse_vdso.c:39:33: note: in expansion of macro 'ELF_BITS_XFORM2'
    39 | #define ELF_BITS_XFORM(bits, x) ELF_BITS_XFORM2(bits, x)
       |                                 ^~~~~~~~~~~~~~~
parse_vdso.c:40:16: note: in expansion of macro 'ELF_BITS_XFORM'
    40 | #define ELF(x) ELF_BITS_XFORM(ELF_BITS, x)
       |                ^~~~~~~~~~~~~~
parse_vdso.c:150:45: note: in expansion of macro 'ELF'
   150 |                         vdso_info.versym = (ELF(Versym) *)
       |                                             ^~~
parse_vdso.c:38:34: note: each undeclared identifier is reported only 
once for each function it appears in
    38 | #define ELF_BITS_XFORM2(bits, x) Elf##bits##_##x
       |                                  ^~~
parse_vdso.c:39:33: note: in expansion of macro 'ELF_BITS_XFORM2'
    39 | #define ELF_BITS_XFORM(bits, x) ELF_BITS_XFORM2(bits, x)
       |                                 ^~~~~~~~~~~~~~~
parse_vdso.c:40:16: note: in expansion of macro 'ELF_BITS_XFORM'
    40 | #define ELF(x) ELF_BITS_XFORM(ELF_BITS, x)
       |                ^~~~~~~~~~~~~~
parse_vdso.c:150:45: note: in expansion of macro 'ELF'
   150 |                         vdso_info.versym = (ELF(Versym) *)
       |                                             ^~~
parse_vdso.c:150:58: error: expected expression before ')' token
   150 |                         vdso_info.versym = (ELF(Versym) *)
       |                                                          ^
parse_vdso.c:38:34: error: 'Elf64_Verdef' undeclared (first use in this 
function); did you mean 'Elf64_Word'?
    38 | #define ELF_BITS_XFORM2(bits, x) Elf##bits##_##x
       |                                  ^~~
parse_vdso.c:39:33: note: in expansion of macro 'ELF_BITS_XFORM2'
    39 | #define ELF_BITS_XFORM(bits, x) ELF_BITS_XFORM2(bits, x)
       |                                 ^~~~~~~~~~~~~~~
parse_vdso.c:40:16: note: in expansion of macro 'ELF_BITS_XFORM'
    40 | #define ELF(x) ELF_BITS_XFORM(ELF_BITS, x)
       |                ^~~~~~~~~~~~~~
parse_vdso.c:155:45: note: in expansion of macro 'ELF'
   155 |                         vdso_info.verdef = (ELF(Verdef) *)
       |                                             ^~~
parse_vdso.c:155:58: error: expected expression before ')' token
   155 |                         vdso_info.verdef = (ELF(Verdef) *)
       |                                                          ^
parse_vdso.c: At top level:
parse_vdso.c:38:34: error: unknown type name 'Elf64_Versym'; did you 
mean 'Elf64_Sym'?
    38 | #define ELF_BITS_XFORM2(bits, x) Elf##bits##_##x
       |                                  ^~~
parse_vdso.c:39:33: note: in expansion of macro 'ELF_BITS_XFORM2'
    39 | #define ELF_BITS_XFORM(bits, x) ELF_BITS_XFORM2(bits, x)
       |                                 ^~~~~~~~~~~~~~~
parse_vdso.c:40:16: note: in expansion of macro 'ELF_BITS_XFORM'
    40 | #define ELF(x) ELF_BITS_XFORM(ELF_BITS, x)
       |                ^~~~~~~~~~~~~~
parse_vdso.c:177:32: note: in expansion of macro 'ELF'
   177 | static bool vdso_match_version(ELF(Versym) ver,
       |                                ^~~
parse_vdso.c: In function 'vdso_sym':
parse_vdso.c:224:25: error: 'STN_UNDEF' undeclared (first use in this 
function); did you mean 'SHN_UNDEF'?
   224 |         for (; chain != STN_UNDEF; chain = 
vdso_info.chain[chain]) {
       |                         ^~~~~~~~~
       |                         SHN_UNDEF
parse_vdso.c:240:25: warning: implicit declaration of function 
'vdso_match_version' [-Wimplicit-function-declaration]
   240 |                     && !vdso_match_version(vdso_info.versym[chain],
       |                         ^~~~~~~~~~~~~~~~~~
make: *** [../lib.mk:222: 
/home/chleroy/linux-powerpc/tools/testing/selftests/vDSO/vdso_test_gettimeofday] 
Error 1
make: Leaving directory 
'/home/chleroy/linux-powerpc/tools/testing/selftests/vDSO'

Christophe

> 
> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
> ---
> Thomas Weißschuh (16):
>        MAINTAINERS: Add vDSO selftests
>        elf, uapi: Add definition for STN_UNDEF
>        elf, uapi: Add definition for DT_GNU_HASH
>        elf, uapi: Add definitions for VER_FLG_BASE and VER_FLG_WEAK
>        elf, uapi: Add type ElfXX_Versym
>        elf, uapi: Add types ElfXX_Verdef and ElfXX_Veraux
>        tools/include: Add uapi/linux/elf.h
>        selftests: Add headers target
>        selftests: vDSO: vdso_standalone_test_x86: Use vdso_init_form_sysinfo_ehdr
>        selftests: vDSO: parse_vdso: Drop vdso_init_from_auxv()
>        selftests: vDSO: parse_vdso: Use UAPI headers instead of libc headers
>        selftests: vDSO: parse_vdso: Test __SIZEOF_LONG__ instead of ULONG_MAX
>        selftests: vDSO: parse_vdso: Make compatible with nolibc
>        selftests: vDSO: vdso_test_gettimeofday: Clean up includes
>        selftests: vDSO: vdso_test_gettimeofday: Make compatible with nolibc
>        selftests: vDSO: vdso_standalone_test_x86: Switch to nolibc
> 
>   MAINTAINERS                                        |   1 +
>   include/uapi/linux/elf.h                           |  38 ++
>   tools/include/uapi/linux/elf.h                     | 524 +++++++++++++++++++++
>   tools/testing/selftests/lib.mk                     |   5 +-
>   tools/testing/selftests/vDSO/Makefile              |  11 +-
>   tools/testing/selftests/vDSO/parse_vdso.c          |  21 +-
>   tools/testing/selftests/vDSO/parse_vdso.h          |   1 -
>   .../selftests/vDSO/vdso_standalone_test_x86.c      | 143 +-----
>   .../selftests/vDSO/vdso_test_gettimeofday.c        |   4 +-
>   9 files changed, 584 insertions(+), 164 deletions(-)
> ---
> base-commit: 2014c95afecee3e76ca4a56956a936e23283f05b
> change-id: 20241017-parse_vdso-nolibc-e069baa7ff48
> 
> Best regards,

Re: [PATCH 00/16] selftests: vDSO: parse_vdso: Make compatible with nolibc

[Thomas Weißschuh]

On Mon, Feb 03, 2025 at 12:23:29PM +0100, Christophe Leroy wrote:
> Le 03/02/2025 à 10:05, Thomas Weißschuh a écrit :
> > For testing the functionality of the vDSO, it is necessary to build
> > userspace programs for multiple different architectures.
> > It is additional work to acquire matching userspace cross-compilers with
> > full C libraries and then building root images out of those.
> > The kernel tree already contains nolibc, a small, header-only C library.
> > By using it, it is possible to build userspace programs without any
> > additional dependencies.
> > For example the kernel.org crosstools or multi-target clang can be used
> > to build test programs for a multitude of architectures.
> > While nolibc is very limited, it is enough for many selftests.
> > With some minor adjustments it is possible to make parse_vdso.c
> > compatible with nolibc.
> > As an example, vdso_standalone_test_x86 is now built from the same C
> > code as the regular vdso_test_gettimeofday, while still being completely
> > standalone.
> > 
> > This should probably go through the kselftest tree.
> 
> Not sure what are the expectations with this series.

In general it should also work for PPC,
thanks for testing it.

> I gave it a try with vdso_test_gettimeofday and get the following:
> 
> $ powerpc64-linux-gcc -nostdlib -nostdinc -ffreestanding
> -fno-asynchronous-unwind-tables -fno-stack-protector -include /home/chleroy/linux-powerpc/tools/testing/selftests/../../../tools/include/nolibc/nolibc.h -I/home/chleroy/linux-powerpc/tools/testing/selftests/../../../tools/include/nolibc/
> -isystem
> /home/chleroy/linux-powerpc/tools/testing/selftests/../../../usr/include
> -std=gnu99 -O2 -D_GNU_SOURCE= -isystem /home/chleroy/linux-powerpc/tools/testing/selftests/../../../tools/include/uapi
> vdso_test_gettimeofday.c parse_vdso.c  -o /home/chleroy/linux-powerpc/tools/testing/selftests/vDSO/vdso_test_gettimeofday
> 
> make: Entering directory
> '/home/chleroy/linux-powerpc/tools/testing/selftests/vDSO'
> powerpc64-linux-gcc -nostdlib -nostdinc -ffreestanding
> -fno-asynchronous-unwind-tables -fno-stack-protector -include /home/chleroy/linux-powerpc/tools/testing/selftests/../../../tools/include/nolibc/nolibc.h -I/home/chleroy/linux-powerpc/tools/testing/selftests/../../../tools/include/nolibc/
> -isystem
> /home/chleroy/linux-powerpc/tools/testing/selftests/../../../usr/include
> -std=gnu99 -O2 -D_GNU_SOURCE= -isystem /home/chleroy/linux-powerpc/tools/testing/selftests/../../../tools/include/uapi
> vdso_test_gettimeofday.c parse_vdso.c  -o /home/chleroy/linux-powerpc/tools/testing/selftests/vDSO/vdso_test_gettimeofday

This log is confusing. It contains traces of "make" output but no "make"
invocation. I'm also not sure if there were two different compilations
or only one. Can you give the full commandline?
For your testing it should be enough to enable
"vdso_test_standalone_x86" in the Makefile for PPC.

> parse_vdso.c:38:34: error: unknown type name 'Elf64_Versym'
>    38 | #define ELF_BITS_XFORM2(bits, x) Elf##bits##_##x
>       |                                  ^~~
> parse_vdso.c:39:33: note: in expansion of macro 'ELF_BITS_XFORM2'
>    39 | #define ELF_BITS_XFORM(bits, x) ELF_BITS_XFORM2(bits, x)
>       |                                 ^~~~~~~~~~~~~~~
> parse_vdso.c:40:16: note: in expansion of macro 'ELF_BITS_XFORM'
>    40 | #define ELF(x) ELF_BITS_XFORM(ELF_BITS, x)
>       |                ^~~~~~~~~~~~~~
> parse_vdso.c:63:9: note: in expansion of macro 'ELF'
>    63 |         ELF(Versym) *versym;
>       |         ^~~
> parse_vdso.c:38:34: error: unknown type name 'Elf64_Verdef'
>    38 | #define ELF_BITS_XFORM2(bits, x) Elf##bits##_##x
>       |                                  ^~~
> parse_vdso.c:39:33: note: in expansion of macro 'ELF_BITS_XFORM2'
>    39 | #define ELF_BITS_XFORM(bits, x) ELF_BITS_XFORM2(bits, x)
>       |                                 ^~~~~~~~~~~~~~~
> parse_vdso.c:40:16: note: in expansion of macro 'ELF_BITS_XFORM'
>    40 | #define ELF(x) ELF_BITS_XFORM(ELF_BITS, x)
>       |                ^~~~~~~~~~~~~~
> parse_vdso.c:64:9: note: in expansion of macro 'ELF'
>    64 |         ELF(Verdef) *verdef;
>       |         ^~~
> parse_vdso.c: In function 'vdso_init_from_sysinfo_ehdr':
> parse_vdso.c:38:34: error: 'Elf64_Versym' undeclared (first use in this
> function); did you mean 'Elf64_Sym'?
>    38 | #define ELF_BITS_XFORM2(bits, x) Elf##bits##_##x
>       |                                  ^~~
> parse_vdso.c:39:33: note: in expansion of macro 'ELF_BITS_XFORM2'
>    39 | #define ELF_BITS_XFORM(bits, x) ELF_BITS_XFORM2(bits, x)
>       |                                 ^~~~~~~~~~~~~~~
> parse_vdso.c:40:16: note: in expansion of macro 'ELF_BITS_XFORM'
>    40 | #define ELF(x) ELF_BITS_XFORM(ELF_BITS, x)
>       |                ^~~~~~~~~~~~~~
> parse_vdso.c:150:45: note: in expansion of macro 'ELF'
>   150 |                         vdso_info.versym = (ELF(Versym) *)
>       |                                             ^~~
> parse_vdso.c:38:34: note: each undeclared identifier is reported only once
> for each function it appears in
>    38 | #define ELF_BITS_XFORM2(bits, x) Elf##bits##_##x
>       |                                  ^~~
> parse_vdso.c:39:33: note: in expansion of macro 'ELF_BITS_XFORM2'
>    39 | #define ELF_BITS_XFORM(bits, x) ELF_BITS_XFORM2(bits, x)
>       |                                 ^~~~~~~~~~~~~~~
> parse_vdso.c:40:16: note: in expansion of macro 'ELF_BITS_XFORM'
>    40 | #define ELF(x) ELF_BITS_XFORM(ELF_BITS, x)
>       |                ^~~~~~~~~~~~~~
> parse_vdso.c:150:45: note: in expansion of macro 'ELF'
>   150 |                         vdso_info.versym = (ELF(Versym) *)
>       |                                             ^~~
> parse_vdso.c:150:58: error: expected expression before ')' token
>   150 |                         vdso_info.versym = (ELF(Versym) *)
>       |                                                          ^
> parse_vdso.c:38:34: error: 'Elf64_Verdef' undeclared (first use in this
> function); did you mean 'Elf64_Word'?
>    38 | #define ELF_BITS_XFORM2(bits, x) Elf##bits##_##x
>       |                                  ^~~
> parse_vdso.c:39:33: note: in expansion of macro 'ELF_BITS_XFORM2'
>    39 | #define ELF_BITS_XFORM(bits, x) ELF_BITS_XFORM2(bits, x)
>       |                                 ^~~~~~~~~~~~~~~
> parse_vdso.c:40:16: note: in expansion of macro 'ELF_BITS_XFORM'
>    40 | #define ELF(x) ELF_BITS_XFORM(ELF_BITS, x)
>       |                ^~~~~~~~~~~~~~
> parse_vdso.c:155:45: note: in expansion of macro 'ELF'
>   155 |                         vdso_info.verdef = (ELF(Verdef) *)
>       |                                             ^~~
> parse_vdso.c:155:58: error: expected expression before ')' token
>   155 |                         vdso_info.verdef = (ELF(Verdef) *)
>       |                                                          ^
> parse_vdso.c: At top level:
> parse_vdso.c:38:34: error: unknown type name 'Elf64_Versym'; did you mean
> 'Elf64_Sym'?
>    38 | #define ELF_BITS_XFORM2(bits, x) Elf##bits##_##x
>       |                                  ^~~
> parse_vdso.c:39:33: note: in expansion of macro 'ELF_BITS_XFORM2'
>    39 | #define ELF_BITS_XFORM(bits, x) ELF_BITS_XFORM2(bits, x)
>       |                                 ^~~~~~~~~~~~~~~
> parse_vdso.c:40:16: note: in expansion of macro 'ELF_BITS_XFORM'
>    40 | #define ELF(x) ELF_BITS_XFORM(ELF_BITS, x)
>       |                ^~~~~~~~~~~~~~
> parse_vdso.c:177:32: note: in expansion of macro 'ELF'
>   177 | static bool vdso_match_version(ELF(Versym) ver,
>       |                                ^~~
> parse_vdso.c: In function 'vdso_sym':
> parse_vdso.c:224:25: error: 'STN_UNDEF' undeclared (first use in this
> function); did you mean 'SHN_UNDEF'?
>   224 |         for (; chain != STN_UNDEF; chain = vdso_info.chain[chain]) {
>       |                         ^~~~~~~~~
>       |                         SHN_UNDEF
> parse_vdso.c:240:25: warning: implicit declaration of function
> 'vdso_match_version' [-Wimplicit-function-declaration]
>   240 |                     && !vdso_match_version(vdso_info.versym[chain],
>       |                         ^~~~~~~~~~~~~~~~~~
> make: *** [../lib.mk:222: /home/chleroy/linux-powerpc/tools/testing/selftests/vDSO/vdso_test_gettimeofday]
> Error 1
> make: Leaving directory
> '/home/chleroy/linux-powerpc/tools/testing/selftests/vDSO'
> 
> Christophe
> 
> > 
> > Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
> > ---
> > Thomas Weißschuh (16):
> >        MAINTAINERS: Add vDSO selftests
> >        elf, uapi: Add definition for STN_UNDEF
> >        elf, uapi: Add definition for DT_GNU_HASH
> >        elf, uapi: Add definitions for VER_FLG_BASE and VER_FLG_WEAK
> >        elf, uapi: Add type ElfXX_Versym
> >        elf, uapi: Add types ElfXX_Verdef and ElfXX_Veraux
> >        tools/include: Add uapi/linux/elf.h
> >        selftests: Add headers target
> >        selftests: vDSO: vdso_standalone_test_x86: Use vdso_init_form_sysinfo_ehdr
> >        selftests: vDSO: parse_vdso: Drop vdso_init_from_auxv()
> >        selftests: vDSO: parse_vdso: Use UAPI headers instead of libc headers
> >        selftests: vDSO: parse_vdso: Test __SIZEOF_LONG__ instead of ULONG_MAX
> >        selftests: vDSO: parse_vdso: Make compatible with nolibc
> >        selftests: vDSO: vdso_test_gettimeofday: Clean up includes
> >        selftests: vDSO: vdso_test_gettimeofday: Make compatible with nolibc
> >        selftests: vDSO: vdso_standalone_test_x86: Switch to nolibc
> > 
> >   MAINTAINERS                                        |   1 +
> >   include/uapi/linux/elf.h                           |  38 ++
> >   tools/include/uapi/linux/elf.h                     | 524 +++++++++++++++++++++
> >   tools/testing/selftests/lib.mk                     |   5 +-
> >   tools/testing/selftests/vDSO/Makefile              |  11 +-
> >   tools/testing/selftests/vDSO/parse_vdso.c          |  21 +-
> >   tools/testing/selftests/vDSO/parse_vdso.h          |   1 -
> >   .../selftests/vDSO/vdso_standalone_test_x86.c      | 143 +-----
> >   .../selftests/vDSO/vdso_test_gettimeofday.c        |   4 +-
> >   9 files changed, 584 insertions(+), 164 deletions(-)
> > ---
> > base-commit: 2014c95afecee3e76ca4a56956a936e23283f05b
> > change-id: 20241017-parse_vdso-nolibc-e069baa7ff48
> > 
> > Best regards,
> 

Re: [PATCH 00/16] selftests: vDSO: parse_vdso: Make compatible with nolibc

[Christophe Leroy]

Le 03/02/2025 à 14:50, Thomas Weißschuh a écrit :
> On Mon, Feb 03, 2025 at 12:23:29PM +0100, Christophe Leroy wrote:
>> Le 03/02/2025 à 10:05, Thomas Weißschuh a écrit :
>>> For testing the functionality of the vDSO, it is necessary to build
>>> userspace programs for multiple different architectures.
>>> It is additional work to acquire matching userspace cross-compilers with
>>> full C libraries and then building root images out of those.
>>> The kernel tree already contains nolibc, a small, header-only C library.
>>> By using it, it is possible to build userspace programs without any
>>> additional dependencies.
>>> For example the kernel.org crosstools or multi-target clang can be used
>>> to build test programs for a multitude of architectures.
>>> While nolibc is very limited, it is enough for many selftests.
>>> With some minor adjustments it is possible to make parse_vdso.c
>>> compatible with nolibc.
>>> As an example, vdso_standalone_test_x86 is now built from the same C
>>> code as the regular vdso_test_gettimeofday, while still being completely
>>> standalone.
>>>
>>> This should probably go through the kselftest tree.
>>
>> Not sure what are the expectations with this series.
> 
> In general it should also work for PPC,
> thanks for testing it.
> 
>> I gave it a try with vdso_test_gettimeofday and get the following:
>>
>> $ powerpc64-linux-gcc -nostdlib -nostdinc -ffreestanding
>> -fno-asynchronous-unwind-tables -fno-stack-protector -include /home/chleroy/linux-powerpc/tools/testing/selftests/../../../tools/include/nolibc/nolibc.h -I/home/chleroy/linux-powerpc/tools/testing/selftests/../../../tools/include/nolibc/
>> -isystem
>> /home/chleroy/linux-powerpc/tools/testing/selftests/../../../usr/include
>> -std=gnu99 -O2 -D_GNU_SOURCE= -isystem /home/chleroy/linux-powerpc/tools/testing/selftests/../../../tools/include/uapi
>> vdso_test_gettimeofday.c parse_vdso.c  -o /home/chleroy/linux-powerpc/tools/testing/selftests/vDSO/vdso_test_gettimeofday
>>
>> make: Entering directory
>> '/home/chleroy/linux-powerpc/tools/testing/selftests/vDSO'
>> powerpc64-linux-gcc -nostdlib -nostdinc -ffreestanding
>> -fno-asynchronous-unwind-tables -fno-stack-protector -include /home/chleroy/linux-powerpc/tools/testing/selftests/../../../tools/include/nolibc/nolibc.h -I/home/chleroy/linux-powerpc/tools/testing/selftests/../../../tools/include/nolibc/
>> -isystem
>> /home/chleroy/linux-powerpc/tools/testing/selftests/../../../usr/include
>> -std=gnu99 -O2 -D_GNU_SOURCE= -isystem /home/chleroy/linux-powerpc/tools/testing/selftests/../../../tools/include/uapi
>> vdso_test_gettimeofday.c parse_vdso.c  -o /home/chleroy/linux-powerpc/tools/testing/selftests/vDSO/vdso_test_gettimeofday
> 
> This log is confusing. It contains traces of "make" output but no "make"
> invocation. I'm also not sure if there were two different compilations
> or only one. Can you give the full commandline?
> For your testing it should be enough to enable
> "vdso_test_standalone_x86" in the Makefile for PPC.

Well, yes I copied/pasted too much.

I made some hacky modifications to the Makefile but I forgot the '| 
header' pattern. With it added it works as expected.

Do you have any plan to get it work with nolibc for all test programs in 
selftests/vDSO, not only the standalone x86 test ?

Christophe

Re: [PATCH 00/16] selftests: vDSO: parse_vdso: Make compatible with nolibc

[Thomas Weißschuh]

On Mon, Feb 03, 2025 at 04:43:22PM +0100, Christophe Leroy wrote:
<snip>

> Do you have any plan to get it work with nolibc for all test programs in
> selftests/vDSO, not only the standalone x86 test ?

Not directly as next step. I am focussing on some other work which will
integrate (vDSO) selftests with nolibc slightly differently.
However if you have interest in converting the tests now, that would be
great and will also be useful for my future changes.
The current issues I see:
* Missing architecture support in nolibc (should be fairly easy to implement)
* Missing kselftest_harness.h support in nolibc (I'm working on that)
* Maybe some users want to stick with their regular libc
  (Nothing should prevent that, but the mechanism may need some discussion)


Thomas

Re: [PATCH 00/16] selftests: vDSO: parse_vdso: Make compatible with nolibc

[Willy Tarreau]

On Mon, Feb 03, 2025 at 05:14:37PM +0100, Thomas Weißschuh wrote:
> On Mon, Feb 03, 2025 at 04:43:22PM +0100, Christophe Leroy wrote:
> <snip>
> 
> > Do you have any plan to get it work with nolibc for all test programs in
> > selftests/vDSO, not only the standalone x86 test ?
> 
> Not directly as next step. I am focussing on some other work which will
> integrate (vDSO) selftests with nolibc slightly differently.
> However if you have interest in converting the tests now, that would be
> great and will also be useful for my future changes.
> The current issues I see:
> * Missing architecture support in nolibc (should be fairly easy to implement)
> * Missing kselftest_harness.h support in nolibc (I'm working on that)
> * Maybe some users want to stick with their regular libc
>   (Nothing should prevent that, but the mechanism may need some discussion)

BTW, I wanted to thank you for this work. Originally when I started with
nolibc, I thought the vdso was out of reach due to the many missing
definitions. Turns out you were braver than me ;-)

Cheers,
Willy