svn commit: r348611 - in head/sys: conf kern
Ian Lepore
ian at freebsd.org
Tue Jun 4 14:58:11 UTC 2019
On Tue, 2019-06-04 at 13:07 +0000, Ed Maste wrote:
> Author: emaste
> Date: Tue Jun 4 13:07:10 2019
> New Revision: 348611
> URL: https://svnweb.freebsd.org/changeset/base/348611
>
> Log:
> Expose the kernel's build-ID through sysctl
>
> After our migration (of certain architectures) to lld the kernel is built
> with a unique build-ID. Make it available via a sysctl and uname(1) to
> allow the user to identify their running kernel.
>
Won't this impact WITH_REPRODUCIBLE_BUILD?
-- Ian
> Submitted by: Ali Mashtizadeh <ali_mashtizadeh.com>
> MFC after: 2 weeks
> Relnotes: Yes
> Event: Waterloo Hackathon 2019
> Differential Revision: https://reviews.freebsd.org/D20326
>
> Modified:
> head/sys/conf/ldscript.amd64
> head/sys/conf/ldscript.arm
> head/sys/conf/ldscript.arm64
> head/sys/conf/ldscript.i386
> head/sys/conf/ldscript.mips
> head/sys/conf/ldscript.mips.cfe
> head/sys/conf/ldscript.mips.mips64
> head/sys/conf/ldscript.mips.octeon1
> head/sys/conf/ldscript.powerpc
> head/sys/conf/ldscript.powerpc64
> head/sys/conf/ldscript.powerpcspe
> head/sys/conf/ldscript.riscv
> head/sys/conf/ldscript.sparc64
> head/sys/kern/kern_mib.c
>
> Modified: head/sys/conf/ldscript.amd64
> =====================================================================
> =========
> --- head/sys/conf/ldscript.amd64 Tue Jun 4 13:00:49 2019 (r348
> 610)
> +++ head/sys/conf/ldscript.amd64 Tue Jun 4 13:07:10 2019 (r348
> 611)
> @@ -74,6 +74,11 @@ SECTIONS
> PROVIDE (etext = .);
> .rodata : { *(.rodata .rodata.* .gnu.linkonce.r.*) }
> .rodata1 : { *(.rodata1) }
> + .note.gnu.build-id : {
> + PROVIDE (__build_id_start = .);
> + *(.note.gnu.build-id)
> + PROVIDE (__build_id_end = .);
> + }
> .eh_frame_hdr : { *(.eh_frame_hdr) }
> .eh_frame : ONLY_IF_RO { KEEP (*(.eh_frame)) }
> .gcc_except_table : ONLY_IF_RO { *(.gcc_except_table
> .gcc_except_table.*) }
>
> Modified: head/sys/conf/ldscript.arm
> =====================================================================
> =========
> --- head/sys/conf/ldscript.arm Tue Jun 4 13:00:49 2019 (r348
> 610)
> +++ head/sys/conf/ldscript.arm Tue Jun 4 13:07:10 2019 (r348
> 611)
> @@ -27,6 +27,11 @@ SECTIONS
> .gnu.version : { *(.gnu.version) }
> .gnu.version_d : { *(.gnu.version_d) }
> .gnu.version_r : { *(.gnu.version_r) }
> + .note.gnu.build-id : {
> + PROVIDE (__build_id_start = .);
> + *(.note.gnu.build-id)
> + PROVIDE (__build_id_end = .);
> + }
> .rel.text :
> { *(.rel.text) *(.rel.gnu.linkonce.t*) }
> .rela.text :
>
> Modified: head/sys/conf/ldscript.arm64
> =====================================================================
> =========
> --- head/sys/conf/ldscript.arm64 Tue Jun 4 13:00:49 2019 (r348
> 610)
> +++ head/sys/conf/ldscript.arm64 Tue Jun 4 13:07:10 2019 (r348
> 611)
> @@ -27,6 +27,11 @@ SECTIONS
> .gnu.version : { *(.gnu.version) }
> .gnu.version_d : { *(.gnu.version_d) }
> .gnu.version_r : { *(.gnu.version_r) }
> + .note.gnu.build-id : {
> + PROVIDE (__build_id_start = .);
> + *(.note.gnu.build-id)
> + PROVIDE (__build_id_end = .);
> + }
> .rel.text :
> { *(.rel.text) *(.rel.gnu.linkonce.t*) }
> .rela.text :
>
> Modified: head/sys/conf/ldscript.i386
> =====================================================================
> =========
> --- head/sys/conf/ldscript.i386 Tue Jun 4 13:00:49 2019 (r348
> 610)
> +++ head/sys/conf/ldscript.i386 Tue Jun 4 13:07:10 2019 (r348
> 611)
> @@ -62,6 +62,11 @@ SECTIONS
> PROVIDE (etext = .);
> .rodata : { *(.rodata .rodata.* .gnu.linkonce.r.*) }
> .rodata1 : { *(.rodata1) }
> + .note.gnu.build-id : {
> + PROVIDE (__build_id_start = .);
> + *(.note.gnu.build-id)
> + PROVIDE (__build_id_end = .);
> + }
> .eh_frame_hdr : { *(.eh_frame_hdr) }
> .eh_frame : ONLY_IF_RO { KEEP (*(.eh_frame)) }
> .gcc_except_table : ONLY_IF_RO { *(.gcc_except_table
> .gcc_except_table.*) }
>
> Modified: head/sys/conf/ldscript.mips
> =====================================================================
> =========
> --- head/sys/conf/ldscript.mips Tue Jun 4 13:00:49 2019 (r348
> 610)
> +++ head/sys/conf/ldscript.mips Tue Jun 4 13:07:10 2019 (r348
> 611)
> @@ -63,6 +63,11 @@ SECTIONS
> .gnu.version : { *(.gnu.version) }
> .gnu.version_d : { *(.gnu.version_d) }
> .gnu.version_r : { *(.gnu.version_r) }
> + .note.gnu.build-id : {
> + PROVIDE (__build_id_start = .);
> + *(.note.gnu.build-id)
> + PROVIDE (__build_id_end = .);
> + }
> .rel.init : { *(.rel.init) }
> .rela.init : { *(.rela.init) }
> .rel.text :
>
> Modified: head/sys/conf/ldscript.mips.cfe
> =====================================================================
> =========
> --- head/sys/conf/ldscript.mips.cfe Tue Jun 4 13:00:49 2019 (r348
> 610)
> +++ head/sys/conf/ldscript.mips.cfe Tue Jun 4 13:07:10 2019 (r348
> 611)
> @@ -192,6 +192,11 @@ SECTIONS
> PROVIDE (etext = .);
> .rodata : { *(.rodata) *(.rodata.*) *(.gnu.linkonce.r.*) }
> .rodata1 : { *(.rodata1) }
> + .note.gnu.build-id : {
> + PROVIDE (__build_id_start = .);
> + *(.note.gnu.build-id)
> + PROVIDE (__build_id_end = .);
> + }
> .reginfo : { *(.reginfo) }
> .sdata2 : { *(.sdata2) *(.sdata2.*) *(.gnu.linkonce.s2.*) }
> .sbss2 : { *(.sbss2) *(.sbss2.*) *(.gnu.linkonce.sb2.*) }
>
> Modified: head/sys/conf/ldscript.mips.mips64
> =====================================================================
> =========
> --- head/sys/conf/ldscript.mips.mips64 Tue Jun 4 13:00:49
> 2019 (r348610)
> +++ head/sys/conf/ldscript.mips.mips64 Tue Jun 4 13:07:10
> 2019 (r348611)
> @@ -176,6 +176,11 @@ SECTIONS
> PROVIDE (etext = .);
> .rodata : { *(.rodata) *(.rodata.*) *(.gnu.linkonce.r.*) }
> .rodata1 : { *(.rodata1) }
> + .note.gnu.build-id : {
> + PROVIDE (__build_id_start = .);
> + *(.note.gnu.build-id)
> + PROVIDE (__build_id_end = .);
> + }
> .reginfo : { *(.reginfo) }
> .sdata2 : { *(.sdata2) *(.sdata2.*) *(.gnu.linkonce.s2.*) }
> .sbss2 : { *(.sbss2) *(.sbss2.*) *(.gnu.linkonce.sb2.*) }
>
> Modified: head/sys/conf/ldscript.mips.octeon1
> =====================================================================
> =========
> --- head/sys/conf/ldscript.mips.octeon1 Tue Jun 4 13:00:49
> 2019 (r348610)
> +++ head/sys/conf/ldscript.mips.octeon1 Tue Jun 4 13:07:10
> 2019 (r348611)
> @@ -23,6 +23,12 @@ SECTIONS {
> *(.rodata)
> . = ALIGN(32);
> }
> +
> + .note.gnu.build-id : {
> + PROVIDE (__build_id_start = .);
> + *(.note.gnu.build-id)
> + PROVIDE (__build_id_end = .);
> + }
>
> .data : {
> _rwdata = .;
>
> Modified: head/sys/conf/ldscript.powerpc
> =====================================================================
> =========
> --- head/sys/conf/ldscript.powerpc Tue Jun 4 13:00:49 2019 (r348
> 610)
> +++ head/sys/conf/ldscript.powerpc Tue Jun 4 13:07:10 2019 (r348
> 611)
> @@ -55,6 +55,11 @@ SECTIONS
> .fini : { *(.fini) } =0
> .rodata : { *(.rodata) *(.gnu.linkonce.r*) }
> .rodata1 : { *(.rodata1) }
> + .note.gnu.build-id : {
> + PROVIDE (__build_id_start = .);
> + *(.note.gnu.build-id)
> + PROVIDE (__build_id_end = .);
> + }
> .sdata2 : { *(.sdata2) }
> .sbss2 : { *(.sbss2) }
> /* Adjust the address for the data segment to the next page up. */
>
> Modified: head/sys/conf/ldscript.powerpc64
> =====================================================================
> =========
> --- head/sys/conf/ldscript.powerpc64 Tue Jun 4 13:00:49 2019 (r348
> 610)
> +++ head/sys/conf/ldscript.powerpc64 Tue Jun 4 13:07:10 2019 (r348
> 611)
> @@ -46,6 +46,11 @@ SECTIONS
> .gnu.version : { *(.gnu.version) }
> .gnu.version_d : { *(.gnu.version_d) }
> .gnu.version_r : { *(.gnu.version_r) }
> + .note.gnu.build-id : {
> + PROVIDE (__build_id_start = .);
> + *(.note.gnu.build-id)
> + PROVIDE (__build_id_end = .);
> + }
> .rela.text :
> { *(.rela.text) *(.rela.gnu.linkonce.t*) }
> .rela.data :
>
> Modified: head/sys/conf/ldscript.powerpcspe
> =====================================================================
> =========
> --- head/sys/conf/ldscript.powerpcspe Tue Jun 4 13:00:49 2019 (r348
> 610)
> +++ head/sys/conf/ldscript.powerpcspe Tue Jun 4 13:07:10 2019 (r348
> 611)
> @@ -55,6 +55,11 @@ SECTIONS
> .fini : { *(.fini) } =0
> .rodata : { *(.rodata) *(.gnu.linkonce.r*) }
> .rodata1 : { *(.rodata1) }
> + .note.gnu.build-id : {
> + PROVIDE (__build_id_start = .);
> + *(.note.gnu.build-id)
> + PROVIDE (__build_id_end = .);
> + }
> .sdata2 : { *(.sdata2) }
> .sbss2 : { *(.sbss2) }
> /* Adjust the address for the data segment to the next page up. */
>
> Modified: head/sys/conf/ldscript.riscv
> =====================================================================
> =========
> --- head/sys/conf/ldscript.riscv Tue Jun 4 13:00:49 2019 (r348
> 610)
> +++ head/sys/conf/ldscript.riscv Tue Jun 4 13:07:10 2019 (r348
> 611)
> @@ -27,6 +27,11 @@ SECTIONS
> .gnu.version : { *(.gnu.version) }
> .gnu.version_d : { *(.gnu.version_d) }
> .gnu.version_r : { *(.gnu.version_r) }
> + .note.gnu.build-id : {
> + PROVIDE (__build_id_start = .);
> + *(.note.gnu.build-id)
> + PROVIDE (__build_id_end = .);
> + }
> .rel.text :
> { *(.rel.text) *(.rel.gnu.linkonce.t*) }
> .rela.text :
>
> Modified: head/sys/conf/ldscript.sparc64
> =====================================================================
> =========
> --- head/sys/conf/ldscript.sparc64 Tue Jun 4 13:00:49 2019 (r348
> 610)
> +++ head/sys/conf/ldscript.sparc64 Tue Jun 4 13:07:10 2019 (r348
> 611)
> @@ -146,6 +146,11 @@ SECTIONS
> PROVIDE (etext = .);
> .rodata : { *(.rodata) *(.rodata.*) *(.gnu.linkonce.r.*) }
> .rodata1 : { *(.rodata1) }
> + .note.gnu.build-id : {
> + PROVIDE (__build_id_start = .);
> + *(.note.gnu.build-id)
> + PROVIDE (__build_id_end = .);
> + }
> .sdata2 : { *(.sdata2) *(.sdata2.*) *(.gnu.linkonce.s2.*) }
> .sbss2 : { *(.sbss2) *(.sbss2.*) *(.gnu.linkonce.sb2.*) }
> . = ALIGN(0x2000) + (. & (0x2000 - 1));
>
> Modified: head/sys/kern/kern_mib.c
> =====================================================================
> =========
> --- head/sys/kern/kern_mib.c Tue Jun 4 13:00:49 2019 (r348610)
> +++ head/sys/kern/kern_mib.c Tue Jun 4 13:07:10 2019 (r348611)
> @@ -481,6 +481,54 @@ SYSCTL_PROC(_kern, KERN_OSRELDATE, osreldate,
> CTLTYPE_INT | CTLFLAG_CAPRD | CTLFLAG_RD | CTLFLAG_MPSAFE,
> NULL, 0, sysctl_osreldate, "I", "Kernel release date");
>
> +/*
> + * The build-id is copied from the ELF section .note.gnu.build-
> id. The linker
> + * script defines two variables to expose the beginning and
> end. LLVM
> + * currently uses a SHA-1 hash, but other formats can be supported
> by checking
> + * the length of the section.
> + */
> +
> +extern char __build_id_start[];
> +extern char __build_id_end[];
> +
> +#define BUILD_ID_HEADER_LEN 0x10
> +#define BUILD_ID_HASH_MAXLEN 0x14
> +
> +static int
> +sysctl_build_id(SYSCTL_HANDLER_ARGS)
> +{
> + uintptr_t sectionlen = (uintptr_t)(__build_id_end -
> __build_id_start);
> + int hashlen;
> + char buf[2*BUILD_ID_HASH_MAXLEN+1];
> +
> + /*
> + * The ELF note section has a four byte length for the vendor
> name,
> + * four byte length for the value, and a four byte vendor
> specific
> + * type. The name for the build id is "GNU\0". We skip the
> first 16
> + * bytes to read the build hash. We will return the remaining
> bytes up
> + * to 20 (SHA-1) hash size. If the hash happens to be a custom
> number
> + * of bytes we will pad the value with zeros, as the section
> should be
> + * four byte aligned.
> + */
> + if (sectionlen <= BUILD_ID_HEADER_LEN ||
> + sectionlen > (BUILD_ID_HEADER_LEN + BUILD_ID_HASH_MAXLEN))
> {
> + return (ENOENT);
> + }
> +
> +
> + hashlen = sectionlen - BUILD_ID_HEADER_LEN;
> + for (int i = 0; i < hashlen; i++) {
> + uint8_t c = __build_id_start[i+BUILD_ID_HEADER_LEN];
> + snprintf(&buf[2*i], 3, "%02x", c);
> + }
> +
> + return (SYSCTL_OUT(req, buf, strlen(buf) + 1));
> +}
> +
> +SYSCTL_PROC(_kern, OID_AUTO, build_id,
> + CTLTYPE_STRING | CTLFLAG_CAPRD | CTLFLAG_RD | CTLFLAG_MPSAFE,
> + NULL, 0, sysctl_build_id, "A", "Operating system build-id");
> +
> SYSCTL_NODE(_kern, OID_AUTO, features, CTLFLAG_RD, 0, "Kernel
> Features");
>
> #ifdef COMPAT_FREEBSD4
>
More information about the svn-src-all
mailing list