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 > _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
