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2021-06-26Make lazy binding work on riscv64.Mark Kettenis
prompted by deraadt@
2021-06-26Build ld.so with --march=rv64imac on riscv64 to be absolutely sure thatMark Kettenis
ld.so doesn't use the FP registers. ok deraadt@
2021-06-26Use AFLAGS when building syscall stubs. Drop AINC wich isn't used.Mark Kettenis
ok deraadt@
2021-06-02add RTLD_NODELETE supportSebastien Marie
if RTLD_NODELETE isn't POSIX, it is widely deployed: at least linux, freebsd, dragonfly, netbsd, solaris, illumos, apple, and fuchsia have it. ok kettenis@ on previous version with help from and ok guenther@ diff partially inspired from a diff from brad@
2021-05-25program headers: do not rely on DYNAMIC coming before GNU_RELROkn
Except for some specific cases (thanks guenther) ELF mandates nothing but the file header be at a fixed location, hence ld.so(1) must not assume any specific order for headers, segments, etc. Looping over the program header table to parse segment headers, _dl_boot() creates the executable object upon DYNAMIC and expects it to be set upon GNU_RELRO, resulting in a NULL dereference iff that order is reversed. Store relocation bits in temporary variables and update the executable object once all segment headers are parsed to lift this dependency. Under __mips__ _dl_boot() later on uses the same temporary variable, so move nothing but the declaration out of MI code so as to not alter the MD code's logic/behaviour. Found while porting patchelf(1) from NixOS. OK guenther
2021-05-16Correct problem in riscv64 dtors execution load the function pointerDale Rahn
correctly and do not overwrite it in csu. allows most ld.so regressions to pass confirmed by jsg@, ok kettenis
2021-04-28riscv64 ld.soDale Rahn
derived from arm64 go ahead deraadt@
2021-04-19Same internal consistency check as libc malloc: size in hash tableOtto Moerbeek
should correspond to size of chunk meta data
2021-03-16On i386 don't attempt to map shared libraries in low memory whenKurt Miller
a large executable's .text section crosses the 512MB exec line. Executables that have MAXTSIZ > 64MB can map above the default 512MB exec line. When this happens, shared libs that attempt to map into low memory will find their .data section can not be mapped. ld.so will attempt to remap the share lib at higher addresses until it can be mapped. For very large executables like chrome this process is very time consuming. This change detects how much of the executable's .text section exceeds 512MB and uses that as the initial hint for shared libs to map into which avoids attempting to map into blocked memory. okay deraadt@
2020-12-26Fix a nasty mem leak in ld.so's own malloc. This was hard to diagnose, sinceOtto Moerbeek
malloc dumping and gdb do not help at all when studying ld.so. In the end it turns out ot be a simple merge error causing extra mmap calls. ok miller@ tb@
2020-11-28Add retguard to macppc kernel locore.S, ofwreal.S, setjmp.Sgkoehler
This changes RETGUARD_SETUP(ffs) to RETGUARD_SETUP(ffs, %r11, %r12) and RETGUARD_CHECK(ffs) to RETGUARD_CHECK(ffs, %r11, %r12) to show that r11 and r12 are in use between setup and check, and to pick registers other than r11 and r12 in some kernel functions. ok mortimer@ deraadt@
2020-10-26Retguard asm macros for powerpc libc, ld.sogkoehler
Add retguard to some, but not all, asm functions in libc. Edit SYS.h in libc to remove the PREFIX macros and add SYSENTRY (more like aarch64 and powerpc64), so we can insert RETGUARD_SETUP after SYSENTRY. Some .S files in this commit don't get retguard, but do stop using the old prefix macros. Tested by deraadt@, who put this diff in a macppc snap.
2020-10-16Use the retguard macros from asm.h to protect the system call stubs.Theo de Raadt
ok mortimer kettenis
2020-10-15make three mib[] arrays const, as was done in libcTheo de Raadt
2020-08-11clang 10 now emits calls to __multi3 from libcompiler_rtJeremie Courreges-Anglas
Hints from kettenis@, ok kettenis@ deraadt@
2020-07-18Use the same names as the 64-bit PowerPC ELF ABI for the relocations.Mark Kettenis
2020-07-16Rewrite loop to match what is written down in the ABI document.Mark Kettenis
ok drahn@
2020-07-16Make lazy binding work.Mark Kettenis
Committing on behalf of drahn@ who is a bit busy.
2020-06-28Disable powerpc64 lazy binding, code was not for 64 bit ABIDale Rahn
DT_PPC_GOT is not used on powerpc64, delete.
2020-06-28Powerpc64 ld.so asm code needs to conform to Powerpc64 abi, not 32bit.Dale Rahn
ok kettenis@
2020-06-25PowerPC64 ld.so code.Dale Rahn
Mostly ported, code runs far enough to start first symbol string lookup. build with -gdwarf-4 to remove asm warnings. Do not bother supporting 32 bit non-pic relocations in shared libraries. (however leave the code there for now)
2020-05-08ld.so(1) also ignores LD_LIBRARY_PATH an friends for set-group-ID executablesJeremie Courreges-Anglas
While here, use consistent casing and don't use .Ev for set-user-ID/set-group-ID. from Miod
2020-05-08LD_DEBUG is ignored for set-user-ID and set-group-ID executablesJeremie Courreges-Anglas
from Miod
2020-03-27Add missing space in stack smash handler error message.Matthieu Herrb
ok kettenis@, deraadt@
2020-03-13Anthony Steinhauser reports that 32-bit arm cpus have the same speculationTheo de Raadt
problems as 64-bit models. To resolve the syscall speculation, as a first step "nop; nop" was added after all occurances of the syscall ("swi 0") instruction. Then the kernel was changed to jump over the 2 extra instructions. In this final step, those pair of nops are converted into the speculation-blocking sequence ("dsb nsh; isb"). Don't try to build through these multiple steps, use a snapshot instead. Packages matching the new ABI will be out in a while... ok kettenis
2020-03-13Anthony Steinhauser reports that 32-bit arm cpus have the same speculationTheo de Raadt
problems as 64-bit models. For the syscall instruction issue, add nop;nop after swi 0, in preparation for jumping over a speculation barrier here later. (a lonely swi 0 was hiding in __asm in this file)
2020-03-11Anthony Steinhauser reports that 32-bit arm cpus have the same speculationTheo de Raadt
problems as 64-bit models. For the syscall instruction issue, add nop;nop after swi 0, in preparation for jumping over a speculation barrier here later. ok kettenis
2020-02-18Now that the kernel skips the two instructions immediately followingMark Kettenis
a syscall, replace the double nop with a dsb nsh; isb; sequence which stops the CPU from speculating any further. This fix was suggested by Anthony Steinhauser. ok deraadt@
2020-01-26Insert two nop instructions after each svc #0 instruction in userland.Mark Kettenis
The will be replaced by a speculation barrier as soon as we teach the kernel to skip over these two instructions when returning from a system call. ok patrick@, deraadt@
2019-12-17Eliminate failure returns from _dl_split_path(): if malloc fails just _dl_oom()Philip Guenther
Prompted by Qualys's leveraging malloc failure in _dl_split_path() to get stuff past. ok deraadt@ millert@
2019-12-17Don't look up env variables until we know we'll trust them. Otherwise,Philip Guenther
just delete them without looking. ok millert@
2019-12-11ld.so may fail to remove the LD_LIBRARY_PATH environment variable forTodd C. Miller
set-user-ID and set-group-ID executables in low memory conditions. Reported by Qualys
2019-12-09When loading a library, mmap(2) may fail. Then everything getsAlexander Bluhm
unmapped and ld.so tries again with different random address layout. In this case, use the new libc executable address for msyscall(2), not one from the first try. Fixes sporadic bogus syscall on i386. OK deraadt@
2019-12-09print addresses upon msyscall failure, for nowTheo de Raadt
2019-12-07Disable ltrace for objects linked with -znow, as at least on amd64, linkingPhilip Guenther
that was deletes the lazy relocation trampoline which ltrace currently depends on problem reported by tb@ directional feedback kettenis@ ok mpi@
2019-12-02It is not always clear what ld.so was backed up to ld.so.backup, andTheo de Raadt
better that folk doing development in here use their own cp tooling.
2019-11-30Sigh, fix i386 msyscall() case to permission the correct address range.Theo de Raadt
2019-11-29As additional paranoia, make a copy of system ld.so into obj/ld.so.backupTheo de Raadt
We don't want to CLEANFILES this one. On occasion this comes in useful.
2019-11-29Repurpose the "syscalls must be on a writeable page" mechanism toTheo de Raadt
enforce a new policy: system calls must be in pre-registered regions. We have discussed more strict checks than this, but none satisfy the cost/benefit based upon our understanding of attack methods, anyways let's see what the next iteration looks like. This is intended to harden (translation: attackers must put extra effort into attacking) against a mixture of W^X failures and JIT bugs which allow syscall misinterpretation, especially in environments with polymorphic-instruction/variable-sized instructions. It fits in a bit with libc/libcrypto/ld.so random relink on boot and no-restart-at-crash behaviour, particularily for remote problems. Less effective once on-host since someone the libraries can be read. For static-executables the kernel registers the main program's PIE-mapped exec section valid, as well as the randomly-placed sigtramp page. For dynamic executables ELF ld.so's exec segment is also labelled valid; ld.so then has enough information to register libc's exec section as valid via call-once msyscall(2) For dynamic binaries, we continue to to permit the main program exec segment because "go" (and potentially a few other applications) have embedded system calls in the main program. Hopefully at least go gets fixed soon. We declare the concept of embedded syscalls a bad idea for numerous reasons, as we notice the ecosystem has many of static-syscall-in-base-binary which are dynamically linked against libraries which in turn use libc, which contains another set of syscall stubs. We've been concerned about adding even one additional syscall entry point... but go's approach tends to double the entry-point attack surface. This was started at a nano-hackathon in Bob Beck's basement 2 weeks ago during a long discussion with mortimer trying to hide from the SSL scream-conversations, and finished in more comfortable circumstances next to a wood-stove at Elk Lakes cabin with UVM scream-conversations. ok guenther kettenis mortimer, lots of feedback from others conversations about go with jsing tb sthen
2019-11-28Unrevert: this change was unrelatedPhilip Guenther
2019-11-28Revert yesterday's _dl_md_reloc() and _dl_md_reloc_got() changes:Philip Guenther
something's broken on at least i386.
2019-11-27Delete now obsolete commentsPhilip Guenther
2019-11-27unifdef: hppa does HAVE_JMPREL and does not have DT_PROCNUMPhilip Guenther
2019-11-27armv7 and aarch64 specify GLOB_DAT as having an addend, so treat itPhilip Guenther
exactly like the ABS{32,64} relocation there. noted by and ok kettenis@
2019-11-26Clean up _dl_md_reloc(): instead of having tables and piles of conditionalsPhilip Guenther
that handle a dozen relocation types for each, just have a nice little switch for the four specific relocations that actually occur. Besides being smaller and easier to understand, this fixes the COPY relocation handling to only do one symbol lookup, instead of looking up the symbol and then immediately looking it up again (with the correct flags to find the instance it needs). ok kettenis@
2019-11-26Make aarch64, amd64, arm, and i386 more like sparc64: move non-lazyPhilip Guenther
relocation from _dl_md_reloc() to _dl_md_reloc_all_plt() which has the minimal code to do it. Also, avoid division on PLTRELSZ; just use it to offset to the end. ok kettenis@
2019-11-10Simplify the handling of the explicit relocations based on ld.so onlyPhilip Guenther
have NONE and REL32_64 relocations w/o symbol. ok visa@
2019-11-10unifdef HAVE_JMPREL, delete dt_pltrelsz handling (which was only usedPhilip Guenther
in the HAVE_JMPREL case anyway), and reduce #includes to match boot.c ok visa@
2019-11-10Recommit CHECK_LDSO bits for mips64, verified on both loongson and octeon.Philip Guenther
ok visa@
2019-10-24Delete unused support for relocations that don't require alignment.Philip Guenther
ok mpi@ kettenis@
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