- Include <machine/tls.h> in MD rtld_machdep.h headers.
- Remove local definitions of TLS_* constants from rtld_machdep.h
headers and libc using the values from <machine/tls.h> instead.
- Use _tcb_set() instead of inlined versions in MD
allocate_initial_tls() routines in rtld. The one exception is amd64
whose _tcb_set() invokes the amd64_set_fsbase ifunc. rtld cannot
use ifuncs, so amd64 inlines the logic to optionally write to fsbase
directly.
- Use _tcb_set() instead of _set_tp() in libc.
- Use '&_tcb_get()->tcb_dtv' instead of _get_tp() in both rtld and libc.
This permits removing _get_tp.c from rtld.
- Use TLS_TCB_SIZE and TLS_TCB_ALIGN with allocate_tls() in MD
allocate_initial_tls() routines in rtld.
Reviewed by: kib, jrtc27 (earlier version)
Differential Revision: https://reviews.freebsd.org/D33353
lld 10.0 seems to generate this relocation for rdtsc_mb() ifunc in our libc.
Reported, reviewed, and tested by: dim (amd64, previous version)
Discussed with: emaste
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D23652
TP points to the start of the TLS block after the tcb, but
Obj_Entry.tlsoffset includes the tcb, so subtract the size of the tcb
to compute the offset relative to TP.
This is identical to the same fixes for powerpc in r339072 and r342671.
Reviewed by: James Clarke
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D22661
The original code did not support dynamically loaded libraries and used
suboptimal access to TLS variables.
New implementation removes lazy resolving of TLS relocation - due to flaw
in TLSDESC design is impossible to switch resolver function at runtime
without expensive locking.
Due to this, 3 specialized resolvers are implemented:
- load time resolver for TLS relocation from libraries loaded with main
executable (thus with known TLS offset).
- resolver for undefined thread weak symbols.
- slower lazy resolver for dynamically loaded libraries with fast path for
already resolved symbols.
PR: 228892, 232149, 233204, 232311
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D18417
objects' init functions instead of doing the setup via a constructor
in libc as the init functions may already depend on these handlers
to be in place. This gets us rid of:
- the undefined order in which libc constructors as __guard_setup()
and jemalloc_constructor() are executed WRT __sparc_utrap_setup(),
- the requirement to link libc last so __sparc_utrap_setup() gets
called prior to constructors in other libraries (see r122883).
For static binaries, crt1.o still sets up the user trap handlers.
o Move misplaced prototypes for MD functions in to the MD prototype
section of rtld.h.
o Sprinkle nitems().
New version is not compatible on supervisor mode with v1.9.1
(previous version).
Highlights:
o BBL (Berkeley Boot Loader) provides no initial page tables
anymore allowing us to choose VM, to build page tables manually
and enable MMU in S-mode.
o SBI interface changed.
o GENERIC kernel.
FDT is now chosen standard for RISC-V hardware description.
DTB is now provided by Spike (golden model simulator). This
allows us to introduce GENERIC kernel. However, description
for console and timer devices is not provided in DTB, so move
these devices temporary to nexus bus.
o Supervisor can't access userspace by default. Solution is to
set SUM (permit Supervisor User Memory access) bit in sstatus
register.
o Compressed extension is now turned on by default.
o External GCC 7.1 compiler used.
o _gp renamed to __global_pointer$
o Compiler -march= string is now in use allowing us to choose
required extensions (compressed, FPU, atomic, etc).
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D11800
From the manpage:
When set to a nonempty string, prevents modifications of the PLT slots
when doing bindings. As result, each call of the PLT-resolved
function is resolved. In combination with debug output, this provides
complete account of all bind actions at runtime.
Same feature exists on Linux and Solaris.
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
(hopefully) stock gcc 4.2.1 on i386 and other arches.
In particular:
- Do not use %ebx in the asm constraints on i386, since rtld is
compiled with -fPIC and gcc cannot handle GOT-base register reload
(clang and newer gcc can).
- Avoid direct use of [static N] construct in the function
declaration/definion. In-tree gcc was patched to support this, but
stock 4.2.1 cannot handle the feature.
Requested by: bde
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
CPUID[7].%ebx (cpu_stdext_feature), %ecx (cpu_stdext_feature2) to the
ifunc resolvers on x86.
It is much more clean to use CPUID instruction in usermode to retrieve
this information than to pass AT_HWCAP aux vector from kernel, on
x86. Still, the change does allow for use of AT_HWCAP on arches where it is
needed, by passing aux array to ifunc_init() initializer which should
prepare arguments for ifunc resolvers.
Current signature for resolvers on x86 is
func_t iresolve(uint32_t cpu_feature, uint32_t cpu_feature2,
uint32_t cpu_stdext_feature, uint32_t cpu_stdext_feature2);
where arguments have identical meaning as the kernel variables of the
same name. The ABIs allow to use resolvers with the void or shortened
list of arguments.
Reviewed by: jhb
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D8448
phdr locks locked. This allows to call rtld services from the
callback, which is only reasonable for dlopen(path, RTLD_NOLOAD) to
test existence of the library in the image, and for dlsym(). The
later might still be not quite safe, due to the lazy resolution of
filters.
To allow dropping the locks around iteration in dl_iterate_phdr(3), we
insert markers to track current position between relocks. The global
objects list is converted to tailq and all iterators skip markers,
globallist_next() and globallist_curr() helpers are added.
Reported and tested by: davide
Reviewed by: kan
Sponsored by: The FreeBSD Foundation
MFC after: 3 weeks
