[Git][ghc/ghc][wip/marge_bot_batch_merge_job] 13 commits: rts/linker: Fix relocation overflow in PE linker

Tue Nov 10 15:59:37 UTC 2020

 Marge Bot pushed to branch wip/marge_bot_batch_merge_job at Glasgow Haskell Compiler / GHC

Commits:
d445cf05 by Ben Gamari at 2020-11-10T10:26:20-05:00
rts/linker: Fix relocation overflow in PE linker

Previously the overflow check for the IMAGE_REL_AMD64_ADDR32NB
relocation failed to account for the signed nature of the value.
Specifically, the overflow check was:

    uint64_t v;
    v = S + A;
    if (v >> 32) { ... }

However, `v` ultimately needs to fit into 32-bits as a signed value.
Consequently, values `v > 2^31` in fact overflow yet this is not caught
by the existing overflow check.

Here we rewrite the overflow check to rather ensure that
`INT32_MIN <= v <= INT32_MAX`. There is now quite a bit of repetition
between the `IMAGE_REL_AMD64_REL32` and `IMAGE_REL_AMD64_ADDR32` cases
but I am leaving fixing this for future work.

This bug was first noticed by @awson.

Fixes #15808.

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4c407f6e by Sylvain Henry at 2020-11-10T10:27:00-05:00
Export SPEC from GHC.Exts (#13681)

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7814cd5b by David Eichmann at 2020-11-10T10:27:35-05:00
ghc-heap: expose decoding from heap representation

Co-authored-by: Sven Tennie <sven.tennie at gmail.com>
Co-authored-by: Matthew Pickering <matthewtpickering at gmail.com>
Co-authored-by: Ben Gamari <bgamari.foss at gmail.com>

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fa344d33 by Richard Eisenberg at 2020-11-10T10:28:10-05:00
Add test case for #17186.

This got fixed sometime recently; not worth it trying to
figure out which commit.

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2e63a0fb by David Eichmann at 2020-11-10T10:28:46-05:00
Add code comments for StgInfoTable and StgStack structs

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ed33667f by Ben Gamari at 2020-11-10T10:59:29-05:00
nativeGen: Make makeImportsDoc take an NCGConfig rather than DynFlags

It appears this was an oversight as there is no reason the full DynFlags
is necessary.

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a2d25a49 by Ben Gamari at 2020-11-10T10:59:29-05:00
Move this_module into NCGConfig

In various places in the NCG we need the Module currently being
compiled. Let's move this into the environment instead of chewing threw
another register.

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a3dace81 by Ben Gamari at 2020-11-10T10:59:29-05:00
codeGen: Produce local symbols for module-internal functions

It turns out that some important native debugging/profiling tools (e.g.
perf) rely only on symbol tables for function name resolution (as
opposed to using DWARF DIEs). However, previously GHC would emit
temporary symbols (e.g. `.La42b`) to identify module-internal
entities. Such symbols are dropped during linking and therefore not
visible to runtime tools (in addition to having rather un-helpful unique
names). For instance, `perf report` would often end up attributing all
cost to the libc `frame_dummy` symbol since Haskell code was no covered
by any proper symbol (see #17605).

We now rather follow the model of C compilers and emit
descriptively-named local symbols for module internal things. Since this
will increase object file size this behavior can be disabled with the
`-fno-expose-internal-symbols` flag.

With this `perf record` can finally be used against Haskell executables.
Even more, with `-g3` `perf annotate` provides inline source code.

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f3c2fcfe by Ben Gamari at 2020-11-10T10:59:29-05:00
Enable -fexpose-internal-symbols when debug level >=2

This seems like a reasonable default as the object file size increases
by around 5%.

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a6d62c3e by Ömer Sinan Ağacan at 2020-11-10T10:59:30-05:00
Fix and enable object unloading in GHCi

Fixes #16525 by tracking dependencies between object file symbols and
marking symbol liveness during garbage collection

See Note [Object unloading] in CheckUnload.c for details.

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76dbaae6 by Ray Shih at 2020-11-10T10:59:30-05:00
Add loadNativeObj and unloadNativeObj

(This change is originally written by niteria)

This adds two functions:
* `loadNativeObj`
* `unloadNativeObj`
and implements them for Linux.

They are useful if you want to load a shared object with Haskell code
using the system linker and have GHC call dlclose() after the
code is no longer referenced from the heap.

Using the system linker allows you to load the shared object
above outside the low-mem region. It also loads the DWARF sections
in a way that `perf` understands.

`dl_iterate_phdr` is what makes this implementation Linux specific.

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14d8717c by GHC GitLab CI at 2020-11-10T10:59:30-05:00
rts: Introduce highMemDynamic

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f799294a by GHC GitLab CI at 2020-11-10T10:59:30-05:00
Introduce test for dynamic library unloading

This uses the highMemDynamic flag introduced earlier to verify that
dynamic objects are properly unloaded.

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30 changed files:

- compiler/GHC/Cmm/CLabel.hs
- compiler/GHC/Cmm/Info/Build.hs
- compiler/GHC/CmmToAsm.hs
- compiler/GHC/CmmToAsm/Config.hs
- compiler/GHC/CmmToAsm/Monad.hs
- compiler/GHC/CmmToAsm/PIC.hs
- compiler/GHC/CmmToAsm/X86/Ppr.hs
- compiler/GHC/Driver/Flags.hs
- compiler/GHC/Driver/Session.hs
- compiler/GHC/Linker/Loader.hs
- docs/users_guide/debug-info.rst
- docs/users_guide/phases.rst
- includes/rts/Linker.h
- includes/rts/storage/Closures.h
- includes/rts/storage/GC.h
- includes/rts/storage/Heap.h
- includes/rts/storage/TSO.h
- libraries/base/GHC/Exts.hs
- libraries/ghc-heap/GHC/Exts/Heap.hs
- rts/CheckUnload.c
- rts/CheckUnload.h
- rts/Hash.c
- rts/Hash.h
- rts/Heap.c
- rts/Linker.c
- rts/LinkerInternals.h
- rts/RtsStartup.c
- rts/linker/Elf.c
- rts/linker/LoadArchive.c
- rts/linker/MachO.c

The diff was not included because it is too large.

View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/3903c25fc0d998191940743dafc4ee80b40a7a2c...f799294a63bccbf287e091acd437be225bd57aa8

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