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* rts/linker: Ensure that code isn't writableBen Gamari2019-11-041-1/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | For many years the linker would simply map all of its memory with PROT_READ|PROT_WRITE|PROT_EXEC. However operating systems have been becoming increasingly reluctant to accept this practice (e.g. #17353 and #12657) and for good reason: writable code is ripe for exploitation. Consequently mmapForLinker now maps its memory with PROT_READ|PROT_WRITE. After the linker has finished filling/relocating the mapping it must then call mmapForLinkerMarkExecutable on the sections of the mapping which contain executable code. Moreover, to make all of this possible it was necessary to redesign the m32 allocator. First, we gave (in an earlier commit) each ObjectCode its own m32_allocator. This was necessary since code loading and symbol resolution/relocation are currently interleaved, meaning that it is not possible to enforce W^X when symbols from different objects reside in the same page. We then redesigned the m32 allocator to take advantage of the fact that all of the pages allocated with the allocator die at the same time (namely, when the owning ObjectCode is unloaded). This makes a number of things simpler (e.g. no more page reference counting; the interface provided by the allocator for freeing is simpler). See Note [M32 Allocator] for details.
* rts: Make m32 allocator per-ObjectCodeBen Gamari2019-11-011-4/+5
| | | | | | | | | | | | | | | | | MacOS Catalina is finally going to force our hand in forbidden writable exeutable mappings. Unfortunately, this is quite incompatible with the current global m32 allocator, which mixes symbols from various objects in a single page. The problem here is that some of these symbols may not yet be resolved (e.g. had relocations performed) as this happens lazily (and therefore we can't yet make the section read-only and therefore executable). The easiest way around this is to simply create one m32 allocator per ObjectCode. This may slightly increase fragmentation for short-running programs but I suspect will actually improve fragmentation for programs doing lots of loading/unloading since we can always free all of the pages allocated to an object when it is unloaded (although this ability will only be implemented in a later patch).
* Adjust section placement and relocation logic for Mach-OArtem Pyanykh2019-03-201-0/+1
| | | | | | | | | | | | | | 1. Place each section on a separate page to ensure required alignment (wastes lots ot space, needs to be improved). 2. Unwire relocation logic from macho sections (the most fiddly part is adjusting internal relocations). Other todos: 0. Add a test for section alignment. 1. Investigate 32bit relocations! 2. Fix memory leak in ZEROPAGE section allocation. 3. Fix creating redundant jump islands for GOT. 4. Investigate more compact section placement.
* Allocate bss section within proper range of other sectionsZejun Wu2019-01-301-17/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: This re-applies {D5195} and {D5235}, they were reverted as part of diff stack to unbreak i386. The proper fix is done in {D5289}. Allocate bss section within proper range of other sections: * when `+RTS -xp` is passed, allocate it contiguously as we did for jump islands * when we mmap the code to lower 2Gb, we should allocate bss section there too Test Plan: 1. `./validate` 2. with ``` DYNAMIC_GHC_PROGRAMS = NO DYNAMIC_BY_DEFAULT = NO ``` `TEST="T15729" make test` passed in both linux (both i386 and x86_64) and macos. 3. Also test in a use case where we used to encouter error like: ``` ghc-iserv-prof: R_X86_64_PC32 relocation out of range: (noname) = b90282ba ``` and now, everything works fine. Reviewers: simonmar, bgamari, angerman, erikd Reviewed By: simonmar Subscribers: rwbarton, carter GHC Trac Issues: #15729 Differential Revision: https://phabricator.haskell.org/D5290
* Add a RTS option -xp to load PIC object anywhere in address spaceZejun Wu2019-01-301-22/+39
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: This re-applies {D5195} with fixes for i386: * Fix unused label warnings, see {D5230} or {D5273} * Fix a silly bug introduced by moving `#if` {P190} Add a RTS option -xp to load PIC object anywhere in address space. We do this by relaxing the requirement of <0x80000000 result of `mmapForLinker` and implying USE_CONTIGUOUS_MMAP. We also need to change calls to `ocInit` and `ocGetNames` to avoid dangling pointers when the address of `oc->image` is changed by `ocAllocateSymbolExtra`. Test Plan: See {D5195}, also test under i386: ``` $ uname -a Linux watashi-arch32 4.18.5-arch1-1.0-ARCH #1 SMP PREEMPT Tue Aug 28 20:45:30 CEST 2018 i686 GNU/Linux $ cd testsuite/tests/th/ && make test ... ``` will run `./validate` on stacked diff. Reviewers: simonmar, bgamari, alpmestan, trommler, hvr, erikd Reviewed By: simonmar Subscribers: rwbarton, carter Differential Revision: https://phabricator.haskell.org/D5289
* Revert "Batch merge"Ben Gamari2019-01-301-49/+35
| | | | This reverts commit 76c8fd674435a652c75a96c85abbf26f1f221876.
* Batch mergeBen Gamari2019-01-301-35/+49
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* Revert "Add a RTS option -xp to load PIC object anywhere in address space"Ben Gamari2018-10-301-39/+22
| | | | This reverts commit 5403a8636fe82f971234873564f3a05393b89b7a.
* Revert "Allocate bss section within proper range of other sections"Ben Gamari2018-10-301-14/+17
| | | | | | | | This reverts commit e019ec94f12268dd92ea5d5204e9e57e7ebf10ca. This sadly breaks the external interpreter on i386. For instance, see https://circleci.com/gh/ghc/ghc/10925.
* Allocate bss section within proper range of other sectionsZejun Wu2018-10-151-17/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allocate bss section within proper range of other sections: * when `+RTS -xp` is passed, allocate it contiguously as we did for jump islands * when we mmap the code to lower 2Gb, we should allocate bss section there too This depends on {D5195} Test Plan: 1. `./validate` 2. with ``` DYNAMIC_GHC_PROGRAMS = NO DYNAMIC_BY_DEFAULT = NO ``` `TEST="T15729" make test` passed in both linux and macos. 3. Also test in a use case where we used to encouter error like: ``` ghc-iserv-prof: R_X86_64_PC32 relocation out of range: (noname) = b90282ba ``` and now, everything works fine. Reviewers: simonmar, bgamari, angerman, erikd Reviewed By: simonmar Subscribers: rwbarton, carter GHC Trac Issues: #15729 Differential Revision: https://phabricator.haskell.org/D5219
* Add a RTS option -xp to load PIC object anywhere in address spaceZejun Wu2018-10-151-22/+39
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a RTS option -xp to load PIC object anywhere in address space. We do this by relaxing the requirement of <0x80000000 result of `mmapForLinker` and implying USE_CONTIGUOUS_MMAP. We also need to change calls to `ocInit` and `ocGetNames` to avoid dangling pointers when the address of `oc->image` is changed by `ocAllocateSymbolExtra`. Test Plan: ``` $ uname -a Linux localhost 4.18.8-arch1-1-ARCH #1 SMP PREEMPT Sat Sep 15 20:34:48 UTC 2018 x86_64 GNU/Linux $ cat mk/build.mk DYNAMIC_GHC_PROGRAMS = NO DYNAMIC_BY_DEFAULT = NO GhcRTSWays += thr_debug EXTRA_HC_OPTS += -debug WAY_p_HC_OPTS += -fPIC -fexternal-dynamic-refs $ inplace/bin/ghc-stage2 --interactive -prof +RTS -xp GHCi, version 8.7.20180928: http://www.haskell.org/ghc/ :? for help ghc-stage2: R_X86_64_32 relocation out of range: ghczmprim_GHCziTypes_ZMZN_closure = 7f690bffab59 Recompile /data/users/watashi/ghc/libraries/ghc-prim/dist-install/build/HSghc-prim -0.5.3.o with -fPIC -fexternal-dynamic-refs. ghc-stage2: unable to load package `ghc-prim-0.5.3' $ strace -f -e open,mmap inplace/bin/ghc-stage2 --interactive -prof -fexternal-interpreter -opti+RTS -opti-xp ... [pid 1355283] open("/data/users/watashi/ghc/libraries/base/dist-install/build/libHSbas e-4.12.0.0_p.a", O_RDONLY) = 14 [pid 1355283] mmap(NULL, 8192, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f6a84842000 [pid 1355283] open("/data/users/watashi/ghc/libraries/base/dist-install/build/libHSbas e-4.12.0.0_p.a", O_RDONLY) = 14 [pid 1355283] mmap(NULL, 8192, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f6a84676000 ... Prelude> System.Posix.Process.getProcessID ... [pid 1355283] open("/data/users/watashi/ghc/libraries/unix/dist-install/build/libHSuni x-2.7.2.2_p.a", O_RDONLY) = 14 [pid 1355283] mmap(NULL, 45056, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f6a67d60000 [pid 1355283] open("/data/users/watashi/ghc/libraries/unix/dist-install/build/libHSuni x-2.7.2.2_p.a", O_RDONLY) = 14 [pid 1355283] mmap(NULL, 57344, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f6a67d52000 ... ``` ``` $ uname -a Darwin watashis-iMac.local 18.0.0 Darwin Kernel Version 18.0.0: Wed Aug 22 20:13:40 PDT 2018; root:xnu-4903.201.2~1/RELEASE_X86_64 x86_64 $ mv /Users/watashi/gao/ghc/libraries/integer-gmp/dist-install/build/HSintege r-gmp-1.0.2.0.o{,._DISABLE_GHC_ISSUE_15105} $ inplace/bin/ghc-stage2 --interactive +RTS -xp GHCi, version 8.7.20181003: http://www.haskell.org/ghc/ :? for help Prelude> System.Posix.Process.getProcessID 42791 Prelude> Data.Set.fromList [1 .. 10] fromList [1,2,3,4,5,6,7,8,9,10] Prelude> Leaving GHCi. $ inplace/bin/ghc-stage2 --interactive -prof -fexternal-interpreter GHCi, version 8.7.20181003: http://www.haskell.org/ghc/ :? for help Prelude> System.Posix.Process.getProcessID 42806 Prelude> Data.Set.fromList [1 .. 10] fromList [1,2,3,4,5,6,7,8,9,10] Prelude> Leaving GHCi. ``` Also test with something that used to hit the 2Gb limit and it loads and runs without problem. Reviewers: simonmar, bgamari, angerman, Phyx, hvr, erikd Reviewed By: simonmar Subscribers: rwbarton, carter Differential Revision: https://phabricator.haskell.org/D5195
* rts/linker/{SymbolExtras,elf_got}.c: map code as read-onlySantiago MunĂ­n2018-06-221-2/+6
| | | | | | | | | | | | | | | | protect mmaped addresses from writes after being initially manipulated Test Plan: ./validate Reviewers: bgamari, erikd, simonmar Reviewed By: bgamari Subscribers: angerman, carlostome, rwbarton, thomie, carter GHC Trac Issues: #14069 Differential Revision: https://phabricator.haskell.org/D4817
* [linker] fix armv7 & add aarch64Moritz Angermann2017-06-081-94/+2
| | | | | | | | | | | | | | | This adds Global Offset Table logic, as well as PLT like logic for armv7 and aarch64; which replaces the preexisting symbolExtras logic, by placing the PLT tables next to the separtely loaded sections. This is needed to ensure that the symbol stubs are in range. Reviewers: bgamari, austin, erikd, simonmar Reviewed By: bgamari Subscribers: Ericson2314, ryantrinkle, rwbarton, thomie Differential Revision: https://phabricator.haskell.org/D3448
* Prefer #if defined to #ifdefBen Gamari2017-04-281-4/+4
| | | | Our new CPP linter enforces this.
* rts: Fix lingering #ifsBen Gamari2017-04-041-1/+1
| | | | These were missed in D3278.
* SymbolExtras: A bit of spring cleaningBen Gamari2017-03-021-7/+5
| | | | Const-hygiene and use bool when possible.
* Use C99's boolBen Gamari2016-11-291-1/+1
| | | | | | | | | | | | Test Plan: Validate on lots of platforms Reviewers: erikd, simonmar, austin Reviewed By: erikd, simonmar Subscribers: michalt, thomie Differential Revision: https://phabricator.haskell.org/D2699
* linker: Move ARM interworking note to SymbolExtras.cBen Gamari2016-11-021-0/+28
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* linker: Split symbol extras logic into new source fileBen Gamari2016-11-021-0/+209
Test Plan: Validate Reviewers: erikd, austin, simonmar Reviewed By: simonmar Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D2646