delta/go-git.git/src/debug/elf, branch dev.cmdgo

debug/elf: don't apply DWARF relocations for ET_EXEC binaries

2021-06-14T22:13:47+00:00

Some ET_EXEC binaries might have relocations for non-loadable sections
like .debug_info. These relocations must not be applied, because:
* They may be incorrect
* The correct relocations were already applied at link time

Binaries in Linux Kernel debug packages like Fedora/Centos kernel-debuginfo
are such examples. Relocations for .debug_* sections are included in the
final binaries because they are compiled with --emit-relocs, but the resulting
relocations are incorrect and shouldn't be used when reading DWARF sections.

Fixes #46673

Change-Id: I2b4214f1584bfc243446d0eaee41512657325b95
GitHub-Last-Rev: 8350fad059e70422d13dfaa5bab7fb8a56c0f76f
GitHub-Pull-Request: golang/go#46698
Reviewed-on: https://go-review.googlesource.com/c/go/+/327009
Run-TryBot: Ian Lance Taylor 
TryBot-Result: Go Bot 
Reviewed-by: Ian Lance Taylor 
Reviewed-by: Cherry Mui

all: simplify the spelling of Linux

2021-04-13T13:56:21+00:00

The prefix didn't help clarify anything.

Change-Id: I897fd4022ce9df42a548b15714e4b592618ca547
Reviewed-on: https://go-review.googlesource.com/c/go/+/309573
Run-TryBot: Brad Fitzpatrick 
Reviewed-by: Ian Lance Taylor 
Reviewed-by: Filippo Valsorda

cmd/link,debug/elf: mips32, add .gnu.attributes and .MIPS.abiflags sections

2021-03-02T00:51:00+00:00

MIPS32 uses .gnu.attributes and .MIPS.abiflags sections to mark FP ABI
the object is using, and the kernel will set the correct FP mode for it.

Currrently Go doesn't generate these 2 sections. If we link object
without these 2 sections togather FPXX objects, the result will be FPXX,
which is wrong:
   FP32 + FPXX -> FP32
   FPXX + FP64 -> FP64
   FP32 + FP64 -> reject

These 2 sections is also needed to support FPXX and FP64 in future.

More details about FP32/FPXX/FP64 are explained in:
    https://web.archive.org/web/20180828210612/https://dmz-portal.mips.com/wiki/MIPS_O32_ABI_-_FR0_and_FR1_Interlinking

Fixes #39677

Change-Id: Ia34e7461dee38a4f575dd8ace609988744512ac1
Reviewed-on: https://go-review.googlesource.com/c/go/+/239217
Run-TryBot: Cherry Zhang 
Reviewed-by: Cherry Zhang 
TryBot-Result: Go Bot 
Trust: Meng Zhuo

all: add GOOS=ios

2020-09-23T18:12:59+00:00

Introduce GOOS=ios for iOS systems. GOOS=ios matches "darwin"
build tag, like GOOS=android matches "linux" and GOOS=illumos
matches "solaris". Only ios/arm64 is supported (ios/amd64 is
not).

GOOS=ios and GOOS=darwin remain essentially the same at this
point. They will diverge at later time, to differentiate macOS
and iOS.

Uses of GOOS=="darwin" are changed to (GOOS=="darwin" || GOOS=="ios"),
except if it clearly means macOS (e.g. GOOS=="darwin" && GOARCH=="amd64"),
it remains GOOS=="darwin".

Updates #38485.

Change-Id: I4faacdc1008f42434599efb3c3ad90763a83b67c
Reviewed-on: https://go-review.googlesource.com/c/go/+/254740
Trust: Cherry Zhang 
Run-TryBot: Cherry Zhang 
TryBot-Result: Go Bot 
Reviewed-by: Austin Clements

debug/elf: add many PT_ and DT_ constants

2020-09-18T00:39:35+00:00

Change-Id: Icbb5a0f0ff4aa0a425aa4a15477da7bd0d58339c
Reviewed-on: https://go-review.googlesource.com/c/go/+/255138
Trust: Ian Lance Taylor 
Run-TryBot: Ian Lance Taylor 
TryBot-Result: Go Bot 
Reviewed-by: Tobias Klauser 
Reviewed-by: Cherry Zhang

debug/elf: support relocations relative to sections with non-zero addresses

2020-08-31T18:42:38+00:00

commit 72ec930fa70c20ce69b21bf32a7916c04c2e9c2f added basic support for
relocations, but assumed that the symbol value would be 0, likely because
.debug_info always has address == 0 in the ELF section headers.

CL 195679 added further support for relocations, but explicitly encoded
the original assumption that section addresses would be 0.

This change removes that assumption: all relocations will now be
properly computed based on the target symbol value even when that symbol
is a section with a non-zero address.

Typically, sections that are part of a LOAD program segment have
non-zero addresses. For example, .debug_ranges relocations could be
relative to .text, which usually has an address > 0.

Fixes #40879

Change-Id: Ib0a616bb8b05d6c96d179b03ca33a10946fc5d59
GitHub-Last-Rev: 4200de732641995f3a4958a13a5c78f65b7eae50
GitHub-Pull-Request: golang/go#41038
Reviewed-on: https://go-review.googlesource.com/c/go/+/250559
Run-TryBot: Ian Lance Taylor 
TryBot-Result: Gobot Gobot 
Reviewed-by: Ian Lance Taylor

debug/elf: run relocation tests in parallel

2020-08-30T03:53:59+00:00

Also don't restart DWARF reading from beginning when we are testing
multiple entries.

Also reformat relocationTests slice to use indexed literals.

Change-Id: Ia5f17214483394d0ef033be516df61f0bdc521b6
Reviewed-on: https://go-review.googlesource.com/c/go/+/251637
Run-TryBot: Ian Lance Taylor 
TryBot-Result: Gobot Gobot 
Reviewed-by: Emmanuel Odeke

all: fix a bunch of misspellings

2019-11-15T21:04:43+00:00

Change-Id: I5b909df0fd048cd66c5a27fca1b06466d3bcaac7
GitHub-Last-Rev: 778c5d21311abee09a5fbda2e4005a5fd4cc3f9f
GitHub-Pull-Request: golang/go#35624
Reviewed-on: https://go-review.googlesource.com/c/go/+/207421
Run-TryBot: Ian Lance Taylor 
TryBot-Result: Gobot Gobot 
Reviewed-by: Ian Lance Taylor

all: remove the nacl port (part 1)

2019-10-09T06:14:44+00:00

You were a useful port and you've served your purpose.
Thanks for all the play.

A subsequent CL will remove amd64p32 (including assembly files and
toolchain bits) and remaining bits. The amd64p32 removal will be
separated into its own CL in case we want to support the Linux x32 ABI
in the future and want our old amd64p32 support as a starting point.

Updates #30439

Change-Id: Ia3a0c7d49804adc87bf52a4dea7e3d3007f2b1cd
Reviewed-on: https://go-review.googlesource.com/c/go/+/199499
Run-TryBot: Brad Fitzpatrick 
Reviewed-by: Ian Lance Taylor 
TryBot-Result: Gobot Gobot

debug/elf: apply more relocations when reading DWARF data sections

2019-09-17T18:46:32+00:00

The elf reader's method for reading in DWARF section data has support
for applying selected relocations when the debug/dwarf readers are
being used on relocatable objects. This patch extends the set of
relocations applied slightly. In particlar, prior to this for some
architectures we were only applying relocations whose target symbol
was a section symbol; now we also include some relocations that target
other symbols. This is needed to get meaningful values for compilation
unit DIE low_pc attributes, which typically target a specific function
symbol in text.

Fixes #31363.

Change-Id: I34b02e7904cd7f2dea74197f73fa648141d15212
Reviewed-on: https://go-review.googlesource.com/c/go/+/195679
Reviewed-by: Ian Lance Taylor