Stream: git-wasmtime

Topic: wasmtime / issue #6778 Cranelift: cranelift-object produc...

Wasmtime GitHub notifications bot (Jul 26 2023 at 17:02):

bjorn3 opened issue #6778:

Steps to Reproduce

Write an AArch64 object file with a function using a TLS variable and link it using lld.

Expected Results

It links.

Actual Results

  = note: ld.lld: error: /home/gh-bjorn3/rust/build/aarch64-unknown-linux-gnu/stage1-tools/cg_clif/build/example/mini_core.mini_core.427c9c3b2a3159b4-cgu.0.rcgu.o:(function get_tls: .text+0x6d4): unknown relocation (513) against symbol mini_core::get_tls::A
          ld.lld: error: /home/gh-bjorn3/rust/build/aarch64-unknown-linux-gnu/stage1-tools/cg_clif/build/example/mini_core.mini_core.427c9c3b2a3159b4-cgu.0.rcgu.o:(function get_tls: .text+0x6d8): unknown relocation (514) against symbol mini_core::get_tls::A
          collect2: error: ld returned 1 exit status

Versions and Environment

Cranelift version or commit: 92ccdcb8d68b586715957c2335031bc057e4876d

Operating system: Linux

Architecture: AArch64

Extra Info

Cranelift uses R_AARCH64_TLSGD_ADR_PAGE21 and R_AARCH64_TLSGD_ADD_LO12_NC relocations for TLS, which seems to be unsupported by lld. Instead I think TLSDESC has to be used. This is an improvement on the traditional __tls_get_addr based TLS lookup: https://www.fsfla.org/~lxoliva/writeups/TLS/paper-lk2006.pdf

Wasmtime GitHub notifications bot (Jul 26 2023 at 17:02):

bjorn3 added the bug label to Issue #6778.

Wasmtime GitHub notifications bot (Jul 26 2023 at 17:02):

bjorn3 added the cranelift label to Issue #6778.

Wasmtime GitHub notifications bot (Oct 10 2023 at 11:14):

alexcrichton closed issue #6778:

Steps to Reproduce

Write an AArch64 object file with a function using a TLS variable and link it using lld.

Expected Results

It links.

Actual Results

  = note: ld.lld: error: /home/gh-bjorn3/rust/build/aarch64-unknown-linux-gnu/stage1-tools/cg_clif/build/example/mini_core.mini_core.427c9c3b2a3159b4-cgu.0.rcgu.o:(function get_tls: .text+0x6d4): unknown relocation (513) against symbol mini_core::get_tls::A
          ld.lld: error: /home/gh-bjorn3/rust/build/aarch64-unknown-linux-gnu/stage1-tools/cg_clif/build/example/mini_core.mini_core.427c9c3b2a3159b4-cgu.0.rcgu.o:(function get_tls: .text+0x6d8): unknown relocation (514) against symbol mini_core::get_tls::A
          collect2: error: ld returned 1 exit status

Versions and Environment

Cranelift version or commit: 92ccdcb8d68b586715957c2335031bc057e4876d

Operating system: Linux

Architecture: AArch64

Extra Info

Cranelift uses R_AARCH64_TLSGD_ADR_PAGE21 and R_AARCH64_TLSGD_ADD_LO12_NC relocations for TLS, which seems to be unsupported by lld. Instead I think TLSDESC has to be used. This is an improvement on the traditional __tls_get_addr based TLS lookup: https://www.fsfla.org/~lxoliva/writeups/TLS/paper-lk2006.pdf

Last updated: Oct 23 2024 at 20:03 UTC