On Wed, Oct 23, 2024 at 02:31:30AM +0000, Matthew Maurer wrote:
quoted hunk ↗ jump to hunk
From: Sami Tolvanen <samitolvanen@google.com>
Previously, two things stopped Rust from using MODVERSIONS:
1. Rust symbols are occasionally too long to be represented in the
original versions table
2. Rust types cannot be properly hashed by the existing genksyms
approach because:
* Looking up type definitions in Rust is more complex than C
* Type layout is potentially dependent on the compiler in Rust,
not just the source type declaration.
CONFIG_EXTENDED_MODVERSIONS addresses the first point, and
CONFIG_GENDWARFKSYMS the second. If Rust wants to use MODVERSIONS, allow
it to do so by selecting both features.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Co-developed-by: Matthew Maurer <redacted>
Signed-off-by: Matthew Maurer <redacted>
---
init/Kconfig | 3 ++-
rust/Makefile | 32 ++++++++++++++++++++++++++++++--
2 files changed, 32 insertions(+), 3 deletions(-)
diff --git a/init/Kconfig b/init/Kconfig
index 530a382ee0feb391b4717abdba3672e584a462d0..f5cce579f29b2ed89e97f8075a3bf70e32e71ad0 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1942,7 +1942,8 @@ config RUST
bool "Rust support"
depends on HAVE_RUST
depends on RUST_IS_AVAILABLE
- depends on !MODVERSIONS
+ select EXTENDED_MODVERSIONS if MODVERSIONS
+ depends on (GENDWARFKSYMS || !MODVERSIONS)
Nit: `depends on !MODVERSIONS || GENDWARFKSYMS` would match the
convention used below.
quoted hunk ↗ jump to hunk
+cmd_gendwarfksyms = $(if $(skip_gendwarfksyms),, \
+ $(call rust_exports,$@,"%s\n",$$3) | \
+ scripts/gendwarfksyms/gendwarfksyms \
+ $(if $(KBUILD_SYMTYPES), --symtypes $(@:.o=.symtypes),) \
+ $@ >> $(dot-target).cmd)
Note that Petr suggested adding a KBUILD_ flag for passing the
--stable parameter to gendwarfksyms, which I think would be useful,
so once I send out v5 of that series, we'll have to update this to
also use the parameter when processing Rust objects:
https://lore.kernel.org/linux-modules/8017c328-f039-46c3-b472-f203cd6e2cfe@suse.com/ (local)
Sami