| Message ID | 20241106185513.3096442-5-ardb+git@google.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | arm64: Dynamic shadow call stack fixes | expand |
Hi Ard, On Wed, Nov 6, 2024 at 6:55 PM Ard Biesheuvel <ardb+git@google.com> wrote: > > From: Ard Biesheuvel <ardb@kernel.org> > > When building modules using the large code model, the emitted DWARF > metadata uses large fields for the code references too, and this is > currently not being handled. > > The CIE header frame contains metadata that describes the size of these > fields, and so this should be parsed and taken into account when > processing the FDE frames (patch #2) > > But first, the handling of this CIE frame header needs to be fixed, as > it currently [inadvertently] used hardcoded defaults for some values > that happen to always match what Clang emits in practice (patch #1) > > Cc: Sami Tolvanen <samitolvanen@google.com> > Cc: Kees Cook <kees@kernel.org> > Cc: Nathan Chancellor <nathan@kernel.org> > > Ard Biesheuvel (3): > arm64/scs: Fix handling of DWARF augmentation data in CIE/FDE frames > arm64/scs: Deal with 64-bit relative offsets in FDE frames > arm64/scs: Drop unused prototype __pi_scs_patch_vmlinux() > > arch/arm64/include/asm/scs.h | 8 +- > arch/arm64/kernel/module.c | 10 ++- > arch/arm64/kernel/pi/patch-scs.c | 93 ++++++++++++++------ > 3 files changed, 80 insertions(+), 31 deletions(-) I was able to reproduce the issue by building modules with -mcmodel=large, and I confirmed that this series fixes it. For the series: Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Tested-by: Sami Tolvanen <samitolvanen@google.com> Sami
From: Ard Biesheuvel <ardb@kernel.org> When building modules using the large code model, the emitted DWARF metadata uses large fields for the code references too, and this is currently not being handled. The CIE header frame contains metadata that describes the size of these fields, and so this should be parsed and taken into account when processing the FDE frames (patch #2) But first, the handling of this CIE frame header needs to be fixed, as it currently [inadvertently] used hardcoded defaults for some values that happen to always match what Clang emits in practice (patch #1) Cc: Sami Tolvanen <samitolvanen@google.com> Cc: Kees Cook <kees@kernel.org> Cc: Nathan Chancellor <nathan@kernel.org> Ard Biesheuvel (3): arm64/scs: Fix handling of DWARF augmentation data in CIE/FDE frames arm64/scs: Deal with 64-bit relative offsets in FDE frames arm64/scs: Drop unused prototype __pi_scs_patch_vmlinux() arch/arm64/include/asm/scs.h | 8 +- arch/arm64/kernel/module.c | 10 ++- arch/arm64/kernel/pi/patch-scs.c | 93 ++++++++++++++------ 3 files changed, 80 insertions(+), 31 deletions(-)