| Message ID | 20240510112645.3625702-7-ptosi@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: arm64: Add support for hypervisor kCFI | expand |
On Fri, May 10, 2024 at 12:26:35PM +0100, Pierre-Clément Tosi wrote: > Ignore R_AARCH64_ABS32 relocations, instead of panicking, when emitting > the relocation table of the hypervisor. The toolchain might produce them > when generating function calls with kCFI, to allow type ID resolution > across compilation units (between the call-site check and the callee's > prefixed u32) at link time. They are therefore not needed in the final > (runtime) relocation table. Hmm. Please can you elaborate a bit more on this? Are these absolute addresses in the kernel VA space or the hypervisor VA space? Generally, absolute addressing at EL2 is going to cause problems, so I'm not keen on waving all R_AARCH64_ABS32 relocs through. Will
diff --git a/arch/arm64/kvm/hyp/nvhe/gen-hyprel.c b/arch/arm64/kvm/hyp/nvhe/gen-hyprel.c index 6bc88a756cb7..b63f4e1c1033 100644 --- a/arch/arm64/kvm/hyp/nvhe/gen-hyprel.c +++ b/arch/arm64/kvm/hyp/nvhe/gen-hyprel.c @@ -50,6 +50,9 @@ #ifndef R_AARCH64_ABS64 #define R_AARCH64_ABS64 257 #endif +#ifndef R_AARCH64_ABS32 +#define R_AARCH64_ABS32 258 +#endif #ifndef R_AARCH64_PREL64 #define R_AARCH64_PREL64 260 #endif @@ -383,6 +386,9 @@ static void emit_rela_section(Elf64_Shdr *sh_rela) case R_AARCH64_ABS64: emit_rela_abs64(rela, sh_orig_name); break; + /* Allow 32-bit absolute relocation, for kCFI type hashes. */ + case R_AARCH64_ABS32: + break; /* Allow position-relative data relocations. */ case R_AARCH64_PREL64: case R_AARCH64_PREL32:
Ignore R_AARCH64_ABS32 relocations, instead of panicking, when emitting the relocation table of the hypervisor. The toolchain might produce them when generating function calls with kCFI, to allow type ID resolution across compilation units (between the call-site check and the callee's prefixed u32) at link time. They are therefore not needed in the final (runtime) relocation table. Signed-off-by: Pierre-Clément Tosi <ptosi@google.com> --- arch/arm64/kvm/hyp/nvhe/gen-hyprel.c | 6 ++++++ 1 file changed, 6 insertions(+)