diff options
| -rw-r--r-- | manual/tunables.texi | 3 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/aarch64/cpu-features.c | 8 |
2 files changed, 10 insertions, 1 deletions
diff --git a/manual/tunables.texi b/manual/tunables.texi index 2c076019ae..83cdcdac6d 100644 --- a/manual/tunables.texi +++ b/manual/tunables.texi @@ -602,6 +602,9 @@ Bit 1 enables precise faulting mode for tag violations on systems that support deferred tag violation reporting. This may cause programs to run more slowly. +Bit 2 enables either precise or deferred faulting mode for tag violations +whichever is preferred by the system. + Other bits are currently reserved. @Theglibc{} startup code will automatically enable memory tagging diff --git a/sysdeps/unix/sysv/linux/aarch64/cpu-features.c b/sysdeps/unix/sysv/linux/aarch64/cpu-features.c index 41dda8d003..d14c0f4e1f 100644 --- a/sysdeps/unix/sysv/linux/aarch64/cpu-features.c +++ b/sysdeps/unix/sysv/linux/aarch64/cpu-features.c @@ -108,7 +108,13 @@ init_cpu_features (struct cpu_features *cpu_features) TUNABLE_SET (glibc, mem, tagging, cpu_features->mte_state); # endif - if (cpu_features->mte_state & 2) + if (cpu_features->mte_state & 4) + /* Enable choosing system-preferred faulting mode. */ + __prctl (PR_SET_TAGGED_ADDR_CTRL, + (PR_TAGGED_ADDR_ENABLE | PR_MTE_TCF_SYNC | PR_MTE_TCF_ASYNC + | MTE_ALLOWED_TAGS), + 0, 0, 0); + else if (cpu_features->mte_state & 2) __prctl (PR_SET_TAGGED_ADDR_CTRL, (PR_TAGGED_ADDR_ENABLE | PR_MTE_TCF_SYNC | MTE_ALLOWED_TAGS), 0, 0, 0); |