diff options
Diffstat (limited to 'arch/powerpc/perf/core-book3s.c')
| -rw-r--r-- | arch/powerpc/perf/core-book3s.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c index bf949623de90..771edffa2d40 100644 --- a/arch/powerpc/perf/core-book3s.c +++ b/arch/powerpc/perf/core-book3s.c @@ -448,6 +448,16 @@ static void power_pmu_bhrb_read(struct cpu_hw_events *cpuhw) /* invalid entry */ continue; + /* + * BHRB rolling buffer could very much contain the kernel + * addresses at this point. Check the privileges before + * exporting it to userspace (avoid exposure of regions + * where we could have speculative execution) + */ + if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN) && + is_kernel_addr(addr)) + continue; + /* Branches are read most recent first (ie. mfbhrb 0 is * the most recent branch). * There are two types of valid entries: @@ -1188,6 +1198,7 @@ static void power_pmu_disable(struct pmu *pmu) */ write_mmcr0(cpuhw, val); mb(); + isync(); /* * Disable instruction sampling if it was enabled @@ -1196,12 +1207,26 @@ static void power_pmu_disable(struct pmu *pmu) mtspr(SPRN_MMCRA, cpuhw->mmcr[2] & ~MMCRA_SAMPLE_ENABLE); mb(); + isync(); } cpuhw->disabled = 1; cpuhw->n_added = 0; ebb_switch_out(mmcr0); + +#ifdef CONFIG_PPC64 + /* + * These are readable by userspace, may contain kernel + * addresses and are not switched by context switch, so clear + * them now to avoid leaking anything to userspace in general + * including to another process. + */ + if (ppmu->flags & PPMU_ARCH_207S) { + mtspr(SPRN_SDAR, 0); + mtspr(SPRN_SIAR, 0); + } +#endif } local_irq_restore(flags); |