Merge even more updates from Andrew Morton:
- a kernel-wide sweep of show_stack()
- pagetable cleanups
- abstract out accesses to mmap_sem - prep for mmap_sem scalability work
- hch's user acess work
Subsystems affected by this patch series: debug, mm/pagemap, mm/maccess,
mm/documentation.
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (93 commits)
include/linux/cache.h: expand documentation over __read_mostly
maccess: return -ERANGE when probe_kernel_read() fails
x86: use non-set_fs based maccess routines
maccess: allow architectures to provide kernel probing directly
maccess: move user access routines together
maccess: always use strict semantics for probe_kernel_read
maccess: remove strncpy_from_unsafe
tracing/kprobes: handle mixed kernel/userspace probes better
bpf: rework the compat kernel probe handling
bpf:bpf_seq_printf(): handle potentially unsafe format string better
bpf: handle the compat string in bpf_trace_copy_string better
bpf: factor out a bpf_trace_copy_string helper
maccess: unify the probe kernel arch hooks
maccess: remove probe_read_common and probe_write_common
maccess: rename strnlen_unsafe_user to strnlen_user_nofault
maccess: rename strncpy_from_unsafe_strict to strncpy_from_kernel_nofault
maccess: rename strncpy_from_unsafe_user to strncpy_from_user_nofault
maccess: update the top of file comment
maccess: clarify kerneldoc comments
maccess: remove duplicate kerneldoc comments
...
#include <linux/nospec.h>
#include <linux/prctl.h>
#include <linux/sched/smt.h>
+ #include <linux/pgtable.h>
#include <asm/spec-ctrl.h>
#include <asm/cmdline.h>
#include <asm/vmx.h>
#include <asm/paravirt.h>
#include <asm/alternative.h>
- #include <asm/pgtable.h>
#include <asm/set_memory.h>
#include <asm/intel-family.h>
#include <asm/e820/api.h>
static void __init mds_select_mitigation(void);
static void __init mds_print_mitigation(void);
static void __init taa_select_mitigation(void);
+static void __init srbds_select_mitigation(void);
/* The base value of the SPEC_CTRL MSR that always has to be preserved. */
u64 x86_spec_ctrl_base;
l1tf_select_mitigation();
mds_select_mitigation();
taa_select_mitigation();
+ srbds_select_mitigation();
/*
* As MDS and TAA mitigations are inter-related, print MDS
}
early_param("tsx_async_abort", tsx_async_abort_parse_cmdline);
+#undef pr_fmt
+#define pr_fmt(fmt) "SRBDS: " fmt
+
+enum srbds_mitigations {
+ SRBDS_MITIGATION_OFF,
+ SRBDS_MITIGATION_UCODE_NEEDED,
+ SRBDS_MITIGATION_FULL,
+ SRBDS_MITIGATION_TSX_OFF,
+ SRBDS_MITIGATION_HYPERVISOR,
+};
+
+static enum srbds_mitigations srbds_mitigation __ro_after_init = SRBDS_MITIGATION_FULL;
+
+static const char * const srbds_strings[] = {
+ [SRBDS_MITIGATION_OFF] = "Vulnerable",
+ [SRBDS_MITIGATION_UCODE_NEEDED] = "Vulnerable: No microcode",
+ [SRBDS_MITIGATION_FULL] = "Mitigation: Microcode",
+ [SRBDS_MITIGATION_TSX_OFF] = "Mitigation: TSX disabled",
+ [SRBDS_MITIGATION_HYPERVISOR] = "Unknown: Dependent on hypervisor status",
+};
+
+static bool srbds_off;
+
+void update_srbds_msr(void)
+{
+ u64 mcu_ctrl;
+
+ if (!boot_cpu_has_bug(X86_BUG_SRBDS))
+ return;
+
+ if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
+ return;
+
+ if (srbds_mitigation == SRBDS_MITIGATION_UCODE_NEEDED)
+ return;
+
+ rdmsrl(MSR_IA32_MCU_OPT_CTRL, mcu_ctrl);
+
+ switch (srbds_mitigation) {
+ case SRBDS_MITIGATION_OFF:
+ case SRBDS_MITIGATION_TSX_OFF:
+ mcu_ctrl |= RNGDS_MITG_DIS;
+ break;
+ case SRBDS_MITIGATION_FULL:
+ mcu_ctrl &= ~RNGDS_MITG_DIS;
+ break;
+ default:
+ break;
+ }
+
+ wrmsrl(MSR_IA32_MCU_OPT_CTRL, mcu_ctrl);
+}
+
+static void __init srbds_select_mitigation(void)
+{
+ u64 ia32_cap;
+
+ if (!boot_cpu_has_bug(X86_BUG_SRBDS))
+ return;
+
+ /*
+ * Check to see if this is one of the MDS_NO systems supporting
+ * TSX that are only exposed to SRBDS when TSX is enabled.
+ */
+ ia32_cap = x86_read_arch_cap_msr();
+ if ((ia32_cap & ARCH_CAP_MDS_NO) && !boot_cpu_has(X86_FEATURE_RTM))
+ srbds_mitigation = SRBDS_MITIGATION_TSX_OFF;
+ else if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
+ srbds_mitigation = SRBDS_MITIGATION_HYPERVISOR;
+ else if (!boot_cpu_has(X86_FEATURE_SRBDS_CTRL))
+ srbds_mitigation = SRBDS_MITIGATION_UCODE_NEEDED;
+ else if (cpu_mitigations_off() || srbds_off)
+ srbds_mitigation = SRBDS_MITIGATION_OFF;
+
+ update_srbds_msr();
+ pr_info("%s\n", srbds_strings[srbds_mitigation]);
+}
+
+static int __init srbds_parse_cmdline(char *str)
+{
+ if (!str)
+ return -EINVAL;
+
+ if (!boot_cpu_has_bug(X86_BUG_SRBDS))
+ return 0;
+
+ srbds_off = !strcmp(str, "off");
+ return 0;
+}
+early_param("srbds", srbds_parse_cmdline);
+
#undef pr_fmt
#define pr_fmt(fmt) "Spectre V1 : " fmt
return "";
}
+static ssize_t srbds_show_state(char *buf)
+{
+ return sprintf(buf, "%s\n", srbds_strings[srbds_mitigation]);
+}
+
static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr,
char *buf, unsigned int bug)
{
case X86_BUG_ITLB_MULTIHIT:
return itlb_multihit_show_state(buf);
+ case X86_BUG_SRBDS:
+ return srbds_show_state(buf);
+
default:
break;
}
{
return cpu_show_common(dev, attr, buf, X86_BUG_ITLB_MULTIHIT);
}
+
+ssize_t cpu_show_srbds(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ return cpu_show_common(dev, attr, buf, X86_BUG_SRBDS);
+}
#endif
#include <linux/smp.h>
#include <linux/io.h>
#include <linux/syscore_ops.h>
+ #include <linux/pgtable.h>
#include <asm/stackprotector.h>
#include <asm/perf_event.h>
#include <asm/vsyscall.h>
#include <linux/topology.h>
#include <linux/cpumask.h>
- #include <asm/pgtable.h>
#include <linux/atomic.h>
#include <asm/proto.h>
#include <asm/setup.h>
{}
};
-static bool __init cpu_matches(unsigned long which)
+#define VULNBL_INTEL_STEPPINGS(model, steppings, issues) \
+ X86_MATCH_VENDOR_FAM_MODEL_STEPPINGS_FEATURE(INTEL, 6, \
+ INTEL_FAM6_##model, steppings, \
+ X86_FEATURE_ANY, issues)
+
+#define SRBDS BIT(0)
+
+static const struct x86_cpu_id cpu_vuln_blacklist[] __initconst = {
+ VULNBL_INTEL_STEPPINGS(IVYBRIDGE, X86_STEPPING_ANY, SRBDS),
+ VULNBL_INTEL_STEPPINGS(HASWELL, X86_STEPPING_ANY, SRBDS),
+ VULNBL_INTEL_STEPPINGS(HASWELL_L, X86_STEPPING_ANY, SRBDS),
+ VULNBL_INTEL_STEPPINGS(HASWELL_G, X86_STEPPING_ANY, SRBDS),
+ VULNBL_INTEL_STEPPINGS(BROADWELL_G, X86_STEPPING_ANY, SRBDS),
+ VULNBL_INTEL_STEPPINGS(BROADWELL, X86_STEPPING_ANY, SRBDS),
+ VULNBL_INTEL_STEPPINGS(SKYLAKE_L, X86_STEPPING_ANY, SRBDS),
+ VULNBL_INTEL_STEPPINGS(SKYLAKE, X86_STEPPING_ANY, SRBDS),
+ VULNBL_INTEL_STEPPINGS(KABYLAKE_L, X86_STEPPINGS(0x0, 0xC), SRBDS),
+ VULNBL_INTEL_STEPPINGS(KABYLAKE, X86_STEPPINGS(0x0, 0xD), SRBDS),
+ {}
+};
+
+static bool __init cpu_matches(const struct x86_cpu_id *table, unsigned long which)
{
- const struct x86_cpu_id *m = x86_match_cpu(cpu_vuln_whitelist);
+ const struct x86_cpu_id *m = x86_match_cpu(table);
return m && !!(m->driver_data & which);
}
u64 ia32_cap = x86_read_arch_cap_msr();
/* Set ITLB_MULTIHIT bug if cpu is not in the whitelist and not mitigated */
- if (!cpu_matches(NO_ITLB_MULTIHIT) && !(ia32_cap & ARCH_CAP_PSCHANGE_MC_NO))
+ if (!cpu_matches(cpu_vuln_whitelist, NO_ITLB_MULTIHIT) &&
+ !(ia32_cap & ARCH_CAP_PSCHANGE_MC_NO))
setup_force_cpu_bug(X86_BUG_ITLB_MULTIHIT);
- if (cpu_matches(NO_SPECULATION))
+ if (cpu_matches(cpu_vuln_whitelist, NO_SPECULATION))
return;
setup_force_cpu_bug(X86_BUG_SPECTRE_V1);
- if (!cpu_matches(NO_SPECTRE_V2))
+ if (!cpu_matches(cpu_vuln_whitelist, NO_SPECTRE_V2))
setup_force_cpu_bug(X86_BUG_SPECTRE_V2);
- if (!cpu_matches(NO_SSB) && !(ia32_cap & ARCH_CAP_SSB_NO) &&
+ if (!cpu_matches(cpu_vuln_whitelist, NO_SSB) &&
+ !(ia32_cap & ARCH_CAP_SSB_NO) &&
!cpu_has(c, X86_FEATURE_AMD_SSB_NO))
setup_force_cpu_bug(X86_BUG_SPEC_STORE_BYPASS);
if (ia32_cap & ARCH_CAP_IBRS_ALL)
setup_force_cpu_cap(X86_FEATURE_IBRS_ENHANCED);
- if (!cpu_matches(NO_MDS) && !(ia32_cap & ARCH_CAP_MDS_NO)) {
+ if (!cpu_matches(cpu_vuln_whitelist, NO_MDS) &&
+ !(ia32_cap & ARCH_CAP_MDS_NO)) {
setup_force_cpu_bug(X86_BUG_MDS);
- if (cpu_matches(MSBDS_ONLY))
+ if (cpu_matches(cpu_vuln_whitelist, MSBDS_ONLY))
setup_force_cpu_bug(X86_BUG_MSBDS_ONLY);
}
- if (!cpu_matches(NO_SWAPGS))
+ if (!cpu_matches(cpu_vuln_whitelist, NO_SWAPGS))
setup_force_cpu_bug(X86_BUG_SWAPGS);
/*
(ia32_cap & ARCH_CAP_TSX_CTRL_MSR)))
setup_force_cpu_bug(X86_BUG_TAA);
- if (cpu_matches(NO_MELTDOWN))
+ /*
+ * SRBDS affects CPUs which support RDRAND or RDSEED and are listed
+ * in the vulnerability blacklist.
+ */
+ if ((cpu_has(c, X86_FEATURE_RDRAND) ||
+ cpu_has(c, X86_FEATURE_RDSEED)) &&
+ cpu_matches(cpu_vuln_blacklist, SRBDS))
+ setup_force_cpu_bug(X86_BUG_SRBDS);
+
+ if (cpu_matches(cpu_vuln_whitelist, NO_MELTDOWN))
return;
/* Rogue Data Cache Load? No! */
setup_force_cpu_bug(X86_BUG_CPU_MELTDOWN);
- if (cpu_matches(NO_L1TF))
+ if (cpu_matches(cpu_vuln_whitelist, NO_L1TF))
return;
setup_force_cpu_bug(X86_BUG_L1TF);
mtrr_ap_init();
validate_apic_and_package_id(c);
x86_spec_ctrl_setup_ap();
+ update_srbds_msr();
}
static __init int setup_noclflush(char *arg)
* @vaddr: the virtual address to store the opcode.
* @opcode: opcode to be written at @vaddr.
*
- * Called with mm->mmap_sem held for write.
+ * Called with mm->mmap_lock held for write.
* Return 0 (success) or a negative errno.
*/
int uprobe_write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm,
if (ret)
goto out;
- /* uprobe_write_opcode() assumes we don't cross page boundary */
- BUG_ON((uprobe->offset & ~PAGE_MASK) +
- UPROBE_SWBP_INSN_SIZE > PAGE_SIZE);
-
smp_wmb(); /* pairs with the smp_rmb() in handle_swbp() */
set_bit(UPROBE_COPY_INSN, &uprobe->flags);
if (err && is_register)
goto free;
- down_write(&mm->mmap_sem);
+ mmap_write_lock(mm);
vma = find_vma(mm, info->vaddr);
if (!vma || !valid_vma(vma, is_register) ||
file_inode(vma->vm_file) != uprobe->inode)
}
unlock:
- up_write(&mm->mmap_sem);
+ mmap_write_unlock(mm);
free:
mmput(mm);
info = free_map_info(info);
if (offset > i_size_read(inode))
return -EINVAL;
+ /*
+ * This ensures that copy_from_page(), copy_to_page() and
+ * __update_ref_ctr() can't cross page boundary.
+ */
+ if (!IS_ALIGNED(offset, UPROBE_SWBP_INSN_SIZE))
+ return -EINVAL;
+ if (!IS_ALIGNED(ref_ctr_offset, sizeof(short)))
+ return -EINVAL;
+
retry:
uprobe = alloc_uprobe(inode, offset, ref_ctr_offset);
if (!uprobe)
struct vm_area_struct *vma;
int err = 0;
- down_read(&mm->mmap_sem);
+ mmap_read_lock(mm);
for (vma = mm->mmap; vma; vma = vma->vm_next) {
unsigned long vaddr;
loff_t offset;
vaddr = offset_to_vaddr(vma, uprobe->offset);
err |= remove_breakpoint(uprobe, mm, vaddr);
}
- up_read(&mm->mmap_sem);
+ mmap_read_unlock(mm);
return err;
}
}
/*
- * Called from mmap_region/vma_adjust with mm->mmap_sem acquired.
+ * Called from mmap_region/vma_adjust with mm->mmap_lock acquired.
*
* Currently we ignore all errors and always return 0, the callers
* can't handle the failure anyway.
struct vm_area_struct *vma;
int ret;
- if (down_write_killable(&mm->mmap_sem))
+ if (mmap_write_lock_killable(mm))
return -EINTR;
if (mm->uprobes_state.xol_area) {
/* pairs with get_xol_area() */
smp_store_release(&mm->uprobes_state.xol_area, area); /* ^^^ */
fail:
- up_write(&mm->mmap_sem);
+ mmap_write_unlock(mm);
return ret;
}
uprobe_opcode_t opcode;
int result;
+ if (WARN_ON_ONCE(!IS_ALIGNED(vaddr, UPROBE_SWBP_INSN_SIZE)))
+ return -EINVAL;
+
pagefault_disable();
result = __get_user(opcode, (uprobe_opcode_t __user *)vaddr);
pagefault_enable();
struct uprobe *uprobe = NULL;
struct vm_area_struct *vma;
- down_read(&mm->mmap_sem);
+ mmap_read_lock(mm);
vma = find_vma(mm, bp_vaddr);
if (vma && vma->vm_start <= bp_vaddr) {
if (valid_vma(vma, false)) {
if (!uprobe && test_and_clear_bit(MMF_RECALC_UPROBES, &mm->flags))
mmf_recalc_uprobes(mm);
- up_read(&mm->mmap_sem);
+ mmap_read_unlock(mm);
return uprobe;
}
projects / linux-2.6-microblaze.git / commitdiff