diff options
| -rw-r--r-- | arch/x86/events/intel/pt.c | 63 |
1 files changed, 50 insertions, 13 deletions
diff --git a/arch/x86/events/intel/pt.c b/arch/x86/events/intel/pt.c index 7f406c14715f..0ebcf9a56f97 100644 --- a/arch/x86/events/intel/pt.c +++ b/arch/x86/events/intel/pt.c @@ -13,6 +13,8 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/types.h> +#include <linux/bits.h> +#include <linux/limits.h> #include <linux/slab.h> #include <linux/device.h> @@ -1347,11 +1349,37 @@ static void pt_addr_filters_fini(struct perf_event *event) event->hw.addr_filters = NULL; } -static inline bool valid_kernel_ip(unsigned long ip) +#ifdef CONFIG_X86_64 +static u64 canonical_address(u64 vaddr, u8 vaddr_bits) { - return virt_addr_valid(ip) && kernel_ip(ip); + return ((s64)vaddr << (64 - vaddr_bits)) >> (64 - vaddr_bits); } +static u64 is_canonical_address(u64 vaddr, u8 vaddr_bits) +{ + return canonical_address(vaddr, vaddr_bits) == vaddr; +} + +/* Clamp to a canonical address greater-than-or-equal-to the address given */ +static u64 clamp_to_ge_canonical_addr(u64 vaddr, u8 vaddr_bits) +{ + return is_canonical_address(vaddr, vaddr_bits) ? + vaddr : + -BIT_ULL(vaddr_bits - 1); +} + +/* Clamp to a canonical address less-than-or-equal-to the address given */ +static u64 clamp_to_le_canonical_addr(u64 vaddr, u8 vaddr_bits) +{ + return is_canonical_address(vaddr, vaddr_bits) ? + vaddr : + BIT_ULL(vaddr_bits - 1) - 1; +} +#else +#define clamp_to_ge_canonical_addr(x, y) (x) +#define clamp_to_le_canonical_addr(x, y) (x) +#endif + static int pt_event_addr_filters_validate(struct list_head *filters) { struct perf_addr_filter *filter; @@ -1366,14 +1394,6 @@ static int pt_event_addr_filters_validate(struct list_head *filters) filter->action == PERF_ADDR_FILTER_ACTION_START) return -EOPNOTSUPP; - if (!filter->path.dentry) { - if (!valid_kernel_ip(filter->offset)) - return -EINVAL; - - if (!valid_kernel_ip(filter->offset + filter->size)) - return -EINVAL; - } - if (++range > intel_pt_validate_hw_cap(PT_CAP_num_address_ranges)) return -EOPNOTSUPP; } @@ -1397,9 +1417,26 @@ static void pt_event_addr_filters_sync(struct perf_event *event) if (filter->path.dentry && !fr[range].start) { msr_a = msr_b = 0; } else { - /* apply the offset */ - msr_a = fr[range].start; - msr_b = msr_a + fr[range].size - 1; + unsigned long n = fr[range].size - 1; + unsigned long a = fr[range].start; + unsigned long b; + + if (a > ULONG_MAX - n) + b = ULONG_MAX; + else + b = a + n; + /* + * Apply the offset. 64-bit addresses written to the + * MSRs must be canonical, but the range can encompass + * non-canonical addresses. Since software cannot + * execute at non-canonical addresses, adjusting to + * canonical addresses does not affect the result of the + * address filter. + */ + msr_a = clamp_to_ge_canonical_addr(a, boot_cpu_data.x86_virt_bits); + msr_b = clamp_to_le_canonical_addr(b, boot_cpu_data.x86_virt_bits); + if (msr_b < msr_a) + msr_a = msr_b = 0; } filters->filter[range].msr_a = msr_a; |