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authorLinus Torvalds <torvalds@linux-foundation.org>2018-10-23 13:32:18 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2018-10-23 13:32:18 +0100
commitc05f3642f4304dd081876e77a68555b6aba4483f (patch)
tree915baf10c3518d162c00e62b5d855cf92282ed79 /arch/x86/include/asm/ptrace.h
parent0200fbdd431519d730b5d399a12840ec832b27cc (diff)
parentdda93b45389f025fd3422d22cc31cc1ea6040305 (diff)
Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf updates from Ingo Molnar: "The main updates in this cycle were: - Lots of perf tooling changes too voluminous to list (big perf trace and perf stat improvements, lots of libtraceevent reorganization, etc.), so I'll list the authors and refer to the changelog for details: Benjamin Peterson, Jérémie Galarneau, Kim Phillips, Peter Zijlstra, Ravi Bangoria, Sangwon Hong, Sean V Kelley, Steven Rostedt, Thomas Gleixner, Ding Xiang, Eduardo Habkost, Thomas Richter, Andi Kleen, Sanskriti Sharma, Adrian Hunter, Tzvetomir Stoyanov, Arnaldo Carvalho de Melo, Jiri Olsa. ... with the bulk of the changes written by Jiri Olsa, Tzvetomir Stoyanov and Arnaldo Carvalho de Melo. - Continued intel_rdt work with a focus on playing well with perf events. This also imported some non-perf RDT work due to dependencies. (Reinette Chatre) - Implement counter freezing for Arch Perfmon v4 (Skylake and newer). This allows to speed up the PMI handler by avoiding unnecessary MSR writes and make it more accurate. (Andi Kleen) - kprobes cleanups and simplification (Masami Hiramatsu) - Intel Goldmont PMU updates (Kan Liang) - ... plus misc other fixes and updates" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (155 commits) kprobes/x86: Use preempt_enable() in optimized_callback() x86/intel_rdt: Prevent pseudo-locking from using stale pointers kprobes, x86/ptrace.h: Make regs_get_kernel_stack_nth() not fault on bad stack perf/x86/intel: Export mem events only if there's PEBS support x86/cpu: Drop pointless static qualifier in punit_dev_state_show() x86/intel_rdt: Fix initial allocation to consider CDP x86/intel_rdt: CBM overlap should also check for overlap with CDP peer x86/intel_rdt: Introduce utility to obtain CDP peer tools lib traceevent, perf tools: Move struct tep_handler definition in a local header file tools lib traceevent: Separate out tep_strerror() for strerror_r() issues perf python: More portable way to make CFLAGS work with clang perf python: Make clang_has_option() work on Python 3 perf tools: Free temporary 'sys' string in read_event_files() perf tools: Avoid double free in read_event_file() perf tools: Free 'printk' string in parse_ftrace_printk() perf tools: Cleanup trace-event-info 'tdata' leak perf strbuf: Match va_{add,copy} with va_end perf test: S390 does not support watchpoints in test 22 perf auxtrace: Include missing asm/bitsperlong.h to get BITS_PER_LONG tools include: Adopt linux/bits.h ...
Diffstat (limited to 'arch/x86/include/asm/ptrace.h')
-rw-r--r--arch/x86/include/asm/ptrace.h42
1 files changed, 35 insertions, 7 deletions
diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h
index 5e58a74bfd3a..25f49af1b13c 100644
--- a/arch/x86/include/asm/ptrace.h
+++ b/arch/x86/include/asm/ptrace.h
@@ -239,23 +239,51 @@ static inline int regs_within_kernel_stack(struct pt_regs *regs,
}
/**
+ * regs_get_kernel_stack_nth_addr() - get the address of the Nth entry on stack
+ * @regs: pt_regs which contains kernel stack pointer.
+ * @n: stack entry number.
+ *
+ * regs_get_kernel_stack_nth() returns the address of the @n th entry of the
+ * kernel stack which is specified by @regs. If the @n th entry is NOT in
+ * the kernel stack, this returns NULL.
+ */
+static inline unsigned long *regs_get_kernel_stack_nth_addr(struct pt_regs *regs, unsigned int n)
+{
+ unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
+
+ addr += n;
+ if (regs_within_kernel_stack(regs, (unsigned long)addr))
+ return addr;
+ else
+ return NULL;
+}
+
+/* To avoid include hell, we can't include uaccess.h */
+extern long probe_kernel_read(void *dst, const void *src, size_t size);
+
+/**
* regs_get_kernel_stack_nth() - get Nth entry of the stack
* @regs: pt_regs which contains kernel stack pointer.
* @n: stack entry number.
*
* regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
- * is specified by @regs. If the @n th entry is NOT in the kernel stack,
+ * is specified by @regs. If the @n th entry is NOT in the kernel stack
* this returns 0.
*/
static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
unsigned int n)
{
- unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
- addr += n;
- if (regs_within_kernel_stack(regs, (unsigned long)addr))
- return *addr;
- else
- return 0;
+ unsigned long *addr;
+ unsigned long val;
+ long ret;
+
+ addr = regs_get_kernel_stack_nth_addr(regs, n);
+ if (addr) {
+ ret = probe_kernel_read(&val, addr, sizeof(val));
+ if (!ret)
+ return val;
+ }
+ return 0;
}
#define arch_has_single_step() (1)