perf/x86: Fix 32-bit perf user callgraph collection

[cascardo/linux.git] / arch / x86 / events / core.c

diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index 33787ee..26ced53 100644 (file)
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -2319,7 +2319,7 @@ void
 perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs)
 {
        struct stack_frame frame;
-       const void __user *fp;
+       const unsigned long __user *fp;
 
        if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
                /* TODO: We don't support guest os callchain now */
@@ -2332,7 +2332,7 @@ perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs
        if (regs->flags & (X86_VM_MASK | PERF_EFLAGS_VM))
                return;
 
-       fp = (void __user *)regs->bp;
+       fp = (unsigned long __user *)regs->bp;
 
        perf_callchain_store(entry, regs->ip);
 
@@ -2345,16 +2345,17 @@ perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs
        pagefault_disable();
        while (entry->nr < entry->max_stack) {
                unsigned long bytes;
+
                frame.next_frame             = NULL;
                frame.return_address = 0;
 
-               if (!access_ok(VERIFY_READ, fp, 16))
+               if (!access_ok(VERIFY_READ, fp, sizeof(*fp) * 2))
                        break;
 
-               bytes = __copy_from_user_nmi(&frame.next_frame, fp, 8);
+               bytes = __copy_from_user_nmi(&frame.next_frame, fp, sizeof(*fp));
                if (bytes != 0)
                        break;
-               bytes = __copy_from_user_nmi(&frame.return_address, fp+8, 8);
+               bytes = __copy_from_user_nmi(&frame.return_address, fp + 1, sizeof(*fp));
                if (bytes != 0)
                        break;