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authorAl Viro <viro@zeniv.linux.org.uk>2020-02-15 11:28:09 -0500
committerAl Viro <viro@zeniv.linux.org.uk>2020-02-15 17:26:26 -0500
commitc8e3dd86600a1a7b165478cc626d69bf07967c15 (patch)
tree78340dbc13eea3b70f43b1a0c9f4df3bc238db1e /arch/x86/events
parentbb6d3fb354c5ee8d6bde2d576eb7220ea09862b9 (diff)
downloadlinux-c8e3dd86600a1a7b165478cc626d69bf07967c15.tar.gz
x86 user stack frame reads: switch to explicit __get_user()
rather than relying upon the magic in raw_copy_from_user() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'arch/x86/events')
-rw-r--r--arch/x86/events/core.c27
1 files changed, 7 insertions, 20 deletions
diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index 3bb738f5a472..a619763e96e1 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -2490,7 +2490,7 @@ perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry_ctx *ent
/* 32-bit process in 64-bit kernel. */
unsigned long ss_base, cs_base;
struct stack_frame_ia32 frame;
- const void __user *fp;
+ const struct stack_frame_ia32 __user *fp;
if (!test_thread_flag(TIF_IA32))
return 0;
@@ -2501,18 +2501,12 @@ perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry_ctx *ent
fp = compat_ptr(ss_base + regs->bp);
pagefault_disable();
while (entry->nr < entry->max_stack) {
- unsigned long bytes;
- frame.next_frame = 0;
- frame.return_address = 0;
-
if (!valid_user_frame(fp, sizeof(frame)))
break;
- bytes = __copy_from_user_nmi(&frame.next_frame, fp, 4);
- if (bytes != 0)
+ if (__get_user(frame.next_frame, &fp->next_frame))
break;
- bytes = __copy_from_user_nmi(&frame.return_address, fp+4, 4);
- if (bytes != 0)
+ if (__get_user(frame.return_address, &fp->return_address))
break;
perf_callchain_store(entry, cs_base + frame.return_address);
@@ -2533,7 +2527,7 @@ void
perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs)
{
struct stack_frame frame;
- const unsigned long __user *fp;
+ const struct stack_frame __user *fp;
if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
/* TODO: We don't support guest os callchain now */
@@ -2546,7 +2540,7 @@ perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs
if (regs->flags & (X86_VM_MASK | PERF_EFLAGS_VM))
return;
- fp = (unsigned long __user *)regs->bp;
+ fp = (void __user *)regs->bp;
perf_callchain_store(entry, regs->ip);
@@ -2558,19 +2552,12 @@ 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 (!valid_user_frame(fp, sizeof(frame)))
break;
- bytes = __copy_from_user_nmi(&frame.next_frame, fp, sizeof(*fp));
- if (bytes != 0)
+ if (__get_user(frame.next_frame, &fp->next_frame))
break;
- bytes = __copy_from_user_nmi(&frame.return_address, fp + 1, sizeof(*fp));
- if (bytes != 0)
+ if (__get_user(frame.return_address, &fp->return_address))
break;
perf_callchain_store(entry, frame.return_address);