[PATCH -tip tracing/kprobes 3/6] kprobes/x86: Fix to add __kprobes toin-kernel fault handing functions

[Masami Hiramatsu]

Add __kprobes to the functions which handles in-kernel fixable page faults.
Since kprobes can cause those in-kernel page faults by accessing kprobe data
structures, probing those fault functions will cause fault-int3-loop
(do_page_fault has already been marked as __kprobes).

Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Ananth N Mavinakayanahalli <ananth@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
---

 arch/x86/mm/fault.c |   11 ++++++-----
 1 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index bfae139..c322e59 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -38,7 +38,8 @@ enum x86_pf_error_code {
  * Returns 0 if mmiotrace is disabled, or if the fault is not
  * handled by mmiotrace:
  */
-static inline int kmmio_fault(struct pt_regs *regs, unsigned long addr)
+static inline int __kprobes
+kmmio_fault(struct pt_regs *regs, unsigned long addr)
 {
 	if (unlikely(is_kmmio_active()))
 		if (kmmio_handler(regs, addr) == 1)
@@ -46,7 +47,7 @@ static inline int kmmio_fault(struct pt_regs *regs, unsigned long addr)
 	return 0;
 }
 
-static inline int notify_page_fault(struct pt_regs *regs)
+static inline int __kprobes notify_page_fault(struct pt_regs *regs)
 {
 	int ret = 0;
 
@@ -239,7 +240,7 @@ void vmalloc_sync_all(void)
  *
  *   Handle a fault on the vmalloc or module mapping area
  */
-static noinline int vmalloc_fault(unsigned long address)
+static noinline __kprobes int vmalloc_fault(unsigned long address)
 {
 	unsigned long pgd_paddr;
 	pmd_t *pmd_k;
@@ -361,7 +362,7 @@ void vmalloc_sync_all(void)
  *
  * This assumes no large pages in there.
  */
-static noinline int vmalloc_fault(unsigned long address)
+static noinline __kprobes int vmalloc_fault(unsigned long address)
 {
 	pgd_t *pgd, *pgd_ref;
 	pud_t *pud, *pud_ref;
@@ -858,7 +859,7 @@ static int spurious_fault_check(unsigned long error_code, pte_t *pte)
  * There are no security implications to leaving a stale TLB when
  * increasing the permissions on a page.
  */
-static noinline int
+static noinline __kprobes int
 spurious_fault(unsigned long error_code, unsigned long address)
 {
 	pgd_t *pgd;


-- 
Masami Hiramatsu

Software Engineer
Hitachi Computer Products (America), Inc.
Software Solutions Division

e-mail: mhiramat@xxxxxxxxxx
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