'notrace'

Christophe Leroy Fri, 16 Oct 2020 00:03:24 -0700



Le 15/10/2020 à 17:01, Christopher M. Riedl a écrit :

Functions called between user_*_access_begin() and user_*_access_end()
should be either inlined or marked 'notrace' to prevent leaving
userspace access exposed. Mark any such functions relevant to signal
handling so that subsequent patches can call them inside uaccess blocks.

Is it enough to mark it "notrace" ? I see that when I activate KASAN, there are still KASAN calls inthose functions.

In my series for 32 bits, I re-ordered stuff in order to do all those calls before doing the_access_begin(), can't you do the same on PPC64 ? (Seehttps://patchwork.ozlabs.org/project/linuxppc-dev/patch/f6eac65781b4a57220477c8864bca2b57f29a5d5.1597770847.git.christophe.le...@csgroup.eu/)


Christophe


Signed-off-by: Christopher M. Riedl <c...@codefail.de>
---
  arch/powerpc/kernel/process.c | 20 ++++++++++----------
  arch/powerpc/mm/mem.c         |  4 ++--
  2 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index ba2c987b8403..bf5d9654bd2c 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -84,7 +84,7 @@ extern unsigned long _get_SP(void);
   */
  bool tm_suspend_disabled __ro_after_init = false;

-static void check_if_tm_restore_required(struct task_struct *tsk)

+static void notrace check_if_tm_restore_required(struct task_struct *tsk)
  {
        /*
         * If we are saving the current thread's registers, and the
@@ -151,7 +151,7 @@ void notrace __msr_check_and_clear(unsigned long bits)
  EXPORT_SYMBOL(__msr_check_and_clear);

#ifdef CONFIG_PPC_FPU

-static void __giveup_fpu(struct task_struct *tsk)
+static void notrace __giveup_fpu(struct task_struct *tsk)
  {
        unsigned long msr;

@@ -163,7 +163,7 @@ static void __giveup_fpu(struct task_struct *tsk)

        tsk->thread.regs->msr = msr;
  }

-void giveup_fpu(struct task_struct *tsk)

+void notrace giveup_fpu(struct task_struct *tsk)
  {
        check_if_tm_restore_required(tsk);

@@ -177,7 +177,7 @@ EXPORT_SYMBOL(giveup_fpu);

   * Make sure the floating-point register state in the
   * the thread_struct is up to date for task tsk.
   */
-void flush_fp_to_thread(struct task_struct *tsk)
+void notrace flush_fp_to_thread(struct task_struct *tsk)
  {
        if (tsk->thread.regs) {
                /*
@@ -234,7 +234,7 @@ static inline void __giveup_fpu(struct task_struct *tsk) { }
  #endif /* CONFIG_PPC_FPU */

#ifdef CONFIG_ALTIVEC

-static void __giveup_altivec(struct task_struct *tsk)
+static void notrace __giveup_altivec(struct task_struct *tsk)
  {
        unsigned long msr;

@@ -246,7 +246,7 @@ static void __giveup_altivec(struct task_struct *tsk)

        tsk->thread.regs->msr = msr;
  }

-void giveup_altivec(struct task_struct *tsk)

+void notrace giveup_altivec(struct task_struct *tsk)
  {
        check_if_tm_restore_required(tsk);

@@ -285,7 +285,7 @@ EXPORT_SYMBOL(enable_kernel_altivec);

   * Make sure the VMX/Altivec register state in the
   * the thread_struct is up to date for task tsk.
   */
-void flush_altivec_to_thread(struct task_struct *tsk)
+void notrace flush_altivec_to_thread(struct task_struct *tsk)
  {
        if (tsk->thread.regs) {
                preempt_disable();
@@ -300,7 +300,7 @@ EXPORT_SYMBOL_GPL(flush_altivec_to_thread);
  #endif /* CONFIG_ALTIVEC */

#ifdef CONFIG_VSX

-static void __giveup_vsx(struct task_struct *tsk)
+static void notrace __giveup_vsx(struct task_struct *tsk)
  {
        unsigned long msr = tsk->thread.regs->msr;

@@ -317,7 +317,7 @@ static void __giveup_vsx(struct task_struct *tsk)

                __giveup_altivec(tsk);
  }

-static void giveup_vsx(struct task_struct *tsk)

+static void notrace giveup_vsx(struct task_struct *tsk)
  {
        check_if_tm_restore_required(tsk);

@@ -352,7 +352,7 @@ void enable_kernel_vsx(void)

  }
  EXPORT_SYMBOL(enable_kernel_vsx);

-void flush_vsx_to_thread(struct task_struct *tsk)

+void notrace flush_vsx_to_thread(struct task_struct *tsk)
  {
        if (tsk->thread.regs) {
                preempt_disable();
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index ddc32cc1b6cf..da2345a2abc6 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -378,7 +378,7 @@ static inline bool flush_coherent_icache(unsigned long addr)
   * @start: the start address
   * @stop: the stop address (exclusive)
   */
-static void invalidate_icache_range(unsigned long start, unsigned long stop)
+static void notrace invalidate_icache_range(unsigned long start, unsigned long 
stop)
  {
        unsigned long shift = l1_icache_shift();
        unsigned long bytes = l1_icache_bytes();
@@ -402,7 +402,7 @@ static void invalidate_icache_range(unsigned long start, 
unsigned long stop)
   * @start: the start address
   * @stop: the stop address (exclusive)
   */
-void flush_icache_range(unsigned long start, unsigned long stop)
+void notrace flush_icache_range(unsigned long start, unsigned long stop)
  {
        if (flush_coherent_icache(start))
                return;

Re: [PATCH 3/8] powerpc: Mark functions called inside uaccess blocks w/ 'notrace'

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