Patchwork [v11,10/14] tracing, arm64: untag user pointers in seq_print_user_ip

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Submitter Andrey Konovalov
Date March 15, 2019, 7:51 p.m.
Message ID <355e7c0dadaa2bb79d22e0b7aac7e4efc1114d49.1552679409.git.andreyknvl@google.com>
Download mbox | patch
Permalink /patch/749981/
State New
Headers show

Comments

Andrey Konovalov - March 15, 2019, 7:51 p.m.
This patch is a part of a series that extends arm64 kernel ABI to allow to
pass tagged user pointers (with the top byte set to something else other
than 0x00) as syscall arguments.

seq_print_user_ip() uses provided user pointers for vma lookups, which
can only by done with untagged pointers.

Untag user pointers in this function.

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
---
 kernel/trace/trace_output.c |  5 +++--
 p                           | 45 +++++++++++++++++++++++++++++++++++++
 2 files changed, 48 insertions(+), 2 deletions(-)
 create mode 100644 p
Andrey Konovalov - March 18, 2019, 1:11 p.m.
On Fri, Mar 15, 2019 at 9:14 PM Steven Rostedt <rostedt@goodmis.org> wrote:
>
> On Fri, 15 Mar 2019 20:51:34 +0100
> Andrey Konovalov <andreyknvl@google.com> wrote:
>
> > This patch is a part of a series that extends arm64 kernel ABI to allow to
> > pass tagged user pointers (with the top byte set to something else other
> > than 0x00) as syscall arguments.
> >
> > seq_print_user_ip() uses provided user pointers for vma lookups, which
> > can only by done with untagged pointers.
> >
> > Untag user pointers in this function.
> >
> > Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
> > ---
> >  kernel/trace/trace_output.c |  5 +++--
> >  p                           | 45 +++++++++++++++++++++++++++++++++++++
> >  2 files changed, 48 insertions(+), 2 deletions(-)
> >  create mode 100644 p
> >
> > diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
> > index 54373d93e251..6376bee93c84 100644
> > --- a/kernel/trace/trace_output.c
> > +++ b/kernel/trace/trace_output.c
> > @@ -370,6 +370,7 @@ static int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
> >  {
> >       struct file *file = NULL;
> >       unsigned long vmstart = 0;
> > +     unsigned long untagged_ip = untagged_addr(ip);
> >       int ret = 1;
> >
> >       if (s->full)
> > @@ -379,7 +380,7 @@ static int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
> >               const struct vm_area_struct *vma;
> >
> >               down_read(&mm->mmap_sem);
> > -             vma = find_vma(mm, ip);
> > +             vma = find_vma(mm, untagged_ip);
> >               if (vma) {
> >                       file = vma->vm_file;
> >                       vmstart = vma->vm_start;
> > @@ -388,7 +389,7 @@ static int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
> >                       ret = trace_seq_path(s, &file->f_path);
> >                       if (ret)
> >                               trace_seq_printf(s, "[+0x%lx]",
> > -                                              ip - vmstart);
> > +                                              untagged_ip - vmstart);
> >               }
> >               up_read(&mm->mmap_sem);
> >       }
> > diff --git a/p b/p
> > new file mode 100644
> > index 000000000000..9d6fa5386e55
> > --- /dev/null
> > +++ b/p
> > @@ -0,0 +1,45 @@
> > +commit 1fa6fadf644859e8a6a8ecce258444b49be8c7ee
> > +Author: Andrey Konovalov <andreyknvl@google.com>
> > +Date:   Mon Mar 4 17:20:32 2019 +0100
> > +
> > +    kasan: fix coccinelle warnings in kasan_p*_table
> > +
> > +    kasan_p4d_table, kasan_pmd_table and kasan_pud_table are declared as
> > +    returning bool, but return 0 instead of false, which produces a coccinelle
> > +    warning. Fix it.
> > +
> > +    Fixes: 0207df4fa1a8 ("kernel/memremap, kasan: make ZONE_DEVICE with work with KASAN")
> > +    Reported-by: kbuild test robot <lkp@intel.com>
> > +    Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
>
> Did you mean to append this commit to this patch?

No, did it by mistake. Will remove in v12, thanks for noticing!

>
> -- Steve
>
> > +
> > +diff --git a/mm/kasan/init.c b/mm/kasan/init.c
> > +index 45a1b5e38e1e..fcaa1ca03175 100644
> > +--- a/mm/kasan/init.c
> > ++++ b/mm/kasan/init.c
> > +@@ -42,7 +42,7 @@ static inline bool kasan_p4d_table(pgd_t pgd)
> > + #else
> > + static inline bool kasan_p4d_table(pgd_t pgd)
> > + {
> > +-    return 0;
> > ++    return false;
> > + }
> > + #endif
> > + #if CONFIG_PGTABLE_LEVELS > 3
> > +@@ -54,7 +54,7 @@ static inline bool kasan_pud_table(p4d_t p4d)
> > + #else
> > + static inline bool kasan_pud_table(p4d_t p4d)
> > + {
> > +-    return 0;
> > ++    return false;
> > + }
> > + #endif
> > + #if CONFIG_PGTABLE_LEVELS > 2
> > +@@ -66,7 +66,7 @@ static inline bool kasan_pmd_table(pud_t pud)
> > + #else
> > + static inline bool kasan_pmd_table(pud_t pud)
> > + {
> > +-    return 0;
> > ++    return false;
> > + }
> > + #endif
> > + pte_t kasan_early_shadow_pte[PTRS_PER_PTE] __page_aligned_bss;
>

Patch

diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 54373d93e251..6376bee93c84 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -370,6 +370,7 @@  static int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
 {
 	struct file *file = NULL;
 	unsigned long vmstart = 0;
+	unsigned long untagged_ip = untagged_addr(ip);
 	int ret = 1;
 
 	if (s->full)
@@ -379,7 +380,7 @@  static int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
 		const struct vm_area_struct *vma;
 
 		down_read(&mm->mmap_sem);
-		vma = find_vma(mm, ip);
+		vma = find_vma(mm, untagged_ip);
 		if (vma) {
 			file = vma->vm_file;
 			vmstart = vma->vm_start;
@@ -388,7 +389,7 @@  static int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
 			ret = trace_seq_path(s, &file->f_path);
 			if (ret)
 				trace_seq_printf(s, "[+0x%lx]",
-						 ip - vmstart);
+						 untagged_ip - vmstart);
 		}
 		up_read(&mm->mmap_sem);
 	}
diff --git a/p b/p
new file mode 100644
index 000000000000..9d6fa5386e55
--- /dev/null
+++ b/p
@@ -0,0 +1,45 @@ 
+commit 1fa6fadf644859e8a6a8ecce258444b49be8c7ee
+Author: Andrey Konovalov <andreyknvl@google.com>
+Date:   Mon Mar 4 17:20:32 2019 +0100
+
+    kasan: fix coccinelle warnings in kasan_p*_table
+    
+    kasan_p4d_table, kasan_pmd_table and kasan_pud_table are declared as
+    returning bool, but return 0 instead of false, which produces a coccinelle
+    warning. Fix it.
+    
+    Fixes: 0207df4fa1a8 ("kernel/memremap, kasan: make ZONE_DEVICE with work with KASAN")
+    Reported-by: kbuild test robot <lkp@intel.com>
+    Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
+
+diff --git a/mm/kasan/init.c b/mm/kasan/init.c
+index 45a1b5e38e1e..fcaa1ca03175 100644
+--- a/mm/kasan/init.c
++++ b/mm/kasan/init.c
+@@ -42,7 +42,7 @@ static inline bool kasan_p4d_table(pgd_t pgd)
+ #else
+ static inline bool kasan_p4d_table(pgd_t pgd)
+ {
+-	return 0;
++	return false;
+ }
+ #endif
+ #if CONFIG_PGTABLE_LEVELS > 3
+@@ -54,7 +54,7 @@ static inline bool kasan_pud_table(p4d_t p4d)
+ #else
+ static inline bool kasan_pud_table(p4d_t p4d)
+ {
+-	return 0;
++	return false;
+ }
+ #endif
+ #if CONFIG_PGTABLE_LEVELS > 2
+@@ -66,7 +66,7 @@ static inline bool kasan_pmd_table(pud_t pud)
+ #else
+ static inline bool kasan_pmd_table(pud_t pud)
+ {
+-	return 0;
++	return false;
+ }
+ #endif
+ pte_t kasan_early_shadow_pte[PTRS_PER_PTE] __page_aligned_bss;