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 + +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;