X-Git-Url: https://gerrit.automotivelinux.org/gerrit/gitweb?a=blobdiff_plain;f=meta-agl-bsp%2Fmeta-qcom%2Frecipes-kernel%2Flinux%2Ffiles%2F0003-mm-fix-new-crash-in-unmapped_area_topdown.patch;fp=meta-agl-bsp%2Fmeta-qcom%2Frecipes-kernel%2Flinux%2Ffiles%2F0003-mm-fix-new-crash-in-unmapped_area_topdown.patch;h=aa6c0dbb97e9bb0f0c7d9ce261f5945d14f1a3c4;hb=834b16ca1898968af62169bfe62b8cd6a5cbe8d7;hp=0000000000000000000000000000000000000000;hpb=56b115af69a2cdcc9db26ca249dfce575ef1bb9f;p=AGL%2Fmeta-agl.git diff --git a/meta-agl-bsp/meta-qcom/recipes-kernel/linux/files/0003-mm-fix-new-crash-in-unmapped_area_topdown.patch b/meta-agl-bsp/meta-qcom/recipes-kernel/linux/files/0003-mm-fix-new-crash-in-unmapped_area_topdown.patch new file mode 100644 index 000000000..aa6c0dbb9 --- /dev/null +++ b/meta-agl-bsp/meta-qcom/recipes-kernel/linux/files/0003-mm-fix-new-crash-in-unmapped_area_topdown.patch @@ -0,0 +1,52 @@ +From 166258fc1e072a1dbcac678427291854d01f2163 Mon Sep 17 00:00:00 2001 +From: Hugh Dickins +Date: Tue, 20 Jun 2017 02:10:44 -0700 +Subject: [PATCH 3/3] mm: fix new crash in unmapped_area_topdown() + +commit f4cb767d76cf7ee72f97dd76f6cfa6c76a5edc89 upstream. + +Trinity gets kernel BUG at mm/mmap.c:1963! in about 3 minutes of +mmap testing. That's the VM_BUG_ON(gap_end < gap_start) at the +end of unmapped_area_topdown(). Linus points out how MAP_FIXED +(which does not have to respect our stack guard gap intentions) +could result in gap_end below gap_start there. Fix that, and +the similar case in its alternative, unmapped_area(). + +Fixes: 1be7107fbe18 ("mm: larger stack guard gap, between vmas") +Reported-by: Dave Jones +Debugged-by: Linus Torvalds +Signed-off-by: Hugh Dickins +Acked-by: Michal Hocko +Signed-off-by: Linus Torvalds +Signed-off-by: Greg Kroah-Hartman +--- + mm/mmap.c | 6 ++++-- + 1 file changed, 4 insertions(+), 2 deletions(-) + +diff --git a/mm/mmap.c b/mm/mmap.c +index d71a61e..145d3d5 100644 +--- a/mm/mmap.c ++++ b/mm/mmap.c +@@ -1813,7 +1813,8 @@ unsigned long unmapped_area(struct vm_unmapped_area_info *info) + /* Check if current node has a suitable gap */ + if (gap_start > high_limit) + return -ENOMEM; +- if (gap_end >= low_limit && gap_end - gap_start >= length) ++ if (gap_end >= low_limit && ++ gap_end > gap_start && gap_end - gap_start >= length) + goto found; + + /* Visit right subtree if it looks promising */ +@@ -1916,7 +1917,8 @@ unsigned long unmapped_area_topdown(struct vm_unmapped_area_info *info) + gap_end = vm_start_gap(vma); + if (gap_end < low_limit) + return -ENOMEM; +- if (gap_start <= high_limit && gap_end - gap_start >= length) ++ if (gap_start <= high_limit && ++ gap_end > gap_start && gap_end - gap_start >= length) + goto found; + + /* Visit left subtree if it looks promising */ +-- +2.1.4 +