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authorLinus Torvalds <torvalds@linux-foundation.org>2019-05-19 20:23:24 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2019-05-19 20:23:24 +0300
commit1335d9a1fb2abbe5022de3c517989cc7c7161dee (patch)
tree23e4a27cb22bb09fefea09a62e419a8c5bcc32cd
parent4c4a5c99af7f479a14759196f8df9467128f3baf (diff)
parent8ea58f1e8b11cca3087b294779bf5959bf89cc10 (diff)
downloadlinux-1335d9a1fb2abbe5022de3c517989cc7c7161dee.tar.xz
Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core fixes from Ingo Molnar: "This fixes a particularly thorny munmap() bug with MPX, plus fixes a host build environment assumption in objtool" * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: objtool: Allow AR to be overridden with HOSTAR x86/mpx, mm/core: Fix recursive munmap() corruption
-rw-r--r--arch/powerpc/include/asm/mmu_context.h1
-rw-r--r--arch/um/include/asm/mmu_context.h1
-rw-r--r--arch/unicore32/include/asm/mmu_context.h1
-rw-r--r--arch/x86/include/asm/mmu_context.h6
-rw-r--r--arch/x86/include/asm/mpx.h15
-rw-r--r--arch/x86/mm/mpx.c10
-rw-r--r--include/asm-generic/mm_hooks.h1
-rw-r--r--mm/mmap.c15
-rw-r--r--tools/objtool/Makefile3
9 files changed, 27 insertions, 26 deletions
diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h
index 611204e588b9..58efca934311 100644
--- a/arch/powerpc/include/asm/mmu_context.h
+++ b/arch/powerpc/include/asm/mmu_context.h
@@ -232,7 +232,6 @@ static inline void enter_lazy_tlb(struct mm_struct *mm,
extern void arch_exit_mmap(struct mm_struct *mm);
static inline void arch_unmap(struct mm_struct *mm,
- struct vm_area_struct *vma,
unsigned long start, unsigned long end)
{
if (start <= mm->context.vdso_base && mm->context.vdso_base < end)
diff --git a/arch/um/include/asm/mmu_context.h b/arch/um/include/asm/mmu_context.h
index fca34b2177e2..9f4b4bb78120 100644
--- a/arch/um/include/asm/mmu_context.h
+++ b/arch/um/include/asm/mmu_context.h
@@ -22,7 +22,6 @@ static inline int arch_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm)
}
extern void arch_exit_mmap(struct mm_struct *mm);
static inline void arch_unmap(struct mm_struct *mm,
- struct vm_area_struct *vma,
unsigned long start, unsigned long end)
{
}
diff --git a/arch/unicore32/include/asm/mmu_context.h b/arch/unicore32/include/asm/mmu_context.h
index 5c205a9cb5a6..9f06ea5466dd 100644
--- a/arch/unicore32/include/asm/mmu_context.h
+++ b/arch/unicore32/include/asm/mmu_context.h
@@ -88,7 +88,6 @@ static inline int arch_dup_mmap(struct mm_struct *oldmm,
}
static inline void arch_unmap(struct mm_struct *mm,
- struct vm_area_struct *vma,
unsigned long start, unsigned long end)
{
}
diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h
index 93dff1963337..9024236693d2 100644
--- a/arch/x86/include/asm/mmu_context.h
+++ b/arch/x86/include/asm/mmu_context.h
@@ -278,8 +278,8 @@ static inline void arch_bprm_mm_init(struct mm_struct *mm,
mpx_mm_init(mm);
}
-static inline void arch_unmap(struct mm_struct *mm, struct vm_area_struct *vma,
- unsigned long start, unsigned long end)
+static inline void arch_unmap(struct mm_struct *mm, unsigned long start,
+ unsigned long end)
{
/*
* mpx_notify_unmap() goes and reads a rarely-hot
@@ -299,7 +299,7 @@ static inline void arch_unmap(struct mm_struct *mm, struct vm_area_struct *vma,
* consistently wrong.
*/
if (unlikely(cpu_feature_enabled(X86_FEATURE_MPX)))
- mpx_notify_unmap(mm, vma, start, end);
+ mpx_notify_unmap(mm, start, end);
}
/*
diff --git a/arch/x86/include/asm/mpx.h b/arch/x86/include/asm/mpx.h
index d0b1434fb0b6..143a5c193ed3 100644
--- a/arch/x86/include/asm/mpx.h
+++ b/arch/x86/include/asm/mpx.h
@@ -64,12 +64,15 @@ struct mpx_fault_info {
};
#ifdef CONFIG_X86_INTEL_MPX
-int mpx_fault_info(struct mpx_fault_info *info, struct pt_regs *regs);
-int mpx_handle_bd_fault(void);
+
+extern int mpx_fault_info(struct mpx_fault_info *info, struct pt_regs *regs);
+extern int mpx_handle_bd_fault(void);
+
static inline int kernel_managing_mpx_tables(struct mm_struct *mm)
{
return (mm->context.bd_addr != MPX_INVALID_BOUNDS_DIR);
}
+
static inline void mpx_mm_init(struct mm_struct *mm)
{
/*
@@ -78,11 +81,10 @@ static inline void mpx_mm_init(struct mm_struct *mm)
*/
mm->context.bd_addr = MPX_INVALID_BOUNDS_DIR;
}
-void mpx_notify_unmap(struct mm_struct *mm, struct vm_area_struct *vma,
- unsigned long start, unsigned long end);
-unsigned long mpx_unmapped_area_check(unsigned long addr, unsigned long len,
- unsigned long flags);
+extern void mpx_notify_unmap(struct mm_struct *mm, unsigned long start, unsigned long end);
+extern unsigned long mpx_unmapped_area_check(unsigned long addr, unsigned long len, unsigned long flags);
+
#else
static inline int mpx_fault_info(struct mpx_fault_info *info, struct pt_regs *regs)
{
@@ -100,7 +102,6 @@ static inline void mpx_mm_init(struct mm_struct *mm)
{
}
static inline void mpx_notify_unmap(struct mm_struct *mm,
- struct vm_area_struct *vma,
unsigned long start, unsigned long end)
{
}
diff --git a/arch/x86/mm/mpx.c b/arch/x86/mm/mpx.c
index 59726aaf4671..0d1c47cbbdd6 100644
--- a/arch/x86/mm/mpx.c
+++ b/arch/x86/mm/mpx.c
@@ -881,9 +881,10 @@ static int mpx_unmap_tables(struct mm_struct *mm,
* the virtual address region start...end have already been split if
* necessary, and the 'vma' is the first vma in this range (start -> end).
*/
-void mpx_notify_unmap(struct mm_struct *mm, struct vm_area_struct *vma,
- unsigned long start, unsigned long end)
+void mpx_notify_unmap(struct mm_struct *mm, unsigned long start,
+ unsigned long end)
{
+ struct vm_area_struct *vma;
int ret;
/*
@@ -902,11 +903,12 @@ void mpx_notify_unmap(struct mm_struct *mm, struct vm_area_struct *vma,
* which should not occur normally. Being strict about it here
* helps ensure that we do not have an exploitable stack overflow.
*/
- do {
+ vma = find_vma(mm, start);
+ while (vma && vma->vm_start < end) {
if (vma->vm_flags & VM_MPX)
return;
vma = vma->vm_next;
- } while (vma && vma->vm_start < end);
+ }
ret = mpx_unmap_tables(mm, start, end);
if (ret)
diff --git a/include/asm-generic/mm_hooks.h b/include/asm-generic/mm_hooks.h
index 8ac4e68a12f0..6736ed2f632b 100644
--- a/include/asm-generic/mm_hooks.h
+++ b/include/asm-generic/mm_hooks.h
@@ -18,7 +18,6 @@ static inline void arch_exit_mmap(struct mm_struct *mm)
}
static inline void arch_unmap(struct mm_struct *mm,
- struct vm_area_struct *vma,
unsigned long start, unsigned long end)
{
}
diff --git a/mm/mmap.c b/mm/mmap.c
index bd7b9f293b39..2d6a6662edb9 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2735,9 +2735,17 @@ int __do_munmap(struct mm_struct *mm, unsigned long start, size_t len,
return -EINVAL;
len = PAGE_ALIGN(len);
+ end = start + len;
if (len == 0)
return -EINVAL;
+ /*
+ * arch_unmap() might do unmaps itself. It must be called
+ * and finish any rbtree manipulation before this code
+ * runs and also starts to manipulate the rbtree.
+ */
+ arch_unmap(mm, start, end);
+
/* Find the first overlapping VMA */
vma = find_vma(mm, start);
if (!vma)
@@ -2746,7 +2754,6 @@ int __do_munmap(struct mm_struct *mm, unsigned long start, size_t len,
/* we have start < vma->vm_end */
/* if it doesn't overlap, we have nothing.. */
- end = start + len;
if (vma->vm_start >= end)
return 0;
@@ -2816,12 +2823,6 @@ int __do_munmap(struct mm_struct *mm, unsigned long start, size_t len,
/* Detach vmas from rbtree */
detach_vmas_to_be_unmapped(mm, vma, prev, end);
- /*
- * mpx unmap needs to be called with mmap_sem held for write.
- * It is safe to call it before unmap_region().
- */
- arch_unmap(mm, vma, start, end);
-
if (downgrade)
downgrade_write(&mm->mmap_sem);
diff --git a/tools/objtool/Makefile b/tools/objtool/Makefile
index 53f8be0f4a1f..88158239622b 100644
--- a/tools/objtool/Makefile
+++ b/tools/objtool/Makefile
@@ -7,11 +7,12 @@ ARCH := x86
endif
# always use the host compiler
+HOSTAR ?= ar
HOSTCC ?= gcc
HOSTLD ?= ld
+AR = $(HOSTAR)
CC = $(HOSTCC)
LD = $(HOSTLD)
-AR = ar
ifeq ($(srctree),)
srctree := $(patsubst %/,%,$(dir $(CURDIR)))