Thread (18 messages) 18 messages, 6 authors, 2024-09-04
STALE661d

[PATCH 1/3] mm: Make arch_get_unmapped_area() take vm_flags by default

From: Mark Brown <broonie@kernel.org>
Date: 2024-09-02 19:08:53
Also in: linux-alpha, linux-mm, linux-s390, linux-sh, lkml, loongarch, sparclinux
Subsystem: alpha port, arm port, c-sky architecture, linux for powerpc (32-bit and 64-bit), loongarch, memory management, memory mapping, mips, parisc architecture, s390 architecture, sparc + ultrasparc (sparc/sparc64), superh, synopsys arc architecture, tensilica xtensa port (xtensa), the rest, x86 architecture (32-bit and 64-bit) · Maintainers: Richard Henderson, Matt Turner, Magnus Lindholm, Russell King, Guo Ren, Madhavan Srinivasan, Michael Ellerman, Huacai Chen, Andrew Morton, Liam R. Howlett, Lorenzo Stoakes, Thomas Bogendoerfer, "James E.J. Bottomley", Helge Deller, Heiko Carstens, Vasily Gorbik, Alexander Gordeev, "David S. Miller", Andreas Larsson, Yoshinori Sato, Rich Felker, John Paul Adrian Glaubitz, Vineet Gupta, Chris Zankel, Max Filippov, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen

When we introduced arch_get_unmapped_area_vmflags() in 961148704acd
("mm: introduce arch_get_unmapped_area_vmflags()") we did so as part of
properly supporting guard pages for shadow stacks on x86_64, which uses
a custom arch_get_unmapped_area(). Equivalent features are also present
on both arm64 and RISC-V, both of which use the generic implementation
of arch_get_unmapped_area() and will require equivalent modification
there. Rather than continue to deal with having two versions of the
functions let's bite the bullet and have all implementations of
arch_get_unmapped_area() take vm_flags as a parameter.

The new parameter is currently ignored by all implementations other than
x86. The only caller that doesn't have a vm_flags available is
mm_get_unmapped_area(), as for the x86 implementation and the wrapper used
on other architectures this is modified to supply no flags.

No functional changes.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 arch/alpha/kernel/osf_sys.c       |  2 +-
 arch/arc/mm/mmap.c                |  3 ++-
 arch/arm/mm/mmap.c                |  7 ++++---
 arch/csky/abiv1/mmap.c            |  3 ++-
 arch/loongarch/mm/mmap.c          |  5 +++--
 arch/mips/mm/mmap.c               |  2 +-
 arch/parisc/kernel/sys_parisc.c   |  5 +++--
 arch/parisc/mm/hugetlbpage.c      |  2 +-
 arch/powerpc/mm/book3s64/slice.c  |  6 ++++--
 arch/s390/mm/mmap.c               |  4 ++--
 arch/sh/mm/mmap.c                 |  5 +++--
 arch/sparc/kernel/sys_sparc_32.c  |  2 +-
 arch/sparc/kernel/sys_sparc_64.c  |  4 ++--
 arch/x86/include/asm/pgtable_64.h |  1 -
 arch/x86/kernel/sys_x86_64.c      | 21 +++------------------
 arch/xtensa/kernel/syscall.c      |  3 ++-
 include/linux/sched/mm.h          | 23 ++++++++---------------
 mm/mmap.c                         | 31 +++++++------------------------
 18 files changed, 49 insertions(+), 80 deletions(-)
diff --git a/arch/alpha/kernel/osf_sys.c b/arch/alpha/kernel/osf_sys.c
index e5f881bc8288..8886ab539273 100644
--- a/arch/alpha/kernel/osf_sys.c
+++ b/arch/alpha/kernel/osf_sys.c
@@ -1229,7 +1229,7 @@ arch_get_unmapped_area_1(unsigned long addr, unsigned long len,
 unsigned long
 arch_get_unmapped_area(struct file *filp, unsigned long addr,
 		       unsigned long len, unsigned long pgoff,
-		       unsigned long flags)
+		       unsigned long flags, vm_flags_t vm_flags)
 {
 	unsigned long limit;
 
diff --git a/arch/arc/mm/mmap.c b/arch/arc/mm/mmap.c
index 69a915297155..2185afe8d59f 100644
--- a/arch/arc/mm/mmap.c
+++ b/arch/arc/mm/mmap.c
@@ -23,7 +23,8 @@
  */
 unsigned long
 arch_get_unmapped_area(struct file *filp, unsigned long addr,
-		unsigned long len, unsigned long pgoff, unsigned long flags)
+		unsigned long len, unsigned long pgoff,
+		unsigned long flags, vm_flags_t vm_flags)
 {
 	struct mm_struct *mm = current->mm;
 	struct vm_area_struct *vma;
diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c
index d65d0e6ed10a..3dbb383c26d5 100644
--- a/arch/arm/mm/mmap.c
+++ b/arch/arm/mm/mmap.c
@@ -28,7 +28,8 @@
  */
 unsigned long
 arch_get_unmapped_area(struct file *filp, unsigned long addr,
-		unsigned long len, unsigned long pgoff, unsigned long flags)
+		unsigned long len, unsigned long pgoff,
+		unsigned long flags, vm_flags_t vm_flags)
 {
 	struct mm_struct *mm = current->mm;
 	struct vm_area_struct *vma;
@@ -78,8 +79,8 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
 
 unsigned long
 arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
-			const unsigned long len, const unsigned long pgoff,
-			const unsigned long flags)
+		        const unsigned long len, const unsigned long pgoff,
+		        const unsigned long flags, vm_flags_t vm_flags)
 {
 	struct vm_area_struct *vma;
 	struct mm_struct *mm = current->mm;
diff --git a/arch/csky/abiv1/mmap.c b/arch/csky/abiv1/mmap.c
index 7f826331d409..1047865e82a9 100644
--- a/arch/csky/abiv1/mmap.c
+++ b/arch/csky/abiv1/mmap.c
@@ -23,7 +23,8 @@
  */
 unsigned long
 arch_get_unmapped_area(struct file *filp, unsigned long addr,
-		unsigned long len, unsigned long pgoff, unsigned long flags)
+		unsigned long len, unsigned long pgoff,
+		unsigned long flags, vm_flags_t vm_flags)
 {
 	struct mm_struct *mm = current->mm;
 	struct vm_area_struct *vma;
diff --git a/arch/loongarch/mm/mmap.c b/arch/loongarch/mm/mmap.c
index 889030985135..914e82ff3f65 100644
--- a/arch/loongarch/mm/mmap.c
+++ b/arch/loongarch/mm/mmap.c
@@ -89,7 +89,8 @@ static unsigned long arch_get_unmapped_area_common(struct file *filp,
 }
 
 unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr0,
-	unsigned long len, unsigned long pgoff, unsigned long flags)
+	unsigned long len, unsigned long pgoff, unsigned long flags,
+	vm_flags_t vm_flags)
 {
 	return arch_get_unmapped_area_common(filp,
 			addr0, len, pgoff, flags, UP);
@@ -101,7 +102,7 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr0,
  */
 unsigned long arch_get_unmapped_area_topdown(struct file *filp,
 	unsigned long addr0, unsigned long len, unsigned long pgoff,
-	unsigned long flags)
+	unsigned long flags, vm_flags_t vm_flags)
 {
 	return arch_get_unmapped_area_common(filp,
 			addr0, len, pgoff, flags, DOWN);
diff --git a/arch/mips/mm/mmap.c b/arch/mips/mm/mmap.c
index 7e11d7b58761..02bf5353efbd 100644
--- a/arch/mips/mm/mmap.c
+++ b/arch/mips/mm/mmap.c
@@ -110,7 +110,7 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr0,
  */
 unsigned long arch_get_unmapped_area_topdown(struct file *filp,
 	unsigned long addr0, unsigned long len, unsigned long pgoff,
-	unsigned long flags)
+	unsigned long flags, vm_flags_t vm_flags)
 {
 	return arch_get_unmapped_area_common(filp,
 			addr0, len, pgoff, flags, DOWN);
diff --git a/arch/parisc/kernel/sys_parisc.c b/arch/parisc/kernel/sys_parisc.c
index f7722451276e..f852fe274abe 100644
--- a/arch/parisc/kernel/sys_parisc.c
+++ b/arch/parisc/kernel/sys_parisc.c
@@ -167,7 +167,8 @@ static unsigned long arch_get_unmapped_area_common(struct file *filp,
 }
 
 unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
-	unsigned long len, unsigned long pgoff, unsigned long flags)
+	unsigned long len, unsigned long pgoff, unsigned long flags,
+	vm_flags_t vm_flags)
 {
 	return arch_get_unmapped_area_common(filp,
 			addr, len, pgoff, flags, UP);
@@ -175,7 +176,7 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
 
 unsigned long arch_get_unmapped_area_topdown(struct file *filp,
 	unsigned long addr, unsigned long len, unsigned long pgoff,
-	unsigned long flags)
+	unsigned long flags, vm_flags_t vm_flags)
 {
 	return arch_get_unmapped_area_common(filp,
 			addr, len, pgoff, flags, DOWN);
diff --git a/arch/parisc/mm/hugetlbpage.c b/arch/parisc/mm/hugetlbpage.c
index 0356199bd9e7..aa664f7ddb63 100644
--- a/arch/parisc/mm/hugetlbpage.c
+++ b/arch/parisc/mm/hugetlbpage.c
@@ -40,7 +40,7 @@ hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
 		addr = ALIGN(addr, huge_page_size(h));
 
 	/* we need to make sure the colouring is OK */
-	return arch_get_unmapped_area(file, addr, len, pgoff, flags);
+	return arch_get_unmapped_area(file, addr, len, pgoff, flags, 0);
 }
 
 
diff --git a/arch/powerpc/mm/book3s64/slice.c b/arch/powerpc/mm/book3s64/slice.c
index ef3ce37f1bb3..ada6bf896ef8 100644
--- a/arch/powerpc/mm/book3s64/slice.c
+++ b/arch/powerpc/mm/book3s64/slice.c
@@ -637,7 +637,8 @@ unsigned long arch_get_unmapped_area(struct file *filp,
 				     unsigned long addr,
 				     unsigned long len,
 				     unsigned long pgoff,
-				     unsigned long flags)
+				     unsigned long flags,
+				     vm_flags_t vm_flags)
 {
 	if (radix_enabled())
 		return generic_get_unmapped_area(filp, addr, len, pgoff, flags);
@@ -650,7 +651,8 @@ unsigned long arch_get_unmapped_area_topdown(struct file *filp,
 					     const unsigned long addr0,
 					     const unsigned long len,
 					     const unsigned long pgoff,
-					     const unsigned long flags)
+					     const unsigned long flags,
+					     vm_flags_t vm_flags)
 {
 	if (radix_enabled())
 		return generic_get_unmapped_area_topdown(filp, addr0, len, pgoff, flags);
diff --git a/arch/s390/mm/mmap.c b/arch/s390/mm/mmap.c
index 206756946589..96efa061ce01 100644
--- a/arch/s390/mm/mmap.c
+++ b/arch/s390/mm/mmap.c
@@ -82,7 +82,7 @@ static int get_align_mask(struct file *filp, unsigned long flags)
 
 unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
 				     unsigned long len, unsigned long pgoff,
-				     unsigned long flags)
+				     unsigned long flags, vm_flags_t vm_flags)
 {
 	struct mm_struct *mm = current->mm;
 	struct vm_area_struct *vma;
@@ -117,7 +117,7 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
 
 unsigned long arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
 					     unsigned long len, unsigned long pgoff,
-					     unsigned long flags)
+					     unsigned long flags, vm_flags_t vm_flags)
 {
 	struct vm_area_struct *vma;
 	struct mm_struct *mm = current->mm;
diff --git a/arch/sh/mm/mmap.c b/arch/sh/mm/mmap.c
index bee329d4149a..c442734d9b0c 100644
--- a/arch/sh/mm/mmap.c
+++ b/arch/sh/mm/mmap.c
@@ -52,7 +52,8 @@ static inline unsigned long COLOUR_ALIGN(unsigned long addr,
 }
 
 unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
-	unsigned long len, unsigned long pgoff, unsigned long flags)
+	unsigned long len, unsigned long pgoff, unsigned long flags,
+	vm_flags_t vm_flags)
 {
 	struct mm_struct *mm = current->mm;
 	struct vm_area_struct *vma;
@@ -99,7 +100,7 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
 unsigned long
 arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
 			  const unsigned long len, const unsigned long pgoff,
-			  const unsigned long flags)
+			  const unsigned long flags, vm_flags_t vm_flags)
 {
 	struct vm_area_struct *vma;
 	struct mm_struct *mm = current->mm;
diff --git a/arch/sparc/kernel/sys_sparc_32.c b/arch/sparc/kernel/sys_sparc_32.c
index 08a19727795c..80822f922e76 100644
--- a/arch/sparc/kernel/sys_sparc_32.c
+++ b/arch/sparc/kernel/sys_sparc_32.c
@@ -39,7 +39,7 @@ SYSCALL_DEFINE0(getpagesize)
 	return PAGE_SIZE; /* Possibly older binaries want 8192 on sun4's? */
 }
 
-unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags)
+unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags, vm_flags_t vm_flags)
 {
 	struct vm_unmapped_area_info info = {};
 
diff --git a/arch/sparc/kernel/sys_sparc_64.c b/arch/sparc/kernel/sys_sparc_64.c
index d9c3b34ca744..acade309dc2f 100644
--- a/arch/sparc/kernel/sys_sparc_64.c
+++ b/arch/sparc/kernel/sys_sparc_64.c
@@ -87,7 +87,7 @@ static inline unsigned long COLOR_ALIGN(unsigned long addr,
 	return base + off;
 }
 
-unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags)
+unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags, vm_flags_t vm_flags)
 {
 	struct mm_struct *mm = current->mm;
 	struct vm_area_struct * vma;
@@ -146,7 +146,7 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsi
 unsigned long
 arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
 			  const unsigned long len, const unsigned long pgoff,
-			  const unsigned long flags)
+			  const unsigned long flags, vm_flags_t vm_flags)
 {
 	struct vm_area_struct *vma;
 	struct mm_struct *mm = current->mm;
diff --git a/arch/x86/include/asm/pgtable_64.h b/arch/x86/include/asm/pgtable_64.h
index 3c4407271d08..7e9db77231ac 100644
--- a/arch/x86/include/asm/pgtable_64.h
+++ b/arch/x86/include/asm/pgtable_64.h
@@ -245,7 +245,6 @@ extern void cleanup_highmap(void);
 
 #define HAVE_ARCH_UNMAPPED_AREA
 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
-#define HAVE_ARCH_UNMAPPED_AREA_VMFLAGS
 
 #define PAGE_AGP    PAGE_KERNEL_NOCACHE
 #define HAVE_PAGE_AGP 1
diff --git a/arch/x86/kernel/sys_x86_64.c b/arch/x86/kernel/sys_x86_64.c
index 01d7cd85ef97..87f8c9a71c49 100644
--- a/arch/x86/kernel/sys_x86_64.c
+++ b/arch/x86/kernel/sys_x86_64.c
@@ -121,7 +121,7 @@ static inline unsigned long stack_guard_placement(vm_flags_t vm_flags)
 }
 
 unsigned long
-arch_get_unmapped_area_vmflags(struct file *filp, unsigned long addr, unsigned long len,
+arch_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len,
 		       unsigned long pgoff, unsigned long flags, vm_flags_t vm_flags)
 {
 	struct mm_struct *mm = current->mm;
@@ -158,7 +158,7 @@ arch_get_unmapped_area_vmflags(struct file *filp, unsigned long addr, unsigned l
 }
 
 unsigned long
-arch_get_unmapped_area_topdown_vmflags(struct file *filp, unsigned long addr0,
+arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr0,
 			  unsigned long len, unsigned long pgoff,
 			  unsigned long flags, vm_flags_t vm_flags)
 {
@@ -228,20 +228,5 @@ arch_get_unmapped_area_topdown_vmflags(struct file *filp, unsigned long addr0,
 	 * can happen with large stack limits and large mmap()
 	 * allocations.
 	 */
-	return arch_get_unmapped_area(filp, addr0, len, pgoff, flags);
-}
-
-unsigned long
-arch_get_unmapped_area(struct file *filp, unsigned long addr,
-		unsigned long len, unsigned long pgoff, unsigned long flags)
-{
-	return arch_get_unmapped_area_vmflags(filp, addr, len, pgoff, flags, 0);
-}
-
-unsigned long
-arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr,
-			  const unsigned long len, const unsigned long pgoff,
-			  const unsigned long flags)
-{
-	return arch_get_unmapped_area_topdown_vmflags(filp, addr, len, pgoff, flags, 0);
+	return arch_get_unmapped_area(filp, addr0, len, pgoff, flags, 0);
 }
diff --git a/arch/xtensa/kernel/syscall.c b/arch/xtensa/kernel/syscall.c
index b3c2450d6f23..7f048d368dba 100644
--- a/arch/xtensa/kernel/syscall.c
+++ b/arch/xtensa/kernel/syscall.c
@@ -55,7 +55,8 @@ asmlinkage long xtensa_fadvise64_64(int fd, int advice,
 
 #ifdef CONFIG_MMU
 unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
-		unsigned long len, unsigned long pgoff, unsigned long flags)
+		unsigned long len, unsigned long pgoff, unsigned long flags,
+		vm_flgs_t vm_flags)
 {
 	struct vm_area_struct *vmm;
 	struct vma_iterator vmi;
diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h
index 91546493c43d..c4d34abc45d4 100644
--- a/include/linux/sched/mm.h
+++ b/include/linux/sched/mm.h
@@ -179,27 +179,20 @@ static inline void mm_update_next_owner(struct mm_struct *mm)
 
 extern void arch_pick_mmap_layout(struct mm_struct *mm,
 				  struct rlimit *rlim_stack);
-extern unsigned long
-arch_get_unmapped_area(struct file *, unsigned long, unsigned long,
-		       unsigned long, unsigned long);
-extern unsigned long
+
+unsigned long
+arch_get_unmapped_area(struct file *filp, unsigned long addr,
+		       unsigned long len, unsigned long pgoff,
+		       unsigned long flags, vm_flags_t vm_flags);
+unsigned long
 arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
-			  unsigned long len, unsigned long pgoff,
-			  unsigned long flags);
+			       unsigned long len, unsigned long pgoff,
+			       unsigned long flags, vm_flags_t);
 
 unsigned long mm_get_unmapped_area(struct mm_struct *mm, struct file *filp,
 				   unsigned long addr, unsigned long len,
 				   unsigned long pgoff, unsigned long flags);
 
-unsigned long
-arch_get_unmapped_area_vmflags(struct file *filp, unsigned long addr,
-			       unsigned long len, unsigned long pgoff,
-			       unsigned long flags, vm_flags_t vm_flags);
-unsigned long
-arch_get_unmapped_area_topdown_vmflags(struct file *filp, unsigned long addr,
-				       unsigned long len, unsigned long pgoff,
-				       unsigned long flags, vm_flags_t);
-
 unsigned long mm_get_unmapped_area_vmflags(struct mm_struct *mm,
 					   struct file *filp,
 					   unsigned long addr,
diff --git a/mm/mmap.c b/mm/mmap.c
index d0dfc85b209b..7528146f886f 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1821,7 +1821,7 @@ generic_get_unmapped_area(struct file *filp, unsigned long addr,
 unsigned long
 arch_get_unmapped_area(struct file *filp, unsigned long addr,
 		       unsigned long len, unsigned long pgoff,
-		       unsigned long flags)
+		       unsigned long flags, vm_flags_t vm_flags)
 {
 	return generic_get_unmapped_area(filp, addr, len, pgoff, flags);
 }
@@ -1885,38 +1885,21 @@ generic_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
 unsigned long
 arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
 			       unsigned long len, unsigned long pgoff,
-			       unsigned long flags)
+			       unsigned long flags, vm_flags_t vm_flags)
 {
 	return generic_get_unmapped_area_topdown(filp, addr, len, pgoff, flags);
 }
 #endif
 
-#ifndef HAVE_ARCH_UNMAPPED_AREA_VMFLAGS
-unsigned long
-arch_get_unmapped_area_vmflags(struct file *filp, unsigned long addr, unsigned long len,
-			       unsigned long pgoff, unsigned long flags, vm_flags_t vm_flags)
-{
-	return arch_get_unmapped_area(filp, addr, len, pgoff, flags);
-}
-
-unsigned long
-arch_get_unmapped_area_topdown_vmflags(struct file *filp, unsigned long addr,
-				       unsigned long len, unsigned long pgoff,
-				       unsigned long flags, vm_flags_t vm_flags)
-{
-	return arch_get_unmapped_area_topdown(filp, addr, len, pgoff, flags);
-}
-#endif
-
 unsigned long mm_get_unmapped_area_vmflags(struct mm_struct *mm, struct file *filp,
 					   unsigned long addr, unsigned long len,
 					   unsigned long pgoff, unsigned long flags,
 					   vm_flags_t vm_flags)
 {
 	if (test_bit(MMF_TOPDOWN, &mm->flags))
-		return arch_get_unmapped_area_topdown_vmflags(filp, addr, len, pgoff,
-							      flags, vm_flags);
-	return arch_get_unmapped_area_vmflags(filp, addr, len, pgoff, flags, vm_flags);
+		return arch_get_unmapped_area_topdown(filp, addr, len, pgoff,
+						      flags, vm_flags);
+	return arch_get_unmapped_area(filp, addr, len, pgoff, flags, vm_flags);
 }
 
 unsigned long
@@ -1978,8 +1961,8 @@ mm_get_unmapped_area(struct mm_struct *mm, struct file *file,
 		     unsigned long pgoff, unsigned long flags)
 {
 	if (test_bit(MMF_TOPDOWN, &mm->flags))
-		return arch_get_unmapped_area_topdown(file, addr, len, pgoff, flags);
-	return arch_get_unmapped_area(file, addr, len, pgoff, flags);
+		return arch_get_unmapped_area_topdown(file, addr, len, pgoff, flags, 0);
+	return arch_get_unmapped_area(file, addr, len, pgoff, flags, 0);
 }
 EXPORT_SYMBOL(mm_get_unmapped_area);
 
-- 
2.39.2

Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help