| Message ID | 20211121121056.2870061-1-willy@infradead.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mm,fs: Split dump_mapping() out from dump_page() | expand |
On Sun 21-11-21 12:10:56, Matthew Wilcox wrote: > dump_mapping() is a big chunk of dump_page(), and it'd be handy to be > able to call it when we don't have a struct page. Split it out and move > it to fs/inode.c. Take the opportunity to simplify some of the debug > messages a little. Makes sense. I haven't checked the head files inclusion side of this but I suspect mm heads do include uaccess.h. Not sure inode.c does as well. > Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Michal Hocko <mhocko@suse.com> > --- > fs/inode.c | 49 +++++++++++++++++++++++++++++++++++++++++++ > include/linux/fs.h | 1 + > mm/debug.c | 52 ++-------------------------------------------- > 3 files changed, 52 insertions(+), 50 deletions(-) > > diff --git a/fs/inode.c b/fs/inode.c > index bdfbd5962f2b..67758b2b702f 100644 > --- a/fs/inode.c > +++ b/fs/inode.c > @@ -522,6 +522,55 @@ void __remove_inode_hash(struct inode *inode) > } > EXPORT_SYMBOL(__remove_inode_hash); > > +void dump_mapping(const struct address_space *mapping) > +{ > + struct inode *host; > + const struct address_space_operations *a_ops; > + struct hlist_node *dentry_first; > + struct dentry *dentry_ptr; > + struct dentry dentry; > + unsigned long ino; > + > + /* > + * If mapping is an invalid pointer, we don't want to crash > + * accessing it, so probe everything depending on it carefully. > + */ > + if (get_kernel_nofault(host, &mapping->host) || > + get_kernel_nofault(a_ops, &mapping->a_ops)) { > + pr_warn("invalid mapping:%px\n", mapping); > + return; > + } > + > + if (!host) { > + pr_warn("aops:%ps\n", a_ops); > + return; > + } > + > + if (get_kernel_nofault(dentry_first, &host->i_dentry.first) || > + get_kernel_nofault(ino, &host->i_ino)) { > + pr_warn("aops:%ps invalid inode:%px\n", a_ops, host); > + return; > + } > + > + if (!dentry_first) { > + pr_warn("aops:%ps ino:%lx\n", a_ops, ino); > + return; > + } > + > + dentry_ptr = container_of(dentry_first, struct dentry, d_u.d_alias); > + if (get_kernel_nofault(dentry, dentry_ptr)) { > + pr_warn("aops:%ps ino:%lx invalid dentry:%px\n", > + a_ops, ino, dentry_ptr); > + return; > + } > + > + /* > + * if dentry is corrupted, the %pd handler may still crash, > + * but it's unlikely that we reach here with a corrupt mapping > + */ > + pr_warn("aops:%ps ino:%lx dentry name:\"%pd\"\n", a_ops, ino, &dentry); > +} > + > void clear_inode(struct inode *inode) > { > /* > diff --git a/include/linux/fs.h b/include/linux/fs.h > index d6a4eb6cf825..acaad2b0d5b9 100644 > --- a/include/linux/fs.h > +++ b/include/linux/fs.h > @@ -3149,6 +3149,7 @@ extern void unlock_new_inode(struct inode *); > extern void discard_new_inode(struct inode *); > extern unsigned int get_next_ino(void); > extern void evict_inodes(struct super_block *sb); > +void dump_mapping(const struct address_space *); > > /* > * Userspace may rely on the the inode number being non-zero. For example, glibc > diff --git a/mm/debug.c b/mm/debug.c > index fae0f81ad831..b3ebfab21cb3 100644 > --- a/mm/debug.c > +++ b/mm/debug.c > @@ -110,56 +110,8 @@ static void __dump_page(struct page *page) > type = "ksm "; > else if (PageAnon(page)) > type = "anon "; > - else if (mapping) { > - struct inode *host; > - const struct address_space_operations *a_ops; > - struct hlist_node *dentry_first; > - struct dentry *dentry_ptr; > - struct dentry dentry; > - unsigned long ino; > - > - /* > - * mapping can be invalid pointer and we don't want to crash > - * accessing it, so probe everything depending on it carefully > - */ > - if (get_kernel_nofault(host, &mapping->host) || > - get_kernel_nofault(a_ops, &mapping->a_ops)) { > - pr_warn("failed to read mapping contents, not a valid kernel address?\n"); > - goto out_mapping; > - } > - > - if (!host) { > - pr_warn("aops:%ps\n", a_ops); > - goto out_mapping; > - } > - > - if (get_kernel_nofault(dentry_first, &host->i_dentry.first) || > - get_kernel_nofault(ino, &host->i_ino)) { > - pr_warn("aops:%ps with invalid host inode %px\n", > - a_ops, host); > - goto out_mapping; > - } > - > - if (!dentry_first) { > - pr_warn("aops:%ps ino:%lx\n", a_ops, ino); > - goto out_mapping; > - } > - > - dentry_ptr = container_of(dentry_first, struct dentry, d_u.d_alias); > - if (get_kernel_nofault(dentry, dentry_ptr)) { > - pr_warn("aops:%ps ino:%lx with invalid dentry %px\n", > - a_ops, ino, dentry_ptr); > - } else { > - /* > - * if dentry is corrupted, the %pd handler may still > - * crash, but it's unlikely that we reach here with a > - * corrupted struct page > - */ > - pr_warn("aops:%ps ino:%lx dentry name:\"%pd\"\n", > - a_ops, ino, &dentry); > - } > - } > -out_mapping: > + else if (mapping) > + dump_mapping(mapping); > BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS + 1); > > pr_warn("%sflags: %#lx(%pGp)%s\n", type, head->flags, &head->flags, > -- > 2.33.0
On Mon, Nov 22, 2021 at 08:11:32AM +0100, Michal Hocko wrote: > On Sun 21-11-21 12:10:56, Matthew Wilcox wrote: > > dump_mapping() is a big chunk of dump_page(), and it'd be handy to be > > able to call it when we don't have a struct page. Split it out and move > > it to fs/inode.c. Take the opportunity to simplify some of the debug > > messages a little. > > Makes sense. I haven't checked the head files inclusion side of this but > I suspect mm heads do include uaccess.h. Not sure inode.c does as well. It does ... convolutedly: linux/fs.h linux/percpu-rwsem.h linux/rcuwait.h linux/sched/signal.h linux/sched/task.h linux/uaccess.h There may be shorter paths to including that file, but that's the one that's actually used according to cpp. fs/inode.c includes linux/mm.h, so it also gets it through linux/pgtable.h x86/include/asm/pgtable.h x86/include/asm/pkru.h x86/include/asm/fpu/xstate.h which is probably not how you think the mm files get uaccess.h, but again, that's the first way that cpp tells me it gets pulled in. Our header files remain a mess. > > Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> > > Acked-by: Michal Hocko <mhocko@suse.com> Thanks!
Looks good to me. Reviewed-by: William Kucharski <william.kucharski@oracle.com> > On Nov 21, 2021, at 5:10 AM, Matthew Wilcox (Oracle) <willy@infradead.org> wrote: > > dump_mapping() is a big chunk of dump_page(), and it'd be handy to be > able to call it when we don't have a struct page. Split it out and move > it to fs/inode.c. Take the opportunity to simplify some of the debug > messages a little. > > Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> > --- > fs/inode.c | 49 +++++++++++++++++++++++++++++++++++++++++++ > include/linux/fs.h | 1 + > mm/debug.c | 52 ++-------------------------------------------- > 3 files changed, 52 insertions(+), 50 deletions(-) > > diff --git a/fs/inode.c b/fs/inode.c > index bdfbd5962f2b..67758b2b702f 100644 > --- a/fs/inode.c > +++ b/fs/inode.c > @@ -522,6 +522,55 @@ void __remove_inode_hash(struct inode *inode) > } > EXPORT_SYMBOL(__remove_inode_hash); > > +void dump_mapping(const struct address_space *mapping) > +{ > + struct inode *host; > + const struct address_space_operations *a_ops; > + struct hlist_node *dentry_first; > + struct dentry *dentry_ptr; > + struct dentry dentry; > + unsigned long ino; > + > + /* > + * If mapping is an invalid pointer, we don't want to crash > + * accessing it, so probe everything depending on it carefully. > + */ > + if (get_kernel_nofault(host, &mapping->host) || > + get_kernel_nofault(a_ops, &mapping->a_ops)) { > + pr_warn("invalid mapping:%px\n", mapping); > + return; > + } > + > + if (!host) { > + pr_warn("aops:%ps\n", a_ops); > + return; > + } > + > + if (get_kernel_nofault(dentry_first, &host->i_dentry.first) || > + get_kernel_nofault(ino, &host->i_ino)) { > + pr_warn("aops:%ps invalid inode:%px\n", a_ops, host); > + return; > + } > + > + if (!dentry_first) { > + pr_warn("aops:%ps ino:%lx\n", a_ops, ino); > + return; > + } > + > + dentry_ptr = container_of(dentry_first, struct dentry, d_u.d_alias); > + if (get_kernel_nofault(dentry, dentry_ptr)) { > + pr_warn("aops:%ps ino:%lx invalid dentry:%px\n", > + a_ops, ino, dentry_ptr); > + return; > + } > + > + /* > + * if dentry is corrupted, the %pd handler may still crash, > + * but it's unlikely that we reach here with a corrupt mapping > + */ > + pr_warn("aops:%ps ino:%lx dentry name:\"%pd\"\n", a_ops, ino, &dentry); > +} > + > void clear_inode(struct inode *inode) > { > /* > diff --git a/include/linux/fs.h b/include/linux/fs.h > index d6a4eb6cf825..acaad2b0d5b9 100644 > --- a/include/linux/fs.h > +++ b/include/linux/fs.h > @@ -3149,6 +3149,7 @@ extern void unlock_new_inode(struct inode *); > extern void discard_new_inode(struct inode *); > extern unsigned int get_next_ino(void); > extern void evict_inodes(struct super_block *sb); > +void dump_mapping(const struct address_space *); > > /* > * Userspace may rely on the the inode number being non-zero. For example, glibc > diff --git a/mm/debug.c b/mm/debug.c > index fae0f81ad831..b3ebfab21cb3 100644 > --- a/mm/debug.c > +++ b/mm/debug.c > @@ -110,56 +110,8 @@ static void __dump_page(struct page *page) > type = "ksm "; > else if (PageAnon(page)) > type = "anon "; > - else if (mapping) { > - struct inode *host; > - const struct address_space_operations *a_ops; > - struct hlist_node *dentry_first; > - struct dentry *dentry_ptr; > - struct dentry dentry; > - unsigned long ino; > - > - /* > - * mapping can be invalid pointer and we don't want to crash > - * accessing it, so probe everything depending on it carefully > - */ > - if (get_kernel_nofault(host, &mapping->host) || > - get_kernel_nofault(a_ops, &mapping->a_ops)) { > - pr_warn("failed to read mapping contents, not a valid kernel address?\n"); > - goto out_mapping; > - } > - > - if (!host) { > - pr_warn("aops:%ps\n", a_ops); > - goto out_mapping; > - } > - > - if (get_kernel_nofault(dentry_first, &host->i_dentry.first) || > - get_kernel_nofault(ino, &host->i_ino)) { > - pr_warn("aops:%ps with invalid host inode %px\n", > - a_ops, host); > - goto out_mapping; > - } > - > - if (!dentry_first) { > - pr_warn("aops:%ps ino:%lx\n", a_ops, ino); > - goto out_mapping; > - } > - > - dentry_ptr = container_of(dentry_first, struct dentry, d_u.d_alias); > - if (get_kernel_nofault(dentry, dentry_ptr)) { > - pr_warn("aops:%ps ino:%lx with invalid dentry %px\n", > - a_ops, ino, dentry_ptr); > - } else { > - /* > - * if dentry is corrupted, the %pd handler may still > - * crash, but it's unlikely that we reach here with a > - * corrupted struct page > - */ > - pr_warn("aops:%ps ino:%lx dentry name:\"%pd\"\n", > - a_ops, ino, &dentry); > - } > - } > -out_mapping: > + else if (mapping) > + dump_mapping(mapping); > BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS + 1); > > pr_warn("%sflags: %#lx(%pGp)%s\n", type, head->flags, &head->flags, > -- > 2.33.0 > >
diff --git a/fs/inode.c b/fs/inode.c index bdfbd5962f2b..67758b2b702f 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -522,6 +522,55 @@ void __remove_inode_hash(struct inode *inode) } EXPORT_SYMBOL(__remove_inode_hash); +void dump_mapping(const struct address_space *mapping) +{ + struct inode *host; + const struct address_space_operations *a_ops; + struct hlist_node *dentry_first; + struct dentry *dentry_ptr; + struct dentry dentry; + unsigned long ino; + + /* + * If mapping is an invalid pointer, we don't want to crash + * accessing it, so probe everything depending on it carefully. + */ + if (get_kernel_nofault(host, &mapping->host) || + get_kernel_nofault(a_ops, &mapping->a_ops)) { + pr_warn("invalid mapping:%px\n", mapping); + return; + } + + if (!host) { + pr_warn("aops:%ps\n", a_ops); + return; + } + + if (get_kernel_nofault(dentry_first, &host->i_dentry.first) || + get_kernel_nofault(ino, &host->i_ino)) { + pr_warn("aops:%ps invalid inode:%px\n", a_ops, host); + return; + } + + if (!dentry_first) { + pr_warn("aops:%ps ino:%lx\n", a_ops, ino); + return; + } + + dentry_ptr = container_of(dentry_first, struct dentry, d_u.d_alias); + if (get_kernel_nofault(dentry, dentry_ptr)) { + pr_warn("aops:%ps ino:%lx invalid dentry:%px\n", + a_ops, ino, dentry_ptr); + return; + } + + /* + * if dentry is corrupted, the %pd handler may still crash, + * but it's unlikely that we reach here with a corrupt mapping + */ + pr_warn("aops:%ps ino:%lx dentry name:\"%pd\"\n", a_ops, ino, &dentry); +} + void clear_inode(struct inode *inode) { /* diff --git a/include/linux/fs.h b/include/linux/fs.h index d6a4eb6cf825..acaad2b0d5b9 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3149,6 +3149,7 @@ extern void unlock_new_inode(struct inode *); extern void discard_new_inode(struct inode *); extern unsigned int get_next_ino(void); extern void evict_inodes(struct super_block *sb); +void dump_mapping(const struct address_space *); /* * Userspace may rely on the the inode number being non-zero. For example, glibc diff --git a/mm/debug.c b/mm/debug.c index fae0f81ad831..b3ebfab21cb3 100644 --- a/mm/debug.c +++ b/mm/debug.c @@ -110,56 +110,8 @@ static void __dump_page(struct page *page) type = "ksm "; else if (PageAnon(page)) type = "anon "; - else if (mapping) { - struct inode *host; - const struct address_space_operations *a_ops; - struct hlist_node *dentry_first; - struct dentry *dentry_ptr; - struct dentry dentry; - unsigned long ino; - - /* - * mapping can be invalid pointer and we don't want to crash - * accessing it, so probe everything depending on it carefully - */ - if (get_kernel_nofault(host, &mapping->host) || - get_kernel_nofault(a_ops, &mapping->a_ops)) { - pr_warn("failed to read mapping contents, not a valid kernel address?\n"); - goto out_mapping; - } - - if (!host) { - pr_warn("aops:%ps\n", a_ops); - goto out_mapping; - } - - if (get_kernel_nofault(dentry_first, &host->i_dentry.first) || - get_kernel_nofault(ino, &host->i_ino)) { - pr_warn("aops:%ps with invalid host inode %px\n", - a_ops, host); - goto out_mapping; - } - - if (!dentry_first) { - pr_warn("aops:%ps ino:%lx\n", a_ops, ino); - goto out_mapping; - } - - dentry_ptr = container_of(dentry_first, struct dentry, d_u.d_alias); - if (get_kernel_nofault(dentry, dentry_ptr)) { - pr_warn("aops:%ps ino:%lx with invalid dentry %px\n", - a_ops, ino, dentry_ptr); - } else { - /* - * if dentry is corrupted, the %pd handler may still - * crash, but it's unlikely that we reach here with a - * corrupted struct page - */ - pr_warn("aops:%ps ino:%lx dentry name:\"%pd\"\n", - a_ops, ino, &dentry); - } - } -out_mapping: + else if (mapping) + dump_mapping(mapping); BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS + 1); pr_warn("%sflags: %#lx(%pGp)%s\n", type, head->flags, &head->flags,
dump_mapping() is a big chunk of dump_page(), and it'd be handy to be able to call it when we don't have a struct page. Split it out and move it to fs/inode.c. Take the opportunity to simplify some of the debug messages a little. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> --- fs/inode.c | 49 +++++++++++++++++++++++++++++++++++++++++++ include/linux/fs.h | 1 + mm/debug.c | 52 ++-------------------------------------------- 3 files changed, 52 insertions(+), 50 deletions(-)