| Message ID | 20171204142553.GA3344@pjb1027-Latitude-E5410 (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Dec 4, 2017 at 6:25 AM, Jinbum Park <jinb.park7@gmail.com> wrote: > This patch refactors the arm page table dumping code, > so multiple tables may be registered with the framework. > > This patch refers below commits of arm64. > (4674fdb9f149 ("arm64: mm: dump: make page table dumping reusable")) > (4ddb9bf83349 ("arm64: dump: Make ptdump debugfs a separate option")) > > Signed-off-by: Jinbum Park <jinb.park7@gmail.com> > --- > v3: No changes > > arch/arm/Kconfig.debug | 6 +++- > arch/arm/include/asm/ptdump.h | 48 ++++++++++++++++++++++++++++++++ > arch/arm/mm/Makefile | 3 +- > arch/arm/mm/dump.c | 65 +++++++++++++++++++------------------------ > arch/arm/mm/ptdump_debugfs.c | 34 ++++++++++++++++++++++ > 5 files changed, 117 insertions(+), 39 deletions(-) > create mode 100644 arch/arm/include/asm/ptdump.h > create mode 100644 arch/arm/mm/ptdump_debugfs.c > > diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug > index 17685e1..e7b94db 100644 > --- a/arch/arm/Kconfig.debug > +++ b/arch/arm/Kconfig.debug > @@ -3,10 +3,14 @@ menu "Kernel hacking" > > source "lib/Kconfig.debug" > > -config ARM_PTDUMP > +config ARM_PTDUMP_CORE > + def_bool n > + > +config ARM_PTDUMP_DEBUGFS > bool "Export kernel pagetable layout to userspace via debugfs" > depends on DEBUG_KERNEL > depends on MMU > + select ARM_PTDUMP_CORE > select DEBUG_FS > ---help--- > Say Y here if you want to show the kernel pagetable layout in a > diff --git a/arch/arm/include/asm/ptdump.h b/arch/arm/include/asm/ptdump.h > new file mode 100644 > index 0000000..3a6c0b7 > --- /dev/null > +++ b/arch/arm/include/asm/ptdump.h > @@ -0,0 +1,48 @@ > +/* > + * Copyright (C) 2014 ARM Ltd. > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + * > + * You should have received a copy of the GNU General Public License > + * along with this program. If not, see <http://www.gnu.org/licenses/>. > + */ > +#ifndef __ASM_PTDUMP_H > +#define __ASM_PTDUMP_H > + > +#ifdef CONFIG_ARM_PTDUMP_CORE Is this #ifdef needed? I think this file is only included in dump.c and ptdump_debugfs.c, both of which are only built when CONFIG_ARM_PTDUMP_CORE is defined. > + > +#include <linux/mm_types.h> > +#include <linux/seq_file.h> > + > +struct addr_marker { > + unsigned long start_address; > + char *name; > +}; > + > +struct ptdump_info { > + struct mm_struct *mm; > + const struct addr_marker *markers; > + unsigned long base_addr; > +}; > + > +void ptdump_walk_pgd(struct seq_file *s, struct ptdump_info *info); > +#ifdef CONFIG_ARM_PTDUMP_DEBUGFS > +int ptdump_debugfs_register(struct ptdump_info *info, const char *name); > +#else > +static inline int ptdump_debugfs_register(struct ptdump_info *info, > + const char *name) > +{ > + return 0; > +} > +#endif /* CONFIG_ARM_PTDUMP_DEBUGFS */ > + > +#endif /* CONFIG_ARM_PTDUMP_CORE */ > + > +#endif /* __ASM_PTDUMP_H */ > diff --git a/arch/arm/mm/Makefile b/arch/arm/mm/Makefile > index 01bcc33..28be5f4 100644 > --- a/arch/arm/mm/Makefile > +++ b/arch/arm/mm/Makefile > @@ -13,7 +13,8 @@ obj-y += nommu.o > obj-$(CONFIG_ARM_MPU) += pmsa-v7.o > endif > > -obj-$(CONFIG_ARM_PTDUMP) += dump.o > +obj-$(CONFIG_ARM_PTDUMP_CORE) += dump.o > +obj-$(CONFIG_ARM_PTDUMP_DEBUGFS) += ptdump_debugfs.o > obj-$(CONFIG_MODULES) += proc-syms.o > obj-$(CONFIG_DEBUG_VIRTUAL) += physaddr.o > > diff --git a/arch/arm/mm/dump.c b/arch/arm/mm/dump.c > index fc3b440..8dfe7c3 100644 > --- a/arch/arm/mm/dump.c > +++ b/arch/arm/mm/dump.c > @@ -21,11 +21,7 @@ > #include <asm/fixmap.h> > #include <asm/memory.h> > #include <asm/pgtable.h> > - > -struct addr_marker { > - unsigned long start_address; > - const char *name; > -}; > +#include <asm/ptdump.h> > > static struct addr_marker address_markers[] = { > { MODULES_VADDR, "Modules" }, > @@ -335,50 +331,36 @@ static void walk_pud(struct pg_state *st, pgd_t *pgd, unsigned long start) > } > } > > -static void walk_pgd(struct seq_file *m) > +static void walk_pgd(struct pg_state *st, struct mm_struct *mm, > + unsigned long start) > { > - pgd_t *pgd = swapper_pg_dir; > - struct pg_state st; > - unsigned long addr; > + pgd_t *pgd = pgd_offset(mm, 0UL); > unsigned i; > - > - memset(&st, 0, sizeof(st)); > - st.seq = m; > - st.marker = address_markers; > + unsigned long addr; > > for (i = 0; i < PTRS_PER_PGD; i++, pgd++) { > - addr = i * PGDIR_SIZE; > + addr = start + i * PGDIR_SIZE; > if (!pgd_none(*pgd)) { > - walk_pud(&st, pgd, addr); > + walk_pud(st, pgd, addr); > } else { > - note_page(&st, addr, 1, pgd_val(*pgd), NULL); > + note_page(st, addr, 1, pgd_val(*pgd), NULL); > } > } > - > - note_page(&st, 0, 0, 0, NULL); > } > > -static int ptdump_show(struct seq_file *m, void *v) > +void ptdump_walk_pgd(struct seq_file *m, struct ptdump_info *info) > { > - walk_pgd(m); > - return 0; > -} > + struct pg_state st = { > + .seq = m, > + .marker = info->markers, > + }; > > -static int ptdump_open(struct inode *inode, struct file *file) > -{ > - return single_open(file, ptdump_show, NULL); > + walk_pgd(&st, info->mm, info->base_addr); > + note_page(&st, 0, 0, 0, NULL); > } > > -static const struct file_operations ptdump_fops = { > - .open = ptdump_open, > - .read = seq_read, > - .llseek = seq_lseek, > - .release = single_release, > -}; > - > -static int ptdump_init(void) > +static void ptdump_initialize(void) > { > - struct dentry *pe; > unsigned i, j; > > for (i = 0; i < ARRAY_SIZE(pg_level); i++) > @@ -387,9 +369,18 @@ static int ptdump_init(void) > pg_level[i].mask |= pg_level[i].bits[j].mask; > > address_markers[2].start_address = VMALLOC_START; > +} > > - pe = debugfs_create_file("kernel_page_tables", 0400, NULL, NULL, > - &ptdump_fops); > - return pe ? 0 : -ENOMEM; > +static struct ptdump_info kernel_ptdump_info = { > + .mm = &init_mm, > + .markers = address_markers, > + .base_addr = 0, > +}; > + > +static int ptdump_init(void) > +{ > + ptdump_initialize(); > + return ptdump_debugfs_register(&kernel_ptdump_info, > + "kernel_page_tables"); This changes the return value of ptdump_init. This should do similar to what was done before: return ptdump_debugfs_register(&kernel_ptdump_info, "kernel_page_tables") ? 0 : -ENOMEM; > } > __initcall(ptdump_init); > diff --git a/arch/arm/mm/ptdump_debugfs.c b/arch/arm/mm/ptdump_debugfs.c > new file mode 100644 > index 0000000..be8d87b > --- /dev/null > +++ b/arch/arm/mm/ptdump_debugfs.c > @@ -0,0 +1,34 @@ > +// SPDX-License-Identifier: GPL-2.0 > +#include <linux/debugfs.h> > +#include <linux/seq_file.h> > + > +#include <asm/ptdump.h> > + > +static int ptdump_show(struct seq_file *m, void *v) > +{ > + struct ptdump_info *info = m->private; > + > + ptdump_walk_pgd(m, info); > + return 0; > +} > + > +static int ptdump_open(struct inode *inode, struct file *file) > +{ > + return single_open(file, ptdump_show, inode->i_private); > +} > + > +static const struct file_operations ptdump_fops = { > + .open = ptdump_open, > + .read = seq_read, > + .llseek = seq_lseek, > + .release = single_release, > +}; > + > +int ptdump_debugfs_register(struct ptdump_info *info, const char *name) > +{ > + struct dentry *pe; > + > + pe = debugfs_create_file(name, 0400, NULL, info, &ptdump_fops); > + return pe ? 0 : -ENOMEM; > + > +} > -- > 1.9.1 > -Kees
>> +#ifndef __ASM_PTDUMP_H >> +#define __ASM_PTDUMP_H >> + >> +#ifdef CONFIG_ARM_PTDUMP_CORE > > Is this #ifdef needed? I think this file is only included in dump.c > and ptdump_debugfs.c, both of which are only built when > CONFIG_ARM_PTDUMP_CORE is defined. Looking at next patch in this patch-set series ([PATCH v3 3/3] arm: mm: dump: add checking for writable and executable pages), Not only dump.c and ptdump_debugfs.c but also arch/arm/mm/init.c include this file (ptdump.h) to call debug_checkwx(). mm/init.c is not built only when CONFIG_ARM_PTDUMP_CORE is defined. So, This #ifdef seems not be needed for this patch, but is needed for this patch-set series. >> +static int ptdump_init(void) >> +{ >> + ptdump_initialize(); >> + return ptdump_debugfs_register(&kernel_ptdump_info, >> + "kernel_page_tables"); > > This changes the return value of ptdump_init. This should do similar > to what was done before: > > return ptdump_debugfs_register(&kernel_ptdump_info, > "kernel_page_tables") ? 0 : -ENOMEM; ptdump_debugfs_register() already returns what you think. >> +int ptdump_debugfs_register(struct ptdump_info *info, const char *name) >> +{ >> + struct dentry *pe; >> + >> + pe = debugfs_create_file(name, 0400, NULL, info, &ptdump_fops); >> + return pe ? 0 : -ENOMEM; >> + >> +} So "return ptdump_debugfs_register(~~)" is fine. Thanks. Jinbum Park.
On Wed, Dec 6, 2017 at 1:45 AM, Jinbum Park <jinb.park7@gmail.com> wrote: >>> +#ifndef __ASM_PTDUMP_H >>> +#define __ASM_PTDUMP_H >>> + >>> +#ifdef CONFIG_ARM_PTDUMP_CORE >> >> Is this #ifdef needed? I think this file is only included in dump.c >> and ptdump_debugfs.c, both of which are only built when >> CONFIG_ARM_PTDUMP_CORE is defined. > > Looking at next patch in this patch-set series ([PATCH v3 3/3] arm: > mm: dump: add checking for writable and executable pages), > Not only dump.c and ptdump_debugfs.c but also arch/arm/mm/init.c > include this file (ptdump.h) to call debug_checkwx(). > mm/init.c is not built only when CONFIG_ARM_PTDUMP_CORE is defined. > So, This #ifdef seems not be needed for this patch, but is needed for > this patch-set series. > > >>> +static int ptdump_init(void) >>> +{ >>> + ptdump_initialize(); >>> + return ptdump_debugfs_register(&kernel_ptdump_info, >>> + "kernel_page_tables"); >> >> This changes the return value of ptdump_init. This should do similar >> to what was done before: >> >> return ptdump_debugfs_register(&kernel_ptdump_info, >> "kernel_page_tables") ? 0 : -ENOMEM; > > > ptdump_debugfs_register() already returns what you think. > >>> +int ptdump_debugfs_register(struct ptdump_info *info, const char *name) >>> +{ >>> + struct dentry *pe; >>> + >>> + pe = debugfs_create_file(name, 0400, NULL, info, &ptdump_fops); >>> + return pe ? 0 : -ENOMEM; >>> + >>> +} > > So "return ptdump_debugfs_register(~~)" is fine. Ah! Yes, I totally missed the change from create_file to debugfs_register. Sorry for the noise! -Kees
diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug index 17685e1..e7b94db 100644 --- a/arch/arm/Kconfig.debug +++ b/arch/arm/Kconfig.debug @@ -3,10 +3,14 @@ menu "Kernel hacking" source "lib/Kconfig.debug" -config ARM_PTDUMP +config ARM_PTDUMP_CORE + def_bool n + +config ARM_PTDUMP_DEBUGFS bool "Export kernel pagetable layout to userspace via debugfs" depends on DEBUG_KERNEL depends on MMU + select ARM_PTDUMP_CORE select DEBUG_FS ---help--- Say Y here if you want to show the kernel pagetable layout in a diff --git a/arch/arm/include/asm/ptdump.h b/arch/arm/include/asm/ptdump.h new file mode 100644 index 0000000..3a6c0b7 --- /dev/null +++ b/arch/arm/include/asm/ptdump.h @@ -0,0 +1,48 @@ +/* + * Copyright (C) 2014 ARM Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ +#ifndef __ASM_PTDUMP_H +#define __ASM_PTDUMP_H + +#ifdef CONFIG_ARM_PTDUMP_CORE + +#include <linux/mm_types.h> +#include <linux/seq_file.h> + +struct addr_marker { + unsigned long start_address; + char *name; +}; + +struct ptdump_info { + struct mm_struct *mm; + const struct addr_marker *markers; + unsigned long base_addr; +}; + +void ptdump_walk_pgd(struct seq_file *s, struct ptdump_info *info); +#ifdef CONFIG_ARM_PTDUMP_DEBUGFS +int ptdump_debugfs_register(struct ptdump_info *info, const char *name); +#else +static inline int ptdump_debugfs_register(struct ptdump_info *info, + const char *name) +{ + return 0; +} +#endif /* CONFIG_ARM_PTDUMP_DEBUGFS */ + +#endif /* CONFIG_ARM_PTDUMP_CORE */ + +#endif /* __ASM_PTDUMP_H */ diff --git a/arch/arm/mm/Makefile b/arch/arm/mm/Makefile index 01bcc33..28be5f4 100644 --- a/arch/arm/mm/Makefile +++ b/arch/arm/mm/Makefile @@ -13,7 +13,8 @@ obj-y += nommu.o obj-$(CONFIG_ARM_MPU) += pmsa-v7.o endif -obj-$(CONFIG_ARM_PTDUMP) += dump.o +obj-$(CONFIG_ARM_PTDUMP_CORE) += dump.o +obj-$(CONFIG_ARM_PTDUMP_DEBUGFS) += ptdump_debugfs.o obj-$(CONFIG_MODULES) += proc-syms.o obj-$(CONFIG_DEBUG_VIRTUAL) += physaddr.o diff --git a/arch/arm/mm/dump.c b/arch/arm/mm/dump.c index fc3b440..8dfe7c3 100644 --- a/arch/arm/mm/dump.c +++ b/arch/arm/mm/dump.c @@ -21,11 +21,7 @@ #include <asm/fixmap.h> #include <asm/memory.h> #include <asm/pgtable.h> - -struct addr_marker { - unsigned long start_address; - const char *name; -}; +#include <asm/ptdump.h> static struct addr_marker address_markers[] = { { MODULES_VADDR, "Modules" }, @@ -335,50 +331,36 @@ static void walk_pud(struct pg_state *st, pgd_t *pgd, unsigned long start) } } -static void walk_pgd(struct seq_file *m) +static void walk_pgd(struct pg_state *st, struct mm_struct *mm, + unsigned long start) { - pgd_t *pgd = swapper_pg_dir; - struct pg_state st; - unsigned long addr; + pgd_t *pgd = pgd_offset(mm, 0UL); unsigned i; - - memset(&st, 0, sizeof(st)); - st.seq = m; - st.marker = address_markers; + unsigned long addr; for (i = 0; i < PTRS_PER_PGD; i++, pgd++) { - addr = i * PGDIR_SIZE; + addr = start + i * PGDIR_SIZE; if (!pgd_none(*pgd)) { - walk_pud(&st, pgd, addr); + walk_pud(st, pgd, addr); } else { - note_page(&st, addr, 1, pgd_val(*pgd), NULL); + note_page(st, addr, 1, pgd_val(*pgd), NULL); } } - - note_page(&st, 0, 0, 0, NULL); } -static int ptdump_show(struct seq_file *m, void *v) +void ptdump_walk_pgd(struct seq_file *m, struct ptdump_info *info) { - walk_pgd(m); - return 0; -} + struct pg_state st = { + .seq = m, + .marker = info->markers, + }; -static int ptdump_open(struct inode *inode, struct file *file) -{ - return single_open(file, ptdump_show, NULL); + walk_pgd(&st, info->mm, info->base_addr); + note_page(&st, 0, 0, 0, NULL); } -static const struct file_operations ptdump_fops = { - .open = ptdump_open, - .read = seq_read, - .llseek = seq_lseek, - .release = single_release, -}; - -static int ptdump_init(void) +static void ptdump_initialize(void) { - struct dentry *pe; unsigned i, j; for (i = 0; i < ARRAY_SIZE(pg_level); i++) @@ -387,9 +369,18 @@ static int ptdump_init(void) pg_level[i].mask |= pg_level[i].bits[j].mask; address_markers[2].start_address = VMALLOC_START; +} - pe = debugfs_create_file("kernel_page_tables", 0400, NULL, NULL, - &ptdump_fops); - return pe ? 0 : -ENOMEM; +static struct ptdump_info kernel_ptdump_info = { + .mm = &init_mm, + .markers = address_markers, + .base_addr = 0, +}; + +static int ptdump_init(void) +{ + ptdump_initialize(); + return ptdump_debugfs_register(&kernel_ptdump_info, + "kernel_page_tables"); } __initcall(ptdump_init); diff --git a/arch/arm/mm/ptdump_debugfs.c b/arch/arm/mm/ptdump_debugfs.c new file mode 100644 index 0000000..be8d87b --- /dev/null +++ b/arch/arm/mm/ptdump_debugfs.c @@ -0,0 +1,34 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/debugfs.h> +#include <linux/seq_file.h> + +#include <asm/ptdump.h> + +static int ptdump_show(struct seq_file *m, void *v) +{ + struct ptdump_info *info = m->private; + + ptdump_walk_pgd(m, info); + return 0; +} + +static int ptdump_open(struct inode *inode, struct file *file) +{ + return single_open(file, ptdump_show, inode->i_private); +} + +static const struct file_operations ptdump_fops = { + .open = ptdump_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +int ptdump_debugfs_register(struct ptdump_info *info, const char *name) +{ + struct dentry *pe; + + pe = debugfs_create_file(name, 0400, NULL, info, &ptdump_fops); + return pe ? 0 : -ENOMEM; + +}
This patch refactors the arm page table dumping code, so multiple tables may be registered with the framework. This patch refers below commits of arm64. (4674fdb9f149 ("arm64: mm: dump: make page table dumping reusable")) (4ddb9bf83349 ("arm64: dump: Make ptdump debugfs a separate option")) Signed-off-by: Jinbum Park <jinb.park7@gmail.com> --- v3: No changes arch/arm/Kconfig.debug | 6 +++- arch/arm/include/asm/ptdump.h | 48 ++++++++++++++++++++++++++++++++ arch/arm/mm/Makefile | 3 +- arch/arm/mm/dump.c | 65 +++++++++++++++++++------------------------ arch/arm/mm/ptdump_debugfs.c | 34 ++++++++++++++++++++++ 5 files changed, 117 insertions(+), 39 deletions(-) create mode 100644 arch/arm/include/asm/ptdump.h create mode 100644 arch/arm/mm/ptdump_debugfs.c