mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-28 11:18:45 +07:00
e47690d756
struct mm_struct is quite large (~1664 bytes) and so allocating on the stack may cause problems as the kernel stack size is small. Since ptdump_walk_pgd_level_core() was only allocating the structure so that it could modify the pgd argument we can instead introduce a pgd override in struct mm_walk and pass this down the call stack to where it is needed. Since the correct mm_struct is now being passed down, it is now also unnecessary to take the mmap_sem semaphore because ptdump_walk_pgd() will now take the semaphore on the real mm. [steven.price@arm.com: restore missed arm64 changes] Link: http://lkml.kernel.org/r/20200108145710.34314-1-steven.price@arm.com Link: http://lkml.kernel.org/r/20200108145710.34314-1-steven.price@arm.com Signed-off-by: Steven Price <steven.price@arm.com> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David S. Miller <davem@davemloft.net> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Hogan <jhogan@kernel.org> Cc: James Morse <james.morse@arm.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: "Liang, Kan" <kan.liang@linux.intel.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Burton <paul.burton@mips.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Will Deacon <will@kernel.org> Cc: Zong Li <zong.li@sifive.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
77 lines
1.8 KiB
C
77 lines
1.8 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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#include <linux/debugfs.h>
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#include <linux/efi.h>
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#include <linux/module.h>
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#include <linux/seq_file.h>
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#include <asm/pgtable.h>
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static int ptdump_show(struct seq_file *m, void *v)
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{
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ptdump_walk_pgd_level_debugfs(m, &init_mm, false);
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return 0;
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}
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DEFINE_SHOW_ATTRIBUTE(ptdump);
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static int ptdump_curknl_show(struct seq_file *m, void *v)
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{
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if (current->mm->pgd)
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ptdump_walk_pgd_level_debugfs(m, current->mm, false);
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return 0;
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}
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DEFINE_SHOW_ATTRIBUTE(ptdump_curknl);
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#ifdef CONFIG_PAGE_TABLE_ISOLATION
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static int ptdump_curusr_show(struct seq_file *m, void *v)
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{
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if (current->mm->pgd)
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ptdump_walk_pgd_level_debugfs(m, current->mm, true);
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return 0;
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}
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DEFINE_SHOW_ATTRIBUTE(ptdump_curusr);
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#endif
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#if defined(CONFIG_EFI) && defined(CONFIG_X86_64)
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static int ptdump_efi_show(struct seq_file *m, void *v)
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{
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if (efi_mm.pgd)
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ptdump_walk_pgd_level_debugfs(m, &efi_mm, false);
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return 0;
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}
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DEFINE_SHOW_ATTRIBUTE(ptdump_efi);
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#endif
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static struct dentry *dir;
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static int __init pt_dump_debug_init(void)
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{
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dir = debugfs_create_dir("page_tables", NULL);
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debugfs_create_file("kernel", 0400, dir, NULL, &ptdump_fops);
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debugfs_create_file("current_kernel", 0400, dir, NULL,
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&ptdump_curknl_fops);
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#ifdef CONFIG_PAGE_TABLE_ISOLATION
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debugfs_create_file("current_user", 0400, dir, NULL,
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&ptdump_curusr_fops);
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#endif
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#if defined(CONFIG_EFI) && defined(CONFIG_X86_64)
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debugfs_create_file("efi", 0400, dir, NULL, &ptdump_efi_fops);
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#endif
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return 0;
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}
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static void __exit pt_dump_debug_exit(void)
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{
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debugfs_remove_recursive(dir);
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}
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module_init(pt_dump_debug_init);
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module_exit(pt_dump_debug_exit);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Arjan van de Ven <arjan@linux.intel.com>");
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MODULE_DESCRIPTION("Kernel debugging helper that dumps pagetables");
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