[RFC PATCH 06/15] x86/pks: Add a debugfs file for allocated PKS keys
From: <hidden>
Date: 2020-07-14 07:05:36
Also in:
linux-fsdevel, linux-kselftest, linux-mm, lkml, nvdimm
Subsystem:
the rest, x86 architecture (32-bit and 64-bit), x86 mm · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen, Andy Lutomirski, Peter Zijlstra
From: Fenghua Yu <redacted> The sysadmin may need to know which PKS keys are currently being used. Add a debugfs file to show the allocated PKS keys and their names. Signed-off-by: Fenghua Yu <redacted> --- arch/x86/mm/pkeys.c | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+)
diff --git a/arch/x86/mm/pkeys.c b/arch/x86/mm/pkeys.c
index 16f735c12fcd..e565fadd74d7 100644
--- a/arch/x86/mm/pkeys.c
+++ b/arch/x86/mm/pkeys.c@@ -328,3 +328,43 @@ void pks_key_free(int pkey) mutex_unlock(&pks_lock); } EXPORT_SYMBOL_GPL(pks_key_free); + +static int pks_keys_allocated_show(struct seq_file *m, void *p) +{ + int i; + + mutex_lock(&pks_lock); + for (i = PKS_KERN_DEFAULT_KEY; i < PKS_NUM_KEYS; i++) { + /* It is ok for pks_key_users[i] to be NULL */ + if (test_bit(i, &pks_key_allocation_map)) + seq_printf(m, "%d: %s\n", i, pks_key_users[i]); + } + mutex_unlock(&pks_lock); + + return 0; +} + +static int pks_keys_allocated_open(struct inode *inode, struct file *file) +{ + return single_open(file, pks_keys_allocated_show, NULL); +} + +static const struct file_operations pks_keys_allocated_fops = { + .open = pks_keys_allocated_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static int __init pks_keys_initcall(void) +{ + if (cpu_feature_enabled(X86_FEATURE_PKS)) { + /* Create a debugfs file to show allocated PKS keys. */ + debugfs_create_file("pks_keys_allocated", 0400, + arch_debugfs_dir, NULL, + &pks_keys_allocated_fops); + } + + return 0; +} +late_initcall(pks_keys_initcall);
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2.25.1