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vsprintf: Shuffle restricted_pointer()
This is just a preparation step for further changes. The patch does not change the code. Link: http://lkml.kernel.org/r/20190417115350.20479-2-pmladek@suse.com To: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: "Tobin C . Harding" <me@tobin.cc> Cc: Joe Perches <joe@perches.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: linux-kernel@vger.kernel.org Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
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@ -717,6 +717,55 @@ static char *ptr_to_id(char *buf, char *end, const void *ptr,
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return pointer_string(buf, end, (const void *)hashval, spec);
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}
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int kptr_restrict __read_mostly;
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static noinline_for_stack
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char *restricted_pointer(char *buf, char *end, const void *ptr,
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struct printf_spec spec)
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{
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switch (kptr_restrict) {
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case 0:
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/* Always print %pK values */
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break;
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case 1: {
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const struct cred *cred;
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/*
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* kptr_restrict==1 cannot be used in IRQ context
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* because its test for CAP_SYSLOG would be meaningless.
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*/
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if (in_irq() || in_serving_softirq() || in_nmi()) {
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if (spec.field_width == -1)
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spec.field_width = 2 * sizeof(ptr);
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return string(buf, end, "pK-error", spec);
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}
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/*
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* Only print the real pointer value if the current
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* process has CAP_SYSLOG and is running with the
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* same credentials it started with. This is because
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* access to files is checked at open() time, but %pK
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* checks permission at read() time. We don't want to
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* leak pointer values if a binary opens a file using
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* %pK and then elevates privileges before reading it.
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*/
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cred = current_cred();
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if (!has_capability_noaudit(current, CAP_SYSLOG) ||
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!uid_eq(cred->euid, cred->uid) ||
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!gid_eq(cred->egid, cred->gid))
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ptr = NULL;
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break;
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}
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case 2:
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default:
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/* Always print 0's for %pK */
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ptr = NULL;
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break;
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}
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return pointer_string(buf, end, ptr, spec);
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}
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static noinline_for_stack
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char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
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const char *fmt)
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@ -1476,55 +1525,6 @@ char *uuid_string(char *buf, char *end, const u8 *addr,
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return string(buf, end, uuid, spec);
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}
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int kptr_restrict __read_mostly;
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static noinline_for_stack
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char *restricted_pointer(char *buf, char *end, const void *ptr,
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struct printf_spec spec)
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{
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switch (kptr_restrict) {
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case 0:
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/* Always print %pK values */
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break;
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case 1: {
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const struct cred *cred;
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/*
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* kptr_restrict==1 cannot be used in IRQ context
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* because its test for CAP_SYSLOG would be meaningless.
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*/
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if (in_irq() || in_serving_softirq() || in_nmi()) {
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if (spec.field_width == -1)
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spec.field_width = 2 * sizeof(ptr);
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return string(buf, end, "pK-error", spec);
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}
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/*
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* Only print the real pointer value if the current
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* process has CAP_SYSLOG and is running with the
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* same credentials it started with. This is because
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* access to files is checked at open() time, but %pK
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* checks permission at read() time. We don't want to
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* leak pointer values if a binary opens a file using
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* %pK and then elevates privileges before reading it.
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*/
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cred = current_cred();
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if (!has_capability_noaudit(current, CAP_SYSLOG) ||
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!uid_eq(cred->euid, cred->uid) ||
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!gid_eq(cred->egid, cred->gid))
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ptr = NULL;
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break;
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}
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case 2:
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default:
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/* Always print 0's for %pK */
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ptr = NULL;
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break;
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}
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return pointer_string(buf, end, ptr, spec);
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}
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static noinline_for_stack
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char *netdev_bits(char *buf, char *end, const void *addr,
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struct printf_spec spec, const char *fmt)
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