Commit e63732db authored by Patrick Daly's avatar Patrick Daly Committed by Vinayak Menon

lib/vsprintf: Less restrictive hashed pointer printing

Commit ad67b74d ("printk: hash addresses printed with %p") and
Commit ef0010a3 ("vsprintf: don't use 'restricted_pointer()'
when not restricting") effectively removed the ability to display
kernel addresses in the kernel log. While this may be a useful feature
in production builds, it is undesirable when trying to debug.

%px is not a possible alternative, because it is unable to differentiate
between a debug and production build.

Change-Id: I139fae7b8488936d214efdd2b5b807fa1c005467
Signed-off-by: default avatarPatrick Daly <pdaly@codeaurora.org>
[vinmenon@codeaurora.org: fixed the Kconfig conflicts]
Signed-off-by: default avatarVinayak Menon <vinmenon@codeaurora.org>
parent 0e58b739
......@@ -144,6 +144,14 @@ config DEBUG_MODULE_LOAD_INFO
If unsure, say N.
config DEBUG_CONSOLE_UNHASHED_POINTERS
bool "Display unhashed kernel pointers"
depends on DEBUG_KERNEL
help
Pointers %p and %pK are normally hashed prior to being displayed to
prevent leaking kernel addresses. On debug builds, always print
actual pointer values, ignoring the kptr_restrict setting.
Not to be enabled on production builds.
endmenu # "printk and dmesg options"
......
......@@ -1928,7 +1928,8 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
return buf;
}
case 'K':
if (!kptr_restrict)
if (!kptr_restrict ||
IS_ENABLED(CONFIG_DEBUG_CONSOLE_UNHASHED_POINTERS))
break;
return restricted_pointer(buf, end, ptr, spec);
case 'N':
......@@ -1959,6 +1960,9 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
return pointer_string(buf, end, ptr, spec);
}
if (IS_ENABLED(CONFIG_DEBUG_CONSOLE_UNHASHED_POINTERS))
return pointer_string(buf, end, ptr, spec);
/* default is to _not_ leak addresses, hash before printing */
return ptr_to_id(buf, end, ptr, spec);
}
......
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