From ce041c43f22298485122bab15c14d062383fbc67 Mon Sep 17 00:00:00 2001 From: Thierry Escande Date: Wed, 13 Jun 2018 19:18:40 +0200 Subject: [PATCH] lib/test_printf.c: accept "ptrval" as valid result for plain 'p' tests If the test_printf module is loaded before the crng is initialized, the plain 'p' tests will fail because the printed address will not be hashed and the buffer will contain "(____ptrval____)" or "(ptrval)" instead (64-bit vs 32-bit). Since we cannot wait for the crng to be initialized for an undefined time, both plain 'p' tests now accept the strings "(____ptrval____)" or "(ptrval)" as a valid result and print a warning message. Link: http://lkml.kernel.org/r/20180613171840.29827-1-thierry.escande@linaro.org Fixes: ad67b74d2469d9b82 ("printk: hash addresses printed with %p") To: Andrew Morton To: David Miller Cc: Rasmus Villemoes Cc: "Tobin C . Harding" Cc: linux-kernel@vger.kernel.org Signed-off-by: Thierry Escande Reviewed-by: Andy Shevchenko Signed-off-by: Petr Mladek --- lib/test_printf.c | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-) diff --git a/lib/test_printf.c b/lib/test_printf.c index cea592f402ed..53527ea822b5 100644 --- a/lib/test_printf.c +++ b/lib/test_printf.c @@ -206,6 +206,7 @@ test_string(void) #define PTR_WIDTH 16 #define PTR ((void *)0xffff0123456789abUL) #define PTR_STR "ffff0123456789ab" +#define PTR_VAL_NO_CRNG "(____ptrval____)" #define ZEROS "00000000" /* hex 32 zero bits */ static int __init @@ -216,7 +217,16 @@ plain_format(void) nchars = snprintf(buf, PLAIN_BUF_SIZE, "%p", PTR); - if (nchars != PTR_WIDTH || strncmp(buf, ZEROS, strlen(ZEROS)) != 0) + if (nchars != PTR_WIDTH) + return -1; + + if (strncmp(buf, PTR_VAL_NO_CRNG, PTR_WIDTH) == 0) { + pr_warn("crng possibly not yet initialized. plain 'p' buffer contains \"%s\"", + PTR_VAL_NO_CRNG); + return 0; + } + + if (strncmp(buf, ZEROS, strlen(ZEROS)) != 0) return -1; return 0; @@ -227,6 +237,7 @@ plain_format(void) #define PTR_WIDTH 8 #define PTR ((void *)0x456789ab) #define PTR_STR "456789ab" +#define PTR_VAL_NO_CRNG "(ptrval)" static int __init plain_format(void) @@ -245,7 +256,16 @@ plain_hash(void) nchars = snprintf(buf, PLAIN_BUF_SIZE, "%p", PTR); - if (nchars != PTR_WIDTH || strncmp(buf, PTR_STR, PTR_WIDTH) == 0) + if (nchars != PTR_WIDTH) + return -1; + + if (strncmp(buf, PTR_VAL_NO_CRNG, PTR_WIDTH) == 0) { + pr_warn("crng possibly not yet initialized. plain 'p' buffer contains \"%s\"", + PTR_VAL_NO_CRNG); + return 0; + } + + if (strncmp(buf, PTR_STR, PTR_WIDTH) == 0) return -1; return 0;