From 469277ff5ac8058c2e716bca7a4cda5a4a5c1d9b Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Thu, 17 Feb 2022 09:49:59 +0100 Subject: vsprintf: Fix %pK with kptr_restrict == 0 [ Upstream commit 84842911322fc6a02a03ab9e728a48c691fe3efd ] Although kptr_restrict is set to 0 and the kernel is booted with no_hash_pointers parameter, the content of /proc/vmallocinfo is lacking the real addresses. / # cat /proc/vmallocinfo 0x(ptrval)-0x(ptrval) 8192 load_module+0xc0c/0x2c0c pages=1 vmalloc 0x(ptrval)-0x(ptrval) 12288 start_kernel+0x4e0/0x690 pages=2 vmalloc 0x(ptrval)-0x(ptrval) 12288 start_kernel+0x4e0/0x690 pages=2 vmalloc 0x(ptrval)-0x(ptrval) 8192 _mpic_map_mmio.constprop.0+0x20/0x44 phys=0x80041000 ioremap 0x(ptrval)-0x(ptrval) 12288 _mpic_map_mmio.constprop.0+0x20/0x44 phys=0x80041000 ioremap ... According to the documentation for /proc/sys/kernel/, %pK is equivalent to %p when kptr_restrict is set to 0. Fixes: 5ead723a20e0 ("lib/vsprintf: no_hash_pointers prints all addresses as unhashed") Signed-off-by: Christophe Leroy Reviewed-by: Petr Mladek Signed-off-by: Petr Mladek Link: https://lore.kernel.org/r/107476128e59bff11a309b5bf7579a1753a41aca.1645087605.git.christophe.leroy@csgroup.eu Signed-off-by: Sasha Levin --- Documentation/admin-guide/kernel-parameters.txt | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'Documentation') diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index ed55ea20352b..bb25aae69860 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -3452,8 +3452,7 @@ difficult since unequal pointers can no longer be compared. However, if this command-line option is specified, then all normal pointers will have their true - value printed. Pointers printed via %pK may still be - hashed. This option should only be specified when + value printed. This option should only be specified when debugging the kernel. Please do not use on production kernels. -- cgit v1.2.3