From 4188f063e3694ccbf2a2044cf17cc325f91e458f Mon Sep 17 00:00:00 2001 From: Dmitry Vyukov Date: Mon, 25 Jun 2018 14:38:08 +0200 Subject: x86/mm: Get rid of KERN_CONT in show_fault_oops() KERN_CONT leads to split lines in kernel output and complicates useful changes to printk like printing context before each line. Only acceptable use of continuations is basically boot-time testing. Get rid of it. Signed-off-by: Dmitry Vyukov Reviewed-by: Sergey Senozhatsky Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20180625123808.227417-1-dvyukov@gmail.com [ Removed unnecessary parentheses and prettified the printk statement. ] Signed-off-by: Ingo Molnar --- arch/x86/mm/fault.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) (limited to 'arch/x86/mm/fault.c') diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 9a84a0d08727..ee85766e6329 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -671,13 +671,9 @@ show_fault_oops(struct pt_regs *regs, unsigned long error_code, printk(smep_warning, from_kuid(&init_user_ns, current_uid())); } - printk(KERN_ALERT "BUG: unable to handle kernel "); - if (address < PAGE_SIZE) - printk(KERN_CONT "NULL pointer dereference"); - else - printk(KERN_CONT "paging request"); - - printk(KERN_CONT " at %px\n", (void *) address); + pr_alert("BUG: unable to handle kernel %s at %px\n", + address < PAGE_SIZE ? "NULL pointer dereference" : "paging request", + (void *)address); dump_pagetable(address); } -- cgit v1.2.3 From d79d0d8ad0cb3d782b41631dfeac8eb05e414bcd Mon Sep 17 00:00:00 2001 From: Dmitry Vyukov Date: Wed, 27 Jun 2018 11:07:15 +0200 Subject: x86/mm: Clean up the printk()s in show_fault_oops() - Remove 'nx_warning' and 'smep_warning', which are just pointless obfuscation. - Also convert to pr_crit(). Suggested-by: Joe Perches Signed-off-by: Dmitry Vyukov Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20180627090715.28076-1-dvyukov@gmail.com Signed-off-by: Ingo Molnar --- arch/x86/mm/fault.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) (limited to 'arch/x86/mm/fault.c') diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index ee85766e6329..2aafa6ab6103 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -641,11 +641,6 @@ static int is_f00f_bug(struct pt_regs *regs, unsigned long address) return 0; } -static const char nx_warning[] = KERN_CRIT -"kernel tried to execute NX-protected page - exploit attempt? (uid: %d)\n"; -static const char smep_warning[] = KERN_CRIT -"unable to execute userspace code (SMEP?) (uid: %d)\n"; - static void show_fault_oops(struct pt_regs *regs, unsigned long error_code, unsigned long address) @@ -664,11 +659,13 @@ show_fault_oops(struct pt_regs *regs, unsigned long error_code, pte = lookup_address_in_pgd(pgd, address, &level); if (pte && pte_present(*pte) && !pte_exec(*pte)) - printk(nx_warning, from_kuid(&init_user_ns, current_uid())); + pr_crit("kernel tried to execute NX-protected page - exploit attempt? (uid: %d)\n", + from_kuid(&init_user_ns, current_uid())); if (pte && pte_present(*pte) && pte_exec(*pte) && (pgd_flags(*pgd) & _PAGE_USER) && (__read_cr4() & X86_CR4_SMEP)) - printk(smep_warning, from_kuid(&init_user_ns, current_uid())); + pr_crit("unable to execute userspace code (SMEP?) (uid: %d)\n", + from_kuid(&init_user_ns, current_uid())); } pr_alert("BUG: unable to handle kernel %s at %px\n", -- cgit v1.2.3