From 3a62583c2853b0ab37a57dde79decea210b5fb89 Mon Sep 17 00:00:00 2001 From: William Roche Date: Tue, 6 Apr 2021 11:28:59 -0400 Subject: [PATCH 1/2] RAS/CEC: Correct ce_add_elem()'s returned values ce_add_elem() uses different return values to signal a result from adding an element to the collector. Commit in Fixes: broke the case where the element being added is not found in the array. Correct that. [ bp: Rewrite commit message, add kernel-doc comments. ] Fixes: de0e0624d86f ("RAS/CEC: Check count_threshold unconditionally") Signed-off-by: William Roche Signed-off-by: Borislav Petkov Cc: Link: https://lkml.kernel.org/r/1617722939-29670-1-git-send-email-william.roche@oracle.com --- drivers/ras/cec.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/ras/cec.c b/drivers/ras/cec.c index ddecf25b5dd4..d7894f178bd4 100644 --- a/drivers/ras/cec.c +++ b/drivers/ras/cec.c @@ -309,11 +309,20 @@ static bool sanity_check(struct ce_array *ca) return ret; } +/** + * cec_add_elem - Add an element to the CEC array. + * @pfn: page frame number to insert + * + * Return values: + * - <0: on error + * - 0: on success + * - >0: when the inserted pfn was offlined + */ static int cec_add_elem(u64 pfn) { struct ce_array *ca = &ce_arr; + int count, err, ret = 0; unsigned int to = 0; - int count, ret = 0; /* * We can be called very early on the identify_cpu() path where we are @@ -330,8 +339,8 @@ static int cec_add_elem(u64 pfn) if (ca->n == MAX_ELEMS) WARN_ON(!del_lru_elem_unlocked(ca)); - ret = find_elem(ca, pfn, &to); - if (ret < 0) { + err = find_elem(ca, pfn, &to); + if (err < 0) { /* * Shift range [to-end] to make room for one more element. */ From 632a1c209b8773cb0119fe3aada9f1db14fa357c Mon Sep 17 00:00:00 2001 From: Thomas Tai Date: Thu, 8 Apr 2021 13:28:33 -0400 Subject: [PATCH 2/2] x86/traps: Correct exc_general_protection() and math_error() return paths Commit 334872a09198 ("x86/traps: Attempt to fixup exceptions in vDSO before signaling") added return statements which bypass calling cond_local_irq_disable(). According to ca4c6a9858c2 ("x86/traps: Make interrupt enable/disable symmetric in C code"), cond_local_irq_disable() is needed because the asm return code no longer disables interrupts. Follow the existing code as an example to use "goto exit" instead of "return" statement. [ bp: Massage commit message. ] Fixes: 334872a09198 ("x86/traps: Attempt to fixup exceptions in vDSO before signaling") Signed-off-by: Thomas Tai Signed-off-by: Borislav Petkov Reviewed-by: Alexandre Chartre Link: https://lkml.kernel.org/r/1617902914-83245-1-git-send-email-thomas.tai@oracle.com --- arch/x86/kernel/traps.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index ac1874a2a70e..651e3e508959 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -556,7 +556,7 @@ DEFINE_IDTENTRY_ERRORCODE(exc_general_protection) tsk->thread.trap_nr = X86_TRAP_GP; if (fixup_vdso_exception(regs, X86_TRAP_GP, error_code, 0)) - return; + goto exit; show_signal(tsk, SIGSEGV, "", desc, regs, error_code); force_sig(SIGSEGV); @@ -1057,7 +1057,7 @@ static void math_error(struct pt_regs *regs, int trapnr) goto exit; if (fixup_vdso_exception(regs, trapnr, 0, 0)) - return; + goto exit; force_sig_fault(SIGFPE, si_code, (void __user *)uprobe_get_trap_addr(regs));