From 566ffa3ae9649f7aa1debcf559ee7e26ed4a110f Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 25 Jul 2023 14:17:39 +0200 Subject: [PATCH 01/11] x86/cpu: Fix amd_check_microcode() declaration The newly added amd_check_microcode() function has two conflicting definitions if CONFIG_CPU_SUP_AMD is enabled and CONFIG_MICROCODE_AMD is disabled. Since the header with the stub definition is not included in cpu/amd.c, this only causes a -Wmissing-prototype warning with W=1: arch/x86/kernel/cpu/amd.c:1289:6: error: no previous prototype for 'amd_check_microcode' [-Werror=missing-prototypes] Adding the missing #include shows the other problem: arch/x86/kernel/cpu/amd.c:1290:6: error: redefinition of 'amd_check_microcode' arch/x86/include/asm/microcode_amd.h:58:20: note: previous definition of 'amd_check_microcode' with type 'void(void)' Move the declaration into a more appropriate header that is already included, with the #ifdef check changed to match the definition's. Fixes: 522b1d69219d8 ("x86/cpu/amd: Add a Zenbleed fix") Signed-off-by: Arnd Bergmann Signed-off-by: Borislav Petkov (AMD) Link: https://lore.kernel.org/r/20230725121751.2007665-1-arnd@kernel.org --- arch/x86/include/asm/microcode_amd.h | 3 +-- arch/x86/include/asm/processor.h | 2 ++ 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/microcode_amd.h b/arch/x86/include/asm/microcode_amd.h index 9675c621c1ca..2ed09a1da4a2 100644 --- a/arch/x86/include/asm/microcode_amd.h +++ b/arch/x86/include/asm/microcode_amd.h @@ -48,13 +48,12 @@ extern void __init load_ucode_amd_bsp(unsigned int family); extern void load_ucode_amd_ap(unsigned int family); extern int __init save_microcode_in_initrd_amd(unsigned int family); void reload_ucode_amd(unsigned int cpu); -extern void amd_check_microcode(void); #else static inline void __init load_ucode_amd_bsp(unsigned int family) {} static inline void load_ucode_amd_ap(unsigned int family) {} static inline int __init save_microcode_in_initrd_amd(unsigned int family) { return -EINVAL; } static inline void reload_ucode_amd(unsigned int cpu) {} -static inline void amd_check_microcode(void) {} #endif + #endif /* _ASM_X86_MICROCODE_AMD_H */ diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index d46300e94f85..36d52075fdad 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -682,9 +682,11 @@ extern u16 get_llc_id(unsigned int cpu); #ifdef CONFIG_CPU_SUP_AMD extern u32 amd_get_nodes_per_socket(void); extern u32 amd_get_highest_perf(void); +extern void amd_check_microcode(void); #else static inline u32 amd_get_nodes_per_socket(void) { return 0; } static inline u32 amd_get_highest_perf(void) { return 0; } +static inline void amd_check_microcode(void) { } #endif extern unsigned long arch_align_stack(unsigned long sp); From ac1c6283c45a77431af33fbae435f1a29f23a9f4 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 25 Jul 2023 15:48:33 +0200 Subject: [PATCH 02/11] x86/apic: Hide unused safe_smp_processor_id() on 32-bit UP When CONFIG_SMP is disabled in a 32-bit config, the prototype for safe_smp_processor_id() is hidden, which causes a W=1 warning: arch/x86/kernel/apic/ipi.c:316:5: error: no previous prototype for 'safe_smp_processor_id' [-Werror=missing-prototypes] Since there are no callers in this configuration, just hide the definition as well. [ bp: Clarify it is a 32-bit config. ] Signed-off-by: Arnd Bergmann Signed-off-by: Borislav Petkov (AMD) Link: https://lore.kernel.org/r/20230725134837.1534228-2-arnd@kernel.org --- arch/x86/kernel/apic/ipi.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/kernel/apic/ipi.c b/arch/x86/kernel/apic/ipi.c index 2a6509e8c840..9bfd6e397384 100644 --- a/arch/x86/kernel/apic/ipi.c +++ b/arch/x86/kernel/apic/ipi.c @@ -301,6 +301,7 @@ void default_send_IPI_mask_logical(const struct cpumask *cpumask, int vector) local_irq_restore(flags); } +#ifdef CONFIG_SMP /* must come after the send_IPI functions above for inlining */ static int convert_apicid_to_cpu(int apic_id) { @@ -329,3 +330,4 @@ int safe_smp_processor_id(void) return cpuid >= 0 ? cpuid : 0; } #endif +#endif From 22dc02f81cddd19528fc1d4fbd7404defbf736c5 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 24 Jul 2023 21:30:54 +0200 Subject: [PATCH 03/11] Revert "sched/fair: Move unused stub functions to header" Revert commit 7aa55f2a5902 ("sched/fair: Move unused stub functions to header"), for while it has the right Changelog, the actual patch content a revert of the previous 4 patches: f7df852ad6db ("sched: Make task_vruntime_update() prototype visible") c0bdfd72fbfb ("sched/fair: Hide unused init_cfs_bandwidth() stub") 378be384e01f ("sched: Add schedule_user() declaration") d55ebae3f312 ("sched: Hide unused sched_update_scaling()") So in effect this is a revert of a revert and re-applies those patches. Fixes: 7aa55f2a5902 ("sched/fair: Move unused stub functions to header") Reported-by: Arnd Bergmann Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Borislav Petkov (AMD) --- kernel/sched/fair.c | 6 +++--- kernel/sched/sched.h | 2 ++ 2 files changed, 5 insertions(+), 3 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index b3e25be58e2b..695f8e5c9e77 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -684,7 +684,7 @@ struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq) /************************************************************** * Scheduling class statistics methods: */ - +#ifdef CONFIG_SMP int sched_update_scaling(void) { unsigned int factor = get_update_sysctl_factor(); @@ -702,6 +702,7 @@ int sched_update_scaling(void) return 0; } #endif +#endif /* * delta /= w @@ -6186,9 +6187,8 @@ static inline int throttled_lb_pair(struct task_group *tg, return 0; } -void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b) {} - #ifdef CONFIG_FAIR_GROUP_SCHED +void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b) {} static void init_cfs_rq_runtime(struct cfs_rq *cfs_rq) {} #endif diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index e93e006a942b..44b540ad37b7 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -1245,6 +1245,7 @@ static inline raw_spinlock_t *__rq_lockp(struct rq *rq) bool cfs_prio_less(const struct task_struct *a, const struct task_struct *b, bool fi); +void task_vruntime_update(struct rq *rq, struct task_struct *p, bool in_fi); /* * Helpers to check if the CPU's core cookie matches with the task's cookie @@ -2398,6 +2399,7 @@ static inline struct cpuidle_state *idle_get_state(struct rq *rq) #endif extern void schedule_idle(void); +asmlinkage void schedule_user(void); extern void sysrq_sched_debug_show(void); extern void sched_init_granularity(void); From 65412c8d72741cc6e6b082b478b8957d7e7c0480 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Thu, 3 Aug 2023 10:26:15 +0200 Subject: [PATCH 04/11] x86/asm: Avoid unneeded __div64_32 function definition The __div64_32() function is provided for 32-bit architectures that don't have a custom do_div() implementation. x86_32 has one, and does not use the header file that declares the function prototype, so the definition causes a W=1 warning: lib/math/div64.c:31:32: error: no previous prototype for '__div64_32' [-Werror=missing-prototypes] Define an empty macro to prevent the function definition from getting built, which avoids the warning and saves a little .text space. Signed-off-by: Arnd Bergmann Signed-off-by: Borislav Petkov (AMD) Link: https://lore.kernel.org/r/20230803082619.1369127-4-arnd@kernel.org --- arch/x86/include/asm/div64.h | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/x86/include/asm/div64.h b/arch/x86/include/asm/div64.h index b8f1dc0761e4..9931e4c7d73f 100644 --- a/arch/x86/include/asm/div64.h +++ b/arch/x86/include/asm/div64.h @@ -71,6 +71,12 @@ static inline u64 mul_u32_u32(u32 a, u32 b) } #define mul_u32_u32 mul_u32_u32 +/* + * __div64_32() is never called on x86, so prevent the + * generic definition from getting built. + */ +#define __div64_32 + #else # include From 6d33531bc0234332572ae612232d947f353a4450 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Thu, 3 Aug 2023 10:26:16 +0200 Subject: [PATCH 05/11] x86/purgatory: Include header for warn() declaration The purgatory code uses parts of the decompressor and provides its own warn() function, but has to include the corresponding header file to avoid a -Wmissing-prototypes warning. It turns out that this function prototype actually differs from the declaration, so change it to get a constant pointer in the declaration and the other definition as well. Signed-off-by: Arnd Bergmann Signed-off-by: Borislav Petkov (AMD) Link: https://lore.kernel.org/r/20230803082619.1369127-5-arnd@kernel.org --- arch/x86/boot/compressed/error.c | 2 +- arch/x86/boot/compressed/error.h | 2 +- arch/x86/purgatory/purgatory.c | 1 + 3 files changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/x86/boot/compressed/error.c b/arch/x86/boot/compressed/error.c index 5313c5cb2b80..19a8251de506 100644 --- a/arch/x86/boot/compressed/error.c +++ b/arch/x86/boot/compressed/error.c @@ -7,7 +7,7 @@ #include "misc.h" #include "error.h" -void warn(char *m) +void warn(const char *m) { error_putstr("\n\n"); error_putstr(m); diff --git a/arch/x86/boot/compressed/error.h b/arch/x86/boot/compressed/error.h index 86fe33b93715..31f9e080d61a 100644 --- a/arch/x86/boot/compressed/error.h +++ b/arch/x86/boot/compressed/error.h @@ -4,7 +4,7 @@ #include -void warn(char *m); +void warn(const char *m); void error(char *m) __noreturn; void panic(const char *fmt, ...) __noreturn __cold; diff --git a/arch/x86/purgatory/purgatory.c b/arch/x86/purgatory/purgatory.c index 7558139920f8..aea47e793963 100644 --- a/arch/x86/purgatory/purgatory.c +++ b/arch/x86/purgatory/purgatory.c @@ -14,6 +14,7 @@ #include #include +#include "../boot/compressed/error.h" #include "../boot/string.h" u8 purgatory_sha256_digest[SHA256_DIGEST_SIZE] __section(".kexec-purgatory"); From 1a3e4b4da39bbf540a379e21869faa74bb19d16f Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Thu, 3 Aug 2023 10:26:17 +0200 Subject: [PATCH 06/11] x86/alternative: Add a __alt_reloc_selftest() prototype The newly introduced selftest function causes a warning when -Wmissing-prototypes is enabled: arch/x86/kernel/alternative.c:1461:32: error: no previous prototype for '__alt_reloc_selftest' [-Werror=missing-prototypes] Since it's only used locally, add the prototype directly in front of it. Fixes: 270a69c4485d ("x86/alternative: Support relocations in alternatives") Signed-off-by: Arnd Bergmann Signed-off-by: Borislav Petkov (AMD) Link: https://lore.kernel.org/r/20230803082619.1369127-6-arnd@kernel.org --- arch/x86/kernel/alternative.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index 2dcf3a06af09..934c23f24a3f 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -1531,6 +1531,7 @@ static noinline void __init int3_selftest(void) static __initdata int __alt_reloc_selftest_addr; +extern void __init __alt_reloc_selftest(void *arg); __visible noinline void __init __alt_reloc_selftest(void *arg) { WARN_ON(arg != &__alt_reloc_selftest_addr); From ce0a1b608bfc709cf366f020b520310a3b3272c3 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Thu, 3 Aug 2023 10:26:18 +0200 Subject: [PATCH 07/11] x86/paravirt: Silence unused native_pv_lock_init() function warning The native_pv_lock_init() function is only used in SMP configurations and declared in asm/qspinlock.h which is not used in UP kernels, but the function is still defined for both, which causes a warning: arch/x86/kernel/paravirt.c:76:13: error: no previous prototype for 'native_pv_lock_init' [-Werror=missing-prototypes] Move the declaration to asm/paravirt.h so it is visible even with CONFIG_SMP but short-circuit the definition to turn it into an empty function. Signed-off-by: Arnd Bergmann Signed-off-by: Borislav Petkov (AMD) Link: https://lore.kernel.org/r/20230803082619.1369127-7-arnd@kernel.org --- arch/x86/include/asm/paravirt.h | 7 +++++++ arch/x86/include/asm/qspinlock.h | 7 +------ arch/x86/kernel/paravirt.c | 3 ++- 3 files changed, 10 insertions(+), 7 deletions(-) diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h index b49778664d2b..6c8ff12140ae 100644 --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -739,6 +739,7 @@ static __always_inline unsigned long arch_local_irq_save(void) ".popsection") extern void default_banner(void); +void native_pv_lock_init(void) __init; #else /* __ASSEMBLY__ */ @@ -778,6 +779,12 @@ extern void default_banner(void); #endif /* __ASSEMBLY__ */ #else /* CONFIG_PARAVIRT */ # define default_banner x86_init_noop + +#ifndef __ASSEMBLY__ +static inline void native_pv_lock_init(void) +{ +} +#endif #endif /* !CONFIG_PARAVIRT */ #ifndef __ASSEMBLY__ diff --git a/arch/x86/include/asm/qspinlock.h b/arch/x86/include/asm/qspinlock.h index d87451df480b..cde8357bb226 100644 --- a/arch/x86/include/asm/qspinlock.h +++ b/arch/x86/include/asm/qspinlock.h @@ -74,8 +74,6 @@ static inline bool vcpu_is_preempted(long cpu) */ DECLARE_STATIC_KEY_TRUE(virt_spin_lock_key); -void native_pv_lock_init(void) __init; - /* * Shortcut for the queued_spin_lock_slowpath() function that allows * virt to hijack it. @@ -103,10 +101,7 @@ static inline bool virt_spin_lock(struct qspinlock *lock) return true; } -#else -static inline void native_pv_lock_init(void) -{ -} + #endif /* CONFIG_PARAVIRT */ #include diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c index ac10b46c5832..32e94a320554 100644 --- a/arch/x86/kernel/paravirt.c +++ b/arch/x86/kernel/paravirt.c @@ -75,7 +75,8 @@ DEFINE_STATIC_KEY_TRUE(virt_spin_lock_key); void __init native_pv_lock_init(void) { - if (!boot_cpu_has(X86_FEATURE_HYPERVISOR)) + if (IS_ENABLED(CONFIG_PARAVIRT_SPINLOCKS) && + !boot_cpu_has(X86_FEATURE_HYPERVISOR)) static_branch_disable(&virt_spin_lock_key); } From 8874a414f8f706daf1de467cbf2550988ebec09d Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Thu, 3 Aug 2023 10:26:19 +0200 Subject: [PATCH 08/11] x86/qspinlock-paravirt: Fix missing-prototype warning __pv_queued_spin_unlock_slowpath() is defined in a header file as a global function, and designed to be called from inline asm, but there is no prototype visible in the definition: kernel/locking/qspinlock_paravirt.h:493:1: error: no previous \ prototype for '__pv_queued_spin_unlock_slowpath' [-Werror=missing-prototypes] Add this to the x86 header that contains the inline asm calling it, and ensure this gets included before the definition, rather than after it. Signed-off-by: Arnd Bergmann Signed-off-by: Borislav Petkov (AMD) Link: https://lore.kernel.org/r/20230803082619.1369127-8-arnd@kernel.org --- arch/x86/include/asm/qspinlock_paravirt.h | 2 ++ kernel/locking/qspinlock_paravirt.h | 20 ++++++++++---------- 2 files changed, 12 insertions(+), 10 deletions(-) diff --git a/arch/x86/include/asm/qspinlock_paravirt.h b/arch/x86/include/asm/qspinlock_paravirt.h index 42b17cf10b10..85b6e3609cb9 100644 --- a/arch/x86/include/asm/qspinlock_paravirt.h +++ b/arch/x86/include/asm/qspinlock_paravirt.h @@ -4,6 +4,8 @@ #include +void __lockfunc __pv_queued_spin_unlock_slowpath(struct qspinlock *lock, u8 locked); + /* * For x86-64, PV_CALLEE_SAVE_REGS_THUNK() saves and restores 8 64-bit * registers. For i386, however, only 1 32-bit register needs to be saved diff --git a/kernel/locking/qspinlock_paravirt.h b/kernel/locking/qspinlock_paravirt.h index 6afc249ce697..6a0184e9c234 100644 --- a/kernel/locking/qspinlock_paravirt.h +++ b/kernel/locking/qspinlock_paravirt.h @@ -485,6 +485,16 @@ gotlock: return (u32)(atomic_read(&lock->val) | _Q_LOCKED_VAL); } +/* + * Include the architecture specific callee-save thunk of the + * __pv_queued_spin_unlock(). This thunk is put together with + * __pv_queued_spin_unlock() to make the callee-save thunk and the real unlock + * function close to each other sharing consecutive instruction cachelines. + * Alternatively, architecture specific version of __pv_queued_spin_unlock() + * can be defined. + */ +#include + /* * PV versions of the unlock fastpath and slowpath functions to be used * instead of queued_spin_unlock(). @@ -533,16 +543,6 @@ __pv_queued_spin_unlock_slowpath(struct qspinlock *lock, u8 locked) pv_kick(node->cpu); } -/* - * Include the architecture specific callee-save thunk of the - * __pv_queued_spin_unlock(). This thunk is put together with - * __pv_queued_spin_unlock() to make the callee-save thunk and the real unlock - * function close to each other sharing consecutive instruction cachelines. - * Alternatively, architecture specific version of __pv_queued_spin_unlock() - * can be defined. - */ -#include - #ifndef __pv_queued_spin_unlock __visible __lockfunc void __pv_queued_spin_unlock(struct qspinlock *lock) { From 1e6f01f7285559a5302e85677b8e59a5de9b0ea5 Mon Sep 17 00:00:00 2001 From: Justin Stitt Date: Thu, 24 Aug 2023 18:52:18 +0000 Subject: [PATCH 09/11] x86/platform/uv: Refactor code using deprecated strcpy()/strncpy() interfaces to use strscpy() Both `strncpy` and `strcpy` are deprecated for use on NUL-terminated destination strings [1]. A suitable replacement is `strscpy` [2] due to the fact that it guarantees NUL-termination on its destination buffer argument which is _not_ the case for `strncpy` or `strcpy`! In this case, we can drop both the forced NUL-termination and the `... -1` from: | strncpy(arg, val, ACTION_LEN - 1); as `strscpy` implicitly has this behavior. Also include slight refactor to code removing possible new-line chars as per Yang Yang's work at [3]. This reduces code size and complexity by using more robust and better understood interfaces. Co-developed-by: Yang Yang Signed-off-by: Justin Stitt Signed-off-by: Ingo Molnar Cc: Andy Shevchenko Cc: Kees Cook Cc: Dimitri Sivanich Link: www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings[1] Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2] Link: https://lore.kernel.org/all/202212091545310085328@zte.com.cn/ [3] Link: https://github.com/KSPP/linux/issues/90 Link: https://lore.kernel.org/r/20230824-strncpy-arch-x86-platform-uv-uv_nmi-v2-1-e16d9a3ec570@google.com Signed-off-by: Ingo Molnar --- arch/x86/platform/uv/uv_nmi.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) diff --git a/arch/x86/platform/uv/uv_nmi.c b/arch/x86/platform/uv/uv_nmi.c index a60af0230e27..a6ab43f69b7d 100644 --- a/arch/x86/platform/uv/uv_nmi.c +++ b/arch/x86/platform/uv/uv_nmi.c @@ -202,21 +202,17 @@ static int param_set_action(const char *val, const struct kernel_param *kp) { int i; int n = ARRAY_SIZE(valid_acts); - char arg[ACTION_LEN], *p; + char arg[ACTION_LEN]; /* (remove possible '\n') */ - strncpy(arg, val, ACTION_LEN - 1); - arg[ACTION_LEN - 1] = '\0'; - p = strchr(arg, '\n'); - if (p) - *p = '\0'; + strscpy(arg, val, strnchrnul(val, sizeof(arg)-1, '\n') - val + 1); for (i = 0; i < n; i++) if (!strcmp(arg, valid_acts[i].action)) break; if (i < n) { - strcpy(uv_nmi_action, arg); + strscpy(uv_nmi_action, arg, sizeof(uv_nmi_action)); pr_info("UV: New NMI action:%s\n", uv_nmi_action); return 0; } @@ -959,7 +955,7 @@ static int uv_handle_nmi(unsigned int reason, struct pt_regs *regs) /* Unexpected return, revert action to "dump" */ if (master) - strncpy(uv_nmi_action, "dump", strlen(uv_nmi_action)); + strscpy(uv_nmi_action, "dump", sizeof(uv_nmi_action)); } /* Pause as all CPU's enter the NMI handler */ From 4108d141bfd04cf7b2bbf96e899ee5392f62e8a2 Mon Sep 17 00:00:00 2001 From: Justin Stitt Date: Tue, 22 Aug 2023 22:13:36 +0000 Subject: [PATCH 10/11] x86/hpet: Refactor code using deprecated strncpy() interface to use strscpy() `strncpy` is deprecated for use on NUL-terminated destination strings [1]. A suitable replacement is `strscpy` [2] due to the fact that it guarantees NUL-termination on its destination buffer argument which is _not_ the case for `strncpy`! In this case, it is a simple swap from `strncpy` to `strscpy`. There is one slight difference, though. If NUL-padding is a functional requirement here we should opt for `strscpy_pad`. It seems like this shouldn't be needed as I see no obvious signs of any padding being required. Signed-off-by: Justin Stitt Signed-off-by: Ingo Molnar Link: www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings[1] Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2] Link: https://github.com/KSPP/linux/issues/90 Link: https://lore.kernel.org/r/20230822-strncpy-arch-x86-kernel-hpet-v1-1-2c7d3be86f4a@google.com --- arch/x86/kernel/hpet.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c index c8eb1ac5125a..1648aa0204d9 100644 --- a/arch/x86/kernel/hpet.c +++ b/arch/x86/kernel/hpet.c @@ -421,7 +421,7 @@ static void __init hpet_legacy_clockevent_register(struct hpet_channel *hc) * the IO_APIC has been initialized. */ hc->cpu = boot_cpu_data.cpu_index; - strncpy(hc->name, "hpet", sizeof(hc->name)); + strscpy(hc->name, "hpet", sizeof(hc->name)); hpet_init_clockevent(hc, 50); hc->evt.tick_resume = hpet_clkevt_legacy_resume; From 212f07a21622cbd4bb271b558b2d3ae0652e9875 Mon Sep 17 00:00:00 2001 From: Justin Stitt Date: Tue, 22 Aug 2023 22:05:30 +0000 Subject: [PATCH 11/11] x86/platform/uv: Refactor code using deprecated strncpy() interface to use strscpy() `strncpy` is deprecated for use on NUL-terminated destination strings [1]. A suitable replacement is `strscpy` [2] due to the fact that it guarantees NUL-termination on its destination buffer argument which is _not_ the case for `strncpy`! In this case, it means we can drop the `...-1` from: | strncpy(to, from, len-1); as well as remove the comment mentioning NUL-termination as `strscpy` implicitly grants us this behavior. There should be no functional change as I don't believe the padding from `strncpy` is needed here. If it turns out that the padding is necessary we should use `strscpy_pad` as a direct replacement. Signed-off-by: Justin Stitt Signed-off-by: Ingo Molnar Cc: Andy Shevchenko Cc: Kees Cook Cc: Dimitri Sivanich Link: www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings[1] Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2] Link: https://github.com/KSPP/linux/issues/90 Link: https://lore.kernel.org/r/20230822-strncpy-arch-x86-kernel-apic-x2apic_uv_x-v1-1-91d681d0b3f3@google.com --- arch/x86/kernel/apic/x2apic_uv_x.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c index d9384d5b4b8e..b524dee1cbbb 100644 --- a/arch/x86/kernel/apic/x2apic_uv_x.c +++ b/arch/x86/kernel/apic/x2apic_uv_x.c @@ -294,8 +294,7 @@ static void __init early_get_apic_socketid_shift(void) static void __init uv_stringify(int len, char *to, char *from) { - /* Relies on 'to' being NULL chars so result will be NULL terminated */ - strncpy(to, from, len-1); + strscpy(to, from, len); /* Trim trailing spaces */ (void)strim(to); @@ -1013,7 +1012,7 @@ static void __init calc_mmioh_map(enum mmioh_arch index, /* One (UV2) mapping */ if (index == UV2_MMIOH) { - strncpy(id, "MMIOH", sizeof(id)); + strscpy(id, "MMIOH", sizeof(id)); max_io = max_pnode; mapped = 0; goto map_exit;