Messages in this thread Patch in this message | | | Date | Thu, 9 Dec 2021 14:15:41 -0800 | Subject | [PATCH v4 4/7] uaccess-buffer: add CONFIG_GENERIC_ENTRY support | From | Peter Collingbourne <> |
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Add uaccess logging support on architectures that use CONFIG_GENERIC_ENTRY (currently only s390 and x86).
Link: https://linux-review.googlesource.com/id/I3c5eb19a7e4a1dbe6095f6971f7826c4b0663f7d Signed-off-by: Peter Collingbourne <pcc@google.com> Acked-by: Dmitry Vyukov <dvyukov@google.com> --- v4: - move pre/post-exit-loop calls into if statement
arch/Kconfig | 1 + include/linux/entry-common.h | 2 ++ include/linux/thread_info.h | 4 ++++ kernel/entry/common.c | 14 +++++++++++++- 4 files changed, 20 insertions(+), 1 deletion(-)
diff --git a/arch/Kconfig b/arch/Kconfig index 17819f53ea80..bc849a61b636 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -31,6 +31,7 @@ config HOTPLUG_SMT bool config GENERIC_ENTRY + select HAVE_ARCH_UACCESS_BUFFER bool config KPROBES diff --git a/include/linux/entry-common.h b/include/linux/entry-common.h index 2e2b8d6140ed..973fcd1d48a3 100644 --- a/include/linux/entry-common.h +++ b/include/linux/entry-common.h @@ -42,12 +42,14 @@ SYSCALL_WORK_SYSCALL_EMU | \ SYSCALL_WORK_SYSCALL_AUDIT | \ SYSCALL_WORK_SYSCALL_USER_DISPATCH | \ + SYSCALL_WORK_UACCESS_BUFFER_ENTRY | \ ARCH_SYSCALL_WORK_ENTER) #define SYSCALL_WORK_EXIT (SYSCALL_WORK_SYSCALL_TRACEPOINT | \ SYSCALL_WORK_SYSCALL_TRACE | \ SYSCALL_WORK_SYSCALL_AUDIT | \ SYSCALL_WORK_SYSCALL_USER_DISPATCH | \ SYSCALL_WORK_SYSCALL_EXIT_TRAP | \ + SYSCALL_WORK_UACCESS_BUFFER_EXIT | \ ARCH_SYSCALL_WORK_EXIT) /* diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h index ad0c4e041030..b0f8ea86967f 100644 --- a/include/linux/thread_info.h +++ b/include/linux/thread_info.h @@ -46,6 +46,8 @@ enum syscall_work_bit { SYSCALL_WORK_BIT_SYSCALL_AUDIT, SYSCALL_WORK_BIT_SYSCALL_USER_DISPATCH, SYSCALL_WORK_BIT_SYSCALL_EXIT_TRAP, + SYSCALL_WORK_BIT_UACCESS_BUFFER_ENTRY, + SYSCALL_WORK_BIT_UACCESS_BUFFER_EXIT, }; #define SYSCALL_WORK_SECCOMP BIT(SYSCALL_WORK_BIT_SECCOMP) @@ -55,6 +57,8 @@ enum syscall_work_bit { #define SYSCALL_WORK_SYSCALL_AUDIT BIT(SYSCALL_WORK_BIT_SYSCALL_AUDIT) #define SYSCALL_WORK_SYSCALL_USER_DISPATCH BIT(SYSCALL_WORK_BIT_SYSCALL_USER_DISPATCH) #define SYSCALL_WORK_SYSCALL_EXIT_TRAP BIT(SYSCALL_WORK_BIT_SYSCALL_EXIT_TRAP) +#define SYSCALL_WORK_UACCESS_BUFFER_ENTRY BIT(SYSCALL_WORK_BIT_UACCESS_BUFFER_ENTRY) +#define SYSCALL_WORK_UACCESS_BUFFER_EXIT BIT(SYSCALL_WORK_BIT_UACCESS_BUFFER_EXIT) #endif #include <asm/thread_info.h> diff --git a/kernel/entry/common.c b/kernel/entry/common.c index d5a61d565ad5..59ec6e3f793b 100644 --- a/kernel/entry/common.c +++ b/kernel/entry/common.c @@ -6,6 +6,7 @@ #include <linux/livepatch.h> #include <linux/audit.h> #include <linux/tick.h> +#include <linux/uaccess-buffer.h> #include "common.h" @@ -70,6 +71,9 @@ static long syscall_trace_enter(struct pt_regs *regs, long syscall, return ret; } + if (work & SYSCALL_WORK_UACCESS_BUFFER_ENTRY) + uaccess_buffer_syscall_entry(); + /* Either of the above might have changed the syscall number */ syscall = syscall_get_nr(current, regs); @@ -197,14 +201,19 @@ static unsigned long exit_to_user_mode_loop(struct pt_regs *regs, static void exit_to_user_mode_prepare(struct pt_regs *regs) { unsigned long ti_work = READ_ONCE(current_thread_info()->flags); + bool uaccess_buffer_pending; lockdep_assert_irqs_disabled(); /* Flush pending rcuog wakeup before the last need_resched() check */ tick_nohz_user_enter_prepare(); - if (unlikely(ti_work & EXIT_TO_USER_MODE_WORK)) + if (unlikely(ti_work & EXIT_TO_USER_MODE_WORK)) { + bool uaccess_buffer_pending = uaccess_buffer_pre_exit_loop(); + ti_work = exit_to_user_mode_loop(regs, ti_work); + uaccess_buffer_post_exit_loop(uaccess_buffer_pending); + } arch_exit_to_user_mode_prepare(regs, ti_work); @@ -247,6 +256,9 @@ static void syscall_exit_work(struct pt_regs *regs, unsigned long work) audit_syscall_exit(regs); + if (work & SYSCALL_WORK_UACCESS_BUFFER_EXIT) + uaccess_buffer_syscall_exit(); + if (work & SYSCALL_WORK_SYSCALL_TRACEPOINT) trace_sys_exit(regs, syscall_get_return_value(current, regs)); -- 2.34.1.173.g76aa8bc2d0-goog
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