[RFC PATCH v3 4/8] arm64: Separate in_compat_syscall from is_compat_task
From: Amanieu d'Antras <hidden>
Date: 2021-04-21 19:05:29
Subsystem:
arm64 port (aarch64 architecture), function hooks (ftrace), ptrace support, the rest · Maintainers:
Catalin Marinas, Will Deacon, Steven Rostedt, Masami Hiramatsu, Oleg Nesterov, Linus Torvalds
This is preliminary work for allowing 64-bit processes to invoke compat syscalls. Signed-off-by: Amanieu d'Antras <redacted> Co-developed-by: Ryan Houdek <redacted> Signed-off-by: Ryan Houdek <redacted> --- arch/arm64/include/asm/compat.h | 24 ++++++++++++++++++++---- arch/arm64/include/asm/ftrace.h | 2 +- arch/arm64/include/asm/syscall.h | 6 +++--- arch/arm64/kernel/ptrace.c | 2 +- arch/arm64/kernel/syscall.c | 2 +- 5 files changed, 26 insertions(+), 10 deletions(-)
diff --git a/arch/arm64/include/asm/compat.h b/arch/arm64/include/asm/compat.h
index 23a9fb73c04f..a2f5001f7793 100644
--- a/arch/arm64/include/asm/compat.h
+++ b/arch/arm64/include/asm/compat.h@@ -178,21 +178,37 @@ struct compat_shmid64_ds { compat_ulong_t __unused5; }; -static inline int is_compat_task(void) +static inline bool is_compat_task(void) { return test_thread_flag(TIF_32BIT); } -static inline int is_compat_thread(struct thread_info *thread) +static inline bool is_compat_thread(struct thread_info *thread) { return test_ti_thread_flag(thread, TIF_32BIT); } +static inline bool in_compat_syscall(void) +{ + return is_compat_task(); +} +#define in_compat_syscall in_compat_syscall /* override the generic impl */ + +static inline bool thread_in_compat_syscall(struct thread_info *thread) +{ + return is_compat_thread(thread); +} + #else /* !CONFIG_COMPAT */ -static inline int is_compat_thread(struct thread_info *thread) +static inline bool is_compat_thread(struct thread_info *thread) +{ + return false; +} + +static inline bool thread_in_compat_syscall(struct thread_info *thread) { - return 0; + return false; } #endif /* CONFIG_COMPAT */
diff --git a/arch/arm64/include/asm/ftrace.h b/arch/arm64/include/asm/ftrace.h
index 91fa4baa1a93..f41aad92c67a 100644
--- a/arch/arm64/include/asm/ftrace.h
+++ b/arch/arm64/include/asm/ftrace.h@@ -88,7 +88,7 @@ int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec); #define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs) { - return is_compat_task(); + return in_compat_syscall(); } #define ARCH_HAS_SYSCALL_MATCH_SYM_NAME
diff --git a/arch/arm64/include/asm/syscall.h b/arch/arm64/include/asm/syscall.h
index cfc0672013f6..0dfc01ea386c 100644
--- a/arch/arm64/include/asm/syscall.h
+++ b/arch/arm64/include/asm/syscall.h@@ -35,7 +35,7 @@ static inline long syscall_get_error(struct task_struct *task, { unsigned long error = regs->regs[0]; - if (is_compat_thread(task_thread_info(task))) + if (thread_in_compat_syscall(task_thread_info(task))) error = sign_extend64(error, 31); return IS_ERR_VALUE(error) ? error : 0;
@@ -54,7 +54,7 @@ static inline void syscall_set_return_value(struct task_struct *task, if (error) val = error; - if (is_compat_thread(task_thread_info(task))) + if (thread_in_compat_syscall(task_thread_info(task))) val = lower_32_bits(val); regs->regs[0] = val;
@@ -88,7 +88,7 @@ static inline void syscall_set_arguments(struct task_struct *task, */ static inline int syscall_get_arch(struct task_struct *task) { - if (is_compat_thread(task_thread_info(task))) + if (thread_in_compat_syscall(task_thread_info(task))) return AUDIT_ARCH_ARM; return AUDIT_ARCH_AARCH64;
diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index 170f42fd6101..017a82b24f49 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c@@ -1721,7 +1721,7 @@ const struct user_regset_view *task_user_regset_view(struct task_struct *task) * 32-bit children use an extended user_aarch32_ptrace_view to allow * access to the TLS register. */ - if (is_compat_task()) + if (in_compat_syscall()) return &user_aarch32_view; else if (is_compat_thread(task_thread_info(task))) return &user_aarch32_ptrace_view;
diff --git a/arch/arm64/kernel/syscall.c b/arch/arm64/kernel/syscall.c
index b9cf12b271d7..e0e9d54de0a2 100644
--- a/arch/arm64/kernel/syscall.c
+++ b/arch/arm64/kernel/syscall.c@@ -51,7 +51,7 @@ static void invoke_syscall(struct pt_regs *regs, unsigned int scno, ret = do_ni_syscall(regs, scno); } - if (is_compat_task()) + if (in_compat_syscall()) ret = lower_32_bits(ret); regs->regs[0] = ret;
--
2.31.1
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