[PATCH v5 4/6] x86/syscalls/32 Wire up arch_prctl on x86-32
From: Kyle Huey <hidden>
Date: 2016-09-21 18:59:15
Also in:
linux-um, lkml
Subsystem:
the rest, user-mode linux (uml), x86 architecture (32-bit and 64-bit), x86 entry code · Maintainers:
Linus Torvalds, Richard Weinberger, Anton Ivanov, Johannes Berg, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen, Andy Lutomirski
Hook up arch_prctl to call do_arch_prctl on x86-32, and in 32 bit compat mode on x86-64. This allows us to have arch_prctls that are not specific to 64 bits. On UML, simply stub out this syscall. Signed-off-by: Kyle Huey <khuey-OhBmq/TcCDJWk0Htik3J/w@public.gmane.org> --- arch/x86/entry/syscalls/syscall_32.tbl | 1 + arch/x86/kernel/process_32.c | 7 +++++++ arch/x86/kernel/process_64.c | 7 +++++++ arch/x86/um/Makefile | 2 +- arch/x86/um/syscalls_32.c | 7 +++++++ include/linux/compat.h | 2 ++ 6 files changed, 25 insertions(+), 1 deletion(-) create mode 100644 arch/x86/um/syscalls_32.c
diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
index f848572..300fdf8 100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl@@ -386,3 +386,4 @@ 377 i386 copy_file_range sys_copy_file_range 378 i386 preadv2 sys_preadv2 compat_sys_preadv2 379 i386 pwritev2 sys_pwritev2 compat_sys_pwritev2 +380 i386 arch_prctl sys_arch_prctl compat_sys_arch_prctl
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index d86be29..71770a4 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c@@ -35,6 +35,7 @@ #include <linux/uaccess.h> #include <linux/io.h> #include <linux/kdebug.h> +#include <linux/syscalls.h> #include <asm/pgtable.h> #include <asm/ldt.h>
@@ -54,6 +55,7 @@ #include <asm/debugreg.h> #include <asm/switch_to.h> #include <asm/vm86.h> +#include <asm/proto.h> asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); asmlinkage void ret_from_kernel_thread(void) __asm__("ret_from_kernel_thread");
@@ -316,3 +318,8 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) return prev_p; } + +SYSCALL_DEFINE2(arch_prctl, int, code, unsigned long, arg2) +{ + return do_arch_prctl(current, code, arg2); +}
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 5c60e2c..aa2b99a 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c@@ -599,6 +599,13 @@ SYSCALL_DEFINE2(arch_prctl, int, code, unsigned long, arg2) return ret; } +#ifdef CONFIG_IA32_EMULATION +COMPAT_SYSCALL_DEFINE2(arch_prctl, int, code, unsigned long, arg2) +{ + return do_arch_prctl(current, code, arg2); +} +#endif + unsigned long KSTK_ESP(struct task_struct *task) { return task_pt_regs(task)->sp;
diff --git a/arch/x86/um/Makefile b/arch/x86/um/Makefile
index 3ee2bb6..5e039d6 100644
--- a/arch/x86/um/Makefile
+++ b/arch/x86/um/Makefile@@ -16,7 +16,7 @@ obj-y = bug.o bugs_$(BITS).o delay.o fault.o ksyms.o ldt.o \ ifeq ($(CONFIG_X86_32),y) -obj-y += checksum_32.o +obj-y += checksum_32.o syscalls_32.o obj-$(CONFIG_ELF_CORE) += elfcore.o subarch-y = ../lib/string_32.o ../lib/atomic64_32.o ../lib/atomic64_cx8_32.o
diff --git a/arch/x86/um/syscalls_32.c b/arch/x86/um/syscalls_32.c
new file mode 100644
index 0000000..ccf0598
--- /dev/null
+++ b/arch/x86/um/syscalls_32.c@@ -0,0 +1,7 @@ +#include <linux/syscalls.h> +#include <os.h> + +SYSCALL_DEFINE2(arch_prctl, int, code, unsigned long, arg2) +{ + return -EINVAL; +}
diff --git a/include/linux/compat.h b/include/linux/compat.h
index f964ef7..0039d53 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h@@ -722,6 +722,8 @@ asmlinkage long compat_sys_sched_rr_get_interval(compat_pid_t pid, asmlinkage long compat_sys_fanotify_mark(int, unsigned int, __u32, __u32, int, const char __user *); +asmlinkage long compat_sys_arch_prctl(int, unsigned long); + /* * For most but not all architectures, "am I in a compat syscall?" and * "am I a compat task?" are the same question. For architectures on which
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2.9.3