[GIT PULL] x86/process changes for v4.12

From: Ingo Molnar
Date: Mon May 01 2017 - 06:25:47 EST


Linus,

Please pull the latest x86-process-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-process-for-linus

# HEAD: f3e4559781bf0c393364baa6b772233088a711db x86/syscalls/32: Ignore arch_prctl for other architectures

The main change in this cycle was to add the ARCH_[GET|SET]_CPUID prctl() ABI
extension to control the availability of the CPUID instruction, analogously to the
existing PR_GET|SET_TSC ABI that controls RDTSC.

Motivation: the 'rr' user-space record-and-replay execution debugger would like to
trap and emulate the CPUID instruction - which instruction is normally
unprivileged.

Trapping CPUID is possible on IvyBridge and later Intel CPUs - expose this
hardware capability.

out-of-topic modifications in x86-process-for-linus:
------------------------------------------------------
arch/um/include/shared/os.h # 17a6e1b8e8e8: x86/arch_prctl/64: Rename do
# dd93938a92dc: x86/arch_prctl: Rename 'code
fs/exec.c # e9ea1e7f53b8: x86/arch_prctl: Add ARCH_[GE
include/linux/compat.h # 79170fda313e: x86/syscalls/32: Wire up arc
include/linux/thread_info.h # e9ea1e7f53b8: x86/arch_prctl: Add ARCH_[GE
scripts/checksyscalls.sh # f3e4559781bf: x86/syscalls/32: Ignore arch

Thanks,

Ingo

------------------>
Arnd Bergmann (1):
x86/syscalls/32: Ignore arch_prctl for other architectures

Kyle Huey (11):
x86/process: Optimize TIF checks in __switch_to_xtra()
x86/process: Correct and optimize TIF_BLOCKSTEP switch
x86/msr: Rename MISC_FEATURE_ENABLES to MISC_FEATURES_ENABLES
x86/arch_prctl: Rename 'code' argument to 'option'
x86/arch_prctl/64: Use SYSCALL_DEFINE2 to define sys_arch_prctl()
x86/arch_prctl/64: Rename do_arch_prctl() to do_arch_prctl_64()
x86/arch_prctl: Add do_arch_prctl_common()
x86/syscalls/32: Wire up arch_prctl on x86-32
x86/cpufeature: Detect CPUID faulting support
x86/arch_prctl: Add ARCH_[GET|SET]_CPUID
um/arch_prctl: Fix fallout from x86 arch_prctl() rework

Thomas Gleixner (1):
x86/process: Optimize TIF_NOTSC switch


arch/um/include/shared/os.h | 4 +-
arch/x86/entry/syscalls/syscall_32.tbl | 1 +
arch/x86/include/asm/cpufeatures.h | 1 +
arch/x86/include/asm/msr-index.h | 11 ++-
arch/x86/include/asm/processor.h | 2 +
arch/x86/include/asm/proto.h | 4 +-
arch/x86/include/asm/thread_info.h | 6 +-
arch/x86/include/asm/tlbflush.h | 10 +++
arch/x86/include/uapi/asm/prctl.h | 11 ++-
arch/x86/kernel/cpu/intel.c | 40 +++++++--
arch/x86/kernel/process.c | 151 +++++++++++++++++++++++++--------
arch/x86/kernel/process_32.c | 7 ++
arch/x86/kernel/process_64.c | 48 +++++++----
arch/x86/kernel/ptrace.c | 8 +-
arch/x86/um/Makefile | 2 +-
arch/x86/um/asm/ptrace.h | 2 +-
arch/x86/um/os-Linux/prctl.c | 4 +-
arch/x86/um/syscalls_32.c | 7 ++
arch/x86/um/syscalls_64.c | 20 +++--
fs/exec.c | 1 +
include/linux/compat.h | 2 +
include/linux/thread_info.h | 4 +
scripts/checksyscalls.sh | 1 +
23 files changed, 259 insertions(+), 88 deletions(-)
create mode 100644 arch/x86/um/syscalls_32.c

diff --git a/arch/um/include/shared/os.h b/arch/um/include/shared/os.h
index de5d572225f3..cd1fa97776c3 100644
--- a/arch/um/include/shared/os.h
+++ b/arch/um/include/shared/os.h
@@ -302,8 +302,8 @@ extern int ignore_sigio_fd(int fd);
extern void maybe_sigio_broken(int fd, int read);
extern void sigio_broken(int fd, int read);

-/* sys-x86_64/prctl.c */
-extern int os_arch_prctl(int pid, int code, unsigned long *addr);
+/* prctl.c */
+extern int os_arch_prctl(int pid, int option, unsigned long *arg2);

/* tty.c */
extern int get_pty(void);
diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
index 9ba050fe47f3..0af59fa789ea 100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -390,3 +390,4 @@
381 i386 pkey_alloc sys_pkey_alloc
382 i386 pkey_free sys_pkey_free
383 i386 statx sys_statx
+384 i386 arch_prctl sys_arch_prctl compat_sys_arch_prctl
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index b04bb6dfed7f..0fe00446f9ca 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -187,6 +187,7 @@
* Reuse free bits when adding new feature flags!
*/
#define X86_FEATURE_RING3MWAIT ( 7*32+ 0) /* Ring 3 MONITOR/MWAIT */
+#define X86_FEATURE_CPUID_FAULT ( 7*32+ 1) /* Intel CPUID faulting */
#define X86_FEATURE_CPB ( 7*32+ 2) /* AMD Core Performance Boost */
#define X86_FEATURE_EPB ( 7*32+ 3) /* IA32_ENERGY_PERF_BIAS support */
#define X86_FEATURE_CAT_L3 ( 7*32+ 4) /* Cache Allocation Technology L3 */
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index d8b5f8ab8ef9..673f9ac50f6d 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -45,6 +45,8 @@
#define MSR_IA32_PERFCTR1 0x000000c2
#define MSR_FSB_FREQ 0x000000cd
#define MSR_PLATFORM_INFO 0x000000ce
+#define MSR_PLATFORM_INFO_CPUID_FAULT_BIT 31
+#define MSR_PLATFORM_INFO_CPUID_FAULT BIT_ULL(MSR_PLATFORM_INFO_CPUID_FAULT_BIT)

#define MSR_PKG_CST_CONFIG_CONTROL 0x000000e2
#define NHM_C3_AUTO_DEMOTE (1UL << 25)
@@ -127,6 +129,7 @@

/* DEBUGCTLMSR bits (others vary by model): */
#define DEBUGCTLMSR_LBR (1UL << 0) /* last branch recording */
+#define DEBUGCTLMSR_BTF_SHIFT 1
#define DEBUGCTLMSR_BTF (1UL << 1) /* single-step on branches */
#define DEBUGCTLMSR_TR (1UL << 6)
#define DEBUGCTLMSR_BTS (1UL << 7)
@@ -552,10 +555,12 @@
#define MSR_IA32_MISC_ENABLE_IP_PREF_DISABLE_BIT 39
#define MSR_IA32_MISC_ENABLE_IP_PREF_DISABLE (1ULL << MSR_IA32_MISC_ENABLE_IP_PREF_DISABLE_BIT)

-/* MISC_FEATURE_ENABLES non-architectural features */
-#define MSR_MISC_FEATURE_ENABLES 0x00000140
+/* MISC_FEATURES_ENABLES non-architectural features */
+#define MSR_MISC_FEATURES_ENABLES 0x00000140

-#define MSR_MISC_FEATURE_ENABLES_RING3MWAIT_BIT 1
+#define MSR_MISC_FEATURES_ENABLES_CPUID_FAULT_BIT 0
+#define MSR_MISC_FEATURES_ENABLES_CPUID_FAULT BIT_ULL(MSR_MISC_FEATURES_ENABLES_CPUID_FAULT_BIT)
+#define MSR_MISC_FEATURES_ENABLES_RING3MWAIT_BIT 1

#define MSR_IA32_TSC_DEADLINE 0x000006E0

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index f385eca5407a..a80c1b3997ed 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -884,6 +884,8 @@ extern void start_thread(struct pt_regs *regs, unsigned long new_ip,
extern int get_tsc_mode(unsigned long adr);
extern int set_tsc_mode(unsigned int val);

+DECLARE_PER_CPU(u64, msr_misc_features_shadow);
+
/* Register/unregister a process' MPX related resource */
#define MPX_ENABLE_MANAGEMENT() mpx_enable_management()
#define MPX_DISABLE_MANAGEMENT() mpx_disable_management()
diff --git a/arch/x86/include/asm/proto.h b/arch/x86/include/asm/proto.h
index 9b9b30b19441..8d3964fc5f91 100644
--- a/arch/x86/include/asm/proto.h
+++ b/arch/x86/include/asm/proto.h
@@ -9,6 +9,7 @@ void syscall_init(void);

#ifdef CONFIG_X86_64
void entry_SYSCALL_64(void);
+long do_arch_prctl_64(struct task_struct *task, int option, unsigned long arg2);
#endif

#ifdef CONFIG_X86_32
@@ -30,6 +31,7 @@ void x86_report_nx(void);

extern int reboot_force;

-long do_arch_prctl(struct task_struct *task, int code, unsigned long addr);
+long do_arch_prctl_common(struct task_struct *task, int option,
+ unsigned long cpuid_enabled);

#endif /* _ASM_X86_PROTO_H */
diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index ad6f5eb07a95..9fc44b95f7cb 100644
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -87,6 +87,7 @@ struct thread_info {
#define TIF_SECCOMP 8 /* secure computing */
#define TIF_USER_RETURN_NOTIFY 11 /* notify kernel of userspace return */
#define TIF_UPROBE 12 /* breakpointed or singlestepping */
+#define TIF_NOCPUID 15 /* CPUID is not accessible in userland */
#define TIF_NOTSC 16 /* TSC is not accessible in userland */
#define TIF_IA32 17 /* IA32 compatibility process */
#define TIF_NOHZ 19 /* in adaptive nohz mode */
@@ -110,6 +111,7 @@ struct thread_info {
#define _TIF_SECCOMP (1 << TIF_SECCOMP)
#define _TIF_USER_RETURN_NOTIFY (1 << TIF_USER_RETURN_NOTIFY)
#define _TIF_UPROBE (1 << TIF_UPROBE)
+#define _TIF_NOCPUID (1 << TIF_NOCPUID)
#define _TIF_NOTSC (1 << TIF_NOTSC)
#define _TIF_IA32 (1 << TIF_IA32)
#define _TIF_NOHZ (1 << TIF_NOHZ)
@@ -138,7 +140,7 @@ struct thread_info {

/* flags to check in __switch_to() */
#define _TIF_WORK_CTXSW \
- (_TIF_IO_BITMAP|_TIF_NOTSC|_TIF_BLOCKSTEP)
+ (_TIF_IO_BITMAP|_TIF_NOCPUID|_TIF_NOTSC|_TIF_BLOCKSTEP)

#define _TIF_WORK_CTXSW_PREV (_TIF_WORK_CTXSW|_TIF_USER_RETURN_NOTIFY)
#define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW)
@@ -239,6 +241,8 @@ static inline int arch_within_stack_frames(const void * const stack,
extern void arch_task_cache_init(void);
extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
extern void arch_release_task_struct(struct task_struct *tsk);
+extern void arch_setup_new_exec(void);
+#define arch_setup_new_exec arch_setup_new_exec
#endif /* !__ASSEMBLY__ */

#endif /* _ASM_X86_THREAD_INFO_H */
diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h
index 6fa85944af83..ff4923a19f79 100644
--- a/arch/x86/include/asm/tlbflush.h
+++ b/arch/x86/include/asm/tlbflush.h
@@ -110,6 +110,16 @@ static inline void cr4_clear_bits(unsigned long mask)
}
}

+static inline void cr4_toggle_bits(unsigned long mask)
+{
+ unsigned long cr4;
+
+ cr4 = this_cpu_read(cpu_tlbstate.cr4);
+ cr4 ^= mask;
+ this_cpu_write(cpu_tlbstate.cr4, cr4);
+ __write_cr4(cr4);
+}
+
/* Read the CR4 shadow. */
static inline unsigned long cr4_read_shadow(void)
{
diff --git a/arch/x86/include/uapi/asm/prctl.h b/arch/x86/include/uapi/asm/prctl.h
index 835aa51c7f6e..c45765517092 100644
--- a/arch/x86/include/uapi/asm/prctl.h
+++ b/arch/x86/include/uapi/asm/prctl.h
@@ -1,10 +1,13 @@
#ifndef _ASM_X86_PRCTL_H
#define _ASM_X86_PRCTL_H

-#define ARCH_SET_GS 0x1001
-#define ARCH_SET_FS 0x1002
-#define ARCH_GET_FS 0x1003
-#define ARCH_GET_GS 0x1004
+#define ARCH_SET_GS 0x1001
+#define ARCH_SET_FS 0x1002
+#define ARCH_GET_FS 0x1003
+#define ARCH_GET_GS 0x1004
+
+#define ARCH_GET_CPUID 0x1011
+#define ARCH_SET_CPUID 0x1012

#define ARCH_MAP_VDSO_X32 0x2001
#define ARCH_MAP_VDSO_32 0x2002
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 063197771b8d..dfa90a3a5145 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -90,16 +90,12 @@ static void probe_xeon_phi_r3mwait(struct cpuinfo_x86 *c)
return;
}

- if (ring3mwait_disabled) {
- msr_clear_bit(MSR_MISC_FEATURE_ENABLES,
- MSR_MISC_FEATURE_ENABLES_RING3MWAIT_BIT);
+ if (ring3mwait_disabled)
return;
- }
-
- msr_set_bit(MSR_MISC_FEATURE_ENABLES,
- MSR_MISC_FEATURE_ENABLES_RING3MWAIT_BIT);

set_cpu_cap(c, X86_FEATURE_RING3MWAIT);
+ this_cpu_or(msr_misc_features_shadow,
+ 1UL << MSR_MISC_FEATURES_ENABLES_RING3MWAIT_BIT);

if (c == &boot_cpu_data)
ELF_HWCAP2 |= HWCAP2_RING3MWAIT;
@@ -488,6 +484,34 @@ static void intel_bsp_resume(struct cpuinfo_x86 *c)
init_intel_energy_perf(c);
}

+static void init_cpuid_fault(struct cpuinfo_x86 *c)
+{
+ u64 msr;
+
+ if (!rdmsrl_safe(MSR_PLATFORM_INFO, &msr)) {
+ if (msr & MSR_PLATFORM_INFO_CPUID_FAULT)
+ set_cpu_cap(c, X86_FEATURE_CPUID_FAULT);
+ }
+}
+
+static void init_intel_misc_features(struct cpuinfo_x86 *c)
+{
+ u64 msr;
+
+ if (rdmsrl_safe(MSR_MISC_FEATURES_ENABLES, &msr))
+ return;
+
+ /* Clear all MISC features */
+ this_cpu_write(msr_misc_features_shadow, 0);
+
+ /* Check features and update capabilities and shadow control bits */
+ init_cpuid_fault(c);
+ probe_xeon_phi_r3mwait(c);
+
+ msr = this_cpu_read(msr_misc_features_shadow);
+ wrmsrl(MSR_MISC_FEATURES_ENABLES, msr);
+}
+
static void init_intel(struct cpuinfo_x86 *c)
{
unsigned int l2 = 0;
@@ -602,7 +626,7 @@ static void init_intel(struct cpuinfo_x86 *c)

init_intel_energy_perf(c);

- probe_xeon_phi_r3mwait(c);
+ init_intel_misc_features(c);
}

#ifdef CONFIG_X86_32
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index f67591561711..0bb88428cbf2 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -37,6 +37,7 @@
#include <asm/vm86.h>
#include <asm/switch_to.h>
#include <asm/desc.h>
+#include <asm/prctl.h>

/*
* per-CPU TSS segments. Threads are completely 'soft' on Linux,
@@ -124,11 +125,6 @@ void flush_thread(void)
fpu__clear(&tsk->thread.fpu);
}

-static void hard_disable_TSC(void)
-{
- cr4_set_bits(X86_CR4_TSD);
-}
-
void disable_TSC(void)
{
preempt_disable();
@@ -137,15 +133,10 @@ void disable_TSC(void)
* Must flip the CPU state synchronously with
* TIF_NOTSC in the current running context.
*/
- hard_disable_TSC();
+ cr4_set_bits(X86_CR4_TSD);
preempt_enable();
}

-static void hard_enable_TSC(void)
-{
- cr4_clear_bits(X86_CR4_TSD);
-}
-
static void enable_TSC(void)
{
preempt_disable();
@@ -154,7 +145,7 @@ static void enable_TSC(void)
* Must flip the CPU state synchronously with
* TIF_NOTSC in the current running context.
*/
- hard_enable_TSC();
+ cr4_clear_bits(X86_CR4_TSD);
preempt_enable();
}

@@ -182,54 +173,129 @@ int set_tsc_mode(unsigned int val)
return 0;
}

-void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
- struct tss_struct *tss)
-{
- struct thread_struct *prev, *next;
-
- prev = &prev_p->thread;
- next = &next_p->thread;
+DEFINE_PER_CPU(u64, msr_misc_features_shadow);

- if (test_tsk_thread_flag(prev_p, TIF_BLOCKSTEP) ^
- test_tsk_thread_flag(next_p, TIF_BLOCKSTEP)) {
- unsigned long debugctl = get_debugctlmsr();
+static void set_cpuid_faulting(bool on)
+{
+ u64 msrval;

- debugctl &= ~DEBUGCTLMSR_BTF;
- if (test_tsk_thread_flag(next_p, TIF_BLOCKSTEP))
- debugctl |= DEBUGCTLMSR_BTF;
+ msrval = this_cpu_read(msr_misc_features_shadow);
+ msrval &= ~MSR_MISC_FEATURES_ENABLES_CPUID_FAULT;
+ msrval |= (on << MSR_MISC_FEATURES_ENABLES_CPUID_FAULT_BIT);
+ this_cpu_write(msr_misc_features_shadow, msrval);
+ wrmsrl(MSR_MISC_FEATURES_ENABLES, msrval);
+}

- update_debugctlmsr(debugctl);
+static void disable_cpuid(void)
+{
+ preempt_disable();
+ if (!test_and_set_thread_flag(TIF_NOCPUID)) {
+ /*
+ * Must flip the CPU state synchronously with
+ * TIF_NOCPUID in the current running context.
+ */
+ set_cpuid_faulting(true);
}
+ preempt_enable();
+}

- if (test_tsk_thread_flag(prev_p, TIF_NOTSC) ^
- test_tsk_thread_flag(next_p, TIF_NOTSC)) {
- /* prev and next are different */
- if (test_tsk_thread_flag(next_p, TIF_NOTSC))
- hard_disable_TSC();
- else
- hard_enable_TSC();
+static void enable_cpuid(void)
+{
+ preempt_disable();
+ if (test_and_clear_thread_flag(TIF_NOCPUID)) {
+ /*
+ * Must flip the CPU state synchronously with
+ * TIF_NOCPUID in the current running context.
+ */
+ set_cpuid_faulting(false);
}
+ preempt_enable();
+}
+
+static int get_cpuid_mode(void)
+{
+ return !test_thread_flag(TIF_NOCPUID);
+}
+
+static int set_cpuid_mode(struct task_struct *task, unsigned long cpuid_enabled)
+{
+ if (!static_cpu_has(X86_FEATURE_CPUID_FAULT))
+ return -ENODEV;
+
+ if (cpuid_enabled)
+ enable_cpuid();
+ else
+ disable_cpuid();
+
+ return 0;
+}
+
+/*
+ * Called immediately after a successful exec.
+ */
+void arch_setup_new_exec(void)
+{
+ /* If cpuid was previously disabled for this task, re-enable it. */
+ if (test_thread_flag(TIF_NOCPUID))
+ enable_cpuid();
+}

- if (test_tsk_thread_flag(next_p, TIF_IO_BITMAP)) {
+static inline void switch_to_bitmap(struct tss_struct *tss,
+ struct thread_struct *prev,
+ struct thread_struct *next,
+ unsigned long tifp, unsigned long tifn)
+{
+ if (tifn & _TIF_IO_BITMAP) {
/*
* Copy the relevant range of the IO bitmap.
* Normally this is 128 bytes or less:
*/
memcpy(tss->io_bitmap, next->io_bitmap_ptr,
max(prev->io_bitmap_max, next->io_bitmap_max));
-
/*
* Make sure that the TSS limit is correct for the CPU
* to notice the IO bitmap.
*/
refresh_tss_limit();
- } else if (test_tsk_thread_flag(prev_p, TIF_IO_BITMAP)) {
+ } else if (tifp & _TIF_IO_BITMAP) {
/*
* Clear any possible leftover bits:
*/
memset(tss->io_bitmap, 0xff, prev->io_bitmap_max);
}
+}
+
+void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
+ struct tss_struct *tss)
+{
+ struct thread_struct *prev, *next;
+ unsigned long tifp, tifn;
+
+ prev = &prev_p->thread;
+ next = &next_p->thread;
+
+ tifn = READ_ONCE(task_thread_info(next_p)->flags);
+ tifp = READ_ONCE(task_thread_info(prev_p)->flags);
+ switch_to_bitmap(tss, prev, next, tifp, tifn);
+
propagate_user_return_notify(prev_p, next_p);
+
+ if ((tifp & _TIF_BLOCKSTEP || tifn & _TIF_BLOCKSTEP) &&
+ arch_has_block_step()) {
+ unsigned long debugctl, msk;
+
+ rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctl);
+ debugctl &= ~DEBUGCTLMSR_BTF;
+ msk = tifn & _TIF_BLOCKSTEP;
+ debugctl |= (msk >> TIF_BLOCKSTEP) << DEBUGCTLMSR_BTF_SHIFT;
+ wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctl);
+ }
+
+ if ((tifp ^ tifn) & _TIF_NOTSC)
+ cr4_toggle_bits(X86_CR4_TSD);
+
+ if ((tifp ^ tifn) & _TIF_NOCPUID)
+ set_cpuid_faulting(!!(tifn & _TIF_NOCPUID));
}

/*
@@ -550,3 +616,16 @@ unsigned long get_wchan(struct task_struct *p)
put_task_stack(p);
return ret;
}
+
+long do_arch_prctl_common(struct task_struct *task, int option,
+ unsigned long cpuid_enabled)
+{
+ switch (option) {
+ case ARCH_GET_CPUID:
+ return get_cpuid_mode();
+ case ARCH_SET_CPUID:
+ return set_cpuid_mode(task, cpuid_enabled);
+ }
+
+ return -EINVAL;
+}
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 4c818f8bc135..ff40e74c9181 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -37,6 +37,7 @@
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/kdebug.h>
+#include <linux/syscalls.h>

#include <asm/pgtable.h>
#include <asm/ldt.h>
@@ -56,6 +57,7 @@
#include <asm/switch_to.h>
#include <asm/vm86.h>
#include <asm/intel_rdt.h>
+#include <asm/proto.h>

void __show_regs(struct pt_regs *regs, int all)
{
@@ -304,3 +306,8 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)

return prev_p;
}
+
+SYSCALL_DEFINE2(arch_prctl, int, option, unsigned long, arg2)
+{
+ return do_arch_prctl_common(current, option, arg2);
+}
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index d6b784a5520d..ea1a6180bf39 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -37,6 +37,7 @@
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/ftrace.h>
+#include <linux/syscalls.h>

#include <asm/pgtable.h>
#include <asm/processor.h>
@@ -204,7 +205,7 @@ int copy_thread_tls(unsigned long clone_flags, unsigned long sp,
(struct user_desc __user *)tls, 0);
else
#endif
- err = do_arch_prctl(p, ARCH_SET_FS, tls);
+ err = do_arch_prctl_64(p, ARCH_SET_FS, tls);
if (err)
goto out;
}
@@ -547,70 +548,72 @@ static long prctl_map_vdso(const struct vdso_image *image, unsigned long addr)
}
#endif

-long do_arch_prctl(struct task_struct *task, int code, unsigned long addr)
+long do_arch_prctl_64(struct task_struct *task, int option, unsigned long arg2)
{
int ret = 0;
int doit = task == current;
int cpu;

- switch (code) {
+ switch (option) {
case ARCH_SET_GS:
- if (addr >= TASK_SIZE_MAX)
+ if (arg2 >= TASK_SIZE_MAX)
return -EPERM;
cpu = get_cpu();
task->thread.gsindex = 0;
- task->thread.gsbase = addr;
+ task->thread.gsbase = arg2;
if (doit) {
load_gs_index(0);
- ret = wrmsrl_safe(MSR_KERNEL_GS_BASE, addr);
+ ret = wrmsrl_safe(MSR_KERNEL_GS_BASE, arg2);
}
put_cpu();
break;
case ARCH_SET_FS:
/* Not strictly needed for fs, but do it for symmetry
with gs */
- if (addr >= TASK_SIZE_MAX)
+ if (arg2 >= TASK_SIZE_MAX)
return -EPERM;
cpu = get_cpu();
task->thread.fsindex = 0;
- task->thread.fsbase = addr;
+ task->thread.fsbase = arg2;
if (doit) {
/* set the selector to 0 to not confuse __switch_to */
loadsegment(fs, 0);
- ret = wrmsrl_safe(MSR_FS_BASE, addr);
+ ret = wrmsrl_safe(MSR_FS_BASE, arg2);
}
put_cpu();
break;
case ARCH_GET_FS: {
unsigned long base;
+
if (doit)
rdmsrl(MSR_FS_BASE, base);
else
base = task->thread.fsbase;
- ret = put_user(base, (unsigned long __user *)addr);
+ ret = put_user(base, (unsigned long __user *)arg2);
break;
}
case ARCH_GET_GS: {
unsigned long base;
+
if (doit)
rdmsrl(MSR_KERNEL_GS_BASE, base);
else
base = task->thread.gsbase;
- ret = put_user(base, (unsigned long __user *)addr);
+ ret = put_user(base, (unsigned long __user *)arg2);
break;
}

#ifdef CONFIG_CHECKPOINT_RESTORE
# ifdef CONFIG_X86_X32_ABI
case ARCH_MAP_VDSO_X32:
- return prctl_map_vdso(&vdso_image_x32, addr);
+ return prctl_map_vdso(&vdso_image_x32, arg2);
# endif
# if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
case ARCH_MAP_VDSO_32:
- return prctl_map_vdso(&vdso_image_32, addr);
+ return prctl_map_vdso(&vdso_image_32, arg2);
# endif
case ARCH_MAP_VDSO_64:
- return prctl_map_vdso(&vdso_image_64, addr);
+ return prctl_map_vdso(&vdso_image_64, arg2);
#endif

default:
@@ -621,10 +624,23 @@ long do_arch_prctl(struct task_struct *task, int code, unsigned long addr)
return ret;
}

-long sys_arch_prctl(int code, unsigned long addr)
+SYSCALL_DEFINE2(arch_prctl, int, option, unsigned long, arg2)
+{
+ long ret;
+
+ ret = do_arch_prctl_64(current, option, arg2);
+ if (ret == -EINVAL)
+ ret = do_arch_prctl_common(current, option, arg2);
+
+ return ret;
+}
+
+#ifdef CONFIG_IA32_EMULATION
+COMPAT_SYSCALL_DEFINE2(arch_prctl, int, option, unsigned long, arg2)
{
- return do_arch_prctl(current, code, addr);
+ return do_arch_prctl_common(current, option, arg2);
}
+#endif

unsigned long KSTK_ESP(struct task_struct *task)
{
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 2364b23ea3e5..f37d18124648 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -396,12 +396,12 @@ static int putreg(struct task_struct *child,
if (value >= TASK_SIZE_MAX)
return -EIO;
/*
- * When changing the segment base, use do_arch_prctl
+ * When changing the segment base, use do_arch_prctl_64
* to set either thread.fs or thread.fsindex and the
* corresponding GDT slot.
*/
if (child->thread.fsbase != value)
- return do_arch_prctl(child, ARCH_SET_FS, value);
+ return do_arch_prctl_64(child, ARCH_SET_FS, value);
return 0;
case offsetof(struct user_regs_struct,gs_base):
/*
@@ -410,7 +410,7 @@ static int putreg(struct task_struct *child,
if (value >= TASK_SIZE_MAX)
return -EIO;
if (child->thread.gsbase != value)
- return do_arch_prctl(child, ARCH_SET_GS, value);
+ return do_arch_prctl_64(child, ARCH_SET_GS, value);
return 0;
#endif
}
@@ -869,7 +869,7 @@ long arch_ptrace(struct task_struct *child, long request,
Works just like arch_prctl, except that the arguments
are reversed. */
case PTRACE_ARCH_PRCTL:
- ret = do_arch_prctl(child, data, addr);
+ ret = do_arch_prctl_64(child, data, addr);
break;
#endif

diff --git a/arch/x86/um/Makefile b/arch/x86/um/Makefile
index e7e7055a8658..69f0827d5f53 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 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/asm/ptrace.h b/arch/x86/um/asm/ptrace.h
index e59eef20647b..b291ca5cf66b 100644
--- a/arch/x86/um/asm/ptrace.h
+++ b/arch/x86/um/asm/ptrace.h
@@ -78,7 +78,7 @@ static inline int ptrace_set_thread_area(struct task_struct *child, int idx,
return -ENOSYS;
}

-extern long arch_prctl(struct task_struct *task, int code,
+extern long arch_prctl(struct task_struct *task, int option,
unsigned long __user *addr);

#endif
diff --git a/arch/x86/um/os-Linux/prctl.c b/arch/x86/um/os-Linux/prctl.c
index 96eb2bd28832..8431e87ac333 100644
--- a/arch/x86/um/os-Linux/prctl.c
+++ b/arch/x86/um/os-Linux/prctl.c
@@ -6,7 +6,7 @@
#include <sys/ptrace.h>
#include <asm/ptrace.h>

-int os_arch_prctl(int pid, int code, unsigned long *addr)
+int os_arch_prctl(int pid, int option, unsigned long *arg2)
{
- return ptrace(PTRACE_ARCH_PRCTL, pid, (unsigned long) addr, code);
+ return ptrace(PTRACE_ARCH_PRCTL, pid, (unsigned long) arg2, option);
}
diff --git a/arch/x86/um/syscalls_32.c b/arch/x86/um/syscalls_32.c
new file mode 100644
index 000000000000..627d68836b16
--- /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, option, unsigned long, arg2)
+{
+ return -EINVAL;
+}
diff --git a/arch/x86/um/syscalls_64.c b/arch/x86/um/syscalls_64.c
index 10d907098c26..58f51667e2e4 100644
--- a/arch/x86/um/syscalls_64.c
+++ b/arch/x86/um/syscalls_64.c
@@ -7,13 +7,15 @@

#include <linux/sched.h>
#include <linux/sched/mm.h>
+#include <linux/syscalls.h>
#include <linux/uaccess.h>
#include <asm/prctl.h> /* XXX This should get the constants from libc */
#include <os.h>

-long arch_prctl(struct task_struct *task, int code, unsigned long __user *addr)
+long arch_prctl(struct task_struct *task, int option,
+ unsigned long __user *arg2)
{
- unsigned long *ptr = addr, tmp;
+ unsigned long *ptr = arg2, tmp;
long ret;
int pid = task->mm->context.id.u.pid;

@@ -30,7 +32,7 @@ long arch_prctl(struct task_struct *task, int code, unsigned long __user *addr)
* arch_prctl is run on the host, then the registers are read
* back.
*/
- switch (code) {
+ switch (option) {
case ARCH_SET_FS:
case ARCH_SET_GS:
ret = restore_registers(pid, &current->thread.regs.regs);
@@ -50,11 +52,11 @@ long arch_prctl(struct task_struct *task, int code, unsigned long __user *addr)
ptr = &tmp;
}

- ret = os_arch_prctl(pid, code, ptr);
+ ret = os_arch_prctl(pid, option, ptr);
if (ret)
return ret;

- switch (code) {
+ switch (option) {
case ARCH_SET_FS:
current->thread.arch.fs = (unsigned long) ptr;
ret = save_registers(pid, &current->thread.regs.regs);
@@ -63,19 +65,19 @@ long arch_prctl(struct task_struct *task, int code, unsigned long __user *addr)
ret = save_registers(pid, &current->thread.regs.regs);
break;
case ARCH_GET_FS:
- ret = put_user(tmp, addr);
+ ret = put_user(tmp, arg2);
break;
case ARCH_GET_GS:
- ret = put_user(tmp, addr);
+ ret = put_user(tmp, arg2);
break;
}

return ret;
}

-long sys_arch_prctl(int code, unsigned long addr)
+SYSCALL_DEFINE2(arch_prctl, int, option, unsigned long, arg2)
{
- return arch_prctl(current, code, (unsigned long __user *) addr);
+ return arch_prctl(current, option, (unsigned long __user *) arg2);
}

void arch_switch_to(struct task_struct *to)
diff --git a/fs/exec.c b/fs/exec.c
index 65145a3df065..72934df68471 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1320,6 +1320,7 @@ void setup_new_exec(struct linux_binprm * bprm)
else
set_dumpable(current->mm, suid_dumpable);

+ arch_setup_new_exec();
perf_event_exec();
__set_task_comm(current, kbasename(bprm->filename), true);

diff --git a/include/linux/compat.h b/include/linux/compat.h
index aef47be2a5c1..af9dbc44fd92 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -723,6 +723,8 @@ 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 option, unsigned long arg2);
+
/*
* 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
diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h
index 58373875e8ee..55125d674338 100644
--- a/include/linux/thread_info.h
+++ b/include/linux/thread_info.h
@@ -101,6 +101,10 @@ static inline void check_object_size(const void *ptr, unsigned long n,
{ }
#endif /* CONFIG_HARDENED_USERCOPY */

+#ifndef arch_setup_new_exec
+static inline void arch_setup_new_exec(void) { }
+#endif
+
#endif /* __KERNEL__ */

#endif /* _LINUX_THREAD_INFO_H */
diff --git a/scripts/checksyscalls.sh b/scripts/checksyscalls.sh
index 2c9082ba6137..116b7735ee9f 100755
--- a/scripts/checksyscalls.sh
+++ b/scripts/checksyscalls.sh
@@ -148,6 +148,7 @@ cat << EOF
#define __IGNORE_sysfs
#define __IGNORE_uselib
#define __IGNORE__sysctl
+#define __IGNORE_arch_prctl

/* ... including the "new" 32-bit uid syscalls */
#define __IGNORE_lchown32