From 5cec93c216db77c45f7ce970d46283bcb1933884 Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Sun, 5 Jun 2011 13:50:24 -0400 Subject: x86-64: Emulate legacy vsyscalls There's a fair amount of code in the vsyscall page. It contains a syscall instruction (in the gettimeofday fallback) and who knows what will happen if an exploit jumps into the middle of some other code. Reduce the risk by replacing the vsyscalls with short magic incantations that cause the kernel to emulate the real vsyscalls. These incantations are useless if entered in the middle. This causes vsyscalls to be a little more expensive than real syscalls. Fortunately sensible programs don't use them. The only exception is time() which is still called by glibc through the vsyscall - but calling time() millions of times per second is not sensible. glibc has this fixed in the development tree. This patch is not perfect: the vread_tsc and vread_hpet functions are still at a fixed address. Fixing that might involve making alternative patching work in the vDSO. Signed-off-by: Andy Lutomirski Acked-by: Linus Torvalds Cc: Jesper Juhl Cc: Borislav Petkov Cc: Arjan van de Ven Cc: Jan Beulich Cc: richard -rw- weinberger Cc: Mikael Pettersson Cc: Andi Kleen Cc: Brian Gerst Cc: Louis Rilling Cc: Valdis.Kletnieks@vt.edu Cc: pageexec@freemail.hu Link: http://lkml.kernel.org/r/e64e1b3c64858820d12c48fa739efbd1485e79d5.1307292171.git.luto@mit.edu [ Removed the CONFIG option - it's simpler to just do it unconditionally. Tidied up the code as well. ] Signed-off-by: Ingo Molnar --- include/linux/seccomp.h | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'include') diff --git a/include/linux/seccomp.h b/include/linux/seccomp.h index 167c33361d9c..cc7a4e9cc7ad 100644 --- a/include/linux/seccomp.h +++ b/include/linux/seccomp.h @@ -19,6 +19,11 @@ static inline void secure_computing(int this_syscall) extern long prctl_get_seccomp(void); extern long prctl_set_seccomp(unsigned long); +static inline int seccomp_mode(seccomp_t *s) +{ + return s->mode; +} + #else /* CONFIG_SECCOMP */ #include @@ -37,6 +42,11 @@ static inline long prctl_set_seccomp(unsigned long arg2) return -EINVAL; } +static inline int seccomp_mode(seccomp_t *s) +{ + return 0; +} + #endif /* CONFIG_SECCOMP */ #endif /* _LINUX_SECCOMP_H */ -- cgit v1.2.3 From 433bd805e5fd2c731b3a9025b034f066272d336e Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Wed, 13 Jul 2011 09:24:13 -0400 Subject: clocksource: Replace vread with generic arch data The vread field was bloating struct clocksource everywhere except x86_64, and I want to change the way this works on x86_64, so let's split it out into per-arch data. Cc: x86@kernel.org Cc: Clemens Ladisch Cc: linux-ia64@vger.kernel.org Cc: Tony Luck Cc: Fenghua Yu Cc: John Stultz Cc: Thomas Gleixner Signed-off-by: Andy Lutomirski Link: http://lkml.kernel.org/r/3ae5ec76a168eaaae63f08a2a1060b91aa0b7759.1310563276.git.luto@mit.edu Signed-off-by: H. Peter Anvin --- arch/x86/include/asm/clocksource.h | 16 ++++++++++++++++ arch/x86/kernel/hpet.c | 2 +- arch/x86/kernel/tsc.c | 2 +- arch/x86/kernel/vsyscall_64.c | 2 +- include/asm-generic/clocksource.h | 4 ++++ include/linux/clocksource.h | 10 ++++++++-- 6 files changed, 31 insertions(+), 5 deletions(-) create mode 100644 arch/x86/include/asm/clocksource.h create mode 100644 include/asm-generic/clocksource.h (limited to 'include') diff --git a/arch/x86/include/asm/clocksource.h b/arch/x86/include/asm/clocksource.h new file mode 100644 index 000000000000..a5df33f614c9 --- /dev/null +++ b/arch/x86/include/asm/clocksource.h @@ -0,0 +1,16 @@ +/* x86-specific clocksource additions */ + +#ifndef _ASM_X86_CLOCKSOURCE_H +#define _ASM_X86_CLOCKSOURCE_H + +#ifdef CONFIG_X86_64 + +#define __ARCH_HAS_CLOCKSOURCE_DATA + +struct arch_clocksource_data { + cycle_t (*vread)(void); +}; + +#endif /* CONFIG_X86_64 */ + +#endif /* _ASM_X86_CLOCKSOURCE_H */ diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c index e9f5605e4748..0e07257bb389 100644 --- a/arch/x86/kernel/hpet.c +++ b/arch/x86/kernel/hpet.c @@ -753,7 +753,7 @@ static struct clocksource clocksource_hpet = { .flags = CLOCK_SOURCE_IS_CONTINUOUS, .resume = hpet_resume_counter, #ifdef CONFIG_X86_64 - .vread = vread_hpet, + .archdata = { .vread = vread_hpet }, #endif }; diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index 6cc6922262af..e7a74b889ab3 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -777,7 +777,7 @@ static struct clocksource clocksource_tsc = { .flags = CLOCK_SOURCE_IS_CONTINUOUS | CLOCK_SOURCE_MUST_VERIFY, #ifdef CONFIG_X86_64 - .vread = vread_tsc, + .archdata = { .vread = vread_tsc }, #endif }; diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c index a262400c3479..12d488fd95d9 100644 --- a/arch/x86/kernel/vsyscall_64.c +++ b/arch/x86/kernel/vsyscall_64.c @@ -74,7 +74,7 @@ void update_vsyscall(struct timespec *wall_time, struct timespec *wtm, write_seqlock_irqsave(&vsyscall_gtod_data.lock, flags); /* copy vsyscall data */ - vsyscall_gtod_data.clock.vread = clock->vread; + vsyscall_gtod_data.clock.vread = clock->archdata.vread; vsyscall_gtod_data.clock.cycle_last = clock->cycle_last; vsyscall_gtod_data.clock.mask = clock->mask; vsyscall_gtod_data.clock.mult = mult; diff --git a/include/asm-generic/clocksource.h b/include/asm-generic/clocksource.h new file mode 100644 index 000000000000..0a462d3fb05e --- /dev/null +++ b/include/asm-generic/clocksource.h @@ -0,0 +1,4 @@ +/* + * Architectures should override this file to add private userspace + * clock magic if needed. + */ diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h index d4646b48dc4a..0fb83c224471 100644 --- a/include/linux/clocksource.h +++ b/include/linux/clocksource.h @@ -22,6 +22,8 @@ typedef u64 cycle_t; struct clocksource; +#include + /** * struct cyclecounter - hardware abstraction for a free running counter * Provides completely state-free accessors to the underlying hardware. @@ -153,7 +155,7 @@ extern u64 timecounter_cyc2time(struct timecounter *tc, * @shift: cycle to nanosecond divisor (power of two) * @max_idle_ns: max idle time permitted by the clocksource (nsecs) * @flags: flags describing special properties - * @vread: vsyscall based read + * @archdata: arch-specific data * @suspend: suspend function for the clocksource, if necessary * @resume: resume function for the clocksource, if necessary */ @@ -175,10 +177,14 @@ struct clocksource { #else #define CLKSRC_FSYS_MMIO_SET(mmio, addr) do { } while (0) #endif + +#ifdef __ARCH_HAS_CLOCKSOURCE_DATA + struct arch_clocksource_data archdata; +#endif + const char *name; struct list_head list; int rating; - cycle_t (*vread)(void); int (*enable)(struct clocksource *cs); void (*disable)(struct clocksource *cs); unsigned long flags; -- cgit v1.2.3 From 574c44fa8fa6262ffd5939789ef51a6e98ed62d7 Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Wed, 13 Jul 2011 09:24:15 -0400 Subject: ia64: Replace clocksource.fsys_mmio with generic arch data Now that clocksource.archdata is available, use it for ia64-specific code. Cc: Clemens Ladisch Cc: linux-ia64@vger.kernel.org Cc: Tony Luck Cc: Fenghua Yu Cc: John Stultz Cc: Thomas Gleixner Signed-off-by: Andy Lutomirski Link: http://lkml.kernel.org/r/d31de0ee0842a0e322fb6441571c2b0adb323fa2.1310563276.git.luto@mit.edu Signed-off-by: H. Peter Anvin --- arch/ia64/include/asm/clocksource.h | 12 ++++++++++++ arch/ia64/kernel/cyclone.c | 2 +- arch/ia64/kernel/time.c | 2 +- arch/ia64/sn/kernel/sn2/timer.c | 2 +- drivers/char/hpet.c | 2 +- include/linux/clocksource.h | 7 ------- 6 files changed, 16 insertions(+), 11 deletions(-) create mode 100644 arch/ia64/include/asm/clocksource.h (limited to 'include') diff --git a/arch/ia64/include/asm/clocksource.h b/arch/ia64/include/asm/clocksource.h new file mode 100644 index 000000000000..00eb549a59b0 --- /dev/null +++ b/arch/ia64/include/asm/clocksource.h @@ -0,0 +1,12 @@ +/* IA64-specific clocksource additions */ + +#ifndef _ASM_IA64_CLOCKSOURCE_H +#define _ASM_IA64_CLOCKSOURCE_H + +#define __ARCH_HAS_CLOCKSOURCE_DATA + +struct arch_clocksource_data { + void *fsys_mmio; /* used by fsyscall asm code */ +}; + +#endif /* _ASM_IA64_CLOCKSOURCE_H */ diff --git a/arch/ia64/kernel/cyclone.c b/arch/ia64/kernel/cyclone.c index f64097b5118a..4826ff957a3d 100644 --- a/arch/ia64/kernel/cyclone.c +++ b/arch/ia64/kernel/cyclone.c @@ -115,7 +115,7 @@ int __init init_cyclone_clock(void) } /* initialize last tick */ cyclone_mc = cyclone_timer; - clocksource_cyclone.fsys_mmio = cyclone_timer; + clocksource_cyclone.archdata.fsys_mmio = cyclone_timer; clocksource_register_hz(&clocksource_cyclone, CYCLONE_TIMER_FREQ); return 0; diff --git a/arch/ia64/kernel/time.c b/arch/ia64/kernel/time.c index 85118dfe9bb5..43920de425f1 100644 --- a/arch/ia64/kernel/time.c +++ b/arch/ia64/kernel/time.c @@ -468,7 +468,7 @@ void update_vsyscall(struct timespec *wall, struct timespec *wtm, fsyscall_gtod_data.clk_mask = c->mask; fsyscall_gtod_data.clk_mult = mult; fsyscall_gtod_data.clk_shift = c->shift; - fsyscall_gtod_data.clk_fsys_mmio = c->fsys_mmio; + fsyscall_gtod_data.clk_fsys_mmio = c->archdata.fsys_mmio; fsyscall_gtod_data.clk_cycle_last = c->cycle_last; /* copy kernel time structures */ diff --git a/arch/ia64/sn/kernel/sn2/timer.c b/arch/ia64/sn/kernel/sn2/timer.c index c34efda122e1..0f8844e49363 100644 --- a/arch/ia64/sn/kernel/sn2/timer.c +++ b/arch/ia64/sn/kernel/sn2/timer.c @@ -54,7 +54,7 @@ ia64_sn_udelay (unsigned long usecs) void __init sn_timer_init(void) { - clocksource_sn2.fsys_mmio = RTC_COUNTER_ADDR; + clocksource_sn2.archdata.fsys_mmio = RTC_COUNTER_ADDR; clocksource_register_hz(&clocksource_sn2, sn_rtc_cycles_per_second); ia64_udelay = &ia64_sn_udelay; diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c index 051474c65b78..055765147dc2 100644 --- a/drivers/char/hpet.c +++ b/drivers/char/hpet.c @@ -931,7 +931,7 @@ int hpet_alloc(struct hpet_data *hdp) #ifdef CONFIG_IA64 if (!hpet_clocksource) { hpet_mctr = (void __iomem *)&hpetp->hp_hpet->hpet_mc; - CLKSRC_FSYS_MMIO_SET(clocksource_hpet.fsys_mmio, hpet_mctr); + clocksource_hpet.archdata.fsys_mmio = hpet_mctr; clocksource_register_hz(&clocksource_hpet, hpetp->hp_tick_freq); hpetp->hp_clocksource = &clocksource_hpet; hpet_clocksource = &clocksource_hpet; diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h index 0fb83c224471..6bb69702c4fa 100644 --- a/include/linux/clocksource.h +++ b/include/linux/clocksource.h @@ -171,13 +171,6 @@ struct clocksource { u32 shift; u64 max_idle_ns; -#ifdef CONFIG_IA64 - void *fsys_mmio; /* used by fsyscall asm code */ -#define CLKSRC_FSYS_MMIO_SET(mmio, addr) ((mmio) = (addr)) -#else -#define CLKSRC_FSYS_MMIO_SET(mmio, addr) do { } while (0) -#endif - #ifdef __ARCH_HAS_CLOCKSOURCE_DATA struct arch_clocksource_data archdata; #endif -- cgit v1.2.3 From ae7bd11b471931752e5609094ca0a49386590524 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Thu, 21 Jul 2011 13:34:05 -0700 Subject: clocksource: Change __ARCH_HAS_CLOCKSOURCE_DATA to a CONFIG option The machinery for __ARCH_HAS_CLOCKSOURCE_DATA assumed a file in asm-generic would be the default for architectures without their own file in asm/, but that is not how it works. Replace it with a Kconfig option instead. Link: http://lkml.kernel.org/r/4E288AA6.7090804@zytor.com Signed-off-by: H. Peter Anvin Cc: Andy Lutomirski Cc: Arnd Bergmann Cc: Tony Luck --- arch/ia64/Kconfig | 3 +++ arch/ia64/include/asm/clocksource.h | 2 -- arch/x86/Kconfig | 4 ++++ arch/x86/include/asm/clocksource.h | 2 -- include/asm-generic/clocksource.h | 4 ---- include/linux/clocksource.h | 4 +++- 6 files changed, 10 insertions(+), 9 deletions(-) delete mode 100644 include/asm-generic/clocksource.h (limited to 'include') diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig index 38280ef4a2af..0a9820a77825 100644 --- a/arch/ia64/Kconfig +++ b/arch/ia64/Kconfig @@ -101,6 +101,9 @@ config GENERIC_IOMAP bool default y +config ARCH_CLOCKSOURCE_DATA + def_bool y + config SCHED_OMIT_FRAME_POINTER bool default y diff --git a/arch/ia64/include/asm/clocksource.h b/arch/ia64/include/asm/clocksource.h index 00eb549a59b0..5c8596e4cb02 100644 --- a/arch/ia64/include/asm/clocksource.h +++ b/arch/ia64/include/asm/clocksource.h @@ -3,8 +3,6 @@ #ifndef _ASM_IA64_CLOCKSOURCE_H #define _ASM_IA64_CLOCKSOURCE_H -#define __ARCH_HAS_CLOCKSOURCE_DATA - struct arch_clocksource_data { void *fsys_mmio; /* used by fsyscall asm code */ }; diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index da349723d411..c1e41bccdcb8 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -93,6 +93,10 @@ config CLOCKSOURCE_WATCHDOG config GENERIC_CLOCKEVENTS def_bool y +config ARCH_CLOCKSOURCE_DATA + def_bool y + depends on X86_64 + config GENERIC_CLOCKEVENTS_BROADCAST def_bool y depends on X86_64 || (X86_32 && X86_LOCAL_APIC) diff --git a/arch/x86/include/asm/clocksource.h b/arch/x86/include/asm/clocksource.h index 3882c65dc19b..0bdbbb3b9ce7 100644 --- a/arch/x86/include/asm/clocksource.h +++ b/arch/x86/include/asm/clocksource.h @@ -5,8 +5,6 @@ #ifdef CONFIG_X86_64 -#define __ARCH_HAS_CLOCKSOURCE_DATA - #define VCLOCK_NONE 0 /* No vDSO clock available. */ #define VCLOCK_TSC 1 /* vDSO should use vread_tsc. */ #define VCLOCK_HPET 2 /* vDSO should use vread_hpet. */ diff --git a/include/asm-generic/clocksource.h b/include/asm-generic/clocksource.h deleted file mode 100644 index 0a462d3fb05e..000000000000 --- a/include/asm-generic/clocksource.h +++ /dev/null @@ -1,4 +0,0 @@ -/* - * Architectures should override this file to add private userspace - * clock magic if needed. - */ diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h index 6bb69702c4fa..59ee970cf89e 100644 --- a/include/linux/clocksource.h +++ b/include/linux/clocksource.h @@ -22,7 +22,9 @@ typedef u64 cycle_t; struct clocksource; +#ifdef CONFIG_ARCH_CLOCKSOURCE_DATA #include +#endif /** * struct cyclecounter - hardware abstraction for a free running counter @@ -171,7 +173,7 @@ struct clocksource { u32 shift; u64 max_idle_ns; -#ifdef __ARCH_HAS_CLOCKSOURCE_DATA +#ifdef CONFIG_ARCH_CLOCKSOURCE_DATA struct arch_clocksource_data archdata; #endif -- cgit v1.2.3