summaryrefslogtreecommitdiff
path: root/arch
diff options
context:
space:
mode:
authorThomas Gleixner <tglx@linutronix.de>2019-07-28 15:12:55 +0200
committerThomas Gleixner <tglx@linutronix.de>2019-07-31 00:09:10 +0200
commitd2f5d3fa26196183adb44a413c44caa9872275b4 (patch)
tree626f069300d13e15ccd8f835124cb17e68d113df /arch
parentc60a32ea4f459f99b98d383cad3b1ac7cfb3f4be (diff)
x86/vdso/32: Use 32bit syscall fallback
The generic VDSO implementation uses the Y2038 safe clock_gettime64() and clock_getres_time64() syscalls as fallback for 32bit VDSO. This breaks seccomp setups because these syscalls might be not (yet) allowed. Implement the 32bit variants which use the legacy syscalls and select the variant in the core library. The 64bit time variants are not removed because they are required for the time64 based vdso accessors. Fixes: 7ac870747988 ("x86/vdso: Switch to generic vDSO implementation") Reported-by: Sean Christopherson <sean.j.christopherson@intel.com> Reported-by: Paul Bolle <pebolle@tiscali.nl> Suggested-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20190728131648.879156507@linutronix.de
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/include/asm/vdso/gettimeofday.h36
1 files changed, 36 insertions, 0 deletions
diff --git a/arch/x86/include/asm/vdso/gettimeofday.h b/arch/x86/include/asm/vdso/gettimeofday.h
index ae91429129a6..ba71a63cdac4 100644
--- a/arch/x86/include/asm/vdso/gettimeofday.h
+++ b/arch/x86/include/asm/vdso/gettimeofday.h
@@ -96,6 +96,8 @@ long clock_getres_fallback(clockid_t _clkid, struct __kernel_timespec *_ts)
#else
+#define VDSO_HAS_32BIT_FALLBACK 1
+
static __always_inline
long clock_gettime_fallback(clockid_t _clkid, struct __kernel_timespec *_ts)
{
@@ -114,6 +116,23 @@ long clock_gettime_fallback(clockid_t _clkid, struct __kernel_timespec *_ts)
}
static __always_inline
+long clock_gettime32_fallback(clockid_t _clkid, struct old_timespec32 *_ts)
+{
+ long ret;
+
+ asm (
+ "mov %%ebx, %%edx \n"
+ "mov %[clock], %%ebx \n"
+ "call __kernel_vsyscall \n"
+ "mov %%edx, %%ebx \n"
+ : "=a" (ret), "=m" (*_ts)
+ : "0" (__NR_clock_gettime), [clock] "g" (_clkid), "c" (_ts)
+ : "edx");
+
+ return ret;
+}
+
+static __always_inline
long gettimeofday_fallback(struct __kernel_old_timeval *_tv,
struct timezone *_tz)
{
@@ -148,6 +167,23 @@ clock_getres_fallback(clockid_t _clkid, struct __kernel_timespec *_ts)
return ret;
}
+static __always_inline
+long clock_getres32_fallback(clockid_t _clkid, struct old_timespec32 *_ts)
+{
+ long ret;
+
+ asm (
+ "mov %%ebx, %%edx \n"
+ "mov %[clock], %%ebx \n"
+ "call __kernel_vsyscall \n"
+ "mov %%edx, %%ebx \n"
+ : "=a" (ret), "=m" (*_ts)
+ : "0" (__NR_clock_getres), [clock] "g" (_clkid), "c" (_ts)
+ : "edx");
+
+ return ret;
+}
+
#endif
#ifdef CONFIG_PARAVIRT_CLOCK