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UPSTREAM: mips: compat: vdso: Use legacy syscalls as fallback

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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.

Cc: Paul Burton <paul.burton@mips.com>
Fixes: 00b26474c2f1 ("lib/vdso: Provide generic VDSO implementation")
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@vger.kernel.org
Cc: linux-kselftest@vger.kernel.org
Cc: catalin.marinas@arm.com
Cc: will@kernel.org
Cc: tglx@linutronix.de
Cc: salyzyn@android.com
Cc: 0x7f454c46@gmail.com
Cc: luto@kernel.org
(cherry picked from commit 932bb934ed4d05d4bd5e8e3c3aaa5f92e0a89d90)
Signed-off-by: Mark Salyzyn <salyzyn@google.com>
Bug: 154668398
Change-Id: I9734b0f647b807d5e173cdf4c564d18f63a7748c
This commit is contained in:
Vincenzo Frascino
2019-08-30 14:58:57 +01:00
committed by Alistair Delva
parent 2504bdb5d7
commit 1767547b79
2 changed files with 46 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

45
arch/mips/include/asm/vdso/gettimeofday.h
View File

@@ -105,6 +105,51 @@ static __always_inline int clock_getres_fallback(
return error ? -ret : ret; return error ? -ret : ret;
} }
#if _MIPS_SIM != _MIPS_SIM_ABI64
#define VDSO_HAS_32BIT_FALLBACK 1
static __always_inline long clock_gettime32_fallback(
clockid_t _clkid,
struct old_timespec32 *_ts)
{
register struct old_timespec32 *ts asm("a1") = _ts;
register clockid_t clkid asm("a0") = _clkid;
register long ret asm("v0");
register long nr asm("v0") = __NR_clock_gettime;
register long error asm("a3");
asm volatile(
" syscall\n"
: "=r" (ret), "=r" (error)
: "r" (clkid), "r" (ts), "r" (nr)
: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
"$14", "$15", "$24", "$25", "hi", "lo", "memory");
return error ? -ret : ret;
}
static __always_inline int clock_getres32_fallback(
clockid_t _clkid,
struct old_timespec32 *_ts)
{
register struct old_timespec32 *ts asm("a1") = _ts;
register clockid_t clkid asm("a0") = _clkid;
register long ret asm("v0");
register long nr asm("v0") = __NR_clock_getres;
register long error asm("a3");
asm volatile(
" syscall\n"
: "=r" (ret), "=r" (error)
: "r" (clkid), "r" (ts), "r" (nr)
: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
"$14", "$15", "$24", "$25", "hi", "lo", "memory");
return error ? -ret : ret;
}
#endif
#ifdef CONFIG_CSRC_R4K #ifdef CONFIG_CSRC_R4K
static __always_inline u64 read_r4k_count(void) static __always_inline u64 read_r4k_count(void)

1
arch/mips/vdso/config-n32-o32-env.c
View File

@@ -10,6 +10,7 @@
*/ */
#undef CONFIG_64BIT #undef CONFIG_64BIT
#define BUILD_VDSO32
#define CONFIG_32BIT 1 #define CONFIG_32BIT 1
#define CONFIG_GENERIC_ATOMIC64 1 #define CONFIG_GENERIC_ATOMIC64 1