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| author | Russell King <rmk+kernel@armlinux.org.uk> | 2018-05-11 12:16:22 +0200 |
|---|---|---|
| committer | Russell King <rmk+kernel@armlinux.org.uk> | 2018-06-01 00:27:26 +0200 |
| commit | 10573ae547c85b2c61417ff1a106cffbfceada35 (patch) | |
| tree | dbc21a6b8a94eaa26fdc73b4440affa5ad082e4c /arch/arm/kernel/entry-common.S | |
| parent | ARM: spectre-v1: add array_index_mask_nospec() implementation (diff) | |
| download | linux-10573ae547c85b2c61417ff1a106cffbfceada35.tar.xz linux-10573ae547c85b2c61417ff1a106cffbfceada35.zip | |
ARM: spectre-v1: fix syscall entry
Prevent speculation at the syscall table decoding by clamping the index
used to zero on invalid system call numbers, and using the csdb
speculative barrier.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Diffstat (limited to 'arch/arm/kernel/entry-common.S')
| -rw-r--r-- | arch/arm/kernel/entry-common.S | 18 |
1 files changed, 7 insertions, 11 deletions
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index 3c4f88701f22..20df608bf343 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -242,9 +242,7 @@ local_restart: tst r10, #_TIF_SYSCALL_WORK @ are we tracing syscalls? bne __sys_trace - cmp scno, #NR_syscalls @ check upper syscall limit - badr lr, ret_fast_syscall @ return address - ldrcc pc, [tbl, scno, lsl #2] @ call sys_* routine + invoke_syscall tbl, scno, r10, ret_fast_syscall add r1, sp, #S_OFF 2: cmp scno, #(__ARM_NR_BASE - __NR_SYSCALL_BASE) @@ -278,14 +276,8 @@ __sys_trace: mov r1, scno add r0, sp, #S_OFF bl syscall_trace_enter - - badr lr, __sys_trace_return @ return address - mov scno, r0 @ syscall number (possibly new) - add r1, sp, #S_R0 + S_OFF @ pointer to regs - cmp scno, #NR_syscalls @ check upper syscall limit - ldmccia r1, {r0 - r6} @ have to reload r0 - r6 - stmccia sp, {r4, r5} @ and update the stack args - ldrcc pc, [tbl, scno, lsl #2] @ call sys_* routine + mov scno, r0 + invoke_syscall tbl, scno, r10, __sys_trace_return, reload=1 cmp scno, #-1 @ skip the syscall? bne 2b add sp, sp, #S_OFF @ restore stack @@ -363,6 +355,10 @@ sys_syscall: bic scno, r0, #__NR_OABI_SYSCALL_BASE cmp scno, #__NR_syscall - __NR_SYSCALL_BASE cmpne scno, #NR_syscalls @ check range +#ifdef CONFIG_CPU_SPECTRE + movhs scno, #0 + csdb +#endif stmloia sp, {r5, r6} @ shuffle args movlo r0, r1 movlo r1, r2 |