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authorMark Rutland <mark.rutland@arm.com>2016-03-01 15:18:50 +0100
committerCatalin Marinas <catalin.marinas@arm.com>2016-03-02 16:49:28 +0100
commitdbd4d7ca563fd0a8949718d35ce197e5642d5d9d (patch)
tree35b33dd22bd899a75ad8be3f69e8165084a0d18f /arch/arm64/kernel/signal32.c
parentarm64: mm: check at build time that PAGE_OFFSET divides the VA space evenly (diff)
downloadlinux-dbd4d7ca563fd0a8949718d35ce197e5642d5d9d.tar.xz
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arm64: Rework valid_user_regs
We validate pstate using PSR_MODE32_BIT, which is part of the user-provided pstate (and cannot be trusted). Also, we conflate validation of AArch32 and AArch64 pstate values, making the code difficult to reason about. Instead, validate the pstate value based on the associated task. The task may or may not be current (e.g. when using ptrace), so this must be passed explicitly by callers. To avoid circular header dependencies via sched.h, is_compat_task is pulled out of asm/ptrace.h. To make the code possible to reason about, the AArch64 and AArch32 validation is split into separate functions. Software must respect the RES0 policy for SPSR bits, and thus the kernel mirrors the hardware policy (RAZ/WI) for bits as-yet unallocated. When these acquire an architected meaning writes may be permitted (potentially with additional validation). Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Dave Martin <dave.martin@arm.com> Cc: James Morse <james.morse@arm.com> Cc: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel/signal32.c')
-rw-r--r--arch/arm64/kernel/signal32.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arm64/kernel/signal32.c b/arch/arm64/kernel/signal32.c
index 71ef6dc89ae5..107335637390 100644
--- a/arch/arm64/kernel/signal32.c
+++ b/arch/arm64/kernel/signal32.c
@@ -356,7 +356,7 @@ static int compat_restore_sigframe(struct pt_regs *regs,
*/
regs->syscallno = ~0UL;
- err |= !valid_user_regs(&regs->user_regs);
+ err |= !valid_user_regs(&regs->user_regs, current);
aux = (struct compat_aux_sigframe __user *) sf->uc.uc_regspace;
if (err == 0)