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authorMark Rutland <mark.rutland@arm.com>2013-05-24 12:02:35 +0100
committerCatalin Marinas <catalin.marinas@arm.com>2013-05-31 16:04:44 +0100
commit381cc2b9705512ee7c7f1839cbdde374625a2a9f (patch)
tree7b13ed8486efe15b07f1eb194241667a0f5c1fd9 /arch
parent953dbbed9ee310100bc841cdea8f992d192531c6 (diff)
downloadlinux-381cc2b9705512ee7c7f1839cbdde374625a2a9f.tar.gz
arm64: treat unhandled compat el0 traps as undef
Currently, if a compat process reads or writes from/to a disabled cp15/cp14 register, the trap is not handled by the el0_sync_compat handler, and the kernel will head to bad_mode, where it will die(), and oops(). For 64 bit processes, disabled system register accesses are currently treated as unhandled instructions. This patch modifies entry.S to treat these unhandled traps as undefined instructions, sending a SIGILL to userspace. This gives processes a chance to handle this and stop using inaccessible registers, and prevents further issues in the kernel as a result of the die(). Reported-by: Johannes Jensen <Johannes.Jensen@arm.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm64/kernel/entry.S10
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index c7e047049f2..1d1314280a0 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -390,6 +390,16 @@ el0_sync_compat:
b.eq el0_fpsimd_exc
cmp x24, #ESR_EL1_EC_UNKNOWN // unknown exception in EL0
b.eq el0_undef
+ cmp x24, #ESR_EL1_EC_CP15_32 // CP15 MRC/MCR trap
+ b.eq el0_undef
+ cmp x24, #ESR_EL1_EC_CP15_64 // CP15 MRRC/MCRR trap
+ b.eq el0_undef
+ cmp x24, #ESR_EL1_EC_CP14_MR // CP14 MRC/MCR trap
+ b.eq el0_undef
+ cmp x24, #ESR_EL1_EC_CP14_LS // CP14 LDC/STC trap
+ b.eq el0_undef
+ cmp x24, #ESR_EL1_EC_CP14_64 // CP14 MRRC/MCRR trap
+ b.eq el0_undef
cmp x24, #ESR_EL1_EC_BREAKPT_EL0 // debug exception in EL0
b.ge el0_dbg
b el0_inv