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| author | Amit Daniel Kachhap <amit.kachhap@arm.com> | 2020-09-14 10:36:53 +0200 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2020-09-14 13:07:02 +0200 |
| commit | e16aeb072682d3dcdbdad452c974baa0d2b0c6db (patch) | |
| tree | 20484ed8c1c59204ef50fb524fa206e6198e63f9 /arch/arm64/include/asm/exception.h | |
| parent | arm64: traps: Allow force_signal_inject to pass esr error code (diff) | |
| download | linux-e16aeb072682d3dcdbdad452c974baa0d2b0c6db.tar.xz linux-e16aeb072682d3dcdbdad452c974baa0d2b0c6db.zip | |
arm64: ptrauth: Introduce Armv8.3 pointer authentication enhancements
Some Armv8.3 Pointer Authentication enhancements have been introduced
which are mandatory for Armv8.6 and optional for Armv8.3. These features
are,
* ARMv8.3-PAuth2 - An enhanced PAC generation logic is added which hardens
finding the correct PAC value of the authenticated pointer.
* ARMv8.3-FPAC - Fault is generated now when the ptrauth authentication
instruction fails in authenticating the PAC present in the address.
This is different from earlier case when such failures just adds an
error code in the top byte and waits for subsequent load/store to abort.
The ptrauth instructions which may cause this fault are autiasp, retaa
etc.
The above features are now represented by additional configurations
for the Address Authentication cpufeature and a new ESR exception class.
The userspace fault received in the kernel due to ARMv8.3-FPAC is treated
as Illegal instruction and hence signal SIGILL is injected with ILL_ILLOPN
as the signal code. Note that this is different from earlier ARMv8.3
ptrauth where signal SIGSEGV is issued due to Pointer authentication
failures. The in-kernel PAC fault causes kernel to crash.
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Link: https://lore.kernel.org/r/20200914083656.21428-4-amit.kachhap@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch/arm64/include/asm/exception.h')
| -rw-r--r-- | arch/arm64/include/asm/exception.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/exception.h b/arch/arm64/include/asm/exception.h index 7577a754d443..99b9383cd036 100644 --- a/arch/arm64/include/asm/exception.h +++ b/arch/arm64/include/asm/exception.h @@ -47,4 +47,5 @@ void bad_el0_sync(struct pt_regs *regs, int reason, unsigned int esr); void do_cp15instr(unsigned int esr, struct pt_regs *regs); void do_el0_svc(struct pt_regs *regs); void do_el0_svc_compat(struct pt_regs *regs); +void do_ptrauth_fault(struct pt_regs *regs, unsigned int esr); #endif /* __ASM_EXCEPTION_H */ |