| Message ID | 20200904104209.32385-2-amit.kachhap@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: add Armv8.3 pointer authentication enhancements | expand |
On Fri, Sep 04, 2020 at 04:12:04PM +0530, Amit Daniel Kachhap wrote: > Currently the ARMv8.3-PAuth combined branch instructions (braa, retaa > etc.) are not simulated for out-of-line execution with a handler. Hence the > uprobe of such instructions leads to kernel warnings in a loop as they are > not explicitly checked and fall into INSN_GOOD categories. Other combined > instructions like LDRAA and LDRBB can be probed. > > The issue of the combined branch instructions is fixed by adding > definitions of all such instructions and rejecting their probes. > > Warning log: > WARNING: CPU: 5 PID: 249 at arch/arm64/kernel/probes/uprobes.c:182 uprobe_single_step_handler+0x34/0x50 > Modules linked in: > CPU: 5 PID: 249 Comm: func Tainted: G W 5.8.0-rc4-00005-ge658591d66d1-dirty #160 > Hardware name: Foundation-v8A (DT) > pstate: 204003c9 (nzCv DAIF +PAN -UAO BTYPE=--) > pc : uprobe_single_step_handler+0x34/0x50 > lr : single_step_handler+0x70/0xf8 > sp : ffff800012afbe30 > x29: ffff800012afbe30 x28: ffff000879f00ec0 > x27: 0000000000000000 x26: 0000000000000000 > x25: 0000000000000000 x24: 0000000000000000 > x23: 0000000060001000 x22: 00000000cb000022 > x21: ffff800011fc5a68 x20: ffff800012afbec0 > x19: ffff800011fc86c0 x18: 0000000000000000 > x17: 0000000000000000 x16: 0000000000000000 > x15: 0000000000000000 x14: 0000000000000000 > x13: 0000000000000000 x12: 0000000000000000 > x11: 0000000000000000 x10: 0000000000000000 > x9 : ffff800010085d50 x8 : 0000000000000000 > x7 : 0000000000000000 x6 : ffff800011fba9c0 > x5 : ffff800011fba000 x4 : ffff800012283070 > x3 : ffff8000100a78e0 x2 : 00000000004005f0 > x1 : 0000fffffffff008 x0 : ffff800012afbec0 > Call trace: > uprobe_single_step_handler+0x34/0x50 > single_step_handler+0x70/0xf8 > do_debug_exception+0xb8/0x130 > el0_sync_handler+0x7c/0x188 > el0_sync+0x158/0x180 > > Fixes: 74afda4016a7 ("arm64: compile the kernel with ptrauth return address signing") > Fixes: 04ca3204fa09 ("arm64: enable pointer authentication") > Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com> > Reviewed-by: Dave Martin <Dave.Martin@arm.com> > --- > Changes since v5: > * Slight change in commit log. > * Added Reviewed-by. > > arch/arm64/include/asm/insn.h | 12 ++++++++++++ > arch/arm64/kernel/insn.c | 14 ++++++++++++-- > arch/arm64/kernel/probes/decode-insn.c | 4 +++- > 3 files changed, 27 insertions(+), 3 deletions(-) > > diff --git a/arch/arm64/include/asm/insn.h b/arch/arm64/include/asm/insn.h > index 0bc46149e491..324234068fee 100644 > --- a/arch/arm64/include/asm/insn.h > +++ b/arch/arm64/include/asm/insn.h > @@ -359,9 +359,21 @@ __AARCH64_INSN_FUNCS(brk, 0xFFE0001F, 0xD4200000) > __AARCH64_INSN_FUNCS(exception, 0xFF000000, 0xD4000000) > __AARCH64_INSN_FUNCS(hint, 0xFFFFF01F, 0xD503201F) > __AARCH64_INSN_FUNCS(br, 0xFFFFFC1F, 0xD61F0000) > +__AARCH64_INSN_FUNCS(braaz, 0xFFFFFC1F, 0xD61F081F) > +__AARCH64_INSN_FUNCS(brabz, 0xFFFFFC1F, 0xD61F0C1F) > +__AARCH64_INSN_FUNCS(braa, 0xFFFFFC00, 0xD71F0800) > +__AARCH64_INSN_FUNCS(brab, 0xFFFFFC00, 0xD71F0C00) When do we need to distinguish these variants? Can we modify the mask/value pair so that we catch bra* in one go? That would match how they are documented in the Arm ARM. > __AARCH64_INSN_FUNCS(blr, 0xFFFFFC1F, 0xD63F0000) > +__AARCH64_INSN_FUNCS(blraaz, 0xFFFFFC1F, 0xD63F081F) > +__AARCH64_INSN_FUNCS(blrabz, 0xFFFFFC1F, 0xD63F0C1F) > +__AARCH64_INSN_FUNCS(blraa, 0xFFFFFC00, 0xD73F0800) > +__AARCH64_INSN_FUNCS(blrab, 0xFFFFFC00, 0xD73F0C00) Same here for blra* > __AARCH64_INSN_FUNCS(ret, 0xFFFFFC1F, 0xD65F0000) > +__AARCH64_INSN_FUNCS(retaa, 0xFFFFFFFF, 0xD65F0BFF) > +__AARCH64_INSN_FUNCS(retab, 0xFFFFFFFF, 0xD65F0FFF) > __AARCH64_INSN_FUNCS(eret, 0xFFFFFFFF, 0xD69F03E0) > +__AARCH64_INSN_FUNCS(eretaa, 0xFFFFFFFF, 0xD69F0BFF) > +__AARCH64_INSN_FUNCS(eretab, 0xFFFFFFFF, 0xD69F0FFF) ... and here for ereta*. Will
On Mon, Sep 07, 2020 at 10:45:51PM +0100, Will Deacon wrote: > On Fri, Sep 04, 2020 at 04:12:04PM +0530, Amit Daniel Kachhap wrote: > > Currently the ARMv8.3-PAuth combined branch instructions (braa, retaa > > etc.) are not simulated for out-of-line execution with a handler. Hence the > > uprobe of such instructions leads to kernel warnings in a loop as they are > > not explicitly checked and fall into INSN_GOOD categories. Other combined > > instructions like LDRAA and LDRBB can be probed. > > > > The issue of the combined branch instructions is fixed by adding > > definitions of all such instructions and rejecting their probes. > > > > Warning log: > > WARNING: CPU: 5 PID: 249 at arch/arm64/kernel/probes/uprobes.c:182 uprobe_single_step_handler+0x34/0x50 > > Modules linked in: > > CPU: 5 PID: 249 Comm: func Tainted: G W 5.8.0-rc4-00005-ge658591d66d1-dirty #160 > > Hardware name: Foundation-v8A (DT) > > pstate: 204003c9 (nzCv DAIF +PAN -UAO BTYPE=--) > > pc : uprobe_single_step_handler+0x34/0x50 > > lr : single_step_handler+0x70/0xf8 > > sp : ffff800012afbe30 > > x29: ffff800012afbe30 x28: ffff000879f00ec0 > > x27: 0000000000000000 x26: 0000000000000000 > > x25: 0000000000000000 x24: 0000000000000000 > > x23: 0000000060001000 x22: 00000000cb000022 > > x21: ffff800011fc5a68 x20: ffff800012afbec0 > > x19: ffff800011fc86c0 x18: 0000000000000000 > > x17: 0000000000000000 x16: 0000000000000000 > > x15: 0000000000000000 x14: 0000000000000000 > > x13: 0000000000000000 x12: 0000000000000000 > > x11: 0000000000000000 x10: 0000000000000000 > > x9 : ffff800010085d50 x8 : 0000000000000000 > > x7 : 0000000000000000 x6 : ffff800011fba9c0 > > x5 : ffff800011fba000 x4 : ffff800012283070 > > x3 : ffff8000100a78e0 x2 : 00000000004005f0 > > x1 : 0000fffffffff008 x0 : ffff800012afbec0 > > Call trace: > > uprobe_single_step_handler+0x34/0x50 > > single_step_handler+0x70/0xf8 > > do_debug_exception+0xb8/0x130 > > el0_sync_handler+0x7c/0x188 > > el0_sync+0x158/0x180 > > > > Fixes: 74afda4016a7 ("arm64: compile the kernel with ptrauth return address signing") > > Fixes: 04ca3204fa09 ("arm64: enable pointer authentication") > > Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com> > > Reviewed-by: Dave Martin <Dave.Martin@arm.com> > > --- > > Changes since v5: > > * Slight change in commit log. > > * Added Reviewed-by. > > > > arch/arm64/include/asm/insn.h | 12 ++++++++++++ > > arch/arm64/kernel/insn.c | 14 ++++++++++++-- > > arch/arm64/kernel/probes/decode-insn.c | 4 +++- > > 3 files changed, 27 insertions(+), 3 deletions(-) > > > > diff --git a/arch/arm64/include/asm/insn.h b/arch/arm64/include/asm/insn.h > > index 0bc46149e491..324234068fee 100644 > > --- a/arch/arm64/include/asm/insn.h > > +++ b/arch/arm64/include/asm/insn.h > > @@ -359,9 +359,21 @@ __AARCH64_INSN_FUNCS(brk, 0xFFE0001F, 0xD4200000) > > __AARCH64_INSN_FUNCS(exception, 0xFF000000, 0xD4000000) > > __AARCH64_INSN_FUNCS(hint, 0xFFFFF01F, 0xD503201F) > > __AARCH64_INSN_FUNCS(br, 0xFFFFFC1F, 0xD61F0000) > > +__AARCH64_INSN_FUNCS(braaz, 0xFFFFFC1F, 0xD61F081F) > > +__AARCH64_INSN_FUNCS(brabz, 0xFFFFFC1F, 0xD61F0C1F) > > +__AARCH64_INSN_FUNCS(braa, 0xFFFFFC00, 0xD71F0800) > > +__AARCH64_INSN_FUNCS(brab, 0xFFFFFC00, 0xD71F0C00) > > When do we need to distinguish these variants? Can we modify the mask/value > pair so that we catch bra* in one go? That would match how they are > documented in the Arm ARM. > > > __AARCH64_INSN_FUNCS(blr, 0xFFFFFC1F, 0xD63F0000) > > +__AARCH64_INSN_FUNCS(blraaz, 0xFFFFFC1F, 0xD63F081F) > > +__AARCH64_INSN_FUNCS(blrabz, 0xFFFFFC1F, 0xD63F0C1F) > > +__AARCH64_INSN_FUNCS(blraa, 0xFFFFFC00, 0xD73F0800) > > +__AARCH64_INSN_FUNCS(blrab, 0xFFFFFC00, 0xD73F0C00) > > Same here for blra* > > > __AARCH64_INSN_FUNCS(ret, 0xFFFFFC1F, 0xD65F0000) > > +__AARCH64_INSN_FUNCS(retaa, 0xFFFFFFFF, 0xD65F0BFF) > > +__AARCH64_INSN_FUNCS(retab, 0xFFFFFFFF, 0xD65F0FFF) > > __AARCH64_INSN_FUNCS(eret, 0xFFFFFFFF, 0xD69F03E0) > > +__AARCH64_INSN_FUNCS(eretaa, 0xFFFFFFFF, 0xD69F0BFF) > > +__AARCH64_INSN_FUNCS(eretab, 0xFFFFFFFF, 0xD69F0FFF) > > ... and here for ereta*. From my side: I thought about this myself, but I thought that this may be easier to maintain if we avoid lumping instructions together. Some of these cases are probably trivial enough that they can be merged at low risk, though, and we also have some other merged instruction classes here already. Avoiding pointless distinctions here will also help the efficiency of code that uses these definitions in some cases, though I don't have a feel for how significant the difference will be -- probably not very. If we become concerned about performance, we would probably want a bigger overhaul of the affected code anyway. I guess I'm happy either way. Cheers ---Dave
On Tue, Sep 08, 2020 at 11:51:08AM +0100, Dave Martin wrote: > On Mon, Sep 07, 2020 at 10:45:51PM +0100, Will Deacon wrote: > > On Fri, Sep 04, 2020 at 04:12:04PM +0530, Amit Daniel Kachhap wrote: > > > diff --git a/arch/arm64/include/asm/insn.h b/arch/arm64/include/asm/insn.h > > > index 0bc46149e491..324234068fee 100644 > > > --- a/arch/arm64/include/asm/insn.h > > > +++ b/arch/arm64/include/asm/insn.h > > > @@ -359,9 +359,21 @@ __AARCH64_INSN_FUNCS(brk, 0xFFE0001F, 0xD4200000) > > > __AARCH64_INSN_FUNCS(exception, 0xFF000000, 0xD4000000) > > > __AARCH64_INSN_FUNCS(hint, 0xFFFFF01F, 0xD503201F) > > > __AARCH64_INSN_FUNCS(br, 0xFFFFFC1F, 0xD61F0000) > > > +__AARCH64_INSN_FUNCS(braaz, 0xFFFFFC1F, 0xD61F081F) > > > +__AARCH64_INSN_FUNCS(brabz, 0xFFFFFC1F, 0xD61F0C1F) > > > +__AARCH64_INSN_FUNCS(braa, 0xFFFFFC00, 0xD71F0800) > > > +__AARCH64_INSN_FUNCS(brab, 0xFFFFFC00, 0xD71F0C00) > > > > When do we need to distinguish these variants? Can we modify the mask/value > > pair so that we catch bra* in one go? That would match how they are > > documented in the Arm ARM. > > > > > __AARCH64_INSN_FUNCS(blr, 0xFFFFFC1F, 0xD63F0000) > > > +__AARCH64_INSN_FUNCS(blraaz, 0xFFFFFC1F, 0xD63F081F) > > > +__AARCH64_INSN_FUNCS(blrabz, 0xFFFFFC1F, 0xD63F0C1F) > > > +__AARCH64_INSN_FUNCS(blraa, 0xFFFFFC00, 0xD73F0800) > > > +__AARCH64_INSN_FUNCS(blrab, 0xFFFFFC00, 0xD73F0C00) > > > > Same here for blra* > > > > > __AARCH64_INSN_FUNCS(ret, 0xFFFFFC1F, 0xD65F0000) > > > +__AARCH64_INSN_FUNCS(retaa, 0xFFFFFFFF, 0xD65F0BFF) > > > +__AARCH64_INSN_FUNCS(retab, 0xFFFFFFFF, 0xD65F0FFF) > > > __AARCH64_INSN_FUNCS(eret, 0xFFFFFFFF, 0xD69F03E0) > > > +__AARCH64_INSN_FUNCS(eretaa, 0xFFFFFFFF, 0xD69F0BFF) > > > +__AARCH64_INSN_FUNCS(eretab, 0xFFFFFFFF, 0xD69F0FFF) > > > > ... and here for ereta*. > > From my side: > > I thought about this myself, but I thought that this may be easier to > maintain if we avoid lumping instructions together. Maybe, but I'm just suggesting to lump them together in the same way as the Arm ARM, which I think helps readability because it lines up directly with the text. > I guess I'm happy either way. Ok, thanks. Amit -- can you repost the series with that change, please, and I'll queue the lot for 5.10? Thanks, Will
On 9/11/20 7:25 PM, Will Deacon wrote: > On Tue, Sep 08, 2020 at 11:51:08AM +0100, Dave Martin wrote: >> On Mon, Sep 07, 2020 at 10:45:51PM +0100, Will Deacon wrote: >>> On Fri, Sep 04, 2020 at 04:12:04PM +0530, Amit Daniel Kachhap wrote: >>>> diff --git a/arch/arm64/include/asm/insn.h b/arch/arm64/include/asm/insn.h >>>> index 0bc46149e491..324234068fee 100644 >>>> --- a/arch/arm64/include/asm/insn.h >>>> +++ b/arch/arm64/include/asm/insn.h >>>> @@ -359,9 +359,21 @@ __AARCH64_INSN_FUNCS(brk, 0xFFE0001F, 0xD4200000) >>>> __AARCH64_INSN_FUNCS(exception, 0xFF000000, 0xD4000000) >>>> __AARCH64_INSN_FUNCS(hint, 0xFFFFF01F, 0xD503201F) >>>> __AARCH64_INSN_FUNCS(br, 0xFFFFFC1F, 0xD61F0000) >>>> +__AARCH64_INSN_FUNCS(braaz, 0xFFFFFC1F, 0xD61F081F) >>>> +__AARCH64_INSN_FUNCS(brabz, 0xFFFFFC1F, 0xD61F0C1F) >>>> +__AARCH64_INSN_FUNCS(braa, 0xFFFFFC00, 0xD71F0800) >>>> +__AARCH64_INSN_FUNCS(brab, 0xFFFFFC00, 0xD71F0C00) >>> >>> When do we need to distinguish these variants? Can we modify the mask/value >>> pair so that we catch bra* in one go? That would match how they are >>> documented in the Arm ARM. >>> >>>> __AARCH64_INSN_FUNCS(blr, 0xFFFFFC1F, 0xD63F0000) >>>> +__AARCH64_INSN_FUNCS(blraaz, 0xFFFFFC1F, 0xD63F081F) >>>> +__AARCH64_INSN_FUNCS(blrabz, 0xFFFFFC1F, 0xD63F0C1F) >>>> +__AARCH64_INSN_FUNCS(blraa, 0xFFFFFC00, 0xD73F0800) >>>> +__AARCH64_INSN_FUNCS(blrab, 0xFFFFFC00, 0xD73F0C00) >>> >>> Same here for blra* >>> >>>> __AARCH64_INSN_FUNCS(ret, 0xFFFFFC1F, 0xD65F0000) >>>> +__AARCH64_INSN_FUNCS(retaa, 0xFFFFFFFF, 0xD65F0BFF) >>>> +__AARCH64_INSN_FUNCS(retab, 0xFFFFFFFF, 0xD65F0FFF) >>>> __AARCH64_INSN_FUNCS(eret, 0xFFFFFFFF, 0xD69F03E0) >>>> +__AARCH64_INSN_FUNCS(eretaa, 0xFFFFFFFF, 0xD69F0BFF) >>>> +__AARCH64_INSN_FUNCS(eretab, 0xFFFFFFFF, 0xD69F0FFF) >>> >>> ... and here for ereta*. >> >> From my side: >> >> I thought about this myself, but I thought that this may be easier to >> maintain if we avoid lumping instructions together. > > Maybe, but I'm just suggesting to lump them together in the same way as the > Arm ARM, which I think helps readability because it lines up directly with > the text. > >> I guess I'm happy either way. > > Ok, thanks. Amit -- can you repost the series with that change, please, and > I'll queue the lot for 5.10? My v8 revision posted just now has this clubbing of instructions. Thanks, Amit > > Thanks, > > Will >
diff --git a/arch/arm64/include/asm/insn.h b/arch/arm64/include/asm/insn.h index 0bc46149e491..324234068fee 100644 --- a/arch/arm64/include/asm/insn.h +++ b/arch/arm64/include/asm/insn.h @@ -359,9 +359,21 @@ __AARCH64_INSN_FUNCS(brk, 0xFFE0001F, 0xD4200000) __AARCH64_INSN_FUNCS(exception, 0xFF000000, 0xD4000000) __AARCH64_INSN_FUNCS(hint, 0xFFFFF01F, 0xD503201F) __AARCH64_INSN_FUNCS(br, 0xFFFFFC1F, 0xD61F0000) +__AARCH64_INSN_FUNCS(braaz, 0xFFFFFC1F, 0xD61F081F) +__AARCH64_INSN_FUNCS(brabz, 0xFFFFFC1F, 0xD61F0C1F) +__AARCH64_INSN_FUNCS(braa, 0xFFFFFC00, 0xD71F0800) +__AARCH64_INSN_FUNCS(brab, 0xFFFFFC00, 0xD71F0C00) __AARCH64_INSN_FUNCS(blr, 0xFFFFFC1F, 0xD63F0000) +__AARCH64_INSN_FUNCS(blraaz, 0xFFFFFC1F, 0xD63F081F) +__AARCH64_INSN_FUNCS(blrabz, 0xFFFFFC1F, 0xD63F0C1F) +__AARCH64_INSN_FUNCS(blraa, 0xFFFFFC00, 0xD73F0800) +__AARCH64_INSN_FUNCS(blrab, 0xFFFFFC00, 0xD73F0C00) __AARCH64_INSN_FUNCS(ret, 0xFFFFFC1F, 0xD65F0000) +__AARCH64_INSN_FUNCS(retaa, 0xFFFFFFFF, 0xD65F0BFF) +__AARCH64_INSN_FUNCS(retab, 0xFFFFFFFF, 0xD65F0FFF) __AARCH64_INSN_FUNCS(eret, 0xFFFFFFFF, 0xD69F03E0) +__AARCH64_INSN_FUNCS(eretaa, 0xFFFFFFFF, 0xD69F0BFF) +__AARCH64_INSN_FUNCS(eretab, 0xFFFFFFFF, 0xD69F0FFF) __AARCH64_INSN_FUNCS(mrs, 0xFFF00000, 0xD5300000) __AARCH64_INSN_FUNCS(msr_imm, 0xFFF8F01F, 0xD500401F) __AARCH64_INSN_FUNCS(msr_reg, 0xFFF00000, 0xD5100000) diff --git a/arch/arm64/kernel/insn.c b/arch/arm64/kernel/insn.c index a107375005bc..27d5a52d5058 100644 --- a/arch/arm64/kernel/insn.c +++ b/arch/arm64/kernel/insn.c @@ -176,7 +176,7 @@ bool __kprobes aarch64_insn_uses_literal(u32 insn) bool __kprobes aarch64_insn_is_branch(u32 insn) { - /* b, bl, cb*, tb*, b.cond, br, blr */ + /* b, bl, cb*, tb*, ret*, b.cond, br*, blr* */ return aarch64_insn_is_b(insn) || aarch64_insn_is_bl(insn) || @@ -185,9 +185,19 @@ bool __kprobes aarch64_insn_is_branch(u32 insn) aarch64_insn_is_tbz(insn) || aarch64_insn_is_tbnz(insn) || aarch64_insn_is_ret(insn) || + aarch64_insn_is_retaa(insn) || + aarch64_insn_is_retab(insn) || aarch64_insn_is_br(insn) || aarch64_insn_is_blr(insn) || - aarch64_insn_is_bcond(insn); + aarch64_insn_is_bcond(insn) || + aarch64_insn_is_braaz(insn) || + aarch64_insn_is_brabz(insn) || + aarch64_insn_is_braa(insn) || + aarch64_insn_is_brab(insn) || + aarch64_insn_is_blraaz(insn) || + aarch64_insn_is_blrabz(insn) || + aarch64_insn_is_blraa(insn) || + aarch64_insn_is_blrab(insn); } int __kprobes aarch64_insn_patch_text_nosync(void *addr, u32 insn) diff --git a/arch/arm64/kernel/probes/decode-insn.c b/arch/arm64/kernel/probes/decode-insn.c index 263d5fba4c8a..f9eb8210d6d3 100644 --- a/arch/arm64/kernel/probes/decode-insn.c +++ b/arch/arm64/kernel/probes/decode-insn.c @@ -29,7 +29,9 @@ static bool __kprobes aarch64_insn_is_steppable(u32 insn) aarch64_insn_is_msr_imm(insn) || aarch64_insn_is_msr_reg(insn) || aarch64_insn_is_exception(insn) || - aarch64_insn_is_eret(insn)) + aarch64_insn_is_eret(insn) || + aarch64_insn_is_eretaa(insn) || + aarch64_insn_is_eretab(insn)) return false; /*
Currently the ARMv8.3-PAuth combined branch instructions (braa, retaa etc.) are not simulated for out-of-line execution with a handler. Hence the uprobe of such instructions leads to kernel warnings in a loop as they are not explicitly checked and fall into INSN_GOOD categories. Other combined instructions like LDRAA and LDRBB can be probed. The issue of the combined branch instructions is fixed by adding definitions of all such instructions and rejecting their probes. Warning log: WARNING: CPU: 5 PID: 249 at arch/arm64/kernel/probes/uprobes.c:182 uprobe_single_step_handler+0x34/0x50 Modules linked in: CPU: 5 PID: 249 Comm: func Tainted: G W 5.8.0-rc4-00005-ge658591d66d1-dirty #160 Hardware name: Foundation-v8A (DT) pstate: 204003c9 (nzCv DAIF +PAN -UAO BTYPE=--) pc : uprobe_single_step_handler+0x34/0x50 lr : single_step_handler+0x70/0xf8 sp : ffff800012afbe30 x29: ffff800012afbe30 x28: ffff000879f00ec0 x27: 0000000000000000 x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000 x23: 0000000060001000 x22: 00000000cb000022 x21: ffff800011fc5a68 x20: ffff800012afbec0 x19: ffff800011fc86c0 x18: 0000000000000000 x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 x11: 0000000000000000 x10: 0000000000000000 x9 : ffff800010085d50 x8 : 0000000000000000 x7 : 0000000000000000 x6 : ffff800011fba9c0 x5 : ffff800011fba000 x4 : ffff800012283070 x3 : ffff8000100a78e0 x2 : 00000000004005f0 x1 : 0000fffffffff008 x0 : ffff800012afbec0 Call trace: uprobe_single_step_handler+0x34/0x50 single_step_handler+0x70/0xf8 do_debug_exception+0xb8/0x130 el0_sync_handler+0x7c/0x188 el0_sync+0x158/0x180 Fixes: 74afda4016a7 ("arm64: compile the kernel with ptrauth return address signing") Fixes: 04ca3204fa09 ("arm64: enable pointer authentication") Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Reviewed-by: Dave Martin <Dave.Martin@arm.com> --- Changes since v5: * Slight change in commit log. * Added Reviewed-by. arch/arm64/include/asm/insn.h | 12 ++++++++++++ arch/arm64/kernel/insn.c | 14 ++++++++++++-- arch/arm64/kernel/probes/decode-insn.c | 4 +++- 3 files changed, 27 insertions(+), 3 deletions(-)