From: Nicholas Piggin <npiggin@gmail.com> To: Thomas Huth <thuth@redhat.com> Cc: Nicholas Piggin <npiggin@gmail.com>, Laurent Vivier <lvivier@redhat.com>, Andrew Jones <andrew.jones@linux.dev>, Paolo Bonzini <pbonzini@redhat.com>, Joel Stanley <joel@jms.id.au>, linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org Subject: [kvm-unit-tests PATCH 03/32] powerpc: Fix stack backtrace termination Date: Mon, 26 Feb 2024 20:11:49 +1000 [thread overview] Message-ID: <20240226101218.1472843-4-npiggin@gmail.com> (raw) In-Reply-To: <20240226101218.1472843-1-npiggin@gmail.com> The backtrace handler terminates when it sees a NULL caller address, but the powerpc stack setup does not keep such a NULL caller frame at the start of the stack. This happens to work on pseries because the memory at 0 is mapped and it contains 0 at the location of the return address pointer if it were a stack frame. But this is fragile, and does not work with powernv where address 0 contains firmware instructions. Use the existing dummy frame on stack as the NULL caller, and create a new frame on stack for the entry code. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> --- powerpc/cstart64.S | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/powerpc/cstart64.S b/powerpc/cstart64.S index e18ae9a22..14ab0c6c8 100644 --- a/powerpc/cstart64.S +++ b/powerpc/cstart64.S @@ -46,8 +46,16 @@ start: add r1, r1, r31 add r2, r2, r31 + /* Zero backpointers in initial stack frame so backtrace() stops */ + li r0,0 + std r0,0(r1) + std r0,16(r1) + + /* Create entry frame */ + stdu r1,-INT_FRAME_SIZE(r1) + /* save DTB pointer */ - std r3, 56(r1) + SAVE_GPR(3,r1) /* * Call relocate. relocate is C code, but careful to not use @@ -101,7 +109,7 @@ start: stw r4, 0(r3) /* complete setup */ -1: ld r3, 56(r1) +1: REST_GPR(3, r1) bl setup /* run the test */ -- 2.42.0
WARNING: multiple messages have this Message-ID (diff)
From: Nicholas Piggin <npiggin@gmail.com> To: Thomas Huth <thuth@redhat.com> Cc: Laurent Vivier <lvivier@redhat.com>, kvm@vger.kernel.org, Nicholas Piggin <npiggin@gmail.com>, Andrew Jones <andrew.jones@linux.dev>, Joel Stanley <joel@jms.id.au>, Paolo Bonzini <pbonzini@redhat.com>, linuxppc-dev@lists.ozlabs.org Subject: [kvm-unit-tests PATCH 03/32] powerpc: Fix stack backtrace termination Date: Mon, 26 Feb 2024 20:11:49 +1000 [thread overview] Message-ID: <20240226101218.1472843-4-npiggin@gmail.com> (raw) In-Reply-To: <20240226101218.1472843-1-npiggin@gmail.com> The backtrace handler terminates when it sees a NULL caller address, but the powerpc stack setup does not keep such a NULL caller frame at the start of the stack. This happens to work on pseries because the memory at 0 is mapped and it contains 0 at the location of the return address pointer if it were a stack frame. But this is fragile, and does not work with powernv where address 0 contains firmware instructions. Use the existing dummy frame on stack as the NULL caller, and create a new frame on stack for the entry code. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> --- powerpc/cstart64.S | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/powerpc/cstart64.S b/powerpc/cstart64.S index e18ae9a22..14ab0c6c8 100644 --- a/powerpc/cstart64.S +++ b/powerpc/cstart64.S @@ -46,8 +46,16 @@ start: add r1, r1, r31 add r2, r2, r31 + /* Zero backpointers in initial stack frame so backtrace() stops */ + li r0,0 + std r0,0(r1) + std r0,16(r1) + + /* Create entry frame */ + stdu r1,-INT_FRAME_SIZE(r1) + /* save DTB pointer */ - std r3, 56(r1) + SAVE_GPR(3,r1) /* * Call relocate. relocate is C code, but careful to not use @@ -101,7 +109,7 @@ start: stw r4, 0(r3) /* complete setup */ -1: ld r3, 56(r1) +1: REST_GPR(3, r1) bl setup /* run the test */ -- 2.42.0
next prev parent reply other threads:[~2024-02-26 10:12 UTC|newest] Thread overview: 142+ messages / expand[flat|nested] mbox.gz Atom feed top 2024-02-26 10:11 [kvm-unit-tests PATCH 00/32] powerpc improvements Nicholas Piggin 2024-02-26 10:11 ` Nicholas Piggin 2024-02-26 10:11 ` [kvm-unit-tests PATCH 01/32] powerpc: Fix KVM caps on POWER9 hosts Nicholas Piggin 2024-02-26 10:11 ` Nicholas Piggin 2024-02-26 11:33 ` Thomas Huth 2024-02-26 11:33 ` Thomas Huth 2024-02-26 10:11 ` [kvm-unit-tests PATCH 02/32] powerpc: Fix pseries getchar return value Nicholas Piggin 2024-02-26 10:11 ` Nicholas Piggin 2024-02-26 11:35 ` Thomas Huth 2024-02-26 11:35 ` Thomas Huth 2024-02-26 10:11 ` Nicholas Piggin [this message] 2024-02-26 10:11 ` [kvm-unit-tests PATCH 03/32] powerpc: Fix stack backtrace termination Nicholas Piggin 2024-02-27 8:50 ` Thomas Huth 2024-02-27 8:50 ` Thomas Huth 2024-03-01 9:45 ` Thomas Huth 2024-03-01 9:45 ` Thomas Huth 2024-03-05 2:08 ` Nicholas Piggin 2024-03-05 2:08 ` Nicholas Piggin 2024-03-05 6:29 ` Nicholas Piggin 2024-03-05 6:29 ` Nicholas Piggin 2024-03-05 6:59 ` Thomas Huth 2024-03-05 6:59 ` Thomas Huth 2024-02-26 10:11 ` [kvm-unit-tests PATCH 04/32] powerpc: interrupt stack backtracing Nicholas Piggin 2024-02-26 10:11 ` Nicholas Piggin 2024-02-28 11:46 ` Andrew Jones 2024-02-28 11:46 ` Andrew Jones 2024-02-29 3:50 ` Nicholas Piggin 2024-02-29 3:50 ` Nicholas Piggin 2024-03-01 9:53 ` Thomas Huth 2024-03-01 9:53 ` Thomas Huth 2024-03-05 2:12 ` Nicholas Piggin 2024-03-05 2:12 ` Nicholas Piggin 2024-02-26 10:11 ` [kvm-unit-tests PATCH 05/32] powerpc: Cleanup SPR and MSR definitions Nicholas Piggin 2024-02-26 10:11 ` Nicholas Piggin 2024-03-01 11:11 ` Thomas Huth 2024-03-01 11:11 ` Thomas Huth 2024-02-26 10:11 ` [kvm-unit-tests PATCH 06/32] powerpc/sprs: Specify SPRs with data rather than code Nicholas Piggin 2024-02-26 10:11 ` Nicholas Piggin 2024-02-26 10:11 ` [kvm-unit-tests PATCH 07/32] powerpc/sprs: Don't fail changed SPRs that are used by the test harness Nicholas Piggin 2024-02-26 10:11 ` Nicholas Piggin 2024-03-01 11:15 ` Thomas Huth 2024-03-01 11:15 ` Thomas Huth 2024-03-05 2:14 ` Nicholas Piggin 2024-03-05 2:14 ` Nicholas Piggin 2024-02-26 10:11 ` [kvm-unit-tests PATCH 08/32] powerpc/sprs: Avoid taking PMU interrupts caused by register fuzzing Nicholas Piggin 2024-02-26 10:11 ` Nicholas Piggin 2024-03-01 11:25 ` Thomas Huth 2024-03-01 11:25 ` Thomas Huth 2024-02-26 10:11 ` [kvm-unit-tests PATCH 09/32] scripts: allow machine option to be specified in unittests.cfg Nicholas Piggin 2024-02-26 10:11 ` Nicholas Piggin 2024-02-28 11:47 ` Andrew Jones 2024-02-28 11:47 ` Andrew Jones 2024-02-29 3:52 ` Nicholas Piggin 2024-02-29 3:52 ` Nicholas Piggin 2024-02-26 10:11 ` [kvm-unit-tests PATCH 10/32] scripts: Accommodate powerpc powernv machine differences Nicholas Piggin 2024-02-26 10:11 ` Nicholas Piggin 2024-02-28 11:52 ` Andrew Jones 2024-02-28 11:52 ` Andrew Jones 2024-02-26 10:11 ` [kvm-unit-tests PATCH 11/32] powerpc: Support powernv machine with QEMU TCG Nicholas Piggin 2024-02-26 10:11 ` Nicholas Piggin 2024-02-26 10:11 ` [kvm-unit-tests PATCH 12/32] powerpc: Fix emulator illegal instruction test for powernv Nicholas Piggin 2024-02-26 10:11 ` Nicholas Piggin 2024-03-01 11:50 ` Thomas Huth 2024-03-01 11:50 ` Thomas Huth 2024-03-05 2:14 ` Nicholas Piggin 2024-03-05 2:14 ` Nicholas Piggin 2024-02-26 10:11 ` [kvm-unit-tests PATCH 13/32] powerpc/sprs: Test hypervisor registers on powernv machine Nicholas Piggin 2024-02-26 10:11 ` Nicholas Piggin 2024-02-26 10:12 ` [kvm-unit-tests PATCH 14/32] powerpc: general interrupt tests Nicholas Piggin 2024-02-26 10:12 ` Nicholas Piggin 2024-03-01 12:41 ` Thomas Huth 2024-03-01 12:41 ` Thomas Huth 2024-03-01 13:45 ` Andrew Jones 2024-03-01 13:45 ` Andrew Jones 2024-03-01 13:57 ` Thomas Huth 2024-03-01 13:57 ` Thomas Huth 2024-03-01 14:14 ` Andrew Jones 2024-03-01 14:14 ` Andrew Jones 2024-03-05 2:35 ` Nicholas Piggin 2024-03-05 2:35 ` Nicholas Piggin 2024-03-05 2:30 ` Nicholas Piggin 2024-03-05 2:30 ` Nicholas Piggin 2024-03-05 6:18 ` Thomas Huth 2024-03-05 6:18 ` Thomas Huth 2024-03-05 2:19 ` Nicholas Piggin 2024-03-05 2:19 ` Nicholas Piggin 2024-03-05 6:26 ` Thomas Huth 2024-03-05 6:26 ` Thomas Huth 2024-03-05 12:12 ` Andrew Jones 2024-03-05 12:12 ` Andrew Jones 2024-02-26 10:12 ` [kvm-unit-tests PATCH 15/32] powerpc: Add rtas stop-self support Nicholas Piggin 2024-02-26 10:12 ` Nicholas Piggin 2024-02-26 10:12 ` [kvm-unit-tests PATCH 16/32] powerpc: Remove broken SMP exception stack setup Nicholas Piggin 2024-02-26 10:12 ` Nicholas Piggin 2024-02-26 10:12 ` [kvm-unit-tests PATCH 17/32] arch-run: Fix handling multiple exit status messages Nicholas Piggin 2024-02-26 10:12 ` Nicholas Piggin 2024-02-28 11:51 ` Andrew Jones 2024-02-28 11:51 ` Andrew Jones 2024-02-26 10:12 ` [kvm-unit-tests PATCH 18/32] powerpc: add SMP and IPI support Nicholas Piggin 2024-02-26 10:12 ` Nicholas Piggin 2024-02-26 10:12 ` [kvm-unit-tests PATCH 19/32] powerpc: Permit ACCEL=tcg,thread=single Nicholas Piggin 2024-02-26 10:12 ` Nicholas Piggin 2024-02-26 10:12 ` [kvm-unit-tests PATCH 20/32] powerpc: Avoid using larx/stcx. in spinlocks when only one CPU is running Nicholas Piggin 2024-02-26 10:12 ` Nicholas Piggin 2024-02-26 10:12 ` [kvm-unit-tests PATCH 21/32] powerpc: Add atomics tests Nicholas Piggin 2024-02-26 10:12 ` Nicholas Piggin 2024-02-26 10:12 ` [kvm-unit-tests PATCH 22/32] powerpc: Add timebase tests Nicholas Piggin 2024-02-26 10:12 ` Nicholas Piggin 2024-02-26 10:12 ` [kvm-unit-tests PATCH 23/32] powerpc: Add MMU support Nicholas Piggin 2024-02-26 10:12 ` Nicholas Piggin 2024-02-28 12:01 ` Andrew Jones 2024-02-28 12:01 ` Andrew Jones 2024-02-26 10:12 ` [kvm-unit-tests PATCH 24/32] common/sieve: Use vmalloc.h for setup_mmu definition Nicholas Piggin 2024-02-26 10:12 ` Nicholas Piggin 2024-02-28 12:03 ` Andrew Jones 2024-02-28 12:03 ` Andrew Jones 2024-02-26 10:12 ` [kvm-unit-tests PATCH 25/32] common/sieve: Support machines without MMU Nicholas Piggin 2024-02-26 10:12 ` Nicholas Piggin 2024-02-28 12:04 ` Andrew Jones 2024-02-28 12:04 ` Andrew Jones 2024-02-26 10:12 ` [kvm-unit-tests PATCH 26/32] powerpc: Add sieve.c common test Nicholas Piggin 2024-02-26 10:12 ` Nicholas Piggin 2024-02-26 10:12 ` [kvm-unit-tests PATCH 27/32] powerpc: add usermode support Nicholas Piggin 2024-02-26 10:12 ` Nicholas Piggin 2024-02-26 10:12 ` [kvm-unit-tests PATCH 28/32] powerpc: add pmu tests Nicholas Piggin 2024-02-26 10:12 ` Nicholas Piggin 2024-02-26 10:12 ` [kvm-unit-tests PATCH 29/32] configure: Fail on unknown arch Nicholas Piggin 2024-02-26 10:12 ` Nicholas Piggin 2024-02-28 12:08 ` Andrew Jones 2024-02-28 12:08 ` Andrew Jones 2024-02-26 10:12 ` [kvm-unit-tests PATCH 30/32] configure: Make arch_libdir a first-class entity Nicholas Piggin 2024-02-26 10:12 ` Nicholas Piggin 2024-02-28 12:13 ` Andrew Jones 2024-02-28 12:13 ` Andrew Jones 2024-02-26 10:12 ` [kvm-unit-tests PATCH 31/32] powerpc: Remove remnants of ppc64 directory and build structure Nicholas Piggin 2024-02-26 10:12 ` Nicholas Piggin 2024-02-26 10:12 ` [kvm-unit-tests PATCH 32/32] powerpc: gitlab CI update Nicholas Piggin 2024-02-26 10:12 ` Nicholas Piggin 2024-02-28 12:16 ` Andrew Jones 2024-02-28 12:16 ` Andrew Jones 2024-02-29 3:55 ` Nicholas Piggin 2024-02-29 3:55 ` Nicholas Piggin
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