Date: Wed, 18 Sep 2024 11:42:05 +1200 From: Tao Liu <ltao(a)redhat.com&gt; Subject: [Crash-utility] [PATCH v1 3/3] ppc64: fix the bug eframe won't print for newer kernel To: devel(a)lists.crash-utility.osci.io Cc: adityag(a)linux.ibm.com, Tao Liu <ltao(a)redhat.com&gt; Message-ID: <20240917234205.7783-4-ltao(a)redhat.com&gt; Content-Type: text/plain; charset="US-ASCII"; x-default=true The value of EXCP_FRAME_MARKER is outdated for kernel>=6.1.0, and also its offset is changed since kernel>=6.2.0. This patch will fix the issue

Before: crash> bt ... #8 [c00000000a327b80] system_call_exception at c000000000031a30 #9 [c00000000a327e50] system_call_vectored_common at c00000000000d05c After: crash> bt ... #8 [c00000000a327b80] system_call_exception at c000000000031a30 #9 [c00000000a327e50] system_call_vectored_common at c00000000000d05c System Call Vectored [3000] exception frame: R0: 0000000000000004 R1: 00007fffc3345f40 R2: 0000000000100000 R3: 0000000000000001 R4: 000000012572c620 R5: 0000000000000002 R6: 0000000000000001 R7: 0000000000000004 R8: 0000000000000001 ... Signed-off-by: Tao Liu <ltao(a)redhat.com&gt; --- defs.h | 5 ++++- ppc64.c | 37 +++++++++++++++++++++++++++---------- 2 files changed, 31 insertions(+), 11 deletions(-) diff --git a/defs.h b/defs.h index d5cb8cc..ceeb6cc 100644 --- a/defs.h +++ b/defs.h @@ -4645,7 +4645,10 @@ struct efi_memory_desc_t { #define STACK_SWITCH_FRAME_REGS 48 #define STACK_FRAME_OVERHEAD 112 -#define EXCP_FRAME_MARKER 0x7265677368657265 +#define EXCP_FRAME_MARKER \ + (THIS_KERNEL_VERSION >= LINUX(6,1,0) ? \ + (__BYTE_ORDER == __BIG_ENDIAN ? 0x52454753 : 0x53474552) : \ + 0x7265677368657265)

#define _MAX_PHYSMEM_BITS 44 diff --git a/ppc64.c b/ppc64.c index 8af7b8a..5416281 100644 --- a/ppc64.c +++ b/ppc64.c @@ -2217,19 +2217,34 @@ ppc64_back_trace(struct gnu_request *req, struct bt_info *bt) eframe_found = TRUE; else if (STREQ(req->name, ".ret_from_except")) eframe_found = TRUE; - } else if ((newsp - req->sp - STACK_FRAME_OVERHEAD) >= - sizeof(struct ppc64_pt_regs)) { - readmem(req->sp+0x60, KVADDR, &marker, - sizeof(ulong), "stack frame", FAULT_ON_ERROR); - if (marker == EXCP_FRAME_MARKER) - eframe_found = TRUE; + } else if (THIS_KERNEL_VERSION >= LINUX(6,2,0) && is_ppc64_elf_abi_v2()) {

+ sizeof(struct ppc64_pt_regs)) { + readmem(req->sp+0x20, KVADDR, &marker, + sizeof(ulong), "stack frame", + FAULT_ON_ERROR); + } + } else { + if ((newsp - req->sp - STACK_FRAME_OVERHEAD) >= + sizeof(struct ppc64_pt_regs)) { + readmem(req->sp+0x60, KVADDR, &marker, + sizeof(ulong), "stack frame", + FAULT_ON_ERROR); + } } - if (eframe_found) { + + if (eframe_found || marker == EXCP_FRAME_MARKER) { char *efrm_str = NULL; struct ppc64_pt_regs regs; - readmem(req->sp+STACK_FRAME_OVERHEAD, KVADDR, &regs, - sizeof(struct ppc64_pt_regs), - "exception frame", FAULT_ON_ERROR); + if (THIS_KERNEL_VERSION >= LINUX(6,2,0) && is_ppc64_elf_abi_v2()) { + readmem(req->sp+STACK_SWITCH_FRAME_REGS, KVADDR, &regs, + sizeof(struct ppc64_pt_regs), + "exception frame", FAULT_ON_ERROR); + } else { + readmem(req->sp+STACK_FRAME_OVERHEAD, KVADDR, &regs, + sizeof(struct ppc64_pt_regs), + "exception frame", FAULT_ON_ERROR); + } efrm_str = ppc64_check_eframe(&regs); if (efrm_str) { @@ -2440,6 +2455,8 @@ ppc64_check_eframe(struct ppc64_pt_regs *regs) return("Denormalisation"); case 0x1700: return("Altivec Assist"); + case 0x3000: + return("System Call Vectored"); } /* No exception frame exists */ -- 2.40.1