Re: [Crash-utility] [PATCH] GDB: fix the failure of 'set scope' command

Applied patch and tested against 2 cores known to show the failure. Once the patch was applied, the issue was resolved. Tested-by: John Pittman <jpittman(a)redhat.com&gt;

On Mon, Mar 22, 2021 at 4:31 AM Lianbo Jiang <lijiang(a)redhat.com&gt; wrote: > > Currently, some command such as 'sys' may cause subsequent 'set scope' > commands to fail because it may not find the correct symtab associated > with PC and SECTION in the find_pc_sect_symtab(), eventually, this will > cause the following failure: > > crash> mod -S 3.10.0-957.el7.x86_64 > crash> mod -s dm_service_time > crash> set scope st_create > set: gdb cannot find text block for address: st_create > crash> mod -d dm_service_time > crash> mod -sr dm_service_time > crash> set scope st_create > scope: ffffffffc044d270 (st_create) > crash> sys > KERNEL: 3.10.0-957.el7.x86_64/vmlinux > DUMPFILE: crash/vmcore [PARTIAL DUMP] > CPUS: 48 > DATE: Sat Aug 3 11:41:00 EDT 2019 > UPTIME: 1 days, 10:28:48 > LOAD AVERAGE: 2.95, 1.02, 0.40 > TASKS: 1060 > NODENAME: iop053063.lss.emc.com > RELEASE: 3.10.0-957.el7.x86_64 > VERSION: #1 SMP Thu Oct 4 20:48:51 UTC 2018 > MACHINE: x86_64 (2999 Mhz) > MEMORY: 127.9 GB > PANIC: "SysRq : Trigger a crash" > crash> set scope st_create > set: gdb cannot find text block for address: st_create > > To find the correct symtab, let's check whether there is an address > mapping to 'block' in the symtab searching loop and the PC is in the > range. If the symtab associated with PC is found, and then use it. > > Signed-off-by: Lianbo Jiang <lijiang(a)redhat.com&gt; > --- > gdb-7.6.patch | 38 +++++++++++++++++++++++++++++++++++++- > 1 file changed, 37 insertions(+), 1 deletion(-) > > diff --git a/gdb-7.6.patch b/gdb-7.6.patch > index f64b55fe547a..90629889f8c4 100644 > --- a/gdb-7.6.patch > +++ b/gdb-7.6.patch > @@ -2500,4 +2500,40 @@ diff -up gdb-7.6/opcodes/configure.orig gdb-7.6/opcodes/configure > +struct target_desc *tdesc_aarch64; > #include "features/aarch64.c" > #include "features/aarch64-without-fpu.c" > - > + > +--- gdb-7.6/gdb/symtab.c.orig > ++++ gdb-7.6/gdb/symtab.c > +@@ -2065,7 +2065,7 @@ find_pc_sect_symtab (CORE_ADDR pc, struct obj_section *section) > + struct symtab *s = NULL; > + struct symtab *best_s = NULL; > + struct objfile *objfile; > +- CORE_ADDR distance = 0; > ++ CORE_ADDR distance = 0, start, end; > + struct minimal_symbol *msymbol; > + > + /* If we know that this is not a text address, return failure. This is > +@@ -2102,10 +2102,20 @@ find_pc_sect_symtab (CORE_ADDR pc, struct obj_section *section) > + bv = BLOCKVECTOR (s); > + b = BLOCKVECTOR_BLOCK (bv, GLOBAL_BLOCK); > + > +- if (BLOCK_START (b) <= pc > +- && BLOCK_END (b) > pc > +- && (distance == 0 > +- || BLOCK_END (b) - BLOCK_START (b) < distance)) > ++ start = BLOCK_START (b); > ++ end = BLOCK_END (b); > ++ > ++ /* > ++ * If we have an addrmap mapping code addresses to blocks, and pc > ++ * is in the range [start, end), let's use it. > ++ */ > ++ if ((pc >= start && pc < end) && BLOCKVECTOR_MAP (bv)) { > ++ if (addrmap_find (BLOCKVECTOR_MAP (bv), pc)) > ++ return s; > ++ } > ++ > ++ if ((pc >= start && pc < end) && ((distance == 0) > ++ || (end - start < distance))) > + { > + /* For an objfile that has its functions reordered, > + find_pc_psymtab will find the proper partial symbol table > -- > 2.17.1 > > -- > Crash-utility mailing list > Crash-utility(a)redhat.com > https://listman.redhat.com/mailman/listinfo/crash-utility >