From 4ca611a44e462f8a902c202731dba38f019cb68c Mon Sep 17 00:00:00 2001 From: jhb Date: Thu, 5 Nov 2015 21:22:23 +0000 Subject: [PATCH] MFC 288371: When XSAVE support was added on amd64, the FPU save area was moved out of 'struct pcb' and into a variable-sized region after the structure. The kgdb code currently only reads the pcb. It does not read in the FPU save area but instead passes stack garbage as the FPU's saved context. Fixing this would mean determining the proper size of the area and fetching it. However, this state is not saved for running CPUs in stoppcbs[], so the callback would also have to know to ignore those pcbs. Instead, just remove the call since it is of limited usefulness. It results in kgdb reporting the state of the FPU/SIMD registers in userland, not their current values in the kernel. In particular, it does not report the correct state for any code in the kernel which does use the FPU and would report incorrect values in that case. git-svn-id: svn://svn.freebsd.org/base/stable/10@290413 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f --- gnu/usr.bin/gdb/kgdb/trgt_amd64.c | 1 - 1 file changed, 1 deletion(-) diff --git a/gnu/usr.bin/gdb/kgdb/trgt_amd64.c b/gnu/usr.bin/gdb/kgdb/trgt_amd64.c index cb13d7172..104d8c540 100644 --- a/gnu/usr.bin/gdb/kgdb/trgt_amd64.c +++ b/gnu/usr.bin/gdb/kgdb/trgt_amd64.c @@ -72,7 +72,6 @@ kgdb_trgt_fetch_registers(int regno __unused) supply_register(AMD64_R8_REGNUM + 6, (char *)&pcb.pcb_r14); supply_register(AMD64_R15_REGNUM, (char *)&pcb.pcb_r15); supply_register(AMD64_RIP_REGNUM, (char *)&pcb.pcb_rip); - amd64_supply_fxsave(current_regcache, -1, (struct fpusave *)(&pcb + 1)); } void -- 2.45.0