i386: fix one case of stuck dwarf2 unwinder
PATCH 1/1 i386: fix one case of stuck dwarf2 unwinder
When the dwarf2 unwinder does its thing, sometimes it ends up in kernel startup code in head.S. Changing arch_unw_user_mode() to treat that case as if it were user mode is the easy fix.
Signed-off-by Chuck Ebbert <[email protected]>
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I copied people who posted traces where this happened. Can anyone test if this fixes the problem?
include/asm-i386/unwind.h +2 -1
@@ -71,13 +71,14 @@ extern asmlinkage int arch_unwind_init_r void *arg), void *arg); +extern void stext (void );/* real start of kernel text */ static inline int arch_unw_user_mode (const struct unwind_frame_info *info) {#if 0 /* This can only work when selector register and EFLAGS saves/restores are properly annotated (and tracked in UNW_REGISTER_INFO). */ return user_mode_vm (&info->regs);#else -return info->regs.eip <PAGE_OFFSET +return info->regs.eip < (unsigned long )stext || (info->regs.eip >=__fix_to_virt (FIX_VDSO ) && info->regs.eip <__fix_to_virt (FIX_VDSO ) +PAGE_SIZE ) || info->regs.esp <PAGE_OFFSET ;
Signature · 1 line
Chuck
include/asm-i386/unwind.h extern asmlinkage int arch_unwind_init_r · line 74
Quoted 8 lines
include/asm-i386/unwind.h +1
-0@@ -71,13 +71,14 @@ extern asmlinkage int arch_unwind_init_r void *arg), void *arg); +extern void stext (void );/* real start of kernel text */
Can't you use _stext[] from asm/sections.h?
-Andi