[PATCH 2/3] kgdb,i386: use address that SP register points to in the exception frame

From: Jason Wessel
Date: Fri May 15 2009 - 09:19:41 EST


The treatment of the SP register is different on x86_64 and i386.
This is a regression fix that lived outside the mainline kernel from
2.6.27 to now. The regression was a result of the original merge
consolidation of the i386 and x86_64 archs to x86.

The incorrectly reported SP on i386 prevented stack tracebacks from
working correctly in gdb.

Signed-off-by: Jason Wessel <jason.wessel@xxxxxxxxxxxxx>
---
arch/x86/kernel/kgdb.c | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c
index eedfaeb..b1f4dff 100644
--- a/arch/x86/kernel/kgdb.c
+++ b/arch/x86/kernel/kgdb.c
@@ -88,6 +88,7 @@ void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
gdb_regs[GDB_SS] = __KERNEL_DS;
gdb_regs[GDB_FS] = 0xFFFF;
gdb_regs[GDB_GS] = 0xFFFF;
+ gdb_regs[GDB_SP] = (int)&regs->sp;
#else
gdb_regs[GDB_R8] = regs->r8;
gdb_regs[GDB_R9] = regs->r9;
@@ -100,8 +101,8 @@ void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
gdb_regs32[GDB_PS] = regs->flags;
gdb_regs32[GDB_CS] = regs->cs;
gdb_regs32[GDB_SS] = regs->ss;
-#endif
gdb_regs[GDB_SP] = regs->sp;
+#endif
}

/**
--
1.6.3.1.9.g95405b

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