From: Andi Kleen The EFLAGS checking was not correct. This also fixes some problems with 32bit gdb who would sometimes make the kernel BUG. --- arch/x86_64/ia32/ptrace32.c | 11 +++++++++-- 1 files changed, 9 insertions(+), 2 deletions(-) diff -puN arch/x86_64/ia32/ptrace32.c~x86_64-ptrace-fix arch/x86_64/ia32/ptrace32.c --- 25/arch/x86_64/ia32/ptrace32.c~x86_64-ptrace-fix 2004-01-17 15:23:49.000000000 -0800 +++ 25-akpm/arch/x86_64/ia32/ptrace32.c 2004-01-17 15:23:49.000000000 -0800 @@ -26,6 +26,10 @@ #include #include +/* determines which flags the user has access to. */ +/* 1 = access 0 = no access */ +#define FLAG_MASK 0x44dd5UL + #define R32(l,q) \ case offsetof(struct user32, regs.l): stack[offsetof(struct pt_regs, q)/8] = val; break @@ -70,9 +74,12 @@ static int putreg32(struct task_struct * R32(eip, rip); R32(esp, rsp); - case offsetof(struct user32, regs.eflags): - stack[offsetof(struct pt_regs, eflags)/8] = val & 0x44dd5; + case offsetof(struct user32, regs.eflags): { + __u64 *flags = &stack[offsetof(struct pt_regs, eflags)/8]; + val &= FLAG_MASK; + *flags = val | (*flags & ~FLAG_MASK); break; + } case offsetof(struct user32, u_debugreg[4]): case offsetof(struct user32, u_debugreg[5]): _