From 66e10a44d724f1464b5e8b5a3eae1e2cbbc2cca6 Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Thu, 7 Dec 2006 02:14:02 +0100 Subject: [PATCH] i386: Fix places where using %gs changes the usermode ABI There are a few places where the change in struct pt_regs and the use of %gs affect the userspace ABI. These are primarily debugging interfaces where thread state can be inspected or extracted. Signed-off-by: Jeremy Fitzhardinge Signed-off-by: Andi Kleen Cc: Chuck Ebbert <76306.1226@compuserve.com> Cc: Zachary Amsden Cc: Jan Beulich Cc: Andi Kleen Signed-off-by: Andrew Morton --- arch/i386/kernel/process.c | 6 +++--- arch/i386/kernel/ptrace.c | 18 ++++++------------ 2 files changed, 9 insertions(+), 15 deletions(-) (limited to 'arch') diff --git a/arch/i386/kernel/process.c b/arch/i386/kernel/process.c index 905364d4284..dc427254517 100644 --- a/arch/i386/kernel/process.c +++ b/arch/i386/kernel/process.c @@ -315,8 +315,8 @@ void show_regs(struct pt_regs * regs) regs->eax,regs->ebx,regs->ecx,regs->edx); printk("ESI: %08lx EDI: %08lx EBP: %08lx", regs->esi, regs->edi, regs->ebp); - printk(" DS: %04x ES: %04x\n", - 0xffff & regs->xds,0xffff & regs->xes); + printk(" DS: %04x ES: %04x GS: %04x\n", + 0xffff & regs->xds,0xffff & regs->xes, 0xffff & regs->xgs); cr0 = read_cr0(); cr2 = read_cr2(); @@ -509,7 +509,7 @@ void dump_thread(struct pt_regs * regs, struct user * dump) dump->regs.ds = regs->xds; dump->regs.es = regs->xes; savesegment(fs,dump->regs.fs); - savesegment(gs,dump->regs.gs); + dump->regs.gs = regs->xgs; dump->regs.orig_eax = regs->orig_eax; dump->regs.eip = regs->eip; dump->regs.cs = regs->xcs; diff --git a/arch/i386/kernel/ptrace.c b/arch/i386/kernel/ptrace.c index 775f50e9395..f3f94ac5736 100644 --- a/arch/i386/kernel/ptrace.c +++ b/arch/i386/kernel/ptrace.c @@ -94,13 +94,9 @@ static int putreg(struct task_struct *child, return -EIO; child->thread.fs = value; return 0; - case GS: - if (value && (value & 3) != 3) - return -EIO; - child->thread.gs = value; - return 0; case DS: case ES: + case GS: if (value && (value & 3) != 3) return -EIO; value &= 0xffff; @@ -116,8 +112,8 @@ static int putreg(struct task_struct *child, value |= get_stack_long(child, EFL_OFFSET) & ~FLAG_MASK; break; } - if (regno > GS*4) - regno -= 2*4; + if (regno > ES*4) + regno -= 1*4; put_stack_long(child, regno - sizeof(struct pt_regs), value); return 0; } @@ -131,18 +127,16 @@ static unsigned long getreg(struct task_struct *child, case FS: retval = child->thread.fs; break; - case GS: - retval = child->thread.gs; - break; case DS: case ES: + case GS: case SS: case CS: retval = 0xffff; /* fall through */ default: - if (regno > GS*4) - regno -= 2*4; + if (regno > ES*4) + regno -= 1*4; regno = regno - sizeof(struct pt_regs); retval &= get_stack_long(child, regno); } -- cgit v1.2.3