The patch titled
i386-pda: Fix places where using %gs changes the usermode ABI
has been added to the -mm tree. Its filename is
i386-pda-fix-places-where-using-%gs-changes-the-usermode-abi.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: i386-pda: Fix places where using %gs changes the usermode ABI
From: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
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 <jeremy@xxxxxxxxxxxxx>
Cc: Chuck Ebbert <76306.1226@xxxxxxxxxxxxxx>
Cc: Zachary Amsden <zach@xxxxxxxxxx>
Cc: Jan Beulich <jbeulich@xxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
arch/i386/kernel/process.c | 6 +++---
arch/i386/kernel/ptrace.c | 18 ++++++------------
include/asm-i386/elf.h | 2 +-
include/asm-i386/unwind.h | 1 +
4 files changed, 11 insertions(+), 16 deletions(-)
diff -puN arch/i386/kernel/process.c~i386-pda-fix-places-where-using-%gs-changes-the-usermode-abi arch/i386/kernel/process.c
--- a/arch/i386/kernel/process.c~i386-pda-fix-places-where-using-%gs-changes-the-usermode-abi
+++ a/arch/i386/kernel/process.c
@@ -313,8 +313,8 @@ 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();
@@ -511,7 +511,7 @@ void dump_thread(struct pt_regs * regs,
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 -puN arch/i386/kernel/ptrace.c~i386-pda-fix-places-where-using-%gs-changes-the-usermode-abi arch/i386/kernel/ptrace.c
--- a/arch/i386/kernel/ptrace.c~i386-pda-fix-places-where-using-%gs-changes-the-usermode-abi
+++ a/arch/i386/kernel/ptrace.c
@@ -94,13 +94,9 @@ static int putreg(struct task_struct *ch
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 *ch
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_
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);
}
diff -puN include/asm-i386/elf.h~i386-pda-fix-places-where-using-%gs-changes-the-usermode-abi include/asm-i386/elf.h
--- a/include/asm-i386/elf.h~i386-pda-fix-places-where-using-%gs-changes-the-usermode-abi
+++ a/include/asm-i386/elf.h
@@ -91,7 +91,7 @@ typedef struct user_fxsr_struct elf_fpxr
pr_reg[7] = regs->xds; \
pr_reg[8] = regs->xes; \
savesegment(fs,pr_reg[9]); \
- savesegment(gs,pr_reg[10]); \
+ pr_reg[10] = regs->xgs; \
pr_reg[11] = regs->orig_eax; \
pr_reg[12] = regs->eip; \
pr_reg[13] = regs->xcs; \
diff -puN include/asm-i386/unwind.h~i386-pda-fix-places-where-using-%gs-changes-the-usermode-abi include/asm-i386/unwind.h
--- a/include/asm-i386/unwind.h~i386-pda-fix-places-where-using-%gs-changes-the-usermode-abi
+++ a/include/asm-i386/unwind.h
@@ -71,6 +71,7 @@ static inline void arch_unw_init_blocked
info->regs.xss = __KERNEL_DS;
info->regs.xds = __USER_DS;
info->regs.xes = __USER_DS;
+ info->regs.xgs = __KERNEL_PDA;
}
extern asmlinkage int arch_unwind_init_running(struct unwind_frame_info *,
_
Patches currently in -mm which might be from jeremy@xxxxxxxx are
x86-remove-default_ldt-and-simplify-ldt-setting.patch
i386-use-asm-offsets-for-the-offsets-of-registers-into-the-pt_regs-struct-rather-than-having-hard-coded-constants.patch
i386-pda-basic-definitions-for-i386-pda.patch
i386-pda-initialize-the-per-cpu-data-area.patch
i386-pda-use-%gs-as-the-pda-base-segment-in-the-kernel.patch
i386-pda-fix-places-where-using-%gs-changes-the-usermode-abi.patch
i386-pda-update-sys_vm86-to-cope-with-changed-pt_regs-and-%gs-usage.patch
i386-pda-implement-smp_processor_id-with-the-pda.patch
i386-pda-implement-current-with-the-pda.patch
i386-pda-store-the-interrupt-regs-pointer-in-the-pda.patch
generic-bug-implementation.patch
generic-bug-for-i386.patch
generic-bug-for-x86-64.patch
generic-bug-for-powerpc.patch
uml-add-generic-bug-support.patch
use-generic-bug-for-ppc.patch
bug-test-1.patch
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