* Re: asm-x86/sigcontext.h changes break userland
2008-02-13 0:15 asm-x86/sigcontext.h changes break userland Jakub Jelinek
@ 2008-02-13 7:26 ` Ingo Molnar
2008-02-13 12:49 ` Jakub Jelinek
0 siblings, 1 reply; 3+ messages in thread
From: Ingo Molnar @ 2008-02-13 7:26 UTC (permalink / raw)
To: Jakub Jelinek
Cc: Thomas Gleixner, H. Peter Anvin, Ulrich Drepper, linux-kernel
* Jakub Jelinek <jakub@redhat.com> wrote:
> x86: use generic register names in struct sigcontext
> http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=742fa54a62be6a263df14a553bf832724471dfbe
>
> changeset breaks userland, e.g. it is not possible to compile gcc
> anymore (both 32-bit and 64-bit libgcc), and I expect any other
> program which pokes into struct sigcontext. The register names with e
> resp. r have been in use for years, what's the point breaking it now?
ok - does the patch below solve the problem for you?
Ingo
------------>
Subject: x86: fix sigcontext.h user export
From: Ingo Molnar <mingo@elte.hu>
Jakub Jelinek reported that some user-space code that relies on
kernel headers has built dependency on the sigcontext->eip/rip
register names - which have been unified in commit:
commit 742fa54a62be6a263df14a553bf832724471dfbe
Author: H. Peter Anvin <hpa@zytor.com>
Date: Wed Jan 30 13:30:56 2008 +0100
x86: use generic register names in struct sigcontext
so give the old layout to user-space. This is not particularly
pretty, but it's an ABI so there's no danger of the two definitions
getting out of sync.
Reported-by: Jakub Jelinek <jakub@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
include/asm-x86/sigcontext.h | 66 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 66 insertions(+)
Index: linux/include/asm-x86/sigcontext.h
===================================================================
--- linux.orig/include/asm-x86/sigcontext.h
+++ linux/include/asm-x86/sigcontext.h
@@ -58,6 +58,7 @@ struct _fpstate {
#define X86_FXSR_MAGIC 0x0000
+#ifdef __KERNEL__
struct sigcontext {
unsigned short gs, __gsh;
unsigned short fs, __fsh;
@@ -82,6 +83,35 @@ struct sigcontext {
unsigned long oldmask;
unsigned long cr2;
};
+#else /* __KERNEL__ */
+/*
+ * User-space might still rely on the old definition:
+ */
+struct sigcontext {
+ unsigned short gs, __gsh;
+ unsigned short fs, __fsh;
+ unsigned short es, __esh;
+ unsigned short ds, __dsh;
+ unsigned long edi;
+ unsigned long esi;
+ unsigned long ebp;
+ unsigned long esp;
+ unsigned long ebx;
+ unsigned long edx;
+ unsigned long ecx;
+ unsigned long eax;
+ unsigned long trapno;
+ unsigned long err;
+ unsigned long eip;
+ unsigned short cs, __csh;
+ unsigned long eflags;
+ unsigned long esp_at_signal;
+ unsigned short ss, __ssh;
+ struct _fpstate __user * fpstate;
+ unsigned long oldmask;
+ unsigned long cr2;
+};
+#endif /* !__KERNEL__ */
#else /* __i386__ */
@@ -102,6 +132,7 @@ struct _fpstate {
__u32 reserved2[24];
};
+#ifdef __KERNEL__
struct sigcontext {
unsigned long r8;
unsigned long r9;
@@ -132,6 +163,41 @@ struct sigcontext {
struct _fpstate __user *fpstate; /* zero when no FPU context */
unsigned long reserved1[8];
};
+#else /* __KERNEL__ */
+/*
+ * User-space might still rely on the old definition:
+ */
+struct sigcontext {
+ unsigned long r8;
+ unsigned long r9;
+ unsigned long r10;
+ unsigned long r11;
+ unsigned long r12;
+ unsigned long r13;
+ unsigned long r14;
+ unsigned long r15;
+ unsigned long rdi;
+ unsigned long rsi;
+ unsigned long rbp;
+ unsigned long rbx;
+ unsigned long rdx;
+ unsigned long rax;
+ unsigned long rcx;
+ unsigned long rsp;
+ unsigned long rip;
+ unsigned long eflags; /* RFLAGS */
+ unsigned short cs;
+ unsigned short gs;
+ unsigned short fs;
+ unsigned short __pad0;
+ unsigned long err;
+ unsigned long trapno;
+ unsigned long oldmask;
+ unsigned long cr2;
+ struct _fpstate __user *fpstate; /* zero when no FPU context */
+ unsigned long reserved1[8];
+};
+#endif /* !__KERNEL__ */
#endif /* !__i386__ */
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