This is the mail archive of the
libc-alpha@sourceware.org
mailing list for the glibc project.
[PATCH] aarch64: Revert the change of the __reserved member of mcontext_t
- From: Szabolcs Nagy <szabolcs dot nagy at arm dot com>
- To: GNU C Library <libc-alpha at sourceware dot org>
- Cc: nd at arm dot com, Marcus Shawcroft <Marcus dot Shawcroft at arm dot com>, Joseph Myers <joseph at codesourcery dot com>, Romain Naour <romain dot naour at gmail dot com>
- Date: Tue, 23 Jan 2018 14:35:45 +0000
- Subject: [PATCH] aarch64: Revert the change of the __reserved member of mcontext_t
- Authentication-results: sourceware.org; auth=none
- Authentication-results: spf=none (sender IP is ) smtp.mailfrom=Szabolcs dot Nagy at arm dot com;
- Nodisclaimer: True
- Spamdiagnosticmetadata: NSPM
- Spamdiagnosticoutput: 1:99
The uc_mcontext.__reserved member of ucontext_t is a user visible API,
that should not be changed, because this is the only way to access cpu
states of various extensions of linux asm/sigcontext.h, it does not
violate namespace rules either, so revert this part of the commit
commit 4fa9b3bfe6759c82beb4b043a54a3598ca467289
Commit: Joseph Myers <joseph@codesourcery.com>
Fix mcontext_t sigcontext namespace (bug 21457).
(In principle the user can type cast &uc_mcontext to struct sigcontext*
to use the linux sigcontext fields, but that's not the existing practice
since mcontext_t used to be a typedef of struct sigcontext.)
I plan to commit this soon for 2.27 and backport it to 2.26 if there are
no comments.
2018-01-23 Szabolcs Nagy <szabolcs.nagy@arm.com>
* sysdeps/unix/sysv/linux/aarch64/sys/ucontext.h (__glibc_reserved1):
Rename to __reserved and add comment.
* sysdeps/unix/sysv/linux/aarch64/ucontext_i.sym (__glibc_reserved1):
Rename to __reserved.
diff --git a/sysdeps/unix/sysv/linux/aarch64/sys/ucontext.h b/sysdeps/unix/sysv/linux/aarch64/sys/ucontext.h
index fe72fdd265..f1b3ab59e2 100644
--- a/sysdeps/unix/sysv/linux/aarch64/sys/ucontext.h
+++ b/sysdeps/unix/sysv/linux/aarch64/sys/ucontext.h
@@ -56,7 +56,11 @@ typedef struct
unsigned long long int __ctx(sp);
unsigned long long int __ctx(pc);
unsigned long long int __ctx(pstate);
- unsigned char __glibc_reserved1[4096] __attribute__ ((__aligned__ (16)));
+ /* This field contains extension records for additional processor
+ state such as the FP/SIMD state. It has to match the definition
+ of the corresponding field in the sigcontext struct, see the
+ arch/arm64/include/uapi/asm/sigcontext.h linux header for details. */
+ unsigned char __reserved[4096] __attribute__ ((__aligned__ (16)));
} mcontext_t;
/* Userlevel context. */
diff --git a/sysdeps/unix/sysv/linux/aarch64/ucontext_i.sym b/sysdeps/unix/sysv/linux/aarch64/ucontext_i.sym
index 479bdda5c6..ab3930c173 100644
--- a/sysdeps/unix/sysv/linux/aarch64/ucontext_i.sym
+++ b/sysdeps/unix/sysv/linux/aarch64/ucontext_i.sym
@@ -38,7 +38,7 @@ oX0 mcontext (regs)
oSP mcontext (sp)
oPC mcontext (pc)
oPSTATE mcontext (pstate)
-oEXTENSION mcontext (__glibc_reserved1)
+oEXTENSION mcontext (__reserved)
#define fpsimd_context(member) offsetof (struct fpsimd_context, member)