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6 commits

Author SHA1 Message Date
Mingwei Shi
be91052932 libc: implement kernel vdso syscalls for i386
This patch uses __kernel_vsyscall instead of "int 0x80"
as the syscall entry point. AT_SYSINFO points to
an adapter to mask the arch specific difference and gives a
performance boost on i386 architecture.

Change-ID: Ib340c604d02c6c25714a95793737e3cfdc3fc5d7
Signed-off-by: Mingwei Shi <mingwei.shi@intel.com>
2016-03-25 14:10:05 -07:00
Elliott Hughes
7efad83d43 Ensure __set_errno is still visible on LP32.
The use of the .hidden directive to avoid going via the PLT for
__set_errno had the side-effect of actually making __set_errno
hidden (which is odd because assembler directives don't usually
affect symbols defined in a different file --- you can't even
create a weak reference to a symbol that's defined in a different
file).

This change switches the system call stubs over to a new always-hidden
__set_errno_internal and has a visible __set_errno on LP32 just for
binary compatibility with old NDK apps.

Bug: 17423135
Change-Id: I6b6d7a05dda85f923d22e5ffd169a91e23499b7b
2014-09-08 15:36:21 -07:00
Dan Albert
e35fd48a83 Make __set_errno hidden in asm.
This fixes the build after the -Bsymbolic change.

Bug: 16853291
Change-Id: I989c9fec3c32e0289ea257a3bd2b7fd2709b6ce2
(cherry picked from commit bc9f9f25bf)
2014-08-08 15:37:50 -07:00
Elliott Hughes
15a0456d0b Remove unnecessary instructions from x86/x86_64 syscalls.
__set_errno returns -1 exactly so that callers don't need to bother.
The other architectures were already taking advantage of this, but
no one had ever fixed x86 and x86_64.

Change-Id: Ie131494be664f6c4a1bbf8c61bbbed58eac56122
2014-06-05 17:24:30 -07:00
Christopher Ferris
15b91e92a0 Fix x86 cfi directives for syscalls.
The syscall generation always used 4 bytes for each push cfi directive.
However, the first push should always use an offset of 8 bytes, each
subsequent push after that is only 4 bytes though.

Change-Id: Ibaabd107f399ef67010b9a08213783957c2f74a9
2014-05-29 19:04:36 -07:00
Elliott Hughes
0f461e35f6 Fix <sys/resource.h>.
The situation here is a bit confusing. On 64-bit, rlimit and rlimit64 are
the same, and so getrlimit/getrlimit64, setrlimit/setrlimit64,
and prlimit/prlimit64 are all the same. On 32-bit, rlimit and rlimit64 are
different. 32-bit architectures other than MIPS go one step further by having
an even more limited getrlimit system call, so arm and x86 need to use
ugetrlimit instead of getrlimit. Worse, the 32-bit architectures don't have
64-bit getrlimit- and setrlimit-equivalent system calls, and you have to use
prlimit64 instead. There's no 32-bit prlimit system call, so there's no
easy implementation of that --- what should we do if the result of prlimit64
won't fit in a struct rlimit? Since 32-bit survived without prlimit/prlimit64
for this long, I'm not going to bother implementing prlimit for 32-bit.

We need the rlimit64 functions to be able to build strace 4.8 out of the box.

Change-Id: I1903d913b23016a2fc3b9f452885ac730d71e001
2014-01-09 11:00:04 -08:00