linux/include/asm-i386
Andi Kleen 6e44f12ba6 [PATCH] i386: add memory clobbers to syscall macros
As noted by matz@suse.de

The problem is, that on i386 the syscallN
macro is defined like so:

  long __res; \
  __asm__ volatile ("int $0x80" \
        : "=a" (__res) \
        : "0" (__NR_##name),"b" ((long)(arg1)),"c" ((long)(arg2)), \
          "d" ((long)(arg3)),"S" ((long)(arg4)),"D" ((long)(arg5))); \

If one of the arguments (in the _llseek syscall it's the arg4) is a pointer
which the syscall is expected to write to (to the memory pointed to by this
ptr), then this side-effect is not captured in the asm.

If anyone uses this macro to define it's own version of the syscall
(sometimes necessary when not using glibc) and it's inlined, then GCC
doesn't know that this asm write to "*dest", when called like so for instance:

  out = 1;
  llseek (fd, bla, blubb, &out, trara)
  use (out);

Here nobody tells GCC that "out" actually is written to (just a pointer to it
is passed to the asm).  Hence GCC might (and in the above bug did)
copy-propagate "1" into the second use of "out".

The easiest solution would be to add a "memory" clobber to the definition
of this syscall macro.  As this is a syscall, it shouldn't inhibit too many
optimizations.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-12 10:50:55 -07:00
..
mach-bigsmp [PATCH] Do not enforce unique IO_APIC_ID check for xAPIC systems (i386) 2005-06-23 09:45:09 -07:00
mach-default [PATCH] fix reboot via keyboard controller reset 2005-09-09 13:57:35 -07:00
mach-es7000 [PATCH] ES7000 platform update (i386) 2005-09-05 00:06:10 -07:00
mach-generic [PATCH] x86: sutomatically enable bigsmp when we have more than 8 CPUs 2005-09-05 00:06:10 -07:00
mach-numaq [PATCH] Do not enforce unique IO_APIC_ID check for xAPIC systems (i386) 2005-06-23 09:45:09 -07:00
mach-summit [PATCH] Do not enforce unique IO_APIC_ID check for xAPIC systems (i386) 2005-06-23 09:45:09 -07:00
mach-visws [PATCH] Make visws compile again 2005-08-07 10:00:38 -07:00
mach-voyager Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
8253pit.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
a.out.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
acpi.h [ACPI] delete CONFIG_ACPI_PCI 2005-08-25 12:40:44 -04:00
agp.h [PATCH] i386: inline asm cleanup 2005-09-05 00:06:11 -07:00
apic.h [PATCH] kexec: x86: resture apic virtual wire mode on shutdown 2005-06-25 16:24:47 -07:00
apicdef.h [PATCH] x86: sutomatically enable bigsmp when we have more than 8 CPUs 2005-09-05 00:06:10 -07:00
arch_hooks.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
atomic.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
auxvec.h [PATCH] auxiliary vector cleanups 2005-09-07 16:57:21 -07:00
bitops.h x86: fix new find_first_bit() 2005-07-29 11:01:22 -04:00
boot.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
bug.h [PATCH] remove all kernel BUGs 2005-05-01 08:59:01 -07:00
bugs.h [PATCH] i386: inline asm cleanup 2005-09-05 00:06:11 -07:00
byteorder.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
cache.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
cacheflush.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
checksum.h [NET]: Fix ipl=>ihl typo in ip_fast_csum 2005-08-29 16:02:48 -07:00
cpu.h [PATCH] i386 CPU hotplug 2005-06-25 16:24:29 -07:00
cpufeature.h [PATCH] CPUID bug and inconsistency fix 2005-05-01 08:58:49 -07:00
cputime.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
current.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
debugreg.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
delay.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
desc.h [PATCH] x86: introduce a write acessor for updating the current LDT 2005-09-05 00:06:13 -07:00
div64.h [PATCH] include/asm-i386/: "extern inline" -> "static inline" 2005-09-10 10:06:34 -07:00
dma-mapping.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
dma.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
e820.h [PATCH] Increase number of e820 entries hard limit from 32 to 128 2005-05-01 08:58:51 -07:00
elf.h [PATCH] auxiliary vector cleanups 2005-09-07 16:57:21 -07:00
emergency-restart.h [PATCH] i386: Implement machine_emergency_reboot 2005-07-26 14:35:42 -07:00
errno.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
fcntl.h [PATCH] Clean up struct flock64 definitions 2005-09-07 16:57:38 -07:00
fixmap.h [ACPI] delete CONFIG_ACPI_BOOT 2005-08-24 12:08:54 -04:00
floppy.h [PATCH] make some things static 2005-05-05 16:36:47 -07:00
futex.h [PATCH] FUTEX_WAKE_OP: pthread_cond_signal() speedup 2005-09-07 16:57:17 -07:00
genapic.h [PATCH] Do not enforce unique IO_APIC_ID check for xAPIC systems (i386) 2005-06-23 09:45:09 -07:00
hardirq.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
highmem.h [PATCH] kdump: Routines for copying dump pages 2005-06-25 16:24:53 -07:00
hpet.h [PATCH] i386: fix hpet for systems that don't support legacy replacement 2005-05-01 08:58:50 -07:00
hw_irq.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
i387.h x86: use alternative instructions for fnsave/fxsave too 2005-07-22 18:19:20 -04:00
i8253.h [PATCH] x86: i8253/i8259A lock cleanup 2005-06-30 08:45:10 -07:00
i8259.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
ide.h [PATCH] ide: sensible probing for PCI systems 2005-06-27 17:36:41 -07:00
io_apic.h [ACPI] delete CONFIG_ACPI_BOOT 2005-08-24 12:08:54 -04:00
io.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
ioctl.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
ioctls.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
ipc.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
ipcbuf.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
irq.h [PATCH] cpu state clean after hot remove 2005-06-25 16:24:30 -07:00
ist.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
kdebug.h [PATCH] x86 NMI: better support for debuggers 2005-09-05 00:06:13 -07:00
kexec.h [PATCH] Kdump: Export crash notes section address through sysfs 2005-06-25 16:24:51 -07:00
kmap_types.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
kprobes.h [PATCH] kprobes: function-return probes 2005-06-23 09:45:21 -07:00
ldt.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
linkage.h [PATCH] i386: fix prevent_tail_call 2005-05-26 16:16:16 -07:00
local.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
math_emu.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
mc146818rtc.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
mca_dma.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
mca.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
mman.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
mmu_context.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
mmu.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
mmx.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
mmzone.h [PATCH] i386: CONFIG_ACPI_SRAT typo fix 2005-09-09 13:56:44 -07:00
module.h [PATCH] x86: geode support fixes 2005-05-05 16:36:49 -07:00
mpspec_def.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
mpspec.h Merge linux-2.6 with linux-acpi-2.6 2005-09-08 01:45:47 -04:00
msgbuf.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
msi.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
msr.h [PATCH] x86: more asm cleanups 2005-09-05 00:06:12 -07:00
mtrr.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
namei.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
nmi.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
node.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
numa.h [PATCH] x86-64: Use ACPI PXM to parse PCI<->node assignments 2005-09-12 10:49:57 -07:00
numaq.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
numnodes.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
page.h [PATCH] remove hugetlb_clean_stale_pgtable() and fix huge_pte_alloc() 2005-09-05 00:05:46 -07:00
param.h [PATCH] i386: Selectable Frequency of the Timer Interrupt 2005-06-23 09:45:10 -07:00
parport.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
pci-direct.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
pci.h Revert PCIBIOS_MIN_IO changes for 2.6.13 2005-08-14 18:21:30 -07:00
percpu.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
pgalloc.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
pgtable-2level-defs.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
pgtable-2level.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
pgtable-3level-defs.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
pgtable-3level.h [PATCH] i386: use set_pte macros in a couple places where they were missing 2005-09-05 00:06:12 -07:00
pgtable.h [PATCH] i386: encapsulate copying of pgd entries 2005-09-05 00:06:13 -07:00
poll.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
posix_types.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
processor.h [PATCH] include/asm-i386/: "extern inline" -> "static inline" 2005-09-10 10:06:34 -07:00
ptrace.h [PATCH] x86: privilege cleanup 2005-09-05 00:06:12 -07:00
resource.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
rtc.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
rwlock.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
rwsem.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
scatterlist.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
seccomp.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
sections.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
segment.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
semaphore.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
sembuf.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
serial.h [PATCH] Serial: Split 8250 port table (part 2) 2005-06-29 18:45:19 +01:00
setup.h [PATCH] x86: fix EFI memory map parsing 2005-09-05 00:06:09 -07:00
shmbuf.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
shmparam.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
sigcontext.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
siginfo.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
signal.h [PATCH] asm/signal.h unification 2005-05-04 07:33:15 -07:00
smp.h [PATCH] i386 boottime for_each_cpu broken 2005-09-05 00:06:13 -07:00
socket.h [NET]: Introduce SO_{SND,RCV}BUFFORCE socket options 2005-08-29 15:31:35 -07:00
sockios.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
sparsemem.h [PATCH] sparsemem memory model for i386 2005-06-23 09:45:05 -07:00
spinlock_types.h [PATCH] spinlock consolidation 2005-09-10 10:06:21 -07:00
spinlock.h [PATCH] spinlock consolidation 2005-09-10 10:06:21 -07:00
srat.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
stat.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
statfs.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
string.h Add "memory" clobbers to the x86 inline asm of strncmp and friends 2005-06-24 10:39:17 -07:00
suspend.h [PATCH] i386: Use loaddebug macro consistently 2005-04-16 15:24:46 -07:00
system.h [PATCH] x86: make IOPL explicit 2005-09-05 00:06:12 -07:00
termbits.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
termios.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
thread_info.h kbuild: full dependency check on asm-offsets.h 2005-09-09 19:28:28 +02:00
timer.h [PATCH] add suspend/resume for timer 2005-09-05 00:06:18 -07:00
timex.h [PATCH] x86: cpu_khz type fix 2005-06-23 09:45:11 -07:00
tlb.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
tlbflush.h [PATCH] seccomp: tsc disable 2005-06-27 15:11:44 -07:00
topology.h [PATCH] x86-64: Use ACPI PXM to parse PCI<->node assignments 2005-09-12 10:49:57 -07:00
types.h [PATCH] sab: consolidate kmem_bufctl_t 2005-09-05 00:05:48 -07:00
uaccess.h [PATCH] remove verify_area(): remove verify_area() from various uaccess.h headers 2005-09-07 16:57:35 -07:00
ucontext.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
unaligned.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
unistd.h [PATCH] i386: add memory clobbers to syscall macros 2005-09-12 10:50:55 -07:00
user.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
vga.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
vic.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
vm86.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
voyager.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
xor.h [PATCH] i386: inline asm cleanup 2005-09-05 00:06:11 -07:00