100 lines
3.4 KiB
Diff
100 lines
3.4 KiB
Diff
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commit 2952c70804b48bb5c87eea21df5e401969dc4ec1
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Author: Kevin Cernekee <cernekee@gmail.com>
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Date: Tue Jun 5 15:05:20 2012 -0700
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MIPS: Use $a0 instead of $v0 for __syscall_error() argument
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$a0 is saved across _dl_runtime_resolve(); $v0 is not. Unfortunately,
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__syscall_error() uses $v0 for its argument, not $a0 as is the MIPS ABI
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standard. This means that if lazy binding was used for __syscall_error(),
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the errno value in $v0 could get corrupted.
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The problem can be easily seen in testcases where syscalls in librt fail;
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when librt tries to call __syscall_error() in libc, the argument gets
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lost and errno gets set to a bogus value:
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# ./tst-mqueue1 ; echo $?
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mq_receive on O_WRONLY mqd_t did not fail with EBADF: Unknown error 2004684208
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1
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# ./tst-mqueue2 ; echo $?
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mq_timedreceive with too small msg_len did not fail with EMSGSIZE: Unknown error 1997360560
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1
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# ./tst-mqueue4 ; echo $?
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mq_timedsend did not fail with ETIMEDOUT: Unknown error 2008747440
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1
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When _dl_runtime_resolve() was taken out of the equation, the same test
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cases passed:
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# LD_BIND_NOW=y ./tst-mqueue1 ; echo $?
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0
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# LD_BIND_NOW=y ./tst-mqueue2 ; echo $?
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0
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# LD_BIND_NOW=y ./tst-mqueue4 ; echo $?
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0
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Changing __syscall_error() to look at $a0 instead of $v0 fixed the
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problem.
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(Note that there is also a "__syscall_error.c" file which presumably
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uses the standard C calling conventions, but I do not think it is used
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on MIPS.)
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Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
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Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>
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commit 3c58d95d918c7e2fda374c37a52f81b34b81e4ca
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Author: Kevin Cernekee <cernekee@gmail.com>
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Date: Tue Jun 5 15:05:19 2012 -0700
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MIPS: Convert __syscall_error() callers to use $a0 for argument
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Some callers passed the first argument in $v0, while others used $a0.
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Change the callers to use $a0 consistently.
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Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
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Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>
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--- a/libc/sysdeps/linux/mips/vfork.S
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+++ b/libc/sysdeps/linux/mips/vfork.S
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@@ -84,6 +84,7 @@ NESTED(__vfork,FRAMESZ,sp)
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/* Something bad happened -- no child created. */
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L(error):
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+ move a0, v0
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#ifdef __PIC__
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PTR_LA t9, __syscall_error
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RESTORE_GP64
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--- a/libpthread/linuxthreads/sysdeps/unix/sysv/linux/mips/mips64/sysdep-cancel.h
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+++ b/libpthread/linuxthreads/sysdeps/unix/sysv/linux/mips/mips64/sysdep-cancel.h
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@@ -31,7 +31,7 @@
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# undef PSEUDO
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# define PSEUDO(name, syscall_name, args) \
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.align 2; \
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- 99: \
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+ 99: move a0, v0; \
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PTR_LA t9,__syscall_error; \
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/* manual cpreturn. */ \
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REG_L gp, STKOFF_GP(sp); \
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--- a/libpthread/linuxthreads/sysdeps/unix/sysv/linux/mips/vfork.S
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+++ b/libpthread/linuxthreads/sysdeps/unix/sysv/linux/mips/vfork.S
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@@ -80,6 +80,7 @@ NESTED(__vfork,FRAMESZ,sp)
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/* Something bad happened -- no child created. */
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L(error):
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+ move a0, v0
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#ifdef __PIC__
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PTR_LA t9, __syscall_error
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RESTORE_GP64
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--- a/libc/sysdeps/linux/mips/syscall_error.S
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+++ b/libc/sysdeps/linux/mips/syscall_error.S
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@@ -43,7 +43,7 @@ ENTRY(__syscall_error)
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#ifdef __PIC__
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SAVE_GP(GPOFF)
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#endif
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- REG_S v0, V0OFF(sp)
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+ REG_S a0, V0OFF(sp)
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REG_S ra, RAOFF(sp)
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/* Find our per-thread errno address */
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