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authorAdhemerval Zanella <adhemerval.zanella@linaro.org>2024-02-01 14:29:53 -0300
committerAdhemerval Zanella <adhemerval.zanella@linaro.org>2024-02-02 10:28:16 -0300
commitbbd248ac0d75efdef8fe61ea69b1fb25fb95b6e7 (patch)
tree9cb97b4ac0323c4c24c61805af42cb1a277b7ff5 /sysdeps/unix
parente7b90e6e605cf236d4bd79e4930cd6a46f9932c7 (diff)
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mips: FIx clone3 implementation (BZ 31325)
For o32 we need to setup a minimal stack frame to allow cprestore on __thread_start_clone3 (which instruct the linker to save the gp for PIC). Also, there is no guarantee by kABI that $8 will be preserved after syscall execution, so we need to save it on the provided stack. Checked on mipsel-linux-gnu. Reported-by: Khem Raj <raj.khem@gmail.com> Tested-by: Khem Raj <raj.khem@gmail.com>
Diffstat (limited to 'sysdeps/unix')
-rw-r--r--sysdeps/unix/sysv/linux/mips/clone3.S32
1 files changed, 27 insertions, 5 deletions
diff --git a/sysdeps/unix/sysv/linux/mips/clone3.S b/sysdeps/unix/sysv/linux/mips/clone3.S
index e9fec2f..481b8ae 100644
--- a/sysdeps/unix/sysv/linux/mips/clone3.S
+++ b/sysdeps/unix/sysv/linux/mips/clone3.S
@@ -37,11 +37,6 @@
.text
.set nomips16
-#if _MIPS_SIM == _ABIO32
-# define EXTRA_LOCALS 1
-#else
-# define EXTRA_LOCALS 0
-#endif
#define FRAMESZ ((NARGSAVE*SZREG)+ALSZ)&ALMASK
GPOFF= FRAMESZ-(1*SZREG)
NESTED(__clone3, SZREG, sp)
@@ -68,8 +63,31 @@ NESTED(__clone3, SZREG, sp)
beqz a0, L(error) /* No NULL cl_args pointer. */
beqz a2, L(error) /* No NULL function pointer. */
+#if _MIPS_SIM == _ABIO32
+ /* Both stack and stack_size on clone_args are defined as uint64_t, and
+ there is no need to handle values larger than to 32 bits for o32. */
+# if __BYTE_ORDER == __BIG_ENDIAN
+# define CL_STACKPOINTER_OFFSET 44
+# define CL_STACKSIZE_OFFSET 52
+# else
+# define CL_STACKPOINTER_OFFSET 40
+# define CL_STACKSIZE_OFFSET 48
+# endif
+
+ /* For o32 we need to setup a minimal stack frame to allow cprestore
+ on __thread_start_clone3. Also there is no guarantee by kABI that
+ $8 will be preserved after syscall execution (so we need to save it
+ on the provided stack). */
+ lw t0, CL_STACKPOINTER_OFFSET(a0) /* Load the stack pointer. */
+ lw t1, CL_STACKSIZE_OFFSET(a0) /* Load the stack_size. */
+ addiu t1, -32 /* Update the stack size. */
+ addu t2, t1, t0 /* Calculate the thread stack. */
+ sw a3, 0(t2) /* Save argument pointer. */
+ sw t1, CL_STACKSIZE_OFFSET(a0) /* Save the new stack size. */
+#else
move $8, a3 /* a3 is set to 0/1 for syscall success/error
while a4/$8 is returned unmodified. */
+#endif
/* Do the system call, the kernel expects:
v0: system call number
@@ -125,7 +143,11 @@ L(thread_start_clone3):
/* Restore the arg for user's function. */
move t9, a2 /* Function pointer. */
+#if _MIPS_SIM == _ABIO32
+ PTR_L a0, 0(sp)
+#else
move a0, $8 /* Argument pointer. */
+#endif
/* Call the user's function. */
jal t9