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| author | Michael Karcher <Michael.Karcher@fu-berlin.de> | 2024-07-28 15:30:57 +0200 |
|---|---|---|
| committer | Andreas K. Hüttel <dilfridge@gentoo.org> | 2024-07-29 23:00:39 +0200 |
| commit | faeaa3bc9f76030b9882ccfdee232fc0ca6dcb06 (patch) | |
| tree | 8a57f4fb28d26893b20aa6ae31dea95006a69983 | |
| parent | aedbf08891069fc029ed021e4dba933eb877b394 (diff) | |
| download | glibc-faeaa3bc9f76030b9882ccfdee232fc0ca6dcb06.zip glibc-faeaa3bc9f76030b9882ccfdee232fc0ca6dcb06.tar.gz glibc-faeaa3bc9f76030b9882ccfdee232fc0ca6dcb06.tar.bz2 | |
Mitigation for "clone on sparc might fail with -EFAULT for no valid reason" (bz 31394)
It seems the kernel can not deal with uncommitted stack space in the area intended
for the register window when executing the clone() system call. So create a nested
frame (proxy for the kernel frame) and flush it from the processor to memory to
force committing pages to the stack before invoking the system call.
Bug: https://www.mail-archive.com/debian-glibc@lists.debian.org/msg62592.html
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31394
See-also: https://lore.kernel.org/sparclinux/62f9be9d-a086-4134-9a9f-5df8822708af@mkarcher.dialup.fu-berlin.de/
Signed-off-by: Michael Karcher <sourceware-bugzilla@mkarcher.dialup.fu-berlin.de>
Reviewed-by: DJ Delorie <dj@redhat.com>
| -rw-r--r-- | sysdeps/unix/sysv/linux/sparc/sparc32/clone.S | 3 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/sparc/sparc64/clone.S | 3 |
2 files changed, 6 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/clone.S b/sysdeps/unix/sysv/linux/sparc/sparc32/clone.S index 748d25f..c9cf9bb 100644 --- a/sysdeps/unix/sysv/linux/sparc/sparc32/clone.S +++ b/sysdeps/unix/sysv/linux/sparc/sparc32/clone.S @@ -28,6 +28,9 @@ .text ENTRY (__clone) save %sp,-96,%sp + save %sp,-96,%sp + flushw + restore cfi_def_cfa_register(%fp) cfi_window_save cfi_register(%o7, %i7) diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/clone.S b/sysdeps/unix/sysv/linux/sparc/sparc64/clone.S index e5ff2cf..370d51f 100644 --- a/sysdeps/unix/sysv/linux/sparc/sparc64/clone.S +++ b/sysdeps/unix/sysv/linux/sparc/sparc64/clone.S @@ -32,6 +32,9 @@ ENTRY (__clone) save %sp, -192, %sp + save %sp, -192, %sp + flushw + restore cfi_def_cfa_register(%fp) cfi_window_save cfi_register(%o7, %i7) |