Nicholas Piggin e237506238 powerpc/32: fix syscall wrappers with 64-bit arguments of unaligned register-pairs ... powerpc 32-bit system call (and function) calling convention for 64-bit arguments requires the next available odd-pair (two sequential registers with the first being odd-numbered) from the standard register argument allocation. The first argument register is r3, so a 64-bit argument that appears at an even position in the argument list must skip a register (unless there were preceding 64-bit arguments, which might throw things off). This requires non-standard compat definitions to deal with the holes in the argument register allocation. With pt_regs syscall wrappers which use a standard mapper to map pt_regs GPRs to function arguments, 32-bit kernels hit the same basic problem, the standard definitions don't cope with the unused argument registers. Fix this by having 32-bit kernels share those syscall definitions with compat. Thanks to Jason for spending a lot of time finding and bisecting this and developing a trivial reproducer. The perfect bug report. Reported-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Fixes: 7e92e01b72 ("powerpc: Provide syscall wrapper") Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20221012035335.866440-1-npiggin@gmail.com		2022-10-13 00:49:58 +11:00
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Makefile	arch: syscalls: simplify uapi/kapi directory creation	2022-03-31 12:03:46 +09:00
syscall.tbl	powerpc/32: fix syscall wrappers with 64-bit arguments of unaligned register-pairs	2022-10-13 00:49:58 +11:00