Re: [PATCH 1/3] powerpc/uaccess: Switch __put_user_size_allowed() to __put_user_asm_goto()

2020-11-03 Thread Michael Ellerman
Andreas Schwab writes: > # > # Automatically generated file; DO NOT EDIT. > # Linux/powerpc 5.10.0-rc1 Kernel Configuration > # > CONFIG_CC_VERSION_TEXT="gcc-4.9 (SUSE Linux) 4.9.3" So it seems to be a combination of GCC 4.9 and ... > # CONFIG_PPC_RADIX_MMU is not set That ^, which

Re: [PATCH 1/3] powerpc/uaccess: Switch __put_user_size_allowed() to __put_user_asm_goto()

2020-10-29 Thread Andreas Schwab
# # Automatically generated file; DO NOT EDIT. # Linux/powerpc 5.10.0-rc1 Kernel Configuration # CONFIG_CC_VERSION_TEXT="gcc-4.9 (SUSE Linux) 4.9.3" CONFIG_CC_IS_GCC=y CONFIG_GCC_VERSION=40903 CONFIG_LD_VERSION=23501 CONFIG_CLANG_VERSION=0 CONFIG_CC_CAN_LINK=y CONFIG_CC_CAN_LINK_STATIC=y

Re: [PATCH 1/3] powerpc/uaccess: Switch __put_user_size_allowed() to __put_user_asm_goto()

2020-10-28 Thread Michael Ellerman
Andreas Schwab writes: > On Okt 28 2020, Andreas Schwab wrote: > >> On Sep 04 2020, Christophe Leroy wrote: >> >>> __put_user_asm_goto() provides more flexibility to GCC and avoids using >>> a local variable to tell if the write succeeded or not. >>> GCC can then avoid implementing a cmp in the

Re: [PATCH 1/3] powerpc/uaccess: Switch __put_user_size_allowed() to __put_user_asm_goto()

2020-10-28 Thread Andreas Schwab
On Okt 28 2020, Michael Ellerman wrote: > What config and compiler are you using? gcc 4.9. Andreas. -- Andreas Schwab, sch...@linux-m68k.org GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1 "And now for something completely different."

Re: [PATCH 1/3] powerpc/uaccess: Switch __put_user_size_allowed() to __put_user_asm_goto()

2020-10-27 Thread Andreas Schwab
On Okt 28 2020, Andreas Schwab wrote: > On Sep 04 2020, Christophe Leroy wrote: > >> __put_user_asm_goto() provides more flexibility to GCC and avoids using >> a local variable to tell if the write succeeded or not. >> GCC can then avoid implementing a cmp in the fast path. > > That breaks

Re: [PATCH 1/3] powerpc/uaccess: Switch __put_user_size_allowed() to __put_user_asm_goto()

2020-10-27 Thread Andreas Schwab
On Sep 04 2020, Christophe Leroy wrote: > __put_user_asm_goto() provides more flexibility to GCC and avoids using > a local variable to tell if the write succeeded or not. > GCC can then avoid implementing a cmp in the fast path. That breaks CLONE_CHILD_SETTID. I'm getting an assertion failure

Re: [PATCH 1/3] powerpc/uaccess: Switch __put_user_size_allowed() to __put_user_asm_goto()

2020-09-17 Thread Michael Ellerman
On Fri, 4 Sep 2020 11:01:30 + (UTC), Christophe Leroy wrote: > __put_user_asm_goto() provides more flexibility to GCC and avoids using > a local variable to tell if the write succeeded or not. > GCC can then avoid implementing a cmp in the fast path. > > See the difference for a small

[PATCH 1/3] powerpc/uaccess: Switch __put_user_size_allowed() to __put_user_asm_goto()

2020-09-04 Thread Christophe Leroy
__put_user_asm_goto() provides more flexibility to GCC and avoids using a local variable to tell if the write succeeded or not. GCC can then avoid implementing a cmp in the fast path. See the difference for a small function like the PPC64 version of save_general_regs() in