On Tue, Feb 19, 2019 at 9:56 AM Geert Uytterhoeven [off-list ref] wrote:

Hi Arnd, Yuri,

On Tue, Feb 19, 2019 at 3:35 AM Arnd Bergmann [off-list ref] wrote:

quoted

From: Yury Norov <redacted>

All new 32-bit architectures should have 64-bit userspace off_t type, but
existing architectures has 32-bit ones.

To enforce the rule, new config option is added to arch/Kconfig that defaults
ARCH_32BIT_OFF_T to be disabled for new 32-bit architectures. All existing
32-bit architectures enable it explicitly.

New option affects force_o_largefile() behaviour. Namely, if userspace
off_t is 64-bits long, we have no reason to reject user to open big files.

Note that even if architectures has only 64-bit off_t in the kernel
(arc, c6x, h8300, hexagon, nios2, openrisc, and unicore32),
a libc may use 32-bit off_t, and therefore want to limit the file size
to 4GB unless specified differently in the open flags.

Signed-off-by: Yury Norov <redacted>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Yury Norov <redacted>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

quoted

 arch/m68k/Kconfig       |  1 +

For m68k:
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>

Thanks!

quoted

--- a/arch/Kconfig
+++ b/arch/Kconfig

@@ -276,6 +276,21 @@ config ARCH_THREAD_STACK_ALLOCATOR
 config ARCH_WANTS_DYNAMIC_TASK_STRUCT
        bool

+config ARCH_32BIT_OFF_T
+       bool
+       depends on !64BIT
+       help
+         All new 32-bit architectures should have 64-bit off_t type on
+         userspace side which corresponds to the loff_t kernel type. This
+         is the requirement for modern ABIs. Some existing architectures
+         already have 32-bit off_t. This option is enabled for all such

s/already/still/

quoted

+         architectures explicitly. Namely: arc, arm, blackfin, cris, frv,
+         h8300, hexagon, m32r, m68k, metag, microblaze, mips32, mn10300,
+         nios2, openrisc, parisc32, powerpc32, score, sh, sparc, tile32,
+         unicore32, x86_32 and xtensa. This is the complete list. Any

Do we really need this list here?  It's intended to shrink only.
It includes removed architectures (blackfin, cris, frv, m32r, metag,
mn10300, score, tile32), but lacks several new ones affected by this
patch (c6x, csky, nds32, riscv).

Right, I (finally)  took Yury's patch that was already several years old
without checking this text (I did make sure all architectures are changed
correctly).

I'll just remove the list here.

      Arnd

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