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modpost: fix input MODULE_DEVICE_TABLE() built for 64-bit on 32-bit host

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When building a 64-bit kernel on a 32-bit build host, incorrect
input MODULE_ALIAS() entries may be generated.

For example, when compiling a 64-bit kernel with CONFIG_INPUT_MOUSEDEV=m
on a 64-bit build machine, you will get the correct output:

  $ grep MODULE_ALIAS drivers/input/mousedev.mod.c
  MODULE_ALIAS("input:b*v*p*e*-e*1,*2,*k*110,*r*0,*1,*a*m*l*s*f*w*");
  MODULE_ALIAS("input:b*v*p*e*-e*1,*2,*k*r*8,*a*m*l*s*f*w*");
  MODULE_ALIAS("input:b*v*p*e*-e*1,*3,*k*14A,*r*a*0,*1,*m*l*s*f*w*");
  MODULE_ALIAS("input:b*v*p*e*-e*1,*3,*k*145,*r*a*0,*1,*18,*1C,*m*l*s*f*w*");
  MODULE_ALIAS("input:b*v*p*e*-e*1,*3,*k*110,*r*a*0,*1,*m*l*s*f*w*");

However, building the same kernel on a 32-bit machine results in
incorrect output:

  $ grep MODULE_ALIAS drivers/input/mousedev.mod.c
  MODULE_ALIAS("input:b*v*p*e*-e*1,*2,*k*110,*130,*r*0,*1,*a*m*l*s*f*w*");
  MODULE_ALIAS("input:b*v*p*e*-e*1,*2,*k*r*8,*a*m*l*s*f*w*");
  MODULE_ALIAS("input:b*v*p*e*-e*1,*3,*k*14A,*16A,*r*a*0,*1,*20,*21,*m*l*s*f*w*");
  MODULE_ALIAS("input:b*v*p*e*-e*1,*3,*k*145,*165,*r*a*0,*1,*18,*1C,*20,*21,*38,*3C,*m*l*s*f*w*");
  MODULE_ALIAS("input:b*v*p*e*-e*1,*3,*k*110,*130,*r*a*0,*1,*20,*21,*m*l*s*f*w*");

A similar issue occurs with CONFIG_INPUT_JOYDEV=m. On a 64-bit build
machine, the output is:

  $ grep MODULE_ALIAS drivers/input/joydev.mod.c
  MODULE_ALIAS("input:b*v*p*e*-e*3,*k*r*a*0,*m*l*s*f*w*");
  MODULE_ALIAS("input:b*v*p*e*-e*3,*k*r*a*2,*m*l*s*f*w*");
  MODULE_ALIAS("input:b*v*p*e*-e*3,*k*r*a*8,*m*l*s*f*w*");
  MODULE_ALIAS("input:b*v*p*e*-e*3,*k*r*a*6,*m*l*s*f*w*");
  MODULE_ALIAS("input:b*v*p*e*-e*1,*k*120,*r*a*m*l*s*f*w*");
  MODULE_ALIAS("input:b*v*p*e*-e*1,*k*130,*r*a*m*l*s*f*w*");
  MODULE_ALIAS("input:b*v*p*e*-e*1,*k*2C0,*r*a*m*l*s*f*w*");

However, on a 32-bit machine, the output is incorrect:

  $ grep MODULE_ALIAS drivers/input/joydev.mod.c
  MODULE_ALIAS("input:b*v*p*e*-e*3,*k*r*a*0,*20,*m*l*s*f*w*");
  MODULE_ALIAS("input:b*v*p*e*-e*3,*k*r*a*2,*22,*m*l*s*f*w*");
  MODULE_ALIAS("input:b*v*p*e*-e*3,*k*r*a*8,*28,*m*l*s*f*w*");
  MODULE_ALIAS("input:b*v*p*e*-e*3,*k*r*a*6,*26,*m*l*s*f*w*");
  MODULE_ALIAS("input:b*v*p*e*-e*1,*k*11F,*13F,*r*a*m*l*s*f*w*");
  MODULE_ALIAS("input:b*v*p*e*-e*1,*k*11F,*13F,*r*a*m*l*s*f*w*");
  MODULE_ALIAS("input:b*v*p*e*-e*1,*k*2C0,*2E0,*r*a*m*l*s*f*w*");

When building a 64-bit kernel, BITS_PER_LONG is defined as 64. However,
on a 32-bit build machine, the constant 1L is a signed 32-bit value.
Left-shifting it beyond 32 bits causes wraparound, and shifting by 31
or 63 bits makes it a negative value.

The fix in commit e0e9263271 ("[PATCH] PATCH: 1 line 2.6.18 bugfix:
modpost-64bit-fix.patch") is incorrect; it only addresses cases where
a 64-bit kernel is built on a 64-bit build machine, overlooking cases
on a 32-bit build machine.

Using 1ULL ensures a 64-bit width on both 32-bit and 64-bit machines,
avoiding the wraparound issue.

Fixes: e0e9263271 ("[PATCH] PATCH: 1 line 2.6.18 bugfix: modpost-64bit-fix.patch")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
This commit is contained in:
Masahiro Yamada 2024-11-03 21:52:57 +09:00
parent 2e766a1f5f
commit 77dc55a978
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
scripts/mod/file2alias.c
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@ -743,7 +743,7 @@ static void do_input(char *alias,
for (i = min / BITS_PER_LONG; i < max / BITS_PER_LONG + 1; i++)
arr[i] = TO_NATIVE(arr[i]);
for (i = min; i < max; i++)
if (arr[i / BITS_PER_LONG] & (1L << (i%BITS_PER_LONG)))
if (arr[i / BITS_PER_LONG] & (1ULL << (i%BITS_PER_LONG)))
sprintf(alias + strlen(alias), "%X,*", i);
}