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| author | Arnd Bergmann <arnd@arndb.de> | 2019-07-10 15:04:55 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2019-07-10 17:19:58 +0200 |
| commit | 26515699863d68058e290e18e83f444925920be5 (patch) | |
| tree | 6d55778feb7272b0317e6d9484a6efa184252094 | |
| parent | ecc606103837b98a2b665e8f14e533a6c72bbdc0 (diff) | |
| download | linux-26515699863d68058e290e18e83f444925920be5.tar.bz2 | |
x86/pgtable/32: Fix LOWMEM_PAGES constant
clang points out that the computation of LOWMEM_PAGES causes a signed
integer overflow on 32-bit x86:
arch/x86/kernel/head32.c:83:20: error: signed shift result (0x100000000) requires 34 bits to represent, but 'int' only has 32 bits [-Werror,-Wshift-overflow]
(PAGE_TABLE_SIZE(LOWMEM_PAGES) << PAGE_SHIFT);
^~~~~~~~~~~~
arch/x86/include/asm/pgtable_32.h:109:27: note: expanded from macro 'LOWMEM_PAGES'
#define LOWMEM_PAGES ((((2<<31) - __PAGE_OFFSET) >> PAGE_SHIFT))
~^ ~~
arch/x86/include/asm/pgtable_32.h:98:34: note: expanded from macro 'PAGE_TABLE_SIZE'
#define PAGE_TABLE_SIZE(pages) ((pages) / PTRS_PER_PGD)
Use the _ULL() macro to make it a 64-bit constant.
Fixes: 1e620f9b23e5 ("x86/boot/32: Convert the 32-bit pgtable setup code from assembly to C")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190710130522.1802800-1-arnd@arndb.de
| -rw-r--r-- | arch/x86/include/asm/pgtable_32.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/include/asm/pgtable_32.h b/arch/x86/include/asm/pgtable_32.h index 4fe9e7fc74d3..c78da8eda8f2 100644 --- a/arch/x86/include/asm/pgtable_32.h +++ b/arch/x86/include/asm/pgtable_32.h @@ -106,6 +106,6 @@ do { \ * with only a host target support using a 32-bit type for internal * representation. */ -#define LOWMEM_PAGES ((((2<<31) - __PAGE_OFFSET) >> PAGE_SHIFT)) +#define LOWMEM_PAGES ((((_ULL(2)<<31) - __PAGE_OFFSET) >> PAGE_SHIFT)) #endif /* _ASM_X86_PGTABLE_32_H */ |