| Message ID | 20220916053300.786330-9-rmclure@linux.ibm.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | powerpc: Syscall wrapper and register clearing | expand |
On Fri, Sep 16, 2022, at 7:32 AM, Rohan McLure wrote: > As reported[1] by Arnd, the arch-specific fadvise64_64 and fallocate > compatibility handlers assume parameters are passed with 32-bit > big-endian ABI. This affects the assignment of odd-even parameter pairs > to the high or low words of a 64-bit syscall parameter. > > Fix fadvise64_64 fallocate compat handlers to correctly swap upper/lower > 32 bits conditioned on endianness. > > A future patch will replace the arch-specific compat fallocate with an > asm-generic implementation. This patch is intended for ease of > back-port. > > [1]: > https://lore.kernel.org/all/be29926f-226e-48dc-871a-e29a54e80583@www.fastmail.com/ > > Fixes: 57f48b4b74e7 ("powerpc/compat_sys: swap hi/lo parts of 64-bit > syscall args in LE mode") > Reported-by: Arnd Bergmann <arnd@arndb.de> > Signed-off-by: Rohan McLure <rmclure@linux.ibm.com> Looks good, thanks! Reviewed-by: Arnd Bergmann <arnd@arndb.de> Cc: stable@vger.kernel.org # v5.12+
On Fri Sep 16, 2022 at 3:32 PM AEST, Rohan McLure wrote: > As reported[1] by Arnd, the arch-specific fadvise64_64 and fallocate > compatibility handlers assume parameters are passed with 32-bit > big-endian ABI. This affects the assignment of odd-even parameter pairs > to the high or low words of a 64-bit syscall parameter. > > Fix fadvise64_64 fallocate compat handlers to correctly swap upper/lower > 32 bits conditioned on endianness. > > A future patch will replace the arch-specific compat fallocate with an > asm-generic implementation. This patch is intended for ease of > back-port. > > [1]: https://lore.kernel.org/all/be29926f-226e-48dc-871a-e29a54e80583@www.fastmail.com/ > > Fixes: 57f48b4b74e7 ("powerpc/compat_sys: swap hi/lo parts of 64-bit syscall args in LE mode") > Reported-by: Arnd Bergmann <arnd@arndb.de> > Signed-off-by: Rohan McLure <rmclure@linux.ibm.com> I'm still not sure if ppc32 is usable with LE kernel, but in any case the patch is good I think. Reviewed-by: Nicholas Piggin <npiggin@gmai.com> > --- > V4 -> V5: New patch. > --- > arch/powerpc/include/asm/syscalls.h | 12 ++++++++++++ > arch/powerpc/kernel/sys_ppc32.c | 14 +------------- > arch/powerpc/kernel/syscalls.c | 4 ++-- > 3 files changed, 15 insertions(+), 15 deletions(-) > > diff --git a/arch/powerpc/include/asm/syscalls.h b/arch/powerpc/include/asm/syscalls.h > index 21c2faaa2957..16b668515d15 100644 > --- a/arch/powerpc/include/asm/syscalls.h > +++ b/arch/powerpc/include/asm/syscalls.h > @@ -8,6 +8,18 @@ > #include <linux/types.h> > #include <linux/compat.h> > > +/* > + * long long munging: > + * The 32 bit ABI passes long longs in an odd even register pair. > + * High and low parts are swapped depending on endian mode, > + * so define a macro (similar to mips linux32) to handle that. > + */ > +#ifdef __LITTLE_ENDIAN__ > +#define merge_64(low, high) ((u64)high << 32) | low > +#else > +#define merge_64(high, low) ((u64)high << 32) | low > +#endif > + > struct rtas_args; > > long sys_mmap(unsigned long addr, size_t len, > diff --git a/arch/powerpc/kernel/sys_ppc32.c b/arch/powerpc/kernel/sys_ppc32.c > index f4edcc9489fb..ba363328da2b 100644 > --- a/arch/powerpc/kernel/sys_ppc32.c > +++ b/arch/powerpc/kernel/sys_ppc32.c > @@ -56,18 +56,6 @@ unsigned long compat_sys_mmap2(unsigned long addr, size_t len, > return sys_mmap(addr, len, prot, flags, fd, pgoff << 12); > } > > -/* > - * long long munging: > - * The 32 bit ABI passes long longs in an odd even register pair. > - * High and low parts are swapped depending on endian mode, > - * so define a macro (similar to mips linux32) to handle that. > - */ > -#ifdef __LITTLE_ENDIAN__ > -#define merge_64(low, high) ((u64)high << 32) | low > -#else > -#define merge_64(high, low) ((u64)high << 32) | low > -#endif > - > compat_ssize_t compat_sys_pread64(unsigned int fd, char __user *ubuf, compat_size_t count, > u32 reg6, u32 pos1, u32 pos2) > { > @@ -94,7 +82,7 @@ int compat_sys_truncate64(const char __user * path, u32 reg4, > long compat_sys_fallocate(int fd, int mode, u32 offset1, u32 offset2, > u32 len1, u32 len2) > { > - return ksys_fallocate(fd, mode, ((loff_t)offset1 << 32) | offset2, > + return ksys_fallocate(fd, mode, merge_64(offset1, offset2), > merge_64(len1, len2)); > } > > diff --git a/arch/powerpc/kernel/syscalls.c b/arch/powerpc/kernel/syscalls.c > index fc999140bc27..abc3fbb3c490 100644 > --- a/arch/powerpc/kernel/syscalls.c > +++ b/arch/powerpc/kernel/syscalls.c > @@ -98,8 +98,8 @@ long ppc64_personality(unsigned long personality) > long ppc_fadvise64_64(int fd, int advice, u32 offset_high, u32 offset_low, > u32 len_high, u32 len_low) > { > - return ksys_fadvise64_64(fd, (u64)offset_high << 32 | offset_low, > - (u64)len_high << 32 | len_low, advice); > + return ksys_fadvise64_64(fd, merge_64(offset_high, offset_low), > + merge_64(len_high, len_low), advice); > } > > SYSCALL_DEFINE0(switch_endian) > -- > 2.34.1
diff --git a/arch/powerpc/include/asm/syscalls.h b/arch/powerpc/include/asm/syscalls.h index 21c2faaa2957..16b668515d15 100644 --- a/arch/powerpc/include/asm/syscalls.h +++ b/arch/powerpc/include/asm/syscalls.h @@ -8,6 +8,18 @@ #include <linux/types.h> #include <linux/compat.h> +/* + * long long munging: + * The 32 bit ABI passes long longs in an odd even register pair. + * High and low parts are swapped depending on endian mode, + * so define a macro (similar to mips linux32) to handle that. + */ +#ifdef __LITTLE_ENDIAN__ +#define merge_64(low, high) ((u64)high << 32) | low +#else +#define merge_64(high, low) ((u64)high << 32) | low +#endif + struct rtas_args; long sys_mmap(unsigned long addr, size_t len, diff --git a/arch/powerpc/kernel/sys_ppc32.c b/arch/powerpc/kernel/sys_ppc32.c index f4edcc9489fb..ba363328da2b 100644 --- a/arch/powerpc/kernel/sys_ppc32.c +++ b/arch/powerpc/kernel/sys_ppc32.c @@ -56,18 +56,6 @@ unsigned long compat_sys_mmap2(unsigned long addr, size_t len, return sys_mmap(addr, len, prot, flags, fd, pgoff << 12); } -/* - * long long munging: - * The 32 bit ABI passes long longs in an odd even register pair. - * High and low parts are swapped depending on endian mode, - * so define a macro (similar to mips linux32) to handle that. - */ -#ifdef __LITTLE_ENDIAN__ -#define merge_64(low, high) ((u64)high << 32) | low -#else -#define merge_64(high, low) ((u64)high << 32) | low -#endif - compat_ssize_t compat_sys_pread64(unsigned int fd, char __user *ubuf, compat_size_t count, u32 reg6, u32 pos1, u32 pos2) { @@ -94,7 +82,7 @@ int compat_sys_truncate64(const char __user * path, u32 reg4, long compat_sys_fallocate(int fd, int mode, u32 offset1, u32 offset2, u32 len1, u32 len2) { - return ksys_fallocate(fd, mode, ((loff_t)offset1 << 32) | offset2, + return ksys_fallocate(fd, mode, merge_64(offset1, offset2), merge_64(len1, len2)); } diff --git a/arch/powerpc/kernel/syscalls.c b/arch/powerpc/kernel/syscalls.c index fc999140bc27..abc3fbb3c490 100644 --- a/arch/powerpc/kernel/syscalls.c +++ b/arch/powerpc/kernel/syscalls.c @@ -98,8 +98,8 @@ long ppc64_personality(unsigned long personality) long ppc_fadvise64_64(int fd, int advice, u32 offset_high, u32 offset_low, u32 len_high, u32 len_low) { - return ksys_fadvise64_64(fd, (u64)offset_high << 32 | offset_low, - (u64)len_high << 32 | len_low, advice); + return ksys_fadvise64_64(fd, merge_64(offset_high, offset_low), + merge_64(len_high, len_low), advice); } SYSCALL_DEFINE0(switch_endian)
As reported[1] by Arnd, the arch-specific fadvise64_64 and fallocate compatibility handlers assume parameters are passed with 32-bit big-endian ABI. This affects the assignment of odd-even parameter pairs to the high or low words of a 64-bit syscall parameter. Fix fadvise64_64 fallocate compat handlers to correctly swap upper/lower 32 bits conditioned on endianness. A future patch will replace the arch-specific compat fallocate with an asm-generic implementation. This patch is intended for ease of back-port. [1]: https://lore.kernel.org/all/be29926f-226e-48dc-871a-e29a54e80583@www.fastmail.com/ Fixes: 57f48b4b74e7 ("powerpc/compat_sys: swap hi/lo parts of 64-bit syscall args in LE mode") Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Rohan McLure <rmclure@linux.ibm.com> --- V4 -> V5: New patch. --- arch/powerpc/include/asm/syscalls.h | 12 ++++++++++++ arch/powerpc/kernel/sys_ppc32.c | 14 +------------- arch/powerpc/kernel/syscalls.c | 4 ++-- 3 files changed, 15 insertions(+), 15 deletions(-)