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RAID/s390: Remove VLA usage

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In the quest to remove all stack VLA usage from the kernel[1], this moves
the "$#" replacement from being an argument to being inside the function,
which avoids generating VLAs.

[1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Kees Cook 2018-07-03 12:52:21 -07:00 committed by Martin Schwidefsky
parent d2f2df6988
commit ad5728ce21
1 changed files with 18 additions and 16 deletions
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34
lib/raid6/s390vx.uc
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@ -55,22 +55,24 @@ static inline void XOR(int x, int y, int z)
asm volatile ("VX %0,%1,%2" : : "i" (x), "i" (y), "i" (z));
}
static inline void LOAD_DATA(int x, int n, u8 *ptr)
static inline void LOAD_DATA(int x, u8 *ptr)
{
typedef struct { u8 _[16*n]; } addrtype;
typedef struct { u8 _[16 * $#]; } addrtype;
register addrtype *__ptr asm("1") = (addrtype *) ptr;
asm volatile ("VLM %2,%3,0,%r1"
: : "m" (*__ptr), "a" (__ptr), "i" (x), "i" (x + n - 1));
: : "m" (*__ptr), "a" (__ptr), "i" (x),
"i" (x + $# - 1));
}
static inline void STORE_DATA(int x, int n, u8 *ptr)
static inline void STORE_DATA(int x, u8 *ptr)
{
typedef struct { u8 _[16*n]; } addrtype;
typedef struct { u8 _[16 * $#]; } addrtype;
register addrtype *__ptr asm("1") = (addrtype *) ptr;
asm volatile ("VSTM %2,%3,0,1"
: "=m" (*__ptr) : "a" (__ptr), "i" (x), "i" (x + n - 1));
: "=m" (*__ptr) : "a" (__ptr), "i" (x),
"i" (x + $# - 1));
}
static inline void COPY_VEC(int x, int y)
@ -93,19 +95,19 @@ static void raid6_s390vx$#_gen_syndrome(int disks, size_t bytes, void **ptrs)
q = dptr[z0 + 2]; /* RS syndrome */
for (d = 0; d < bytes; d += $#*NSIZE) {
LOAD_DATA(0,$#,&dptr[z0][d]);
LOAD_DATA(0,&dptr[z0][d]);
COPY_VEC(8+$$,0+$$);
for (z = z0 - 1; z >= 0; z--) {
MASK(16+$$,8+$$);
AND(16+$$,16+$$,25);
SHLBYTE(8+$$,8+$$);
XOR(8+$$,8+$$,16+$$);
LOAD_DATA(16,$#,&dptr[z][d]);
LOAD_DATA(16,&dptr[z][d]);
XOR(0+$$,0+$$,16+$$);
XOR(8+$$,8+$$,16+$$);
}
STORE_DATA(0,$#,&p[d]);
STORE_DATA(8,$#,&q[d]);
STORE_DATA(0,&p[d]);
STORE_DATA(8,&q[d]);
}
kernel_fpu_end(&vxstate, KERNEL_VXR);
}
@ -127,14 +129,14 @@ static void raid6_s390vx$#_xor_syndrome(int disks, int start, int stop,
for (d = 0; d < bytes; d += $#*NSIZE) {
/* P/Q data pages */
LOAD_DATA(0,$#,&dptr[z0][d]);
LOAD_DATA(0,&dptr[z0][d]);
COPY_VEC(8+$$,0+$$);
for (z = z0 - 1; z >= start; z--) {
MASK(16+$$,8+$$);
AND(16+$$,16+$$,25);
SHLBYTE(8+$$,8+$$);
XOR(8+$$,8+$$,16+$$);
LOAD_DATA(16,$#,&dptr[z][d]);
LOAD_DATA(16,&dptr[z][d]);
XOR(0+$$,0+$$,16+$$);
XOR(8+$$,8+$$,16+$$);
}
@ -145,12 +147,12 @@ static void raid6_s390vx$#_xor_syndrome(int disks, int start, int stop,
SHLBYTE(8+$$,8+$$);
XOR(8+$$,8+$$,16+$$);
}
LOAD_DATA(16,$#,&p[d]);
LOAD_DATA(16,&p[d]);
XOR(16+$$,16+$$,0+$$);
STORE_DATA(16,$#,&p[d]);
LOAD_DATA(16,$#,&q[d]);
STORE_DATA(16,&p[d]);
LOAD_DATA(16,&q[d]);
XOR(16+$$,16+$$,8+$$);
STORE_DATA(16,$#,&q[d]);
STORE_DATA(16,&q[d]);
}
kernel_fpu_end(&vxstate, KERNEL_VXR);
}