[PATCH 24/41] arm64: switch to ->get2()

From: Al Viro
Date: Mon Jun 29 2020 - 17:25:38 EST


From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>

Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
arch/arm64/kernel/ptrace.c | 225 +++++++++++++--------------------------------
1 file changed, 62 insertions(+), 163 deletions(-)

diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index 9f769e862f68..8745aecffcae 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -474,11 +474,10 @@ static int ptrace_hbp_set_addr(unsigned int note_type,

static int hw_break_get(struct task_struct *target,
const struct user_regset *regset,
- unsigned int pos, unsigned int count,
- void *kbuf, void __user *ubuf)
+ struct membuf to)
{
unsigned int note_type = regset->core_note_type;
- int ret, idx = 0, offset, limit;
+ int ret, idx = 0;
u32 info, ctrl;
u64 addr;

@@ -487,49 +486,21 @@ static int hw_break_get(struct task_struct *target,
if (ret)
return ret;

- ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &info, 0,
- sizeof(info));
- if (ret)
- return ret;
-
- /* Pad */
- offset = offsetof(struct user_hwdebug_state, pad);
- ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, offset,
- offset + PTRACE_HBP_PAD_SZ);
- if (ret)
- return ret;
-
+ membuf_write(&to, &info, sizeof(info));
+ membuf_zero(&to, sizeof(u32));
/* (address, ctrl) registers */
- offset = offsetof(struct user_hwdebug_state, dbg_regs);
- limit = regset->n * regset->size;
- while (count && offset < limit) {
+ while (to.left) {
ret = ptrace_hbp_get_addr(note_type, target, idx, &addr);
if (ret)
return ret;
- ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &addr,
- offset, offset + PTRACE_HBP_ADDR_SZ);
- if (ret)
- return ret;
- offset += PTRACE_HBP_ADDR_SZ;
-
ret = ptrace_hbp_get_ctrl(note_type, target, idx, &ctrl);
if (ret)
return ret;
- ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &ctrl,
- offset, offset + PTRACE_HBP_CTRL_SZ);
- if (ret)
- return ret;
- offset += PTRACE_HBP_CTRL_SZ;
-
- ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
- offset,
- offset + PTRACE_HBP_PAD_SZ);
- if (ret)
- return ret;
- offset += PTRACE_HBP_PAD_SZ;
+ membuf_store(&to, addr);
+ membuf_store(&to, ctrl);
+ membuf_zero(&to, sizeof(u32));
idx++;
}
-
return 0;
}

@@ -589,11 +560,10 @@ static int hw_break_set(struct task_struct *target,

static int gpr_get(struct task_struct *target,
const struct user_regset *regset,
- unsigned int pos, unsigned int count,
- void *kbuf, void __user *ubuf)
+ struct membuf to)
{
struct user_pt_regs *uregs = &task_pt_regs(target)->user_regs;
- return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0, -1);
+ return membuf_write(&to, uregs, sizeof(*uregs));
}

static int gpr_set(struct task_struct *target, const struct user_regset *regset,
@@ -626,8 +596,7 @@ static int fpr_active(struct task_struct *target, const struct user_regset *regs
*/
static int __fpr_get(struct task_struct *target,
const struct user_regset *regset,
- unsigned int pos, unsigned int count,
- void *kbuf, void __user *ubuf, unsigned int start_pos)
+ struct membuf to)
{
struct user_fpsimd_state *uregs;

@@ -635,13 +604,11 @@ static int __fpr_get(struct task_struct *target,

uregs = &target->thread.uw.fpsimd_state;

- return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs,
- start_pos, start_pos + sizeof(*uregs));
+ return membuf_write(&to, uregs, sizeof(*uregs));
}

static int fpr_get(struct task_struct *target, const struct user_regset *regset,
- unsigned int pos, unsigned int count,
- void *kbuf, void __user *ubuf)
+ struct membuf to)
{
if (!system_supports_fpsimd())
return -EINVAL;
@@ -649,7 +616,7 @@ static int fpr_get(struct task_struct *target, const struct user_regset *regset,
if (target == current)
fpsimd_preserve_current_state();

- return __fpr_get(target, regset, pos, count, kbuf, ubuf, 0);
+ return __fpr_get(target, regset, to);
}

static int __fpr_set(struct task_struct *target,
@@ -699,15 +666,12 @@ static int fpr_set(struct task_struct *target, const struct user_regset *regset,
}

static int tls_get(struct task_struct *target, const struct user_regset *regset,
- unsigned int pos, unsigned int count,
- void *kbuf, void __user *ubuf)
+ struct membuf to)
{
- unsigned long *tls = &target->thread.uw.tp_value;
-
if (target == current)
tls_preserve_current_state();

- return user_regset_copyout(&pos, &count, &kbuf, &ubuf, tls, 0, -1);
+ return membuf_store(&to, target->thread.uw.tp_value);
}

static int tls_set(struct task_struct *target, const struct user_regset *regset,
@@ -727,13 +691,9 @@ static int tls_set(struct task_struct *target, const struct user_regset *regset,

static int system_call_get(struct task_struct *target,
const struct user_regset *regset,
- unsigned int pos, unsigned int count,
- void *kbuf, void __user *ubuf)
+ struct membuf to)
{
- int syscallno = task_pt_regs(target)->syscallno;
-
- return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
- &syscallno, 0, -1);
+ return membuf_store(&to, task_pt_regs(target)->syscallno);
}

static int system_call_set(struct task_struct *target,
@@ -794,10 +754,8 @@ static unsigned int sve_get_size(struct task_struct *target,

static int sve_get(struct task_struct *target,
const struct user_regset *regset,
- unsigned int pos, unsigned int count,
- void *kbuf, void __user *ubuf)
+ struct membuf to)
{
- int ret;
struct user_sve_header header;
unsigned int vq;
unsigned long start, end;
@@ -809,10 +767,7 @@ static int sve_get(struct task_struct *target,
sve_init_header_from_task(&header, target);
vq = sve_vq_from_vl(header.vl);

- ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &header,
- 0, sizeof(header));
- if (ret)
- return ret;
+ membuf_write(&to, &header, sizeof(header));

if (target == current)
fpsimd_preserve_current_state();
@@ -821,26 +776,18 @@ static int sve_get(struct task_struct *target,

BUILD_BUG_ON(SVE_PT_FPSIMD_OFFSET != sizeof(header));
if ((header.flags & SVE_PT_REGS_MASK) == SVE_PT_REGS_FPSIMD)
- return __fpr_get(target, regset, pos, count, kbuf, ubuf,
- SVE_PT_FPSIMD_OFFSET);
+ return __fpr_get(target, regset, to);

/* Otherwise: full SVE case */

BUILD_BUG_ON(SVE_PT_SVE_OFFSET != sizeof(header));
start = SVE_PT_SVE_OFFSET;
end = SVE_PT_SVE_FFR_OFFSET(vq) + SVE_PT_SVE_FFR_SIZE(vq);
- ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
- target->thread.sve_state,
- start, end);
- if (ret)
- return ret;
+ membuf_write(&to, target->thread.sve_state, end - start);

start = end;
end = SVE_PT_SVE_FPSR_OFFSET(vq);
- ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
- start, end);
- if (ret)
- return ret;
+ membuf_zero(&to, end - start);

/*
* Copy fpsr, and fpcr which must follow contiguously in
@@ -848,16 +795,11 @@ static int sve_get(struct task_struct *target,
*/
start = end;
end = SVE_PT_SVE_FPCR_OFFSET(vq) + SVE_PT_SVE_FPCR_SIZE;
- ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
- &target->thread.uw.fpsimd_state.fpsr,
- start, end);
- if (ret)
- return ret;
+ membuf_write(&to, &target->thread.uw.fpsimd_state.fpsr, end - start);

start = end;
end = sve_size_from_header(&header);
- return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
- start, end);
+ return membuf_zero(&to, end - start);
}

static int sve_set(struct task_struct *target,
@@ -961,8 +903,7 @@ static int sve_set(struct task_struct *target,
#ifdef CONFIG_ARM64_PTR_AUTH
static int pac_mask_get(struct task_struct *target,
const struct user_regset *regset,
- unsigned int pos, unsigned int count,
- void *kbuf, void __user *ubuf)
+ struct membuf to)
{
/*
* The PAC bits can differ across data and instruction pointers
@@ -978,7 +919,7 @@ static int pac_mask_get(struct task_struct *target,
if (!system_supports_address_auth())
return -EINVAL;

- return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &uregs, 0, -1);
+ return membuf_write(&to, &uregs, sizeof(uregs));
}

#ifdef CONFIG_CHECKPOINT_RESTORE
@@ -1017,8 +958,7 @@ static void pac_address_keys_from_user(struct ptrauth_keys_user *keys,

static int pac_address_keys_get(struct task_struct *target,
const struct user_regset *regset,
- unsigned int pos, unsigned int count,
- void *kbuf, void __user *ubuf)
+ struct membuf to)
{
struct ptrauth_keys_user *keys = &target->thread.keys_user;
struct user_pac_address_keys user_keys;
@@ -1028,8 +968,7 @@ static int pac_address_keys_get(struct task_struct *target,

pac_address_keys_to_user(&user_keys, keys);

- return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
- &user_keys, 0, -1);
+ return membuf_write(&to, &user_keys, sizeof(user_keys));
}

static int pac_address_keys_set(struct task_struct *target,
@@ -1068,8 +1007,7 @@ static void pac_generic_keys_from_user(struct ptrauth_keys_user *keys,

static int pac_generic_keys_get(struct task_struct *target,
const struct user_regset *regset,
- unsigned int pos, unsigned int count,
- void *kbuf, void __user *ubuf)
+ struct membuf to)
{
struct ptrauth_keys_user *keys = &target->thread.keys_user;
struct user_pac_generic_keys user_keys;
@@ -1079,8 +1017,7 @@ static int pac_generic_keys_get(struct task_struct *target,

pac_generic_keys_to_user(&user_keys, keys);

- return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
- &user_keys, 0, -1);
+ return membuf_write(&to, &user_keys, sizeof(user_keys));
}

static int pac_generic_keys_set(struct task_struct *target,
@@ -1134,7 +1071,7 @@ static const struct user_regset aarch64_regsets[] = {
.n = sizeof(struct user_pt_regs) / sizeof(u64),
.size = sizeof(u64),
.align = sizeof(u64),
- .get = gpr_get,
+ .get2 = gpr_get,
.set = gpr_set
},
[REGSET_FPR] = {
@@ -1147,7 +1084,7 @@ static const struct user_regset aarch64_regsets[] = {
.size = sizeof(u32),
.align = sizeof(u32),
.active = fpr_active,
- .get = fpr_get,
+ .get2 = fpr_get,
.set = fpr_set
},
[REGSET_TLS] = {
@@ -1155,7 +1092,7 @@ static const struct user_regset aarch64_regsets[] = {
.n = 1,
.size = sizeof(void *),
.align = sizeof(void *),
- .get = tls_get,
+ .get2 = tls_get,
.set = tls_set,
},
#ifdef CONFIG_HAVE_HW_BREAKPOINT
@@ -1164,7 +1101,7 @@ static const struct user_regset aarch64_regsets[] = {
.n = sizeof(struct user_hwdebug_state) / sizeof(u32),
.size = sizeof(u32),
.align = sizeof(u32),
- .get = hw_break_get,
+ .get2 = hw_break_get,
.set = hw_break_set,
},
[REGSET_HW_WATCH] = {
@@ -1172,7 +1109,7 @@ static const struct user_regset aarch64_regsets[] = {
.n = sizeof(struct user_hwdebug_state) / sizeof(u32),
.size = sizeof(u32),
.align = sizeof(u32),
- .get = hw_break_get,
+ .get2 = hw_break_get,
.set = hw_break_set,
},
#endif
@@ -1181,7 +1118,7 @@ static const struct user_regset aarch64_regsets[] = {
.n = 1,
.size = sizeof(int),
.align = sizeof(int),
- .get = system_call_get,
+ .get2 = system_call_get,
.set = system_call_set,
},
#ifdef CONFIG_ARM64_SVE
@@ -1191,7 +1128,7 @@ static const struct user_regset aarch64_regsets[] = {
SVE_VQ_BYTES),
.size = SVE_VQ_BYTES,
.align = SVE_VQ_BYTES,
- .get = sve_get,
+ .get2 = sve_get,
.set = sve_set,
.get_size = sve_get_size,
},
@@ -1202,7 +1139,7 @@ static const struct user_regset aarch64_regsets[] = {
.n = sizeof(struct user_pac_mask) / sizeof(u64),
.size = sizeof(u64),
.align = sizeof(u64),
- .get = pac_mask_get,
+ .get2 = pac_mask_get,
/* this cannot be set dynamically */
},
#ifdef CONFIG_CHECKPOINT_RESTORE
@@ -1211,7 +1148,7 @@ static const struct user_regset aarch64_regsets[] = {
.n = sizeof(struct user_pac_address_keys) / sizeof(__uint128_t),
.size = sizeof(__uint128_t),
.align = sizeof(__uint128_t),
- .get = pac_address_keys_get,
+ .get2 = pac_address_keys_get,
.set = pac_address_keys_set,
},
[REGSET_PACG_KEYS] = {
@@ -1219,7 +1156,7 @@ static const struct user_regset aarch64_regsets[] = {
.n = sizeof(struct user_pac_generic_keys) / sizeof(__uint128_t),
.size = sizeof(__uint128_t),
.align = sizeof(__uint128_t),
- .get = pac_generic_keys_get,
+ .get2 = pac_generic_keys_get,
.set = pac_generic_keys_set,
},
#endif
@@ -1255,39 +1192,13 @@ static inline compat_ulong_t compat_get_user_reg(struct task_struct *task, int i

static int compat_gpr_get(struct task_struct *target,
const struct user_regset *regset,
- unsigned int pos, unsigned int count,
- void *kbuf, void __user *ubuf)
+ struct membuf to)
{
- int ret = 0;
- unsigned int i, start, num_regs;
-
- /* Calculate the number of AArch32 registers contained in count */
- num_regs = count / regset->size;
-
- /* Convert pos into an register number */
- start = pos / regset->size;
-
- if (start + num_regs > regset->n)
- return -EIO;
-
- for (i = 0; i < num_regs; ++i) {
- compat_ulong_t reg = compat_get_user_reg(target, start + i);
-
- if (kbuf) {
- memcpy(kbuf, &reg, sizeof(reg));
- kbuf += sizeof(reg);
- } else {
- ret = copy_to_user(ubuf, &reg, sizeof(reg));
- if (ret) {
- ret = -EFAULT;
- break;
- }
+ int i = 0;

- ubuf += sizeof(reg);
- }
- }
-
- return ret;
+ while (to.left)
+ membuf_store(&to, compat_get_user_reg(target, i++));
+ return 0;
}

static int compat_gpr_set(struct task_struct *target,
@@ -1354,12 +1265,10 @@ static int compat_gpr_set(struct task_struct *target,

static int compat_vfp_get(struct task_struct *target,
const struct user_regset *regset,
- unsigned int pos, unsigned int count,
- void *kbuf, void __user *ubuf)
+ struct membuf to)
{
struct user_fpsimd_state *uregs;
compat_ulong_t fpscr;
- int ret, vregs_end_pos;

if (!system_supports_fpsimd())
return -EINVAL;
@@ -1373,19 +1282,10 @@ static int compat_vfp_get(struct task_struct *target,
* The VFP registers are packed into the fpsimd_state, so they all sit
* nicely together for us. We just need to create the fpscr separately.
*/
- vregs_end_pos = VFP_STATE_SIZE - sizeof(compat_ulong_t);
- ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs,
- 0, vregs_end_pos);
-
- if (count && !ret) {
- fpscr = (uregs->fpsr & VFP_FPSCR_STAT_MASK) |
- (uregs->fpcr & VFP_FPSCR_CTRL_MASK);
-
- ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &fpscr,
- vregs_end_pos, VFP_STATE_SIZE);
- }
-
- return ret;
+ membuf_write(&to, uregs, VFP_STATE_SIZE - sizeof(compat_ulong_t));
+ fpscr = (uregs->fpsr & VFP_FPSCR_STAT_MASK) |
+ (uregs->fpcr & VFP_FPSCR_CTRL_MASK);
+ return membuf_store(&to, fpscr);
}

static int compat_vfp_set(struct task_struct *target,
@@ -1420,11 +1320,10 @@ static int compat_vfp_set(struct task_struct *target,
}

static int compat_tls_get(struct task_struct *target,
- const struct user_regset *regset, unsigned int pos,
- unsigned int count, void *kbuf, void __user *ubuf)
+ const struct user_regset *regset,
+ struct membuf to)
{
- compat_ulong_t tls = (compat_ulong_t)target->thread.uw.tp_value;
- return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
+ return membuf_store(&to, (compat_ulong_t)target->thread.uw.tp_value);
}

static int compat_tls_set(struct task_struct *target,
@@ -1449,7 +1348,7 @@ static const struct user_regset aarch32_regsets[] = {
.n = COMPAT_ELF_NGREG,
.size = sizeof(compat_elf_greg_t),
.align = sizeof(compat_elf_greg_t),
- .get = compat_gpr_get,
+ .get2 = compat_gpr_get,
.set = compat_gpr_set
},
[REGSET_COMPAT_VFP] = {
@@ -1458,7 +1357,7 @@ static const struct user_regset aarch32_regsets[] = {
.size = sizeof(compat_ulong_t),
.align = sizeof(compat_ulong_t),
.active = fpr_active,
- .get = compat_vfp_get,
+ .get2 = compat_vfp_get,
.set = compat_vfp_set
},
};
@@ -1474,7 +1373,7 @@ static const struct user_regset aarch32_ptrace_regsets[] = {
.n = COMPAT_ELF_NGREG,
.size = sizeof(compat_elf_greg_t),
.align = sizeof(compat_elf_greg_t),
- .get = compat_gpr_get,
+ .get2 = compat_gpr_get,
.set = compat_gpr_set
},
[REGSET_FPR] = {
@@ -1482,7 +1381,7 @@ static const struct user_regset aarch32_ptrace_regsets[] = {
.n = VFP_STATE_SIZE / sizeof(compat_ulong_t),
.size = sizeof(compat_ulong_t),
.align = sizeof(compat_ulong_t),
- .get = compat_vfp_get,
+ .get2 = compat_vfp_get,
.set = compat_vfp_set
},
[REGSET_TLS] = {
@@ -1490,7 +1389,7 @@ static const struct user_regset aarch32_ptrace_regsets[] = {
.n = 1,
.size = sizeof(compat_ulong_t),
.align = sizeof(compat_ulong_t),
- .get = compat_tls_get,
+ .get2 = compat_tls_get,
.set = compat_tls_set,
},
#ifdef CONFIG_HAVE_HW_BREAKPOINT
@@ -1499,7 +1398,7 @@ static const struct user_regset aarch32_ptrace_regsets[] = {
.n = sizeof(struct user_hwdebug_state) / sizeof(u32),
.size = sizeof(u32),
.align = sizeof(u32),
- .get = hw_break_get,
+ .get2 = hw_break_get,
.set = hw_break_set,
},
[REGSET_HW_WATCH] = {
@@ -1507,7 +1406,7 @@ static const struct user_regset aarch32_ptrace_regsets[] = {
.n = sizeof(struct user_hwdebug_state) / sizeof(u32),
.size = sizeof(u32),
.align = sizeof(u32),
- .get = hw_break_get,
+ .get2 = hw_break_get,
.set = hw_break_set,
},
#endif
@@ -1516,7 +1415,7 @@ static const struct user_regset aarch32_ptrace_regsets[] = {
.n = 1,
.size = sizeof(int),
.align = sizeof(int),
- .get = system_call_get,
+ .get2 = system_call_get,
.set = system_call_set,
},
};
--
2.11.0