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powerpc/signal32: Convert restore_[tm]_user_regs() to user access block

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Convert restore_user_regs() and restore_tm_user_regs()
to use user_access_read_begin/end blocks.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/181adf15a6f644efcd1aeafb355f3578ff1b6bc5.1616151715.git.christophe.leroy@csgroup.eu
This commit is contained in:
Christophe Leroy 2021-03-19 11:06:57 +00:00 • committed by Michael Ellerman
parent 036fc2cb1d
commit 627b72bee8
2 changed files with 72 additions and 71 deletions
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2
arch/powerpc/include/asm/ptrace.h
View file

@ -245,7 +245,7 @@ static inline bool trap_norestart(struct pt_regs *regs)
return regs->trap & 0x10; return regs->trap & 0x10;
} }
static inline void set_trap_norestart(struct pt_regs *regs) static __always_inline void set_trap_norestart(struct pt_regs *regs)
{ {
regs->trap |= 0x10; regs->trap |= 0x10;
} }

141
arch/powerpc/kernel/signal_32.c
View file

@ -116,8 +116,8 @@ failed:
return 1; return 1;
} }
static inline int restore_general_regs(struct pt_regs *regs, static __always_inline int
struct mcontext __user *sr) __unsafe_restore_general_regs(struct pt_regs *regs, struct mcontext __user *sr)
{ {
elf_greg_t64 *gregs = (elf_greg_t64 *)regs; elf_greg_t64 *gregs = (elf_greg_t64 *)regs;
int i; int i;
@ -125,10 +125,12 @@ static inline int restore_general_regs(struct pt_regs *regs,
for (i = 0; i <= PT_RESULT; i++) { for (i = 0; i <= PT_RESULT; i++) {
if ((i == PT_MSR) || (i == PT_SOFTE)) if ((i == PT_MSR) || (i == PT_SOFTE))
continue; continue;
if (__get_user(gregs[i], &sr->mc_gregs[i])) unsafe_get_user(gregs[i], &sr->mc_gregs[i], failed);
return -EFAULT;
} }
return 0; return 0;
failed:
return 1;
} }
#else /* CONFIG_PPC64 */ #else /* CONFIG_PPC64 */
@ -161,18 +163,20 @@ failed:
return 1; return 1;
} }
static inline int restore_general_regs(struct pt_regs *regs, static __always_inline
struct mcontext __user *sr) int __unsafe_restore_general_regs(struct pt_regs *regs, struct mcontext __user *sr)
{ {
/* copy up to but not including MSR */ /* copy up to but not including MSR */
if (__copy_from_user(regs, &sr->mc_gregs, unsafe_copy_from_user(regs, &sr->mc_gregs, PT_MSR * sizeof(elf_greg_t), failed);
PT_MSR * sizeof(elf_greg_t)))
return -EFAULT;
/* copy from orig_r3 (the word after the MSR) up to the end */ /* copy from orig_r3 (the word after the MSR) up to the end */
if (__copy_from_user(&regs->orig_gpr3, &sr->mc_gregs[PT_ORIG_R3], unsafe_copy_from_user(&regs->orig_gpr3, &sr->mc_gregs[PT_ORIG_R3],
GP_REGS_SIZE - PT_ORIG_R3 * sizeof(elf_greg_t))) GP_REGS_SIZE - PT_ORIG_R3 * sizeof(elf_greg_t), failed);
return -EFAULT;
return 0; return 0;
failed:
return 1;
} }
#endif #endif
@ -181,6 +185,11 @@ static inline int restore_general_regs(struct pt_regs *regs,
goto label; \ goto label; \
} while (0) } while (0)
#define unsafe_restore_general_regs(regs, frame, label) do { \
if (__unsafe_restore_general_regs(regs, frame)) \
goto label; \
} while (0)
/* /*
* When we have signals to deliver, we set up on the * When we have signals to deliver, we set up on the
* user stack, going down from the original stack pointer: * user stack, going down from the original stack pointer:
@ -485,14 +494,13 @@ static int save_tm_user_regs_unsafe(struct pt_regs *regs, struct mcontext __user
static long restore_user_regs(struct pt_regs *regs, static long restore_user_regs(struct pt_regs *regs,
struct mcontext __user *sr, int sig) struct mcontext __user *sr, int sig)
{ {
long err;
unsigned int save_r2 = 0; unsigned int save_r2 = 0;
unsigned long msr; unsigned long msr;
#ifdef CONFIG_VSX #ifdef CONFIG_VSX
int i; int i;
#endif #endif
if (!access_ok(sr, sizeof(*sr))) if (!user_read_access_begin(sr, sizeof(*sr)))
return 1; return 1;
/* /*
* restore general registers but not including MSR or SOFTE. Also * restore general registers but not including MSR or SOFTE. Also
@ -500,13 +508,11 @@ static long restore_user_regs(struct pt_regs *regs,
*/ */
if (!sig) if (!sig)
save_r2 = (unsigned int)regs->gpr[2]; save_r2 = (unsigned int)regs->gpr[2];
err = restore_general_regs(regs, sr); unsafe_restore_general_regs(regs, sr, failed);
set_trap_norestart(regs); set_trap_norestart(regs);
err |= __get_user(msr, &sr->mc_gregs[PT_MSR]); unsafe_get_user(msr, &sr->mc_gregs[PT_MSR], failed);
if (!sig) if (!sig)
regs->gpr[2] = (unsigned long) save_r2; regs->gpr[2] = (unsigned long) save_r2;
if (err)
return 1;
/* if doing signal return, restore the previous little-endian mode */ /* if doing signal return, restore the previous little-endian mode */
if (sig) if (sig)
@ -520,22 +526,19 @@ static long restore_user_regs(struct pt_regs *regs,
regs->msr &= ~MSR_VEC; regs->msr &= ~MSR_VEC;
if (msr & MSR_VEC) { if (msr & MSR_VEC) {
/* restore altivec registers from the stack */ /* restore altivec registers from the stack */
if (__copy_from_user(&current->thread.vr_state, &sr->mc_vregs, unsafe_copy_from_user(&current->thread.vr_state, &sr->mc_vregs,
sizeof(sr->mc_vregs))) sizeof(sr->mc_vregs), failed);
return 1;
current->thread.used_vr = true; current->thread.used_vr = true;
} else if (current->thread.used_vr) } else if (current->thread.used_vr)
memset(&current->thread.vr_state, 0, memset(&current->thread.vr_state, 0,
ELF_NVRREG * sizeof(vector128)); ELF_NVRREG * sizeof(vector128));
/* Always get VRSAVE back */ /* Always get VRSAVE back */
if (__get_user(current->thread.vrsave, (u32 __user *)&sr->mc_vregs[32])) unsafe_get_user(current->thread.vrsave, (u32 __user *)&sr->mc_vregs[32], failed);
return 1;
if (cpu_has_feature(CPU_FTR_ALTIVEC)) if (cpu_has_feature(CPU_FTR_ALTIVEC))
mtspr(SPRN_VRSAVE, current->thread.vrsave); mtspr(SPRN_VRSAVE, current->thread.vrsave);
#endif /* CONFIG_ALTIVEC */ #endif /* CONFIG_ALTIVEC */
if (copy_fpr_from_user(current, &sr->mc_fregs)) unsafe_copy_fpr_from_user(current, &sr->mc_fregs, failed);
return 1;
#ifdef CONFIG_VSX #ifdef CONFIG_VSX
/* /*
@ -548,8 +551,7 @@ static long restore_user_regs(struct pt_regs *regs,
* Restore altivec registers from the stack to a local * Restore altivec registers from the stack to a local
* buffer, then write this out to the thread_struct * buffer, then write this out to the thread_struct
*/ */
if (copy_vsx_from_user(current, &sr->mc_vsregs)) unsafe_copy_vsx_from_user(current, &sr->mc_vsregs, failed);
return 1;
current->thread.used_vsr = true; current->thread.used_vsr = true;
} else if (current->thread.used_vsr) } else if (current->thread.used_vsr)
for (i = 0; i < 32 ; i++) for (i = 0; i < 32 ; i++)
@ -567,19 +569,22 @@ static long restore_user_regs(struct pt_regs *regs,
regs->msr &= ~MSR_SPE; regs->msr &= ~MSR_SPE;
if (msr & MSR_SPE) { if (msr & MSR_SPE) {
/* restore spe registers from the stack */ /* restore spe registers from the stack */
if (__copy_from_user(current->thread.evr, &sr->mc_vregs, unsafe_copy_from_user(current->thread.evr, &sr->mc_vregs,
ELF_NEVRREG * sizeof(u32))) ELF_NEVRREG * sizeof(u32));
return 1;
current->thread.used_spe = true; current->thread.used_spe = true;
} else if (current->thread.used_spe) } else if (current->thread.used_spe)
memset(current->thread.evr, 0, ELF_NEVRREG * sizeof(u32)); memset(current->thread.evr, 0, ELF_NEVRREG * sizeof(u32));
/* Always get SPEFSCR back */ /* Always get SPEFSCR back */
if (__get_user(current->thread.spefscr, (u32 __user *)&sr->mc_vregs + ELF_NEVRREG)) unsafe_get_user(current->thread.spefscr, (u32 __user *)&sr->mc_vregs + ELF_NEVRREG, failed);
return 1;
#endif /* CONFIG_SPE */ #endif /* CONFIG_SPE */
user_read_access_end();
return 0; return 0;
failed:
user_read_access_end();
return 1;
} }
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
@ -592,7 +597,6 @@ static long restore_tm_user_regs(struct pt_regs *regs,
struct mcontext __user *sr, struct mcontext __user *sr,
struct mcontext __user *tm_sr) struct mcontext __user *tm_sr)
{ {
long err;
unsigned long msr, msr_hi; unsigned long msr, msr_hi;
#ifdef CONFIG_VSX #ifdef CONFIG_VSX
int i; int i;
@ -607,14 +611,13 @@ static long restore_tm_user_regs(struct pt_regs *regs,
* TFHAR is restored from the checkpointed NIP; TEXASR and TFIAR * TFHAR is restored from the checkpointed NIP; TEXASR and TFIAR
* were set by the signal delivery. * were set by the signal delivery.
*/ */
err = restore_general_regs(&current->thread.ckpt_regs, sr); if (!user_read_access_begin(sr, sizeof(*sr)))
err |= __get_user(current->thread.tm_tfhar, &sr->mc_gregs[PT_NIP]);
err |= __get_user(msr, &sr->mc_gregs[PT_MSR]);
if (err)
return 1; return 1;
unsafe_restore_general_regs(&current->thread.ckpt_regs, sr, failed);
unsafe_get_user(current->thread.tm_tfhar, &sr->mc_gregs[PT_NIP], failed);
unsafe_get_user(msr, &sr->mc_gregs[PT_MSR], failed);
/* Restore the previous little-endian mode */ /* Restore the previous little-endian mode */
regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE); regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE);
@ -622,9 +625,8 @@ static long restore_tm_user_regs(struct pt_regs *regs,
regs->msr &= ~MSR_VEC; regs->msr &= ~MSR_VEC;
if (msr & MSR_VEC) { if (msr & MSR_VEC) {
/* restore altivec registers from the stack */ /* restore altivec registers from the stack */
if (__copy_from_user(&current->thread.ckvr_state, &sr->mc_vregs, unsafe_copy_from_user(&current->thread.ckvr_state, &sr->mc_vregs,
sizeof(sr->mc_vregs))) sizeof(sr->mc_vregs), failed);
return 1;
current->thread.used_vr = true; current->thread.used_vr = true;
} else if (current->thread.used_vr) { } else if (current->thread.used_vr) {
memset(&current->thread.vr_state, 0, memset(&current->thread.vr_state, 0,
@ -634,17 +636,15 @@ static long restore_tm_user_regs(struct pt_regs *regs,
} }
/* Always get VRSAVE back */ /* Always get VRSAVE back */
if (__get_user(current->thread.ckvrsave, unsafe_get_user(current->thread.ckvrsave,
(u32 __user *)&sr->mc_vregs[32])) (u32 __user *)&sr->mc_vregs[32], failed);
return 1;
if (cpu_has_feature(CPU_FTR_ALTIVEC)) if (cpu_has_feature(CPU_FTR_ALTIVEC))
mtspr(SPRN_VRSAVE, current->thread.ckvrsave); mtspr(SPRN_VRSAVE, current->thread.ckvrsave);
#endif /* CONFIG_ALTIVEC */ #endif /* CONFIG_ALTIVEC */
regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1); regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1);
if (copy_fpr_from_user(current, &sr->mc_fregs)) unsafe_copy_fpr_from_user(current, &sr->mc_fregs, failed);
return 1;
#ifdef CONFIG_VSX #ifdef CONFIG_VSX
regs->msr &= ~MSR_VSX; regs->msr &= ~MSR_VSX;
@ -653,8 +653,7 @@ static long restore_tm_user_regs(struct pt_regs *regs,
* Restore altivec registers from the stack to a local * Restore altivec registers from the stack to a local
* buffer, then write this out to the thread_struct * buffer, then write this out to the thread_struct
*/ */
if (copy_ckvsx_from_user(current, &sr->mc_vsregs)) unsafe_copy_ckvsx_from_user(current, &sr->mc_vsregs, failed);
return 1;
current->thread.used_vsr = true; current->thread.used_vsr = true;
} else if (current->thread.used_vsr) } else if (current->thread.used_vsr)
for (i = 0; i < 32 ; i++) { for (i = 0; i < 32 ; i++) {
@ -669,39 +668,36 @@ static long restore_tm_user_regs(struct pt_regs *regs,
*/ */
regs->msr &= ~MSR_SPE; regs->msr &= ~MSR_SPE;
if (msr & MSR_SPE) { if (msr & MSR_SPE) {
if (__copy_from_user(current->thread.evr, &sr->mc_vregs, unsafe_copy_from_user(current->thread.evr, &sr->mc_vregs,
ELF_NEVRREG * sizeof(u32))) ELF_NEVRREG * sizeof(u32), failed);
return 1;
current->thread.used_spe = true; current->thread.used_spe = true;
} else if (current->thread.used_spe) } else if (current->thread.used_spe)
memset(current->thread.evr, 0, ELF_NEVRREG * sizeof(u32)); memset(current->thread.evr, 0, ELF_NEVRREG * sizeof(u32));
/* Always get SPEFSCR back */ /* Always get SPEFSCR back */
if (__get_user(current->thread.spefscr, (u32 __user *)&sr->mc_vregs unsafe_get_user(current->thread.spefscr,
+ ELF_NEVRREG)) (u32 __user *)&sr->mc_vregs + ELF_NEVRREG, failed);
return 1;
#endif /* CONFIG_SPE */ #endif /* CONFIG_SPE */
err = restore_general_regs(regs, tm_sr); user_read_access_end();
if (err)
if (!user_read_access_begin(tm_sr, sizeof(*tm_sr)))
return 1; return 1;
unsafe_restore_general_regs(regs, tm_sr, failed);
#ifdef CONFIG_ALTIVEC #ifdef CONFIG_ALTIVEC
/* restore altivec registers from the stack */ /* restore altivec registers from the stack */
if (msr & MSR_VEC) if (msr & MSR_VEC)
if (__copy_from_user(&current->thread.vr_state, unsafe_copy_from_user(&current->thread.vr_state, &tm_sr->mc_vregs,
&tm_sr->mc_vregs, sizeof(sr->mc_vregs), failed);
sizeof(sr->mc_vregs)))
return 1;
/* Always get VRSAVE back */ /* Always get VRSAVE back */
if (__get_user(current->thread.vrsave, unsafe_get_user(current->thread.vrsave,
(u32 __user *)&tm_sr->mc_vregs[32])) (u32 __user *)&tm_sr->mc_vregs[32], failed);
return 1;
#endif /* CONFIG_ALTIVEC */ #endif /* CONFIG_ALTIVEC */
if (copy_ckfpr_from_user(current, &tm_sr->mc_fregs)) unsafe_copy_ckfpr_from_user(current, &tm_sr->mc_fregs, failed);
return 1;
#ifdef CONFIG_VSX #ifdef CONFIG_VSX
if (msr & MSR_VSX) { if (msr & MSR_VSX) {
@ -709,16 +705,17 @@ static long restore_tm_user_regs(struct pt_regs *regs,
* Restore altivec registers from the stack to a local * Restore altivec registers from the stack to a local
* buffer, then write this out to the thread_struct * buffer, then write this out to the thread_struct
*/ */
if (copy_vsx_from_user(current, &tm_sr->mc_vsregs)) unsafe_copy_vsx_from_user(current, &tm_sr->mc_vsregs, failed);
return 1;
current->thread.used_vsr = true; current->thread.used_vsr = true;
} }
#endif /* CONFIG_VSX */ #endif /* CONFIG_VSX */
/* Get the top half of the MSR from the user context */ /* Get the top half of the MSR from the user context */
if (__get_user(msr_hi, &tm_sr->mc_gregs[PT_MSR])) unsafe_get_user(msr_hi, &tm_sr->mc_gregs[PT_MSR], failed);
return 1;
msr_hi <<= 32; msr_hi <<= 32;
user_read_access_end();
/* If TM bits are set to the reserved value, it's an invalid context */ /* If TM bits are set to the reserved value, it's an invalid context */
if (MSR_TM_RESV(msr_hi)) if (MSR_TM_RESV(msr_hi))
return 1; return 1;
@ -766,6 +763,10 @@ static long restore_tm_user_regs(struct pt_regs *regs,
preempt_enable(); preempt_enable();
return 0; return 0;
failed:
user_read_access_end();
return 1;
} }
#else #else
static long restore_tm_user_regs(struct pt_regs *regs, struct mcontext __user *sr, static long restore_tm_user_regs(struct pt_regs *regs, struct mcontext __user *sr,