Commit dcb30e659287a6b40dafed1362532da42ec27229
Exists in
smarc-imx_3.14.28_1.0.0_ga
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Merge tag 'arm64-stable' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-aarch64
Pull ARM64 fixes from Catalin Marinas: - Compat register fault reporting fix - Documentation clarification on tagged pointers - hwcap widened to 64-bit (user space already reading it as 64-bit) * tag 'arm64-stable' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-aarch64: arm64: Widen hwcap to be 64 bit arm64: Correctly report LR and SP for compat tasks arm64: documentation: tighten up tagged pointer documentation arm64: Make do_bad_area() function static
Showing 5 changed files Side-by-side Diff
Documentation/arm64/tagged-pointers.txt
| ... | ... | @@ -18,17 +18,17 @@ |
| 18 | 18 | parameters containing user virtual addresses *must* have |
| 19 | 19 | their top byte cleared before trapping to the kernel. |
| 20 | 20 | |
| 21 | - (2) Tags are not guaranteed to be preserved when delivering | |
| 22 | - signals. This means that signal handlers in applications | |
| 23 | - making use of tags cannot rely on the tag information for | |
| 24 | - user virtual addresses being maintained for fields inside | |
| 25 | - siginfo_t. One exception to this rule is for signals raised | |
| 26 | - in response to debug exceptions, where the tag information | |
| 21 | + (2) Non-zero tags are not preserved when delivering signals. | |
| 22 | + This means that signal handlers in applications making use | |
| 23 | + of tags cannot rely on the tag information for user virtual | |
| 24 | + addresses being maintained for fields inside siginfo_t. | |
| 25 | + One exception to this rule is for signals raised in response | |
| 26 | + to watchpoint debug exceptions, where the tag information | |
| 27 | 27 | will be preserved. |
| 28 | 28 | |
| 29 | 29 | (3) Special care should be taken when using tagged pointers, |
| 30 | 30 | since it is likely that C compilers will not hazard two |
| 31 | - addresses differing only in the upper bits. | |
| 31 | + virtual addresses differing only in the upper byte. | |
| 32 | 32 | |
| 33 | 33 | The architecture prevents the use of a tagged PC, so the upper byte will |
| 34 | 34 | be set to a sign-extension of bit 55 on exception return. |
arch/arm64/include/asm/hwcap.h
arch/arm64/kernel/process.c
| ... | ... | @@ -143,15 +143,26 @@ |
| 143 | 143 | |
| 144 | 144 | void __show_regs(struct pt_regs *regs) |
| 145 | 145 | { |
| 146 | - int i; | |
| 146 | + int i, top_reg; | |
| 147 | + u64 lr, sp; | |
| 147 | 148 | |
| 149 | + if (compat_user_mode(regs)) { | |
| 150 | + lr = regs->compat_lr; | |
| 151 | + sp = regs->compat_sp; | |
| 152 | + top_reg = 12; | |
| 153 | + } else { | |
| 154 | + lr = regs->regs[30]; | |
| 155 | + sp = regs->sp; | |
| 156 | + top_reg = 29; | |
| 157 | + } | |
| 158 | + | |
| 148 | 159 | show_regs_print_info(KERN_DEFAULT); |
| 149 | 160 | print_symbol("PC is at %s\n", instruction_pointer(regs)); |
| 150 | - print_symbol("LR is at %s\n", regs->regs[30]); | |
| 161 | + print_symbol("LR is at %s\n", lr); | |
| 151 | 162 | printk("pc : [<%016llx>] lr : [<%016llx>] pstate: %08llx\n", |
| 152 | - regs->pc, regs->regs[30], regs->pstate); | |
| 153 | - printk("sp : %016llx\n", regs->sp); | |
| 154 | - for (i = 29; i >= 0; i--) { | |
| 163 | + regs->pc, lr, regs->pstate); | |
| 164 | + printk("sp : %016llx\n", sp); | |
| 165 | + for (i = top_reg; i >= 0; i--) { | |
| 155 | 166 | printk("x%-2d: %016llx ", i, regs->regs[i]); |
| 156 | 167 | if (i % 2 == 0) |
| 157 | 168 | printk("\n"); |
arch/arm64/kernel/setup.c
arch/arm64/mm/fault.c
| ... | ... | @@ -130,7 +130,7 @@ |
| 130 | 130 | force_sig_info(sig, &si, tsk); |
| 131 | 131 | } |
| 132 | 132 | |
| 133 | -void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *regs) | |
| 133 | +static void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *regs) | |
| 134 | 134 | { |
| 135 | 135 | struct task_struct *tsk = current; |
| 136 | 136 | struct mm_struct *mm = tsk->active_mm; |